Low-tech Magazine

The Mechanical Transmission of Power (3): Endless Rope Drives

2013-03-02T18:12:43+01:00

You don't need electricity to send or receive power quickly. In the second half of the nineteenth century, we commonly used fast-moving ropes. These wire rope transmissions were more efficient than electricity for distances up to 5 kilometres. Even today, a nineteenth-century rope drive would be more efficient than electricity over relatively short distances. If we used modern materials for making ropes and pulleys, we could further improve this forgotten method.

Picture: wire rope transmission in Schaffhausen, Switzerland, 1896. Source: Stadtarchiv Schaffhausen.

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The rope drive is the culmination of a long history of mechanical power transmission. In the 1500s, mining engineers designed "Stangenkunsten": a method to transmit power from distant water wheels to machinery at the mineshaft, using reciprocating wooden rods. This early predecessor of electricity was improved in the 1860s oil industry's "Jerker line systems", which used steel cables instead of wooden rods.

The need for long-distance power transmission appeared first in the mining industry because mines could not be relocated to a nearby water power source. In the nineteenth century, the need for power transmission spread to other industries because the demand for power had grown considerably with the arrival of the Industrial Revolution, and most available water power resources had already been put to use -- especially in Europe. A new form of power transmission was needed to make previously inaccessible sources of water power available. For instance, many powerful water sources in mountainous areas were idle because these sites were unsuitable for building factories. The development of steam engines also called for power distribution and transmission, especially in Great Britain and in the US, because smaller engines were uneconomical to operate.

The pioneering power-transmission technology developed by the mining industry was not suited for most of these new demands. A Stangenkunst or jerker line system transmitted power using a reciprocating motion, while most industries required circular motion to drive machinery. Although these systems could be adapted to convert reciprocating motion into circular motion, this was possible only at low speeds and the expense of considerable energy loss [1]. Apart from this, the power that could be transmitted by a mere dead pull was limited. Enormous wooden rods or steel cables would have been needed to transmit the amount of power that could be harvested from mountain streams and waterfalls [2].

The Millwork

Around 1850, the only available technology for the transmission of fast, circular motion was the so-called "millwork". This combination of shafts, gears, belts and pulleys was aimed at the distribution (rather than long-distance transmission) of mechanical energy. It transferred power from a prime mover (a water turbine or a steam engine) to individual machines.

A factory interior in Schaffhausen, Germany.

While the nineteenth-century millwork was considerably more efficient than the large wooden gears and shafts in the pre-industrial wind- and watermills from which it evolved, it was not suited for longer distances. One engineer calculated that 75% of the power transmitted by a lineshaft would be absorbed by friction of the bearings at a distance of between 95 to 600 m [3]. Moreover, millwork required protection from the weather and so could not be operated outdoors.

A factory interior in Schaffhausen, Germany.

Even for short distances, nineteenth century millwork was rather inefficient. A major investigation in the early 1880s covering 55 industrial establishments, chiefly textile mills, revealed that the combined power losses in engines and millwork were on average 25%. For machine shops, the energy loss was on average 40 to 50% [4]. Line shafts were also hungry for space, costly to install, troublesome to maintain and adjust, hazardous in use, and inflexible in arrangement.

Wire Rope Power Transmission

Late nineteenth-century industry was in need of a more efficient and versatile method of power transmission for both short and long distances. Several alternatives were in the running: power could be transmitted by electricity, compressed air, hydraulics, steam, millwork, or ropes. While electricity eventually won the battle, a few others deserve more attention [5].

Rope transmission, the subject of this article, stands apart from all other power transmission technologies because it doesn't involve any conversion of energy. An endless rope drive transmits mechanical energy directly from a power source to machinery. As we will see, this makes rope transmission more efficient than any other alternative up to a distance of a few kilometres.

Contrary to electricity and compressed air, the transmission of power by rope was not a radical departure from traditional methods. Conceptually, wire rope transmission simply extended the range of millwork by improving its efficiency and flexibility, and by making it weather-proof. Rope transmission started in the 1840s as an element of millwork, using fast-spinning fibrous ropes as an alternative to belts transmitting power from the prime mover to the line shafts [6]. When fibrous ropes were replaced by metallic ropes (or "wire ropes"), a long-distance power transmission was born.

Wire Rope

Interestingly, the wire rope itself can be traced back to the same region that invented the Stangenkunst in the 1500s: the Upper Harz mining region in Germany. In the 1830s, mining engineer Wilhelm Albert twisted together several strands of metal wire around a hempen core, resulting in a superior hoisting cable for use in vertical shafts. Compared to a fibrous rope, a wire rope is much stronger, despite being the same weight and diameter. Unlike fibrous rope, it keeps its strength when it is wet, and its length remains constant under all weather conditions.

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Contrary to electricity and compressed air, the transmission of power by rope was not a radical departure from traditional methods

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Metallic ropes were used throughout the global mining industry during the 1800s, replacing metal chains and fibrous cables for hoisting up ores and transporting miners up and down shafts. The wire rope also led to important uses outside the industry. It enabled the invention of the suspension bridge and came in handy as a means to carry other static loads such as smokestacks and masts. But its main applications involved moving passengers and goods, both vertically and horizontally. The wire rope gave birth to the elevator and made cranes and hoisting machines much more powerful. It introduced new transportation options on land (as in cable trains), on water (as in rope-powered canal boats), and in the air (as in aerial ropeways).

How did it Work?

Few know that wire rope was also used to transmit energy across land. A wire rope power transmission, or "telodynamic transmission" as it was initially called, was basically an aerial ropeway running without vehicles, at higher speeds. Both aerial ropeways and wire rope drives were sold by the same manufacturers. Wire rope transmissions used thin wire ropes (up to 2.5 cm in diameter) and large, cast-iron pulleys (up to 5 m in diameter), mounted on wooden, iron or masonry towers placed at maximum intervals of 90 to 150 m. The bottom of the pulley grooves was made of strips of leather to limit the wear of the rope.

Detail of the wire rope transmission in Neuthal, the only remaining wire rope transmission line in Europe. Photo credit: Peter Christener.

The fundamentals of the method were concisely described by Albert Stahl in his 1889 treatise Transmission of Power by Wire Ropes:

"The construction of the apparatus is very simple. A tolerably large iron wheel, having a V-shaped groove in its rim, is connected with the motor, and driven with a perimetral velocity of usually from 50 to 100 feet [per second]. Round this wheel is passed a thin wire rope, which is led away to almost any reasonable distance (the limit being measurable by miles), where it passes over a similar wheel, and then returns as an endless band to the wheel whence it started."

For longer wire rope transmissions, two configurations were possible. Either one, long continuous rope was used, supported at intervals by carrying sheaves, similar to those of an aerial ropeway. Usually, though, a wire rope power transmission used shorter ropes that extended between stations, instead of running the whole length of the transmission. Each tower then served as the driver for another by means of a double pulley arrangement, or a double grooved wheel.

When using carrying sheaves to bridge larger spans, it was often sufficient to support only the slack side of the rope. The illustration above shows the different arrangements used for wire rope transmissions. When the rope drive had to change direction, or when the power had to be distributed to a number of consumers, this could be done by using either horizontal sheaves, or more frequently, bevel gearing/wheels.

Diffusion of the Technology

The use of wire rope for power transmission over long distances was invented by the Hirn brothers in 1850, while they were setting up a weaving factory in an abandoned textile works near Logelbach, Switzerland. The buildings were scattered over considerable distances and setting up multiple steam engines would have been too expensive. Following some initial problems (finding a suited material as a seating for the ropes proved to be one of the biggest) the Hirn Brothers set up power transmission lines between the buildings. The longest line reached 235 m, transmitting 50 horse power (hp).

After the initial success of the Hirn installation, the technology spread rapidly throughout the Alps, and beyond. W.C. Unwin gives a detailed overview of the initial diffusion of telodynamic transmissions in his 1894 book On the Development and Transmission of Power from Central Stations:

"Soon after the erection of the transmissions at Logelbach M. Henri Schlumberger transmitted the power of a turbine 86 yards to work agricultural machinery. In 1857, at Copenhagen, Captain Jagd transmitted 45 hp to saw-mills at a distance of more than 1,000 yards. In 1858, at Cornimont, in the Vosges, 50 hp was transmitted 1,251 yards. In 1859, at Oberursel, 100 hp was transmitted 1,076 yards; and at Emmendingen 60 hp was transmitted 1,372 yards. In 1862 Hirn stated that about 400 applications of the telodynamic system had been constructed by Messrs. Stein & Co., of Mulhouse, carrying an aggregate of 4,200 hp over distances amounting altogether to 80,000 yards."

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Telodynamic transmission was adopted in three of the earliest central power stations in Europe

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These installations had an average capacity of about 10 hp and a transmission distance of about 180 m. By 1869, two years after Hirn's invention received an award at the Universal Exposition in Paris, about 2000 permanent installations had been constructed on the European Continent. Most were relatively small ropeways, but some were fairly large. The Hirn system was adopted in three of the earliest central power stations in Europe: Schaffhausen (1864) and Fribourg (1870) in Switzerland, and Bellegarde (1872) in France. These installations transmitted between 560 and 3150 hp by wire ropes, over distances up to 966 m.

The Schaffhausen Transmission

The Schaffhausen transmission is regarded as the most complex wire rope transmission ever built, using 1027 m of ropes, aggregating more than 600 hp. After a period of trade depression there was a revival of industry at Schaffhausen. The required energy was found in the immense volume of water passing down the rapids of the Rhine in front of the town. Since the steep rocky banks forbade the erection of any factories in the immediate neighbourhood, the power was transferred diagonally across the stream to the town, about a mile lower down, and there distributed, with certain rocks in the water being used to set up the intermediate stations.

The Schaffhausen wire rope transmission in 1896. Source: Stadtarchiv Schaffhausen.

It is interesting to republish Unwin's full description of the Schaffhausen installation, because "it is essential to learn how far wire-rope transmission can be adapted to complex situations where many consumers require power":

"A weir was constructed during favourable seasons in 1864-66, across the rocky bed of the river, which is about 500 feet wide. By placing the turbine-house in the river-bed near the weir and constructing a tunnel tailrace 620 feet in length, a fall was obtained which varies from 15.6 to 13.7 feet. The turbine house contains three turbines with vertical shafts of 200, 260, and 300 hp, or 760 hp altogether. They gear with a common horizontal shaft by means of bevil gears. About 150 hp is transmitted from one of the turbines to a factory on the hill above the turbine-house, by a steel shaft 550 feet in length. From the same shaft also about 22 hp is transmitted, by a small cable passing down the left bank of the river and then crossing it, to a pulp factory on the right bank."

"This leaves a maximum of about 570 hp to be dealt with by the main cable transmission, which crosses the river directly from the turbine-house, and then passes along the right bank to the factories. The turbines are connected to two principal rope pulleys of 14.75 feet in diameter. From these pulleys two cables cross the river in a single span of 385 feet to a pulley station in the river at the left bank, where the direction of the transmission is changed by bevil gearing, and thence the transmission passes up the left bank of the river. The gross power in the horizontal driving shaft in the turbine-house is about 350 hp or, allowing for friction, say 500 effective hp to be transmitted to the factories, or 250 hp for each rope. Either rope is capable of transmitting at any rate a large fraction of the whole power temporarily, if the other rope is broken. The power is delivered by the ropes at the change station on the left bank. At that station about 22 hp is taken off by prolonging the second shaft of the bevil gearing and a subsidiary rope transmission."

"The remaining 478 hp is transmitted along the left bank to the first intermediate pulley station at a distance of 370 feet by a pair of cables. Thence to the second intermediate station, distant 345 feet, by another pair of cables. At 455 feet further is a second change station, at which the direction is again changed by gearing. Thence the ropes pass to two other intermediate stations. From the second intermediate station an underground shaft carries about 27 hp to ten small workshops, and from the second change station, and the third and fourth intermediate stations, cables are carried back across the river to factories on the right bank. From the first shaft on the second change station about 110 hp are distributed, partial by a special rope gear, partly by vertical and underground shafting, to four factories, one of which is the large Mosersche Gebaude; and from the second shaft of this station a steel shaft transmits 200 hp to Scholler's wool factory."

The Schaffhausen installation was a greatly successful undertaking. The number of renters of power grew from 13 in 1867 to 23 in 1887, while the average total horse power supplied grew from 121 to 641. The total income from rental of power rose tenfold.

Other Examples

The wire rope transmission at Fribourg, where the ravine is not suitable for factories, was no less impressive. Here, a wire rope transmitted 300 hp to an industrial site 90 m above the river. Power was distributed via wire ropes to a sawmill, a foundry, a chemical factory, a rope tramway for carrying timber, and a railway carriage works. The total distance of the transmission amounted to more than 1500 m. Part of the line passed through a specially designed tunnel.

At Bellegarde, which lies about 25 km from Geneva, 3150 hp was transmitted in different directions via wire ropes from the river Rhône to the plain above, where it was used to operate a phosphate works, a wood pulp factory, a paper mill, a copper refinery and a pumping station. The transmission lines reached a total length of more than 900 m.

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Most wire rope transmissions were built in France, Switzerland and Germany, but the technology was used all over the world

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Most wire rope transmissions were built in France, Switzerland and Germany, but the technology was used all over the world. Following a serious explosion, an installation was put up at a gunpowder factory at Ochta near St. Petersburg, Russia, in 1867. A total of 274 hp was transmitted by more than 3000 m of wire rope to 34 widely scattered workshops and laboratories. The wire rope transmission was adopted to ensure that the buildings should be at a safe distance from each other were another explosion to occur.

At Gokak, India, a large telodynamic transmission was set to work in 1887. A total of 750 hp was transmitted to a large cotton mill via three wire ropes (illustration below).

Numerous wire rope installations were built in the United States -- a total of 400 telodynamic systems were reported in 1874. Most prominent were those at Lockport (New York), Lawrence (Kansas), and near Great Falls (Montana) on the upper Missouri River [7]. However, none of them approached the size of the Schaffhausen plant in Switzerland. The technology seems not to have attained the popularity and importance that it did in the regions of its principal continental use, writes Louis Hunter, who adds that "this was no doubt owing to the greater abundance of water powers in the US in a wide range of capacities, and to the abundance of coal and the rapidly increasing acceptance of steam power from the 1850s."

Efficiency

It may seem that wire rope power transmissions running over hundreds and sometimes thousands of metres, could not be very efficient. However, a wire rope transmission was considerably more efficient (and cheaper) than electricity up to distances of about 5 km (3 miles). As with jerker line systems, the efficiency advantage was due to the fact that in a telodynamic transmission mechanical energy can be transmitted without conversion losses. This was emphasised by W.C. Unwin in 1894:

"The telodynamic system has the peculiar advantage that it transmits the mechanical energy developed by the prime mover directly, without any intermediate transformation. In electrical distribution a double transformation is necessary: a transformation into electrical energy by a dynamo, and retransformation back into mechanical energy by an electric motor. This double transformation involves waste of power and increase of capital expended."

On the other hand, a wire rope transmission introduces friction losses. The principal source of waste in rope transmission is the friction in the journals of the wheel shafts. The friction losses become larger as the distance increases, because more pulley stations have to be introduced, while the conversion losses of electric transmission are independent of distance. (There were transportation losses for electricity, too, but these were comparatively small). Beyond a certain distance, a wire rope transmission loses its advantage over electricity.

Pulley wheel of the wire rope transmission in Neuthal, Switzerland. Picture credit.

The efficiency of telodynamic transmission was carefully examined by Ziegler, one of the better known manufacturers. He made experiments at Oberursel, where 104 hp was transmitted over a distance of 963 m, in seven spans of about 122 m each. Ziegler's measurements showed that total loss of work over eight stations was 13.5 hp, which comes down to an efficiency of about 87%. The loss of energy was about 1.7 hp per pulley station.

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A wire rope transmission was considerably more efficient than electricity up to distances of about 5 km (3 miles)

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From this he calculated that the efficiency of a wire rope transmission was 97% for a single span (two pulley stations), 95% for two spans (three pulley stations), 93% for three spans (four pulley stations), and 90% for five spans (six pulley stations). For nine spans (ten pulley stations), efficiency went down to 85%.

Another investigation, published in 1886, showed that wire rope had an efficiency that was largely superior for distances up to 900 m (3,000 feet), compared to the main competing technologies (electric, hydraulic and pneumatic transmission). Telodynamic transmission retained this advantage up to a distance of about 4,600 m (15,000 feet), beyond which it was defeated by electricity. In other words, wire rope lost its advantage over electricity when more than 35 pulley stations were involved. Were a wire rope transmission to be used over a distance of 18 km (60,000 feet), efficiency would go down to 13%. [8]

Note that the results are for a full load -- both electrical and wire rope transmission would have been much less efficient at partial loads. Also note that the results for wire rope transmission involve power transmission in a straight line -- every angle station would introduce additional losses. With regards to cost, Hunter notes that copper wire was 1.4 times more expensive than wire rope, and all nineteenth-century authors state that wire rope transmission was cheaper in construction and use than electricity, even though the ropes had to be replaced every two to five years.

How would a Present-day Wire Rope Transmission Compare to Electricity?

The advantages of rope transmission calculated in 1860 and 1886 still hold today. The only difference would be that a comparison of a rope drive and an electrical transmission would now show much better efficiencies for electricity at distances of 10 or 20 km (30,000 or 60,000 feet). In the 1880s, electricity was still transmitted by direct current (DC), which is much less efficient at longer distances than the alternate current (AC) that we use today. With AC, the losses are only 3% over a distance of 1,000 km [9].

A wire rope power transmission leaves a water power plant, heading for a paper factory in Heilbronn, Germany. The line, 90 m long, was constructed in 1888. Photo credit.

However, the efficiency of electricity would still be lower than that of a wire rope transmission over a relatively short distance, because of the double energy conversion that is required to move mechanical energy using electricity. The combined energy losses in a modern electric motor and generator are about 15%, which makes the double energy conversion 85% efficient [10]. This is better than the 69% efficiency in the 1889 table shown above, but still inferior to the efficiency of a nineteenth century wire rope transmission up to a distance of at least 1 km (3,000 feet).

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A wire rope transmission from 1860 is still more efficient than a moden electric transmission up to a distance of at least 1 km

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Of course, it is not fair to compare a nineteenth-century wire rope transmission with a 21st-century electric transmission. With today's knowledge and materials, a rope transmission could be improved in two ways: by using stronger and/or lighter ropes, and by running them at higher speeds. The result would be that more power can be transmitted over longer distances with less friction loss. In 1894, Unwin noted that:

"The amount of work transmitted by a cable is proportional to the product of the effective tension (difference of the tension in the tight and slack sides) and the speed. To transmit power by manageable cables, the strongest material must be used for the cables, and they must be run at the highest practicable speed."

Substituting Velocity for Mass

This brings us to the basic physics of rope power transmission: in executing mechanical work, force can be transformed into velocity and vice versa. In a rope drive, energy can be transmitted at considerable velocity and little force, while at the receiving station it can be delivered in the generally more useful form of large force and little velocity. Increasing the speed of the transmission has a similar effect as increasing the diameter of the rope.

The Schaffhausen wire rope transmission in 1896. Source: Stadtarchiv Schaffhausen.

If a rope with a diameter of 2.5 cm (1 inch) can transmit 50 hp at a velocity of 20 feet per second (22 km/h), the same rope could transmit 250 hp at a velocity of 100 feet per second (110 km/h). Conversely, if a rope with a diameter of 2.5 cm can transmit 50 hp at a velocity of 20 feet per second, a rope of only half that diameter could deliver the same amount of power if it was running at twice the speed, and should run at a velocity of 200 feet per second (220 km/h) in order to transmit 250 hp.

Theoretically, there are no limits to power transmission by rope. "To put an extreme illustration", wrote Albert Stahl in 1889, "we may conceive of a speed at which an iron wire as fine as a human hair would be able to transmit the same amount of work as the original one-inch [rope]". Conversely, we could argue that if we could learn how to run ropes fast enough, a ship hawser could transmit the power of an entire nuclear plant [11]. While this is far from reality at this point, we do have better ropes than 120 years ago, and we can run them faster.

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In executing mechanical work, force can be transformed into velocity and vice versa

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In the nineteenth century, the maximum power able to be transmitted over a single wire rope transmission was about 300 hp. Unwin explains that:

"The amount of power which is practically possible to transmit by a single cable is limited. It is not possible by increasing the size of the cable to transmit an indefinetely large amount of power. The cables become too heavy to be manageable, and the pulleys too large in diameter. (...). The peripheries of the driving wheels may have an anular velocity as great as convenient; the only limit, in fact, being that the speed shall not be so great as to involve any danger of destroying the wheels by centrifugal force. One hundred feet per second has been adopted as the greatest practicable speed."

Running Stronger Ropes at Higher Speeds

Today we have ropes made of artificial fibres, which have a similar tensile strength to wire ropes, but at one fifth the weight. Such ropes make it possible to place pulley towers further apart, reducing the friction loss and improving the efficiency of a rope transmission over longer distances. We could also try to run thicker ropes if they are lighter, thereby converting an efficiency advantage into a higher power capacity.

The Schaffhausen wire rope transmission in 1896. Source: Stadtarchiv Schaffhausen.

It's also possible to build sturdier pullies, allowing us to run these ropes faster. Higher speeds would allow more power to be transmitted at the same rope diameter, or further improve efficiency (because we can transmit a similar amount of power using lighter ropes). Albert Stahl already foresaw this possibility in 1889:

"The wheels themselves are made as light as is consistent with strength, not only for the sake of reducing the friction on the journals of their shafts to a minimum, but for the equally important object of diminishing the resistance of the air. It can hardly be doubted that abandoning spokes entirely, and making the pulley a plain disk, would considerably improve the performance, could such discs be made at once strong enough to fulfill the required functions, and light enough not materially to increase friction."

More Efficient for Small-scale, Decentralized Energy Production

Most telodynamic installations disappeared before the end of the nineteenth century, although some remained in use until the 1930s. Wire rope transmission lost the fight against electricity, mainly because the power network became ever more centralised -- ever larger power plants would send their power over ever larger distances, which could not be bridged efficiently by wire ropes.

Furthermore, a wire rope transmission did not offer a solution for the "last mile" in power transmission. It couldn't be used to distribute power to a great number of individual machines in a factory, because a wire rope transmission was not useful under a distance of about 15 m. In such cases, a wire rope transmission could not operate without millwork. Although the use of fibrous ropes had improved the workings of millwork, in this regard telodynamic transmission could not compete with the alternatives. Electricity, compressed air and hydraulic transmission offered an overall solution for both short and long-distance power transmission.

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The trend towards small-scale, decentralised power production means that rope transmission might have a place in our energy systems

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In spite of these drawbacks, power transmission by ropes might have a place in our energy systems. Today, there is a trend towards small-scale, decentralised power production, based on renewable energy sources. These solar panels, water turbines or wind turbines generate electricity, but whenever we need to produce mechanical energy, eliminating the step of generating electricity could result in a somewhat less practical, but more efficient use of energy.

A wire rope transmission powered by a water wheel in an open-air museum in Switzerland. Source: Historische Werkstätte Gebrüder Giger Mulin, Schnaus.

For instance, it is more efficient to power a circular saw by mechanical energy produced by a modern version of an old-fashioned windmill or waterwheel than to convert the mechanical energy generated by wind or water to electricity by a turbine, and then convert it back into mechanical energy for powering the sawing machine. If power transmission is required in such a scenario, a wire rope transmission would be the most efficient choice.

Long-distance Rope Drives

Another advantage of a wire rope transmission is that it can double as a transportation system, combined with an aerial ropeway for goods or passengers. As we have seen in the article on aerial ropeways, it was not unusual to tap power from a gravity-powered aerial ropeway to power a crane or other machinery. The combination of a wire rope power transmission with an aerial ropeway only works at lower speeds, so that power transmission capacity is limited. (An aerial ropeway was generally five times slower than a rope power transmission). Still, this could offer interesting advantages for small-scale power production, especially in mountainous areas.

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If we could learn how to run ropes fast enough, a ship hawser could transmit the power of an entire nuclear plant

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It may be that the future of wire rope transmission lies in long distance power transmission after all, at least vertically. The only research field that dedicates itself to rope drive technology these days is that of high-altitude kite power. Kites could harvest large amounts of energy at high altitudes, where winds are stronger and steadier. Transmitting this energy to Earth is most advantageously done by mechanical power transmission, says researcher Dave Santos from KiteLab Group in an interview:

"Electric cables would be too heavy. With kites, power-to-mass-plus-aerodrag is critical, and the mechanical case wins by a large factor. Wire rope is not quite so amazing as our new materials, but good enough for a critical advantage over electrical. The main challenge is to learn how to drive ropes at speeds of hundreds-of-miles-an-hour."

Ultimately, the rope drive may turn out to be useful for the same reason it was originally designed: it could unlock the potential of awkwardly-situated sources of renewable energy.

Kris De Decker (edited by Deva Lee)

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Related articles

Sources:

"Transmission of power by wire ropes", Albert W. Stahl, 1889.
"A history of industrial power in the United States, 1780 - 1930. Vol 3: The transmission of power", Louis C. Hunter and Lynwood Bryant, 1991.
"The wire rope and its applications", W.E. Hipkins, 1896
"Description of a new method of transmitting power by means of wire ropes", W.A. Roebling, 1872.
"Rope driving: a treatise on the transmission of power by means of fibrous ropes", John J. Flather, 1900.
"Notice sur la transmission telodynamique / Short notice of the telodynamic transmission of motive power", C.F. Hirn, 1862
"On the development and transmission of power from central stations", W.C. Unwin, 1894. (alternative link).
"Der Constructeur. Ein Handbuch zum Gebrauch beim Mashinen-Entwerfen. Für Mashinen- und Bau-Ingenieure, Fabrikanten und technische Lehranstalten", F. Reuleaux, 1869
"Drahtseil Transmission", Polytechnischen Journals (multiple articles, 1850-1910)
"Drahtseil", Polytechnischen Journals (multiple articles, 1850-1910)
"Transmission des Forces Motrices des Turbine sur le Rhône de la Compagnie Générale à Bellegarde", web page, retrieved February 2013.
"La Télémécanique", web page, retrieved February 2013
"Turbinenanlage und Seiltransmission der Wasserwerkgesellschaft in Schaffhausen", J.H. Kronauer, 1867.
"A trade catalog on the transmission of power by wire rope", Carroll W. Pursell, Jr., Technology and Culture, Vol.16, No.1, January 1975, pp 70-73.
"From shafts to wires", in "Journal of Economic History", Michael Devine, 1983.
"Kritische Vergleichung der Elektrischen Kraftübertragung mit den gebräuchlichsten mechanischen Uebertragungssystemen", A. Beringer, 1883
"Cours de mécanique appliquée aux machines", J. Boulvin, 1891.

Notes:

Stahl, 1889
The Stangenkunst at the Lady Isabella wheel was the most powerful installation ever built, transmitting 150 hp using wooden rods. For pictures, see part one of this series
Flather, 1900
Hunter, 1991
Pneumatic and hydraulic transmission will be discussed in a forthcoming article
Flather, 1900
Hunter, 1991
Beringer, 1886 and Unwin, 1894
AC Transmission Line Losses, Stanford University, fall 2010
More powerful motors are generally more efficient, less powerful motors are less efficient. The figures given are for a 100 hp motor, similar to the power transmitted at Oberursel
Dave Santos, personal communication, February 2013

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The Mechanical Transmission of Power (2): Jerker Line Systems

2013-02-02T18:45:38+01:00

From the 1860s to 1940s, many oil wells were pumped by a technology that originates in a sixteenth-century power transmission system used in the mining industry.

One engine operated up to 45 pumps in different locations, each up to a mile away. Power was transmitted by means of wooden rods or steel cables that moved back and forth, snaking through the landscape.

The system was so efficient that an engine used for pumping an oil well could operate a whole cluster of pump jacks. The technology, which still operates in a handful of small oil fields, could also work with renewable energy sources, and shows great potential for efficient small-scale energy use.

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Jerker line systems can be used to operate water pumps or sawing machines, to forge iron, to process food or fibres, or to make paper.

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From the 1500s onwards, engineers developed mechanical power transmission and distribution systems that became ever more sophisticated: Stangenkunsten. Networks of pivoted, wooden field-rods conveyed power from waterwheels in the valleys to mining machinery in the mountains over distances of up to 4 km, operating pumps and bellows, hoisting ores, and transporting miners up and down shafts.

Steam engines, which started replacing water wheels from the 1860s onwards, were not dependent on the proximity of a stream or river, and could thus be located close to the mine shaft. This eliminated the need for mechanical power transmission. However, the Stangenkunst did not disappear. On the contrary, the technology became even more popular after, rather than before, the invention of the steam engine.

For one, it found a new application in oil production, initially in the United States but later all over the world. It was in the oil industry that the Stangenkunst reached the pinnacle of its development, and became known as the "jerker line system".

The Canadian Jerker Line System

Right from the start of modern oil production in the late 1850s, the Stangenkunst played an important role. It was first used for pumping oil in Oil Springs, Ontario, Canada. While the oil here was of very good quality, production was marginal. The high cost of operating a steam engine at each was not economically viable. In 1863, only four years after the industry came into production, a solution was found by John Henry Fairbank, who set up a system for the transfer of power from a steam engine to multiple oil pumps.

A Stangenkunst in Oil Springs, Ontario, Canada. Source: Markus Wandel.

The method, which became known as the "Canadian Jerker Line System", was remarkably similar to the Stangenkunsten. Fairbank used wooden rods, which swung back and forth from wooden hangers that were suspended from wooden poles, and connected to wooden pump jacks. He didn't even bother to apply the more efficient pantograph system developed in the 1590s, but used the original single-rod system. This made sense: it was cheaper to build, and friction was less of a problem since the system aimed at distributing power rather than transferring it long-distance (most oil pumps were within one mile of the central power source).

Subdividing and Distributing Power

There were some differences between the Fairbank method and the pre-industrial Stangenkunsten. Two cranks converted the circular motion of the steam engine's wheel to a reciprocating motion that moved two parallel wooden rods back and forth, just as in the older systems powered by water wheels. In Fairbank's model, however, a mechanism was introduced to slow down the revolution speed of the steam engine. It consisted of a leather belt placed between the wheel of the steam engine and the cranks. Another addition was the bull wheel, a cast-iron wheel making back-and-forth quarter turns. It was housed in a timber frame just outside the engine shed.

A bull wheel in Oil Springs, Ontario. Source: "Conservation district study appendix", Oil Heritage Conservation District Plan, The Corporation of the County of Lambton.

The bull wheel allowed the reciprocating motion of the two cranks to be subdivided over a greater number of rod lines. In the picture above, for instance, power is distributed from the steam engine to the bull wheel via the two wooden rods on the lower left side. It is transferred to a double field line which runs diagonally from upper left to lower right (the main line) while a single rod line extends to the centre and back of the picture. Thus, in this case, five rod lines branch off from the central power instead of one or two.

A field wheel in Oil Springs, Ontario. Source: "Conservation district study appendix", Oil Heritage Conservation District Plan, The Corporation of the County of Lambton.

Additional subdivision of power to other field rods (branch lines) could happen further along the main line, by means of a "field wheel" -- a similar cast-iron, oscillating wheel in a timber frame. The field wheel was also used for diverting a main rod line 90 degrees, as can be seen in the picture above. Field wheels replaced the "Kunst Kreuzen" or "Engine Crosses" used in pre-industrial Stangenkunsten.

V-shaped wooden assemblies, lying on their sides, were used to make less sharp turns. The point of the V was anchored, and acted as the pivot for the mechanism. When the jerker line pulled on one leg of the V, the lines comes from the other direction were pulled out, too. A similar V-rod placed upright was used to change direction in the vertical plane when the line crossed a hill or valley.

The Pennsylvania Jerker Line System

The Canadian jerker line system spread to other oilfields but was eventually superseded by a more sophisticated system in which steel cables and iron bars replaced wooden rods. The metal rods were usually called "shackle lines". This method was developed in 1879 by Pennsylvania oilman Edward Yates and became known as the "Pennsylvania Jerker Line System".

Pennsylvania jerker line system, Flat Rock, Illinois, US. Source: Old Iron.

The famous Pennsylvania oilfields (home to Rockerfeller's Standard Oil Company) came into production around the same time as the Ontario oil fields. However, unlike in Canada, steam engines were used to power each well for the first two decades. Oil wells in the Allegheny Plateau had a high initial production, which was followed by a rapid drop off. The incentive for pumping these low production wells after their initial outflow was small, as new fields were continually being discovered and drillers would simply sink a new well.

In the late 1870s, following a decline in oil prices and production per well, economising the oil production process became key to profitability. This drive for efficiency resulted in the adoption of the jerker line system, which made using previously-abandoned wells economically viable again.

Pennsylvania jerker line system, Flat Rock, Illinois, US. Source: Old Iron.

By 1885, the jerker line system was used widely in Pennsylvania (then the largest oil producer in North America). Thereafter, it spread to other US oil fields. By the early twentieth century, the system was used in oil fields around the world. By then, the technology had improved and numerous oil-well supply companies had developed standardised systems that could be purchased in part or whole.

Illustration: a schematic of a Pennsylvania jerker line system, showing both geared power and bandwheel power system. Drawing by Eric S. Elmer. Source: Library of Congress.

While the Canadian jerker line system was reminiscent of the Stangenkunsten operating in pre-industrial times, the Pennsylvania jerker line system looked radically different. The prime mover (mostly a gas engine supplied from a nearby well) operated a "central power" (either geared or bandwheel) which slowed down the engine speed, converted the engine's rotary motion to reciprocating motion, and distributed power to all the rod lines.

One Engine Powers 45 pumps

A back-and-forth motion was imparted to the rod lines by an "eccentric", placed either above or below the geared or bandwheel power, to which 8 to 15 rod lines were hooked that fanned out in all directions. The eccentric was mounted slightly off-center from the power's central vertical shaft, with the rod lines attached to the outer slip ring. As the eccentric rotated within the slip ring, the slip ring oscillated, pulling the rod lines. For each rotation of the slip ring, the rod lines completed one full stroke (see the illustration on the right).

Typically, the mechanism produced 12 to 20 oscillations per minute, pulling the attached shackle lines an equal number of times. Depending on the number of wells, up to three eccentrics could be mounted on the central shaft, so that a total of 45 oil wells in different locations could be pumped. (More commonly, however, 10 to 25 pumps were powered as they wanted to limit the amount of temporarily unproductive wells in case of an engine breakdown.)

Implications for Field Layout

These different approaches to subdividing and distributing power led to distinct field layouts. In the Pennsylvania system, all oil pumps in the cluster were directly connected to the central power via jerker lines, which radiated out of the engine shed in all directions:

An axonometric view of the Lockwood Poer (built in 1909), near Warren, pennsylvania, showing the spatial relationship of machinery to structure inside a typical octagonal power. Drawing by Eric S. Elmer. Source: Library of Congress.

In the Canadian jerker line system, none of the pump jacks were directly connected to the central power. Motion was transferred to the bull wheel and then further subdivided along the main lines using field wheels. As a result, the Pennsylvania jerker line system generally produced web-like patterns, while the Canadian jerker line system usually created linear patterns with dendritic lines.

This can be seen clearly in the James Field in Ontario, which still has both systems still operating. The spider-like systems use metal rods, while the linear systems use wooden rods.

Inventory map of the James field with its well numbers, central powers and additional features. The spider-like systems use metal rods, while the linear systems use wooden rods. Source: "Conservation district study appendix", Oil Heritage Conservation District Plan, The Corporation of the County of Lambton.

A Balanced system

The web-like layout of the Pennsylvania system offered an important advantage. Because a Stangenkunst was always a combination of horizontal and vertical power transmission, gravity delivered part of the power. A water wheel or steam engine had to deliver all the power needed to make the horizontal stroke that pulled the vertical mechanism upwards, but gravity aided the return stroke. In the case of oil pumping, the weight of the grasshopper pump made the return stroke, saving energy.

Pennsylvania jerker line system, Flat Rock, Illinois, US. Source: Old Iron.

This effect was doubled when each well was matched with one in the opposite direction. When the sucker rods in one well raised (the upstroke), those in the opposite well lowered under their own weight (the downstroke), helping raise the rods in the well undergoing the upstroke. In other words, the pumps were powering each other with their own weight. This minimized the load on the engine: the only power required was for overcoming inertia and friction, plus the weight of the oil lifted at each stroke.

Pennsylvania jerker line system, Flat Rock, Illinois, US. Source: Old Iron.

The web-like layout of the Pennsylvania system made balancing loads much easier. At all times, half the dead load of rods and mechanisms in the field was being lifted while the other half descended. The steel rods attached to the eccentric could be hooked to, or unhooked from, shackle lines that were connected to the oil pumps. If one well was disconnected, the well in the opposite direction was removed to maintain balance. If this was not possible, the eccentric rod of the disconnected well was hooked to a counterbalance. Since all pumps were directly connected to the central power, one worker could balance the load of all the wells.

This made it possible for a cluster of about 15 to 30 oil wells to be pumped with almost the same engine capacity required to pump one well. In Surface Machinery and Methods for Oil-Well Pumping (1925), H.C. George writes:

"In the early days of the oil industry, all nonflowing wells were pumped individually "on the beam" by steam engines. This system wasted both labor and power, as each well required a man and a steam power plant. At present a group of 15 to 30 similar wells is pumped with a central "power" or "jack" plant with practically the same labor and the same energy capacity as was then used at each well."

"Many oil wells if pumped individually would show a loss, but operated as members of a group they show a profit. The older fields of Pennsylvania, Ohio, West Virginia, and Illinois exemplify efficiency in group operation. In Pennsylvania the 59,000 operating oil wells show an average of less than a quarter of a barrel production per well per day, yet are being operated at a profit by the group method."

"Wells of like characteristics, such as pumping time, length of stroke, and size of tubing should be balanced for best results. Some oil companies pump wells of like characteristics at the same time, then take those wells off the power and put on other wells of like characteristics. This practice is common in some of the eastern oil fields, where many wells do not pump more than a few hours per week, and where powers handle 15 to 30 wells, each pumped only several hours at a time."

Shacklework

The use of steel cables instead of wooden rods also made it easier to navigate difficult terrain. The Pennsylvania jerker line system made use of a variety of devices to support the lines and change their direction -- these were generally called "shacklework". The steel cables were hung from tripods or supported by "friction posts", which were fixed in the ground, or "rocking posts", which were mounted on a pivoting base to allow a rocking motion. "Hold-ups" and "hold-downs" guided the lines up or down, while "butterflies" and "ring swings" allowed them to change direction in order to carry the lines around obstacles.

Pennsylvania jerker line system, Flat Rock, Illinois, US. Source: Old Iron.

A "butterfly" was a triangular wooden or metal frame, which allowed up to 90 degree turns and was reminiscent of the V-rods used in the Canadian and pre-industrial system. A "ring swing" was used for lesser changes in direction and was even simpler. It consisted of three rings: one large ring, attached to a another suitable mounting spot, and two smaller rings attached to the large ring and the shackle line. Pendulums and rockers were sometimes used to make the length of the stroke at the well differ from that imparted to the jerker line at the central power.

Often, the shacklework was made from recycled parts, such as discarded rods or pipes. In 1925, H.C. George wrote that "the power or jack plant, and the machinery, shackle line, and jack are all usually standard and purchased from oil-well supply companies, but the shackle line structures are usually designed and built by the operating oil company. This results in a multiplicity of designs and a variety of material."

In some American towns, shacklework from neighbouring oil fields rocked back and forth over streets and alleys.

Jerker Line Systems Still in Operation

The Pennsylvania jerker line system became the dominant technology used to pump secondary oil wells up till the 1940s, pumping wells up to 3,500 feet deep, and remained in use until the 1960s and 70s. A few installations are stilll running today, or operated until recently. Some of the pictures above and below (there are many more if you follow this link), show the last two oil leases in Flat Rock, Illinois, which used a central power source and rod lines of the Pennsylvania type.

Pennsylvania jerker line system, Flat Rock, Illinois, US. Source: Old Iron.

Each is run with a 35 horse power oil-engine and pumps 10 or 11 wells. The rods rest on wood stakes 15 to 20 feet apart and the power moves the rods about 40 cm back and forth. In some places, the rods are rigged to cross a creek or make a turn and head in a different direction. The systems were photographed in 2003, when they were still operational.

Most remarkable, however, are the central power systems in Oil Springs, Ontario, which have been in operation for 150 years now. Some of these oil fields still make use of the Canadian jerker line system, which was the original technology used to pump oil in the mid-nineteenth century when the fields came into production. Most of the lines on the Fairbank field, and some of the lines on the James field, use wooden rods that operate wooden pump jacks, while some lines on the James field, and all lines on the neighbouring fields, use the original Pennsylvania jerker line system.

Canadian jerker line system, Ontario. Source: Markus Wandel.

While there are obviously sentimental reasons for using nineteenth and early twentieth century technology -- the owner of the fields is a great-grandson of John Henry Fairbank, designer of the Canadian jerker line system -- the site is not a museum, but a working field that is economically viable. Instead of holding on to the past and trying to recreate a historic oil field, the technology has been continuously improved to maintain its profitability.

More Efficient

One major change in the technology is that steam engines have been replaced by small electric motors, which are cheaper, more efficient and easier to maintain. Most are equipped with reduction gearing, which has made the bulky powerhouse mechanism redundant. Individually-powered pump jacks have replaced the central power system in locations where running a jerker line has failed to be cost-effective, but where the central power system is still in use, it is so because it remains the most efficient and economical.

Stangenkunst in Ontario, Canada. Source: Markus Wandel.

Even the remaining wooden field rods have been improved: metal hangers that once supported the wooden jerker lines have been replaced with nylon rope for ease of maintenance. The wood for jerker lines and pump jacks is not original, of course, since it is exposed to the elements: the rebuilding of wood equipment has been an on-going historic process.

Canadian jerker line system, Ontario. Source: Markus Wandel.

Oil extraction is usually thought to be large in scale and finite in its lifecycle. However, in Oil Springs, it has been conducted on a continuous, small-scale basis since the late 1850s, while all other oil fields from those times have long been pumped dry using much more powerful technology. One cannot help but wonder how the world would have looked like if all oilmen had stuck with nineteenth century technology.

Future Applications

The jerker line system has value, and could be very helpful for those looking for ways to live comfortably life without excessive energy use. The system in the picture below -- which still operates today in Oil Springs -- is one that any maker could bolt together quickly in no time. With this set-up, one small electric motor could operate four machines in different locations.

Field motor on steel frame with steel jerker rods on the James Field. Source: "Conservation district study appendix", Oil Heritage Conservation District Plan, The Corporation of the County of Lambton.

Why do this instead of powering each device individually? One: you save three electric motors. Two: there is no need to provide batteries or electric outlets at any of the locations. Three: you can balance the system so that one device helps power the other, saving a considerable amount of energy. The electric motor shown above can also be replaced by a windmill, a water wheel, a solar thermal plant, or a stationary bicycle. In these cases, you can distribute mechanical energy without conversion losses.

Although a Stangenkunst or jerker line system can only transfer mechanical energy via reciprocating motion, it has seen a remarkable variety of applications throughout its 450 years of operation: pumping (either oil or water), ventilation (operating bellows), processing ores (operating trip-hammers), and even transporting people and goods up and down shafts (operating man engines and bucket hoists). Reciprocating motion could also be used to operate sawing machines or, using trip-hammers, to forge iron, process food or fibres, or make paper.

Kris De Decker (edited by Deva Lee)

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Sources:

"Surface Machinery and Methods for Oil-Well Pumping", H.C. George, Bulletin 224, Bureau of Mines, Department of Interior, 1925.

"Oil Heritage Conservation District Plan Documents", The Corporation of the County of Lambton, 2010.

"Historic American Engineering Record; Addendum to Allegheny National Forest Oil Heritage" (PDF), HAER No. PA-436, Michael W. Caplinger, 1997

"Allegheny Oil Powers: Documenting Endangered Cultural Resources in Allegheny National Forest", Christopher Marston, 2000

"Technology on the Frontier - Mining in Old Ontario", Dianne Newell, 1986

"Petroleum Mining and Oil-Field Development -- a Guide to the Exploration of Petroleum Lands, and a Study of the Engineering Problems connected with the Winning of Petroleum.", A. Beeby Thompson, 1910.

"Oil History in Ontario", Markus Wandel

"Early development of oil technology", Wanda Pratt and Phil Morningstar, 1987

Related articles:

The mechanical transmission of power (1): Stangenkunst

The mechanical transmission of power (3): Endless rope drives

Wind-powered factories: the history (and future) of industrial windmills

The sky is the limit: human powered cranes and lifting devices

Medieval smokestacks: fossil fuels in pre-industrial times

Boat mills: water-powered, floating factories

Email in the 18th century: the optical telegraph

Automata: engineering for a post-oil world?

Pedal powered farms and workshops: the forgotten future of the stationary bicycle

The Mechanical Transmission of Power (1): Stangenkunst

2013-01-23T17:07:55+01:00

Long-distance power transmission predates the invention of electricity by almost four centuries. From the 1500s onwards, engineers developed mechanical power transmission and distribution technologies, called "Stangenkunsten", that became ever more sophisticated. Networks of pivoted, wooden field rods conveyed power from water wheels in the valleys to mining machinery up the mountains over distances of up to 4 km, operating pumps and bellows, hoisting ores, and transporting miners up and down shafts. Later systems replaced wooden rods by steel cables. Many Stangenkunsten remained in use well into the twentieth century, long after the introduction of steam engines and electricity.

Illustration: 'Stangenkunst, showing driving wheel, feldkunst, and kunstkreuz'. Source: 'Acta historico-chronologico-mechanica circa Metallurgiam', Hennig Calvör, 1763

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Electricity allows us to build power plants in distant locations because it is easy to transport using power transmission lines. Before the advent of electricity, however, the configuration for any wind or water-powered industrial process usually placed both the machinery and the power source in the same location. A mill not only housed the sails or the wheel, but also the machinery that it operated. The power generated by wind or water was transferred to the machinery over a very short distance via a set of wooden gears or cranks. This meant that factories and workshops using wind or water as an energy source could only be operated in locations were a mill was available.

However, this was not always possible. Power production was especially problematic in the mining industry, since mines are situated in relation to mineral deposits, regardless of whether wind or water power is available. Mines needed mechanical energy for draining and ventilating mine shafts, for hauling up ores, for transporting miners, and for processing ores.

Revival of the Mining Industry

European mining activity had declined substantially after the demise of the Roman Empire, but an urban revival at the turn of the millenium brought a revival of the mining industry along with it. New mines were discovered and exploited, most notably in Germany. The Rammelsberg mines in the Harz Mountains were opened in 968 AD, followed by the Freiberg mining field in the Ore Mountains ("Erzgebirge") in 1168 AD. Silver, copper and lead were the most important products of these famous mines, which would remain active for many centuries.

Stangenkunst in Huttal, east of Clausthal-Zellerfeld in the Harz Mountains, 1765. The drawing was made by the GeoMuseum of the Technische Universität Clausthal.

Initially, mining operations required relatively little energy, as ores were extracted from shallow depths. Hauling up the ores and draining the mine of unwanted water, if necessary, was done by means of human-powered machines. However, when the most easily accessible ore deposits became exhausted and miners were forced deeper underground, more powerful machines were needed.

The Rammelsberg mines resorted to this in the twelfth and thirteenth centuries, with the Freiberg mines following in the fourteenth century. The main problem the mines faced was drainage: once you dig shafts and tunnels below groundwater level, flooding becomes a constant concern. Hauling up water to the surface requires more energy as the mine gets deeper, as does hauling up ores.

A Stangenkunst in Pershyttan, Sweden. Picture: Bengt Oberger.

One solution, already applied by Roman miners, was the construction of drainage adits. These gently sloping tunnels, which could be many kilometres long, connected the mine and a neighbouring valley. Excess water drained into the valleys by gravity alone. However, this only worked as long as the adit could be built above ground level. If miners dug deeper than the valley floor, the problem persisted. Initially, the solution lay in more efficient pumps and in substituting animal-powered lifting machines for human-powered lifting machines.

However, horse whims were very expensive to operate and water-powered machines soon replaced them. (Wind power was not very practical for use in mining.) This implied, of course, that a running stream of water was available at the mine shaft. Most often, this was not the case.

Solution One: Bring Water to the Mine

The common method of sourcing water involved the construction of leats, derivation channels, tunnels and aqueducts. This solution also took care of energy storage by using dams and ponds. The Romans had done it before: one Roman gold mine in Spain (Las Medulas) used seven aqueducts, carved in the rocks, to tap water from local rivers. Starting in the late Middle Ages, ever more sophisticated water distribution networks were built.

Water management methods and Stangenkunsten were often combined, such as in the Harz Mountains in Germany.

The water management infrastructure in the Freiberg mining field had some 50 km of covered ditches, connecting about a dozen large dams. Most of it was built in the sixteenth century, with further extensions in the eighteenth, nineteenth and early twentieth centuries -- today, the system is used to supply drinking water to the city. The water management infrastructure in the Harz Mountains, the largest pre-industrial water management system ever built for mining operations, had more than 600 km of canals and more than 140 dams. Nearly all the infrastructure was built in the sixteenth and seventeenth centuries, with some further improvements added in the nineteenth century. By 1868, the system powered 200 waterwheels.

Stangenkunst: Transporting Water Power Uphill

However, these hydraulic engineering works only made sense when the waterwheels were lower than the river because gravity distributes the water. If the machinery was on a mountain and the river in a valley, quite common in mining operations, a means for energy to be transported uphill was necessary. It was in this context that mechanical power transmission originated during the 1500s. Power was transmitted from a waterwheel in a valley stream to machinery on a mountain by means of long lines of linked levers, rocking back and forth on pivots. This is how it worked:

Wooden rods were hooked together lengthwise, extending from the waterwheel to the mine shaft. The rods were hung from wooden poles, set in the ground along their path at sufficiently close intervals to prevent any undue sag between the points of suspension. Wooden hangers that swung like pendulums were hooked to the top of the poles and to the rods, holding the line up and allowing it to swing back and forth in a reciprocating motion.

Each swing bracket acted as a lateral guide and a support, so that side-wind pressures did not deflect the rods far from a straight line. Friction was reduced to a minimum by the attachment of a strip of wood, against which the swinger rubbed only if deflected from a straight line. The size of the timber used for the rod lines depended on the power to be transmitted. A crank was used (video) to convert the circular motion of the waterwheel to a reciprocating motion that moved the rods back and forth -- a mechanism that was already applied in Roman water-powered stone sawmills.

Power transmission via single suspended rod, Jean Errard, 1584

The system became known as "Stangenkunst", where "Stangen" can be translated as "rods" and "Kunst" refers to a mechanism. Mining nomenclature is largely German in origin, because it was especially German metallurgists who pioneered and exported more sophisticated mining technology from the 1500s onwards, leaving their mark on metal production in large parts of Europe.

According to Graham Hollister-Short, one of the few historians who dedicated himself to the history of the Stangenkunst, the technology was probably invented in 1510 by Italian metallurgist Vanoccio Biringuccio, who designed a contraption that allowed a waterwheel to work the bellows at four separate forges at an ironworks. Though his system was used for distributing rather than transporting energy, some decades later the Germans applied the same approach to the transmission of mechanical energy over much longer distances.

Vanoccio Biringuccio's Stangenkunst, drawing by Graham Hollister-Short.

The first Stangenkunst was introduced in the Ore Mountains in 1550 and at the Harz Mountains in the 1560s. By about 1590, the Stangenkunst was introduced at the Kopparberg mines in Sweden, and by 1600 it had reached Italy, England and what is now Belgium. By 1700, the system was extensively used in North and Central European mines.

Vertical Power Transmission

The development of mechanical power transmission that followed the contours of the landscape, paralleled the development of a similar technology for vertical power transmission in mine shafts. These can only be understood in relation to each other.

Ever deeper mineshafts required a new power source to operate pumps and hoisting machines, as well as new types of pumps and hoisting machines. During the course of the fifteenth century, two new drainage machines appeared that allowed for deeper mining below adit: the rag and chain pump (around 1430) and the bag hoist (around 1470). By the 1530s, however, the limits of these machines had been reached. In his treatise on mine-pumping machinery, Graham Hollister-Short writes:

"Rag and chain pumps could raise water no more than 80 metres, while bag hoists, able to manage about 150 metres, worked so slowly that only modest inflows could be handled. As extraction neared these limits, the prospect of enforced abandonment of mines on a large scale must have appeared alarmingly close."

Under these circumstances, a new type of pumping machine appeared: the rod pumping engine. In this machine, water was transported upwards via a series of communicating suction pumps and water boxes placed above one another. The basic design of the rod engine involved "the rotation of a horizontally acting assembly through 90 degrees so as to produce a vertically operating system". In other words, it was a Stangenkunst turned on its side.

Left: The rod engine, as it is shown in Agricola's De Re Metallica (1556). Right: Agricola's rod engine, as redrawn to scale by Graham Hollister-Short.

One of the first prototypes appeared in Georgius Agricola's famous 1556 book on mining, De Re Metallica, in which the author notes that the machine had been around for ten years. The rod engine spread rapidly during the second half of the sixteenth century, gaining several improvements.

Horizontal "field rods" and vertical "shaft rods" were connected to each other by means of an "engine cross" (or "Kunst Kreuz"), which switched the line of motion by 90 degrees. One beam of the cross was attached to the field rods, the other held the shaft rods.

In fact, from the late seventeenth century onwards, many writers defined the Stangenkunst as the combination of field rods, shaft rods, and a power source (one or more waterwheels), instead of just referring to the reciprocating field rods. It is this definition which is now generally accepted.

A drawing of the 3rd, 4th and 5th mines on the Thurmhof vein made by Valentin Fritzsche in 1608, showing multiple rod engines.

Round Corners, Up-hill, Down-dale

Over the course of three centuries, the technology used to transmit power from waterwheels to mineshafts became more sophisticated. During the 1590s, engineers developed a set of balanced rods, resembling a pantograph, which was more efficient than the single-rod machines because less energy was lost through friction. Single-rod systems remained in use whenever power was abundant, but the double-rod system offered great benefits when this was not the case. Graham Hollister-Short explains:

"There are now a series of pairs of legs, each pair carrying an iron axle on which the swing arm is mounted. The ends of the swing arms support the upper and lower field rods in a rather complex fashion. The ends of each swing arm are cut out to provide slots. The slots housed not only the rods but also the small pivoted pieces of hard wood on which they reciprocated."

The efficiency of the double-rod system allowed for longer power lines. By the 1600s, the system was used to transmit energy over a distance of up to 2 km. By the 1700s, it reached up to 4 km.

Power transmission and contouring by means of double rods, Georg von Löhneyss, 1617

Initially, every Stangenkunst ran in a straight line, but by the 1640s, engineers had learned how to transmit power round corners as well as up-hill and downhill. They managed to round corners using a 'Kunst Kreuz' or 'engine cross', a lever in the shape of a cross. It was this same component that was used to connect horizontal field-rods and vertical shaft-rods, but turned on its side.

The engine cross also allowed the attachment of a new branch of wooden rods to the line, so that one waterwheel could power machines in several locations. V-rods allowed for a change of direction up or down a slope.

Panorama of the Harz mines (detail), Daniel Lindemeier, 1606.

While most Stangenkunsten were used to drive drainage pumps, they were also connected to bellows for ventilating mine shafts, and to pestles for processing ores. In order to further improve the scope of power transmission, the Stangenkunst could be combined with water management infrastructure; for instance, an aqueduct was used to supply a waterwheel which operated a Stangenkunst. Finally, even the horse whim was integrated in the power distribution network by connecting it to a Stangenkunst.

The Hoisting Machines of Christopher Polhem

The water-powered machines designed by Swedish engineer Christopher Polhem between 1690 and 1710 further extended the possibilities of the Stangenkunst. On the one hand, Polhem built several 'traditional' Stangenkunsten for Swedish mines, connecting pumps in mine shafts with waterwheels up to 2,500 m away. The picture below shows the rods of a Stangenkunst at the Bispberg mine. Polhem used a double set of wooden rods, which sat parallel to each other. The system is similar to the pantograph system, but turned on its side and with metal hangers instead of wooden ones.

The Stangenkunst at the Bisperg mine, Sweden, built around 1700 (the picture was taken in 1922).

On the other hand, Polhem also constructed rod systems for hoisting up ore from mines shafts. Strictly speaking, these were not Stangenkunsten (they were called "Hakenkunsten"), but the design principle was nearly identical.

The first Hakenkunst was completed at Blankstöten in the Falun copper mine in 1694. The water-powered machine hoisted buckets loaded with ore out of a mine shaft, carried them to a dump, emptied them, and automatically returned the empty buckets to the mine. The whole mechanism was operated by reciprocating rods.

The energy from a waterwheel was transmitted via horizontal rods to the mine shaft. The horizontal rod was joined to two pairs of hooks furnished with vertical poles suspended into the pit. Buckets were hooked onto the poles at the lowest level, and then lifted vertically to a higher pair of hooks by the alternate motion of the pairs of poles. This motion continued until the bucket was raised up the surface. The buckets were emptied by means of an iron chain which hooked onto the bottom. The vertical poles were 60 metres long and had 15 pairs of hooks.

A similar hoisting machine was completed in 1698 for the Humboberget mine. This machine consisted of two sets of poles with attached hooks. One set brought the loaded carriers to the surface, while the other brought the empty carriers down the mine. In 1701, Polhem completed another hoisting machine for the King Karl XI shaft at the Falun mine. He used two rope drums for raising the ore barrels, which were rotated by a complicated wooden rod transmission from a reversible water-wheel with one crankshaft.

The hoisting mechanism at Blankstöten, Polhem's first machine at the Falun mine, completed in 1694. Note that the distance between the water wheel and the mine shaft is distorted. Engraving by Jan van Vianen, from a drawing by Samuel Buschenfelt.

Polhem's hoisting apparatus at the King Karl XII shaft at the Falun mine in Sweden, built in 1701. Illustration by Samuel Sohlberg (1731)

Hoisting mechanism with double set of rods at the Humboberget mine, Sweden. Drawing by C.J. Cronstedt, 1729.

Man Engines

As mines became deeper, miners needed more time to descend and ascend mine shafts, and it could take up to two hours to ascend a mine which was 500 to 600 m deep. This led to the development of the "man engine", also known as the "power-ladder", which was another adaption of the Stangenkunst. The principle of operation was identical to that of the bucket hoists designed by Polhem, but applied to the transportation of miners. The man engine allowed the miners to ascend and descend the mine about three times faster and with less energy.

The first man engine was installed in 1833 in the Harz mining region. From there the design spread to Belgium, England, Austria-Hungary, Norway, France, Australia, and the United States. In total, more than 100 man engines were built from the 1830s to the 1880s. The average man engine reached a length of 400 to 500 m, with the longest reaching 1,009 metres in 1883. It was not always necessary to hang new rods in the shaft, as the rods needed for pumping could be used at little increased cost.

Man engines were built as single or double-rod systems. In the first case, the single rod was furnished with steps, while a series of platforms was fixed at different levels of the shaft. In the second case, miners jumped between platforms from two reciprocating rods. The miner, quitting one step, waited on the platform until the next step reached him. The rods, which were fastened together and reached to the bottom of the mineshaft, offered a reciprocating motion of typically 3-5 m. (These animations show how double-rod and single-rod man engines work). Counterweights -- large boxes filled with stones -- were installed in order to avoid the full weight of the shaft and men weighing on the top linkage.

Single-rod engines could be used simultaneously by miners ascending and descending, provided that there was sufficient room upon the fixed platforms, while double-rod engines did not have this advantage. The person operating the engine regulated the supply of water according to the number of miners ascending. For descent, no power was required to set the man engine in motion thanks to gravity. Descending miners could also raise the men who had finished their shifts by gravity alone, with the waterwheel only regulating motion and reducing friction.

Stangenkunsten during the Industrial Revolution

Steam engines started replacing waterwheels from the 1860s onwards. Contrary to waterwheels, steam engines were not dependent on the proximity of a stream or river, and could thus be located close to the mine shaft. This eliminated the need for mechanical power transmission. Furthermore, steam engines could be placed at the bottom of the mine to power the pumps directly, making the vertical transmission of power redundant.

However, the Stangenkunst did not disappear. On the contrary, many systems remained in use well into the twentieth century, long after steam engines had been replaced by gas engines, petrol engines and electric motors. Moreover, new systems continued to be built. In fact, most Stangenkunsten appeared after, rather than before, the invention of the steam engine.

Operating Stangenkunst with wooden rods in Lauthental, Harz Mountains, 1932. Source: Technische Kulturdenkmal, C. Matschoss.

There were three reasons for the persistent use of this technology. For one, not all regions were quick to replace waterwheels (and wind mills) with steam engines. By 1900, the mine shafts in the Harz Mountains were more than 1,000 m deep, and both suction pumps and man engines were still powered by waterwheels and wooden field rods. This was probably because the technology worked well, suggests Robert Mulhaus in his treatise on mine pumping technology:

"The connection between the urgency of the problem of mine drainage in England, and the invention of the steam engine, has often been suggested. Perhaps the 'backwardness' of Germany in steam engine experimentation, and later in the introduction of the Newcomen engine, was to some extent due to the adequacy of existing machinery to meet the problem of mine flooding, for it is not clear that this problem existed on the continent."

In the Harz Mountains, some Stangenkunsten powered by waterwheels operated until the 1970s. Even on the British Isles, which were at the forefront of the Industrial Revolution, some water-powered Stangenkunsten could be seen in the 1940s.

Stangenkunsten on Rails

A second reason for the survival of the Stangenkunst was the evolution of the technology during the Industrial Revolution. Most improvements were made possible by the availability of much cheaper and more durable iron and steel.

Flat rods running on rails at the Laxey mine, working for show (1939). Source: "Steam engines and waterwheels: a pictorial study of some early mining machines".

One such innovation was the use of rails, which reduced friction and made it possible to transmit greater amounts of power. (A similar innovation was applied around the same time for turning windmills towards the wind). A good example of this is the Lady Isabella waterwheel on the Isle of Man -- one of the most powerful water wheels ever built. It operated from 1850 to 1929, powering mine pumps up to 200 m away by means of wooden rods, and transmitting about 150 horse power. The wooden field-rods, which ran over a viaduct and worked to and fro with a 3 m stroke, were not supported by metal hangers but ran on wheels, which in turn moved back and forth on rails.

Steel Cables Replace Wooden Rods

The most important innovation, however, was the replacement of wooden rods by round iron bars or steel cables with forged eyes at the end. These metal rods, rocking back and forth, lay either in grooved wheels, which revolved in the tops of forked posts, or were supported by rocking posts. Angle bobs (supported by wheels running on rails) drove the field-rods around corners, while V-rods changed their direction down or up a steep slope. The four pictures below show some examples of their use in England. These devices are part of a Stangenkunst powered by waterwheels and used to drain mines:

Two lines of flat rods at Carloggas in 1938. These rods were led round a small angle by single-arm fend-off bobs, whose outer ends had a small wheel on a curved rail. Source: "Steam engines and waterwheels: a pictorial study of some early mining machines".

An angle bob for turning flat rods through a greater angle than the single-arm fend-off bob shown below. Wheal Remfry Clay Works. Source: "Steam engines and waterwheels: a pictorial study of some early mining machines".

V-bob leading the flat rods down into the pit. Wheal Martyn in 1939. Source: "Steam engines and waterwheels: a pictorial study of some early mining machines".

In the foreground: a flat rod supported on a rocking post at Carloggas Clay Works in 1935. Lines of rods entirely supported on rocking posts have been used elsewhere. Source: "Steam engines and waterwheels: a pictorial study of some early mining machines".

The use of metal rods was more durable, less maintenance-intensive, and allowed for a more flexible system when transmitting mechanical energy over long distances: the steel or iron field rods could easily pass through roofs, bushes, forests, and tunnels. An account of this is given in Frank D. Woodall's book the 1975 book Steam Engines and Waterwheels: a Pictorial Study of some Early Mining Machines:

"Even in 1946 it was still possible to see waterwheels driving pumps in the china clay works of Cornwall. At Wheal Martyn near St. Austell a 35ft diameter waterwheel drove a remarkable layout of rods. Following them away from the wheel one soon found difficulty, for the rods passed through the roof of a large clay-drying shed. Making a detour the observer saw a smaller waterwheel and the rods from the large wheel close at hand. A footpath, presumably used by the man who oiled the wheels in their forked posts, helped one to follow the rods through a thicket of prickly bushes to another hazard. The rods worked in a low tunnel through a mass of made ground."

As Woodall notes, systems like this were still in use in the 1970s:

"Not many years after Wheal Martyn finished working [the pumping shaft was caved in during WWII] the only other set of flat rods, at Carloggas near St Austel, fell into disuse, but although it was the last flat rod system to work in Britain a similar system remained in use in Germany. Two waterwheels each driving two lines of rods were seen working at Bad Kreuznach in 1965. The rods were not on wheels but on inverted pendulums and looked to be of recent construction. Other waterwheels driving pumps can be seen at the salt springs in the Bavarian town of Bad reichenhall."

The Stangenkunst Embraces the Steam Engine

The third reason for the sustained popularity of the Stangenkunst was the fact that field-rods were combined with steam engines (and later also gas and petrol engines as well as electric motors) instead of waterwheels. In this way, one steam engine could operate multiple pumps, which was cheaper than setting up a steam engine (or other power source) for every mine shaft or pump.

Apart from pumping water out of mine shafts, or operating man engines, this configuration found a new application in oil production, initially in the United States but eventually all over the world. It was in the oil industry that the Stangenkunst reached the pinnacle of its development. See part 2: Jerker line systems.

Kris De Decker (edited by Deva Lee)

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Sources:

"The first half century of the rod-engine (c1540-c1600)", Graham Hollister-Short, in "Bulletin of the Peak District Mines Historical Society", Vol. 12, No. 3, Summer 1994. Historical Metallurgy Society Special Publication: Mining before powder.
"The vocabulary of technology", Graham Hollister-Short, in "History of Technology", second annual volume, A. Rupert Hall and Norman Smith, 1977
"Mine pumping in Agricola's time and later", Robert P. Multhauf, in "Contributions from the museum of history and technology: paper 7", United States National Museum Bulletin 218, 1959.
"Polhem, the mining engineer", Herman Sundholm, in "Christopher Polhem, the father of Swedish technology", William A. Johnson, 1963 (original version in Swedish, 1911)
"Steam Engines and Waterwheels: a Pictorial Study of some Early Mining Machines", Frank D. Woodall, 1975
"Dictionary of arts, manufactures, and mines containing a clear exposition of their principles and practice", Part 3, Andrew Ure, 1875
"Fahrkünste - vom Harz in die Welt", Thomas Krassmann, 2010
"Stronger than a hundred men: A history of the vertical water wheel", Terry S. Reynolds, 1983
"De Re Metallica", Georgius Agricola, 1556
"Histoire générale des techniques, Tome I, II, III.", Maurice Daumas, 1962
"Contemporary reviews of mine water studies in Europe", Christian Wolkersdorfer and Rob Bowell, in "Mine water and the environment", 2005, 24.
"Revierwasserlaufanstalt Freiberg" & "Lower Harz Pond and Ditch System", Wikipedia in English and German, retrieved December 2012.
"A textbook of ore and stone mining", Clement Le Neve Foster, 1894

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How to Make Everything Ourselves: Open Modular Hardware

2012-12-15T21:27:32+01:00

Reverting to traditional handicrafts is one way to sabotage the throwaway society. In this article, we discuss another possibility: the design of modular consumer products, whose parts and components could be re-used for the design of other products.

Initiatives like OpenStructures, Grid Beam, and Contraptor combine the modularity of systems like LEGO, Meccano and Erector with the collaborative power of digital success stories like Wikipedia, Linux or WordPress.

An economy based on the concept of re-use would not only bring important advantages in terms of sustainability, but would also save consumers money, speed up innovation, and take manufacturing out of the hands of multinationals.

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A modular system unites the advantages of standardisation (as parts can be produced cheaply in large amounts) with the advantages of customisation (since a large diversity of unique objects can be made with relatively few parts). Modularity can be found to a greater or lesser extent in many products (like bicycles and computers) and systems (like trains and logistics), but the best examples of modular systems are toys: LEGO, Meccano, and Erector (which is now the brand name of Meccano in the US).

LEGO, Meccano and Erector are composed of relatively few elementary building blocks, which can be used to build various objects. The parts can then be disassembled and re-used to build something completely different. Apart from the elementary buildings blocks, these manufacturers have produced many more specific building blocks, which are less versatile, but further increase customisation possibilities.

All the building blocks in a set of LEGO, Meccano or Erector fit together because they are designed according to a set of specific rules. The holes (Meccano and Erector) or studs (LEGO) have a precise diameter and are spaced apart at specific distances. In addition, the dimensions of the building blocks are precisely matched to each other. The long lasting success of LEGO, Meccano and Erector (which appeared on the market in 1947, 1902 and 1911 respectively) is based on the fact that those rules have never changed. All new buildings blocks that were added in the course of the years are compatible with the existing ones. Today, kids can expand their collection of these toys with that of their parents or grandparents, and they are worth as much on the second hand market as they are worth new.

Grid Beam, Bit Beam, Open Beam, Maker Beam and Contraptor

The same principle could be applied to everyday objects, from coffeemakers to furniture, gadgets, cars and renewable energy systems. All you need is a standardisation in design. The design rules can be very simple, as is the case with Grid Beam. This modular construction system, which was developed in 1976, is based on beams with a simple geometry and a repetitive hole-pattern. The beams can be made of wood, aluminium, steel, or any other material.

In spite of the simplicity of the design, a great variety of objects can be constructed. Grid Beam has been used to make all kinds of furniture, greenhouses, constructions for workshops and industrial processes, windmills, wheelbarrows, agricultural machinery, vehicles, sheds and buildings (a book about the system was published in 2009, and can be found online). Grid Beam was inspired by a system envisioned by Ken Isaacs in the 1950s, Living Structures, which used similar beams but contained only a few holes.

In recent years, several systems have appeared that use a very similar set of rules, based on a repetitive hole pattern. Bit Beam is basically a scaled-down version of Grid Beam, aimed at building smaller structures in balsa-wood, like a laptop stand or a prototype device. Contraptor uses a similar approach, but is aimed at providing structural metal frames for DIY 3D-printers, milling machines, or robotics. OpenBeam and MakerBeam are also modular construction systems based on very simple rules. These are not based on a hole-pattern, but use T-slot aluminium profiles. Makeblock combines both approaches and includes electronic modules.

Most of these construction systems are limited to the design of frameworks. There is one system, however, that offers much more possibilities, because it is based on a more sophisticated set of rules: OpenStructures. The project was kicked off in Brussels in 2007. Unlike all the projects above, OpenStructures is still in an experimental phase. However, it is interesting enough to look at in more detail, because it best shows where modular construction systems may be headed in the future.

OpenStructures

The first basic rule of OpenStructures is shared with Grid Beam and similar systems: all parts are connected to each other in such a way that they can be easily disassembled, using bolts and screws rather than nails or glue. However, the OpenStructures design "language" is different: it is based on the OS Grid, which is built around a square of 4x4 cm and is scalable. The squares can be further subdivided or put together to form larger squares, without losing inter-compatibility. The illustration below shows nine complete squares of each 4x4 cm put together.

The borders of the squares mark the cutting lines (which define the dimensions of square parts), the diagonals determine the assembly points, and the circles define the common diameters. As is the case with LEGO, any modular part has to comply with at least one of these conditions in order to be compatible with other parts. Either the dimensions have to correspond with the horizontal and vertical lines, or the assembly points should be spaced according to the grid, or the diameters should be similar. Below is a part that fulfills two of three conditions.

While this set of rules is more sophisticated than that of the Grid Beam system, complicated it is not. Nevertheless, it allows for the design of a much larger variety of objects, not just square or rectangular frames. Over the course of five years, OpenStructures has yielded objects ranging from household devices to cargo bicycles, suitcases and furniture.

Open versus Closed Modular Systems

In spite of the similarities, there is one fundamental difference between modular construction systems such as OpenStructures, Grid Beam and Contraptor, and modular toys such as LEGO, Meccano and Erector. The first group consists of "open" modular systems, where everyone is free to design and produce parts, while the second consists of "closed" modular systems, where all parts are designed and produced by one manufacturer. Closed modular systems produce uniform parts. For instance, all LEGO building blocks are made of plastic. LEGO does not produce building blocks made of wood, aluminium, glass or ceramics. There is a limited range of colours. And because LEGO is a closed system, nobody else is allowed to produce LEGO pieces.

There exist modular construction systems that operate according to the same principles, like the T-profiles made by 80/20 inc. However, in the modular construction systems that we have introduced above, everyone is allowed to design and produce parts, as long as these parts are compatible with the basic set of rules. We find the same approach with open software, like Linux (an operating system), OpenOffice (office software) or WordPress (a blogging platform). The computer code for these systems is being written by a large amount of people, who all build a part of something larger. Because all participants stick to a basic set of rules, a great amount of people can, independently of one another, add parts that are inter-compatible.

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Consumer products based on an open modular system can foster rapid innovation, without the drawback of wasting energy and materials

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An open modular system has many advantages over a closed modular system. Since anyone can design parts in an open system, it generates a much larger diversity of parts: they can be made in different colours and materials, and none of the producers can set a fixed price for all consumers. And because many designers constantly review, adapt and improve each others' work, innovation is accelerated. All open software systems described above are arguably better than their closed counterparts, and some of them have become more successful. A closed modular system only has one advantage: the one who holds the copyright makes a lot of money.

Sustainable Consumer Goods

Modular construction systems encourage the re-use of physical parts, and thus form a sustainable alternative to our present-day system of producing consumer items. Most products that we buy end up in landfills or incinerators within a couple of years, at most. This is because the majority of manufacturers encourages consumers to replace their products as quickly as possible, either by designing objects that break down easily, or by introducing new generations of products which make the former generation of products obsolete. This approach not only generates a massive pile of waste, it squanders an equally massive amount of energy and raw materials.

Consumer products based on an open modular system can foster rapid innovation, without the drawback of wasting energy and materials. The parts of an obsolete generation of products can be used to design the next generation, or something completely different. Furthermore, modular objects have built-in repairability.

Open modular construction systems could greatly speed up the diffusion of low-technologies, such as pedal-powered machines, solar thermal collectors, velomobiles or cargo cycles. Building a windmill or a cargo bike goes much faster when using modular parts than when using carpentry or welding, and there is no need for expensive tools or special skills. Mistakes can be easily corrected -- just unscrew the bolts and start again. It would also be interesting to see modular parts combined with an open hardware project such as the Global Village Construction Set, which generates many interesting designs but makes limited use of modularity.

Circulation of Parts

"While eBay provides a circulation of objects, and cradle-to-cradle provides a circulation of materials, modular construction systems provide a circulation of parts and components", says Thomas Lommée, the creator of OpenStructures. "Our ambition is to create puzzles instead of static objects. The system should generate objects of which it is not entirely clear anymore who designed them. An object evolves as it is taken in hands by more designers."

The kitchen appliances that were designed in the context of the project are good examples. A couple of parts were initially made for a coffee grinder, were then used, together with new parts, by another designer to build a coffeemaker. This appliance was then further developed into a water purification device by a third designer. The plastic bottle that served as a water container was replaced by a cut through glass bottle containing a clay filter. Thomas Lommée: "By adding or removing components, or by using them in a different manner, what you get is a family of objects".

Cargo Cycle

Another prototype that originated from the project, is a cargo cycle. The rear is a sawed through frame of a standard bicycle, the end of which is compatible with the OS Grid. This means that the front of the cycle can be built up in a modular way. Designer Jo Van Bostraeten used this opportunity to design both a cargo bicycle and a cargo tricycle (the latter is carrying a 3D-printer), and it doesn't end there. Together with Lommée, he also constructed a modular motor block. The unit consists of an electric motor and wheels, on top of which a similar unit can be placed that holds a battery. Since the units are compatible with the OS Grid, they can be coupled to the front of the cargo cycle, resulting in a completely modular motorised cargo vehicle.

The latest "family" of objects to come out of the project is aimed at children. It is noteworthy that this collection arose from one component of the cargo cycle -- the container. It is built up from modular parts that can be bolted together, and can thus be combined in different ways. A couple of designers got started with those parts, resulting in (among other things) a sled, a seat, a toy excavator, and a swing. When the child becomes an adolescent, the parts can be used to make a suitcase or a tool box, or become part of a cargo cycle that could make him or her some pocket money.

More interesting than the objects themselves, is their user support system. Grid Beam is obviously a product from the pre-internet age. Those who want to copy a design are encouraged to look at a picture of someone else's creation and "count the holes". OpenStructures, on the other hand, leans heavily on online user support. The re-use of parts is being facilitated by an online database that can be used in three ways.

A Modular Database

First, you can request an overview of all objects that were designed based on the OS grid. The webpage for each object then shows you the parts and components from which it is made. Second, you can request an overview of all parts that were designed based on the OS grid. The webpage for each of these shows you which components and objects they could serve. Third, you can request an overview of all components. The webpage for each component shows you their parts and the objects they can be used for.

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Open modular construction does not mean that everyone should make their own consumer products

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The webpage for each part, component and object also gives additional information: the dimensions, the materials, the designer's name, the licence and the order information. To add to this, all parts and components receive a serial number. This means that after a modular object is taken apart, the serial number of each part and component can be entered into the database to see what else can be made with it. Missing parts can be obtained via the database: either by ordering them online, by finding the address of a shop where they sell them, or by downloading the digital design and making them.

Not Everyone is a Designer

Open modular construction does not mean that everyone should make their own consumer products. An object like a coffee maker or a workbench could be obtained in at least three ways. Firstly, the consumer can download the digital design and then assemble the object with parts that he or she buys, re-uses, or makes using a 3D-printer or laser cutter, whether at home or at a fab lab or tech shop. It can also happen in a more low-tech fashion, as is the case with Grid Beam: the consumer buys wood or metal beams, and drills the holes himself.

A second option is that a company buys the license of the design (if it is not free) and converts it into a building kit, comparable to a kit from LEGO, Meccano or Erector. In this case, the consumer would not have to search for the parts himself, but he still assembles the product himself, just like he would assemble a piece of furniture by IKEA. Similarly, a company could offer a more general building kit, which can be used to make whatever one would like, similar to a box of basic LEGO bricks. Bit Beam, Contraptor, Open Beam, Maker Beam and, recently, Grid Beam offer one or both of these options.

The third possibility is that a manufacturer places the object on the market as a finished, assembled product. The coffee maker or the workbench would then be sold and bought just as any other product today, but it can be disassembled after use, and its parts can be re-used for other objects.

Economic Model: who Produces the Parts?

While the design process behind OpenStructures and other open modular construction systems is identical to that of digital products such as Wikipedia, Linux or WordPress, there is also a fundamental difference. Computer code and digital text accumulate without any material costs. This is not the case with objects. This makes open modular hardware less easy, but it also creates economic opportunities. It's hard to make money with open software or online writing. However, in the case of an open modular system for objects, someone has to provide the materials.

It is also important that the parts are produced by as many manufacturers as possible, so that they are available worldwide. Otherwhise, the shipping costs can be so high that a modular object becomes too expensive.

There are many opportunities to make money with an open modular construction model. A manufacturer can choose to produce a part in which they sees economic potential. Another manufacturer can choose to sell a building kit or a finished product of a design they think will sell. A designer can make money by uploading a design that might be free to download for personal use, but not for commercial use. A manufacturer that wants to commercialise this design, can then buy the licence from the designer.

Craftsmen can focus on the design of exclusive, handmade parts in special materials, which are compatible with popular mass produced items. Others can start a fab lab or a tech shop where people can build their own modular objects for a monthly fee. In short, an open modular construction system offers economic opportunities for everybody.

Collaborative Economy

"It is not our ambition to build a gigantic factory that produces all possible parts", Lommée notes. "OpenStructures should not become a modular IKEA. Our ambition is the creation of a collective economic system, where one producer benefits from the production of another producer. Because parts which are made by one, can be used by another. What we would like to see, are streets full of little shops where everybody generates their own little part of a larger system, a collaborative economy where small, self-employed producers have their place. Not one big player that makes everything. The social dimension is very important."

"If IKEA wants to sell a product that is compatible with our system, then that's fine with me. But the system can only work if it remains open. The larger it becomes, the easier it is for a small company or a craftsman to be a part of it. The ambition is to start a universal, collaborative puzzle that allows the widest possible range of people -- from craftsmen to multinationals -- to design, build and exchange the widest possible range of modular parts and components."

Organising Re-use

Apart from a design language (the OS grid) and an online database, OpenStructures also has set up a prototype of a warehouse in Brussels. This kind of place should become the hub for the organisation of the re-use of parts and components. Think a fab lab or tech shop, but then combined with the storage of modular parts. If a modular product is no longer needed, and the owner does not feel like using the parts to build something new, he or she brings it to one of these places, where it is taken apart, and its parts are stored.

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An open modular construction system offers economic opportunities for everybody

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Other people could come to this place to buy parts or to use them on site to build something new. As Lommée says: "Not everyone has to make their own products, but after its useful life, a modular product always comes into the hands of a group of people who like to make things."

Compatibility between Open Modular Systems

While it is still in an experimental phase, OpenStructures is by far the most ambitious and complete open modular system designed to date. However, being a European project, it follows the international metric system, while the much older Grid Beam follows the imperial system. The systems are not compatible. With more and more open modular systems appearing, would it not be important to provide inter-compatibility between them?

Lommée doesn't think so: "Most of these systems are designed for different applications. For instance, Contraptor aims at precision, because the parts are used to build robots and other sophisticated machines. Esthetics are clearly not important. I am a designer, so what interests me especially is whether or not a modular system can generate beautiful objects, things you would want to put in your interior. There is also Wikispeed, for instance, which concentrates on the development of a modular car. Arduino is aimed at electronics. I don't think that all of these modular systems have to be compatible with each other because the applications are very different."

He goes on to explain why he chose the metric system. "I have been doubting a lot about this. But in the end I decided that the metric system is easier to work with. And I think the world is big enough for two systems -- just look at the variety of energy standards which are in use. Somebody has developed a European version of Contraptor, based on the metric system and compatible with the OS grid. And it is always possible to design a coupling between two systems, so that they can be used together. On the other hand, we live in a networked world where everything is connected and copied. This often means that when standards compete, only one survives. And this is not necessarily the best one. I'll keep my fingers crossed."

Kris De Decker (edited by Deva Lee)

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DIY category at No Tech Magazine
The art of producing sustainable consumer goods: basketry
The bright future of solar thermal powered factories and workshops
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Hand powered drilling tools and machines
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Electric Velomobiles: as Fast and Comfortable as Automobiles, but 80 times more Efficient

2012-10-24T01:23:37+02:00

Both the velomobile and the electric bicycle increase the limited range of the cyclist -- the former optimises aerodynamics and ergonomics, while the latter assists muscle power with an electric motor fuelled by a battery.

The electric velomobile combines both approaches, and so maximises the range of the cyclist -- so much so that it is able to replace most, if not all, automobile trips.

While electric velomobiles have a speed and range that is comparable to that of electric cars, they are up to 80 times more efficient. About a quarter of the existent wind turbines would suffice to power as many electric velomobiles as there are people.

All pictures: Fietser.be

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Few people find the bicycle useful for distances longer than 5 km (3 miles). In the USA, for instance, 85 % of bicycle trips involve a trip of less than 5 km. Even in the Netherlands, the most bicycle-friendly country in the western world, 77 % of bike trips are less than 5 km. Only 1 % of Dutch bicycle trips are more than 15 km (9 miles). In contrast, the average car trip amounts to 15.5 km in the USA and 16.5 km in the Netherlands, with the average trip to work being 19.5 km in the USA and 22 km in the Netherlands. (Sources: 1, 2, 3, 4, 5.)

It's clear that the bicycle is not a viable alternative to the car. Depending on his or her fitness, a cyclist reaches cruising speeds of 10 to 25 km/h, which means that the average trip to work would take at least two to four hours, there and back. A strong headwind would make it even longer, and when the cyclist is in a hurry or has to climb hills, he or she would arrive all sweaty. When it rains, the cyclist arrives soaking wet, and when it's cold hands and feet would freeze. Longer trips on a bicycle also affect the body: wrists, back, shoulders and crotch all suffer, especially when you choose a faster bike.

An electrically-assisted bicycle solves some of these problems, but not all. The electric motor can be used to reach a destination faster, or with less effort, but the cyclist remains unprotected from the weather. Longer trips would still cause discomfort. Moreover, the range of most electric bicycles (about 25 km or 15.5 miles) is just large enough for the average one-way trip to work, which means that it will not suffice for all commutes.

The Advantages of an Electric assist Velomobile

The velomobile -- a recumbent tricycle with aerodynamic bodywork -- offers a more interesting alternative to the bicycle for longer trips. The bodywork protects the driver (and luggage) from the weather, while the comfortable recumbent seat eases the strain on the body, making it possible to take longer trips without discomfort. Furthermore, a velomobile (even without electric assistance) is much faster than an electric bicycle.

At speeds below 10 km/h (6 mph), rolling resistance is the biggest challenge for a cyclist. Air resistance becomes increasingly influential at higher speeds, and becomes the dominant force at speeds above 25 km/h (15.5 mph). This is because rolling resistance increases in proportion to speed, while air drag increases with the square of speed. Because a velomobilist has much better aerodynamics than a bicyclist -- the drag coefficient of a velomobilist is up to 30 times lower -- he or she can attain higher speeds with the same effort.

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If rigged with an electric auxiliary motor, the weak points of the velomobile -- its slower acceleration and climbing speed -- are eliminated

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On the downside, a velomobile is heavier than a bicycle, which means that it takes more effort to accelerate and to climb hills. Acceleration is inversely proportional to the mass of a vehicle, so a velomobile uses roughly twice as much energy during acceleration than a bicycle, depending on the weight of the driver and vehicle.

If rigged with an electric auxiliary motor, the weak points of the velomobile -- its slower acceleration and climbing speed -- are eliminated. At the same time, a motor accentuates its advantages by further improving on the range of a cyclist. Last but not least, a battery will give a much better range in the velomobile, due to its better aerodynamics.

Test Driving a Ferrari

In August, I test drove an electrical velomobile -- the eWAW, a vehicle that is sold by Fietser.be -- in and around Ghent, Belgium. Brecht Vandeputte, the driving force behind the Belgian manufacturer, accompanied me in an unassisted WAW during a one and a half hour trip through the city and along the tow path of the river Schelde.

The WAW velomobile (without electrical assistance) was originally developed for winning human-powered vehicle races. It was adapted for daily use with the addition of, among other things, a leakproof rear tyre, open wheel arches (which make the vehicle more agile), an adjustable seat, and a more durable body -- which consists of a carbon roll bar and safety cage surrounded by aramid crumple zones. The WAW is known worldwide, at least among velomobilists, as one of the fastest velomobiles available on the market -- some call it the Ferrari of the velomobiles.

The WAW stands out because of its weight (it is 28 kg, as opposed to 34 kg, the weight of the most popular velomobiles, the Dutch Quest and Alleweder) and its low centre of gravity (it has a ground clearance of only 9 cm and a height of just 90 cm). Along with a wide wheelbase, a hard suspension, and precise steering (it uses two gear sticks instead of one), this results in high speeds and excellent handling, even on sharp corners. Of course, the WAW also has the drawbacks you can expect from a real sports car, like the very basic interior finish and the fact that the vehicle rattles like a box of rocks when you ride it over a cobblestone road. If road conditions are bad, other velomobiles with more comfortable suspension will be a better choice.

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With 250 watts of power, the electric motor of the eWAW gives a person with an average fitness level the power output of an athlete

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The eWAW that I drove has everything that the WAW has, plus an electric motor of 250 watts and a surprisingly small battery of 288 Wh, which takes you 60 to 130 km further (37 to 81 miles). The battery and the motor add only 5 kg, bringing the total weight of the vehicle to 33 kg. This is comparable to the weight of other velomobiles without electric assistance. Hence, this pedal powered Ferrari is more than 10 kg lighter than other velomobiles, with a 250 watt electric assistance, such as the hybrid Alleweder and the e-Sunrider, which weigh 45 kg.

Cycling at 50 km/h

So how fast is the WAW, and how much faster is the eWAW? First of all, the eWAW is a hybrid vehicle, but the biomass powered motor, also known as the driver, is not included in the package. Because the driver always provides the main part of the total power output, the speed of the vehicle will depend on the power that he or she can deliver. There is no better illustration of this than my test drive. Over a period of about an hour and a half, Brecht and I managed to reach an average speed of 40 km/h (25 mph) -- I was in the eWAW and had the regular assistance of the electric motor, Brecht was in a WAW without pedal assistance.

Cycling literature makes a distinction between three types of cyclists: people with an average fitness level, people with a good fitness level, and top athletes. Riders with an average fitness can maintain a power output of 100 to 150 watts over a period of one hour. Riding a WAW, this translates to speeds of 35 to 40 km/h in ideal conditions -- an unobstructed racetrack, and a completely closed vehicle. Drivers with a good fitness level can deliver 200 watts of power over a period of one hour, which translates to speeds of 45 to 50 km/h under the same circumstances.

With 250 watts of power, the electric motor of the eWAW gives a person with an average fitness level (like me) the power output of an athlete (100 + 250 watts = 350 watts).

Maximizing Range and Efficiency

I am a speed freak, so when I found myself on a nice, open stretch of road, the first thing I did was start the motor at full throttle and pedal like a madman at the same time. If I could have more than 350 watts at my disposal, I calculated, I must be able to reach speeds of at least 70 or 80 km/h (40 to 50 mph). However, my attempt to go any faster than 50 km/h (30 mph) left me frustrated -- the vehicle lacks the high gears needed for those speeds.

Why? Because the eWAW is designed for maximum efficiency. The electric motor is intended to be used for acceleration only (and for climbing hills). Once the velomobilist reaches a cruising speed of about 40 to 50 km/h, he or she switches to pedalling alone.

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The engineer's choice to assist the driver only during acceleration is smart; it increases the range of both the cyclist and the battery spectacularly

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The eWAW does not increase the cruising speed or top speed of the unassisted WAW, although it does increase the average speed because it speeds acceleration. This is a different approach from the electric bicycle, where pedal assistance is continuous at normal cruising speeds. With regards to efficiency, the concept behind the eWAW makes much sense. A bicyclist needs less energy to accelerate than a velomobilist does (because of the bike's lighter weight) but more energy to keep up speed (because of its weak aerodynamics). In contrast, a velomobilist needs more energy to accelerate than a bicyclist does (because of the vehicle's heavier weight) but less energy to keep up speed (because of its excellent aerodynamics).

Because it takes more energy to accelerate in an eWAW than to drive it at a constant speed, the engineer's choice to assist the driver only during acceleration is smart; it increases the range of both the cyclist and the battery. The electric motor supports the driver during peak efforts, so that his or her endurance will increase spectacularly. (Peak efforts have a detrimental effect on endurance, while pedalling at a steady pace can be done for hours.) Meanwhile, the driver offers the same service to the battery. Because the electric motor is shut off at cruising speed, the battery range increases considerably.

This said, the driver of the eWAW can choose to use the motor at cruising speed, because it can be operated at his or her will by means of a throttle. This is how I drove the vehicle. As a consequence, the battery lasted 'only' 60 km (37 miles), but at least I could keep up with Brecht.

80 times More Efficient than Electric Cars

Mounting an electric engine in a velomobile is controversial among velomobilists, just as an electric bicycle is skewed by many biking aficionados. However, when we compare the eWAW with the electric car, still viewed by many as the future of sustainable transportation, it's a clear winner. In fact, the electric velomobile is everything what the electric car wants to be, but isn't: a sustainable alternative to the automobile with combustion engine. It is nearly impossible to design a personal, motorised and practical vehicle that is more efficient than the eWAW.

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If all 300 million Americans replace their car with an electric velomobile, they need only 25 % of the electricity produced by existing American wind turbines

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A simple calculation can illustrate this claim. Imagine that all 300 million Americans replace their car with an electric velomobile and all drive to work on the same day. To charge the 288 Wh battery of each of these 300 million eWAW's, we need 86,4 GWh of electricity. This is only 25 % of the electricity produced by existing American wind turbines (on average per day during the period July 2011 to June 2012, source). In other words, we could make a switch to private vehicles operating on 100 % renewable energy, using existent energy plants.

Photo credit: Bill Bates

Now imagine that all 300 million Americans replaced their cars with an electric version like the Nissan Leaf, and all drive to work on the same day. To charge the 24 kW battery of each of those 300 million vehicles, we need 7,200 Gwh of electricity. This is 20 times more than what American wind turbines produce today, and 80 times more than what electric velomobiles need. In short: scenario one is realistic, scenario two is not.

Even if we all started carpooling, and every electric automobile could carry five people, there remains a large gap in efficiency. Charging 60 million electric cars would still require 16.6 times more electricity than charging 300 million eWAW's. The electric velomobile also makes it fairly easy for a driver to charge his or her own vehicle. A solar panel of about 60 watts (with a surface area of less than one square metre) produces enough energy to charge the battery, even on a dark winter day.

In Europe, it would take an even smaller share of the existent wind turbines to charge every European's eWAW. For the sake of thoroughness, it should be mentioned that the bio-motor also requires energy: the driver needs to eat, and this food needs to be produced. But since western people eat too much, and then drive their cars to the gym in order to lose excess fat, this factor can be safely ignored.

Range Anxiety

The large difference in energy efficiency between electric velomobiles and electric cars is remarkable, because both have a similar range. As mentioned, the eWAW takes you a distance of 60 to 130 km, depending on how intensively you use the motor. The Nissan Leaf takes you at best 160 km, when you drive slowly and steadily, and when you don't make use of the air-conditioning, heating or electronic gadgets on board.

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Adding only 6 kg of batteries increases the range of the electric velomobile to 450 km

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A heating system is not required in a velomobile, not even in winter, because hands and feet are protected from the wind by the bodywork, and because the driver is active (body activity is the most important factor in maintaining thermal comfort). The need for cooling in summer, on the other hand, will decrease the range -- the driver will rely more on the electric motor in order to cool down.

Interestingly, it is easier to increase the range of the electric velomobile than of the electric car, if necessary. The eWAW can be equipped with one or two extra batteries, which increases the range up to 180 km (112 miles, with continuous assistance of the motor) or 450 km (280 miles, when the motor is only used to assist acceleration). Adding two batteries to the eWAW increases the weight of the vehicle by only 6 kg, and still leaves ample space for luggage. If we suppose that the rider weighs 70 kg, then adding two batteries increases the total weight of the eWAW from 103 to 109 kg -- a weight gain of 6 %. If we apply the same trick to the Nissan Leaf (where three times as many batteries take the place of the rear seat and the trunk), total weight increases from 1,582 kg (the driver of 70 kg included) to 2,022 kg -- a weight gain of 30 %.

Another way to increase the range of an electric vehicle is swapping batteries or fast-charging them. These options are available for both electric cars and velomobiles, but developing a charging infrastructure for electric cars is a daunting task, while doing so for electric velomobiles is easy. The battery of the eWAW not only needs 80 times less energy than the battery of a Nissan Leaf (which makes fast-charging a real option), it also weighs 73 times less (which makes swapping batteries a very low-tech operation). While we do have faster vehicles for long distances that are equally sustainable (like trains and trolleybusses), the velomobile offers an alternative for those who prefer a personal means of transportation, or for those who prefer an active lifestyle.

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The capacity of our roads would at least quadruple if we switched from cars to velomobiles

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When the battery of an electric velomobile drains, the velomobilist can still pedal home -- at speeds above those of a bicycle. The driver of the electric car can't do that, because his contraption is too heavy. One Nissan Leaf weighs as much as 46 eWAW's. Most of the energy used by an electric car (and by a car with combustion engine), is used to move the vehicle itself, not the driver -- the Nissan Leaf is 21 times heavier than its driver. In the case of the eWAW, this relation is reversed: the driver weighs two to three times more than the vehicle.

Fast and Smooth Traffic

The eWAW makes cycling a fast and comfortable option for longer distances. At a cruising speed of 50 km/h (31 mph), the average commute in the USA (19.5 km or 12 miles) would take 23.4 minutes. This compares very favourably with the car, for which the average commute time is 22.8 minutes (source). In the Netherlands, where road traffic is heavy, the electric velomobile is potentially faster than a car. The velomobile could cover the average commute of 22 km (13.7 miles) in 26.4 minutes, while it takes 28 minutes by car (source).

Of course, a cruising speed of 50 km/h does not mean that a velomobilist can reach an average speed of 50 km/h during the whole trip. If cars could maintain their maximum cruising speed during the commute, they would be much faster than velomobiles. In reality, however, they can't do that because of speed limits, traffic lights and traffic jams.

Velomobiles could suffer similar delays, but there is an important difference: because a velomobile occupies much less space than a car (one car needs as much space as four velomobiles), free-flowing traffic is a much more realistic option for velomobiles. The capacity of our roads would at least quadruple if we switched from cars to velomobiles. Furthermore, the cruising speed of a velomobile does not exceed most speed limits.

Pimp up your Velomobile

Over and above this, it is easy to equip a velomobile with a more powerful motor and higher gears, allowing for much higher cruising speeds. It would lose efficiency and range, but, since an eWAW is 80 times more efficient than an electric car, there is quite a bit of room for pimping up a velomobile. We'll discuss these possibilities, as well as the legal obstacles for electric velomobiles, in the second part of this article.

Continue Reading: 1 / 2.

Related articles:

Main page.

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Cargo cyclists replace truck drivers on European city streets

2012-09-24T13:14:48+02:00

Those with strong cycling legs have ever more jobs up for grabs in Europe these days. A growing number of businesses are using cargo cycles, a move towards sustainable and free-flowing city traffic that is now strongly backed by public authorities.

Research indicates that at least one quarter of all cargo traffic in European cities could be handled by cycles. And, by using special distribution hubs, larger vehicles and electric assist, this proportion could be even larger.

A cargo cycle is at least as fast as a delivery van in the city - and much cheaper to use, giving a strong economic incentive to make the switch. Cargo cycles also bring important economic advantages to tradesmen, artisans and service providers.

Picture: a cargo bike in Germany (source: "Ich ersetze ein Auto").

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Cargo transport in cities is extremely inefficient. As it currently stands, almost 100 percent of it is done by motorised vehicles, ranging from personal cars to commercial delivery vans and trucks (lorries). However, these heavy vehicles often transport very light goods. The average payload transported in European cities weighs less than 100 kg (220 lbs) and has a volume of less than 1m3 (1). Of the 1,900 vans and trucks that enter the city of Breda in the Netherlands each day, less than 10 percent of the cargo being delivered requires a van or truck and 40 percent of deliveries involve just one box (2).

This means that a large share of the cargo being moved in and out of cities could be transported by cargo cycles. Fast, two-wheeled cargo cycles have a load capacity of up to 180 kg (396 lbs), while slower vehicles with three or four wheels can easily take 250 kg (550 lbs). Using a tandem configuration and/or an electric power assistance can help raise the load capacity even further, to about half a ton. Cargo volume ranges from at least 0.25 m3 for bicycles to more than 1.5 m3 for larger tricycles and quadricycles.

Freight traffic takes up a large portion of total daytime road transport in cities, often as high as 50 percent in large cities, and up to 90 percent in very large cities such as London and Paris (3). The 'last mile' is currently regarded as one of the most expensive, least efficient and most polluting sections of the entire logistics chain. This is because traffic congestion makes the driving cycle very irregular, leading to a very high fuel consumption and a loss of time.

Cargo cycles are fast, efficient, clean and quiet

The positive ecological and social consequences of substituting cargo cycles for delivery vans are obvious: important fuel savings, less pollution, less noise, more space in a more enjoyable city, less congestion, and less serious accidents. However, this is not all. There are as many economic benefits as there are ecological and social benefits, though they are not so obvious at first sight.

Picture: CycleLogistics.

To begin with, cargo cycles operating in the city are as fast as, or even faster than, vans and trucks (4). This is because they are less affected by traffic congestion, and because they can often take faster routes where trucks and vans cannot go, such as pedestrian streets, alleys or bicycle paths. Because cargo cycles are less affected by variable traffic conditions, journey times are more reliable. Moreover, they are able to enter the city 24 hours a day, while many Europeans cities have set very strict time windows for loading and unloading of trucks and vans. Cargo cycles have generally no difficulty finding a place to load or unload and can often stop right in front of the door or even enter a building.

98 percent cheaper

Secondly, cargo cycles are much cheaper than vans. The purchase price of an average cargo cycle does not exceed 3,000 euro, and the largest three- and four-wheeled cargo cycles with electric assist sell for about 7,000 to 10,000 euro. Buying a van sets you back at least 20,000 euro. However, for either mode of transport this cost is small compared with the running and staff costs. The real advantage of the cargo cycle lies in its low cost of use. A car, van or truck consumes fuel, a cargo cycle does not. Moreover, taxes, insurance, storage and depreciation are all lower for cycles than for vans, which can result in significant cost savings (5). All together, a cargo cycle can be up to 98 percent cheaper per km than the alternatives (4/6).

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Because a cargo cycle is as fast as a delivery van in city traffic, and because it can move as much cargo as the van usually does, substituting cargo cycles for delivery vans will not require additional drivers.

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These savings can be achieved without the loss of jobs. Some people promote the use of cargo cycles by saying that they will bring more jobs. However, this is only half true. If cargo cycles become more successful, other jobs will disappear, notably those of van and truck drivers. Because the cargo cycle is as fast as the delivery van in city traffic, and because it can move as much cargo as the van usually does, substituting cargo cycles for delivery vans will not require additional drivers. (On longer routes outside the city, this would be different). This is actually good news, because it means that labour costs will not rise. Indirectly, however, cargo cycles can indeed create jobs (see further).

Europe promotes cargo cycling

European authorities clearly recognize the economic and ecological potential of cargo cycles. Running from May 2011 until April 2014, the EU-funded project CycleLogistics aims to reduce energy used in urban freight transport by replacing unnecessary motorised vehicles with cargo bikes in European cities. The project aims to expand the niche market position of cargo cycles, so that they will be viewed as a serious alternative for the transport of goods in inner cities. According to research undertaken by the project, cyclists could easily move 25 percent of all cargo in cities (considering loads up to 250 kg) (1/2).

CycleLogistics will communicate the potential of cargo cycles to different target groups such as the transport sector, municipalities, service providers, tradesmen, artisans and individuals. In order to stimulate companies and service providers to integrate the cargo cycle into their activities, the project is lending 2,000 cargo cycles to businesses and municipal services so that they can test them out. Their use will be documented and analysed, and the findings will be published in a research paper.

Picture: CycleLogistics.

CycleLogistics will motivate municipalities to create a regulatory framework and policies for cargo cycles, and they will be testing and reporting on various cargo bike models, promoting their uptake by consumers, authorities and businesses alike; UK research has found that perception is probably the biggest single factor inhibiting the use of cycle freight (5). The reluctance to use cycle freight is due more to a lack of information on the vehicles and options now available rather than due to entrenched attitudes against using cycle power.

Electric assisted cargo cycles in Germany

The German Federal Ministry for the Environment has set up a similar pilot project, named "Ich ersetze ein Auto" ("I replace a car"), which began in July 2012 and will continue for two years. Contrary to the European-wide project, it will be aimed exclusively at courier services and make use of electric assist cargo cycles. Forty vehicles will be used for two years in nine major German cities. The cargo bikes can transport a load with a weight of 100 kg and a volume of 250 litres (0.25 m3). Because these loads can also be moved by non-assisted cargo cycles, the electric assist is aimed at further increasing delivery speeds and extending the driver's range.

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In Berlin, it was found that cargo cycles using electric assist can replace up to 85 percent of car trips made by courier services.

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Preliminary research by the German Institute of Transport Research showed that cargo cycles using electrical assist can replace 85 percent of car trips made by courier services in the city. This was demonstrated during an experiment in Berlin using an additional city hub to coordinate distribution of goods (the 'Bentobox'). The German pilot project will result in a research paper detailing the economic potential of cargo cycles, the energy and emissions savings, and the necessary improvements in infrastructure and legislation.

As mentioned earlier, the focus of cargo transport by cycles is on the "first mile" and "last mile". Goods are delivered by vans and trucks to a (central) distribution hub, from where they are taken to their final destination by cargo cycle (or the other way around). An alternative is to use vans (or even boats or cargo trams) as mobile hubs. UK based cargo cycle courier Outspoken Delivery uses folding bikes in combination with trains for speedy intercity deliveries between Cambridge and London. Cargo cycles as a last mile city transport option match very well with the research into trolleytrucks for goods transport on longer distances. Of course, cargo cycles can also be complemented with fully electric light vehicles in the city, such as the Cargohopper.

Courier services

A logical target group for cargo cycles are courier services. The German and the European projects aim to introduce cargo cycles to both courier companies using motorised vehicles and courier enterprises using normal bicycles. The first group can save costs and will be able to offer a faster service when replacing delivery vans by cargo cycles, while the second group can use cargo cycles to extend their market by transporting heavier and/or bulkier loads.

Picture: CycleLogistics.

An additional incentive for traditional courier services is that they will have an easier job finding employees, because the drivers do not require a (special) driving licence. Larger fleet managers already find it hard to recruit drivers. Furthermore, the relatively low price of the cargo cycle allows courier services to build a larger and more diversified fleet of vehicles. In this way, it is always possible to choose the fastest and most compact vehicle.

Cargo cycles are already used by courier services in (for example) Brussels, Londen, New York, Berkeley, Zürich, Basel, Vienna, Graz, Rome, Reggio and San Sebastian. These are often relatively small companies, but sometimes large logistic enterprises use cargo cycles, too. DHL applies cargo cycles in 15 Dutch cities. The largest courier service to date using (electric assist) cargo cycles is the French La Petite Reine, which delivers goods in Bordeaux, Paris, Lyon and Toulouse.

The European project CycleLogistics proposes to develop and implement a next day delivery operation in conjunction with leading national and international delivery companies, in which cargo bikes are used for the final mile delivery. Cooperation with large courier services is important because regular and frequent collections and deliveries are needed to have a sustainable business model. One of the main outputs of these experiments in several cities will be a formalised and transferable business model for running a cycle based courier business which can be adopted by couriers across towns and cities in Europe.

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The cargo cycle allows service providers to start a business with a much lower investment, and to operate it at considerably lower costs.

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Other companies also discover the advantages of cargo cycles, often for the delivery of their goods to customers' houses. These are often small enterprises such as suppliers of organic food, but also larger companies like retail chain FNAC who delivers products ordered online via cargo cycle in Barcelona and Madrid. IKEA puts (large) cargo cycles at the disposal of their customers in some Dutch and Danish cities.

Tradesmen & service providers

Another target group of the European cargo cycle project are commercial service suppliers, tradesmen and artisans such as window cleaners, electricians, builders, chimney sweeps, locksmiths, painters, repairmen, carpenters, gardeners, plumbers, scrap dealers, professional photographers, musicians, street and market vendors, distributors of magazines, newspapers and advertisements, and so on.

Copenhagen has carpenters and electricians using cargo cycles, and window cleaners using cargo cycles have been spotted in Austria and in England. Home bicycle repair is another example. These services, which have been operating in many large cities for some years now, often use vans. However, a mobile bicycle repair that introduces extra automobile traffic is not very logical, so individuals in Copenhagen, Cologne, Berlin and Brussels have taken the idea one step further by using the technology they promote.

Picture: CycleLogistics.

Just as the cargo cycle brings economic advantages to courier services, so it does for tradesmen, artisans and service providers. The vehicle allows them to start a business with a much lower investment, and to operate it at considerably lower costs. No motorised vehicle is required, and even a shop is not a necessity. The cargo cycle can thus indirectly bring more (self-employed) jobs.

Local authorities are another target group for cargo cycles. The vehicles could be used for maintenance of city infrastructure such as parks and roads, for repairs, senior citizens care, garbage collection or transporting official documents. This would lower the costs of municipal services, making it possible to use taxes for other aims (or even lowering them).

Learning from the past

Many proposed applications of the cargo bicycle are everything but new (7). During the first half of the twentieth century, service providers and artisans were among the main users of cargo cycles. Almost every profession made use of cargo cycles which were specially designed to carry the tools of their trade. These were both commercially available models as well as self-adapted vehicles. Cargo cycles also played an important role in the delivery of goods, mostly bread, meat, vegetables, fruit and dairy products. Again, every profession used a cargo cycle that was best suited to perform the specific duty. Cargo cycles were a large improvement over horse, donkey or dog powered carts, which were slower and much more expensive to operate.

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During the first half of the twentieth century, tradesmen and artisans made use of cargo cycles which were specially designed to carry the tools of their trade.

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Delivery of goods such as bread or meat was often done using a sturdy safety bicycle equipped with cargo platforms, boxes or baskets in different sizes fixed to the frame, mostly in the front. These vehicles, which have a payload of about 75 kg (165 lbs), are known as 'bakery bikes' or 'butcher bikes' and can still be seen on the streets of Danish and Dutch cities. In the late 1920s an extended form of carrier bicycle appeared in Denmark, in which a load-carrying platform was inserted between the rider and the front wheel, which now being entirely separate from the handlebars, was steered by a tie-rod passing under the platform.

Picture: transportfiets.nl

This platform was low down for stability and ease of loading. These bikes, which earned the nick-name 'long-john' and have payloads up to 180 kg, were (and are again) used for speedy deliveries of somewhat heavier and bulkier goods. Three-wheeled cargo bikes, still known as a 'bakfiets' and able to carry even heavier loads at the expense of speed, where most often used by craftsmen providing services in different locations.

Private use of cargo cycles

A final target group of cargo cycles are private individuals. People who regularly ride bikes in cities, often still have a car in case something larger or heavier has to be transported, whether this concerns shopping, moving stuff or leisure activities. The cargo cycle is a much cheaper option which is just as effective. However, individual ownership of cargo cycles is impeded by limited parking space in dense, urban centres. Moreover, for people who can't afford a car, buying a cargo cycle might still be too high an investment.

But all this can be solved. The LastenRad Kollektiv in Vienna, Austria, rents out cargo cycles to individuals who want to transport something big or heavy and prefer not to use a car. People pay a voluntary fee, which is used to maintain the bikes. Velogistics, a project that was inspired by it, tries to do the same at a European scale, by building an online database of people owing a cargo cycle and willing to lend it.

Will cargo cycles work everywhere?

The potential of the cargo cycle remains unclear. Presently, research is very scarce. This is remarkable, since no other technology seems to offer so many benefits for urban freight transportation. Yet, the possibilities of cargo cycles will depend on several factors, which might make them less suited in other places. All cities where cargo cycles have taken off to some degree, are flat. Having to pedal a cargo cycle up a hill will raise delivery times considerably, which means loss of time compared to motorised options. Electric assist can help, but there might be better options for city cargo transport in hilly or mountainous regions, such as gravity-powered cable cars and aerial ropeways.

Secondly, cargo cycles are especially useful in European cities with their large historical centres consisting of narrow, winding streets. In North-American cities the average speed of motor traffic in cities is generally higher because of much wider roads, and the speed advantage of cargo cycles may disappear. Population density also influences the usefulness of cargo cycles, which again plays into the hands of European cities. A third observation is that cities where cargo cycles are again in use already had a relatively strong bicycle culture and a decent cycle infrastructure prior to their arrival. If there is no (safe) space for cargo cycles, they cannot be used.

Kris De Decker

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Notes:

(1) "CycleLogistics" (2012)

(2) "Bikes instead of lorries" (2012)

(3) "Das Lastenfahrrad als Transportmittel für städtischen Wirtshaftsverkehr" (2012)

(4) "Ich ersetze ein Auto" (2012)

(5) "Cycle freight in London: a scoping study" (2009)

(6) "Gesamtwirtschaftlicher Vergleich von Pkw- und Radverkehr" (2010)

(7) "Short history of cargo cycling", CycleLogistics (2012)

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Related articles:

How to downsize a transport network: the Chinese wheelbarrow
Aerial ropeways: automatic cargo transport for a bargain
The velomobile: high-tech bike or low-tech car?
Electric velomobiles: as fast and comfortable as a car, but 80 times more efficient
How to make everything ourselves: open modular hardware
Get wired (again): trolleybuses and trolleytrucks
The status quo of electric cars: better batteries, same range
Wood gas vehicles: firewood in the fuel tank
Water powered cable trains
The age of speed: how to reduce global fuel consumption by 75 percent?
The Citroen 2CV: cleantech from the 1940s
A world without trucks: underground freight networks
Low-tech indoor truck: the Monark transport kick-scooter
Why bicycles are faster than cars

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The solar envelope: how to heat and cool cities without fossil fuels

2012-03-24T20:52:33+01:00

1 / 2 / 3

Architects all over the world have demonstrated the usefulness of buildings which are heated and cooled by design rather than by fossil fuel energy. What has received much less attention, however, is the possibility of applying this approach to entire urban neighbourhoods and cities.

Designing a single, often free-standing, passive solar house is quite different from planning a densely populated city where each building is heated and cooled using only natural energy sources. And yet, if we want passive solar design to be more than just a curiosity, this is exactly what we need. Modern research, which combines ancient knowledge with fast computing techniques, shows that passive solar cities are a realistic option, allowing for surprisingly high population densities.

Illustration by Diego Marmolejo for Low-tech Magazine.

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Passive solar design requires the knowledge to design and orientate buildings so that they can be heated by the sun. Coupled with other low-tech solutions such as thermal underwear and oven stoves, passive solar design could all but eliminate the use of fossil fuels and biomass for heating buildings throughout large parts of the world. Indirectly, a passive solar house can also cancel the energy requirements for cooling and ventilation (passive cooling), and for lighting during the day. Of course, passive solar buildings can be outfitted with solar water heaters and PV solar panels, further reducing the use of unsustainable energy resources.

Passive solar design does not involve any new technology. In fact, it has been around for thousands of years, and even predates the use of glass windows. For most of human history, buildings were adapted to the local climate through a consideration of their location, orientation and shape, as well as the appropriate building materials. This resulted in many vernacular building styles in different parts of the world. In contrast, most modern buildings look the same wherever they stand. They are made from the same materials, they follow forms that are driven by fashion rather than by climate, and are most often randomly located and oriented, indifferent to the path of the sun and the prevailing wind conditions.

Modern buildings rely on a massive supply of cheap fossil fuels for heating, cooling, and lighting. Take the supply of cheap fossil fuels away, and they become completely uninhabitable for most of the year: they are too cold, too hot or too dark. This radical change in architectural design was caused by both the arrival of cheap and abundant energy sources and the resultant urbanisation (See part 2). The Industrial Revolution relocated millions of people from the countryside to the cities. When most of us lived and worked on farms or in hamlets, it was fairly easy to orientate one's house towards the sun. In an urban environment, however, building orientation is generally determined by street layout, and one building can easily overshadow another. High-rise buildings further complicate solar access.

From solar oriented buildings to solar oriented cities

This does not mean that passive solar design could not be applied to entire cities. It just takes more sophisticated planning. Solar access to an individual building is determined by only four factors: latitude (the distance north or south from the equator), slope, building shape and orientation.

Solar access to a city (or any other built-up environment) is determined by seven factors: the four just mentioned, plus the height of the buildings, the width of the streets, and the orientation of the streets (See part 2). Providing ventilation in an urban environment is determined by the same factors, with the exception that latitude is replaced by prevailing wind conditions.

While most research in passive solar design during the 1970s was directed at individual buildings, one man began forty years of research into solar oriented cities: Ralph Knowles, professor emeritus at the USC's School of Architecture and author of three fascinating books on the topic (1974, 1981, 2006).

Knowles developed and refined a method that strikes an optimal balance between population density and solar access: the "Solar Envelope". It is a set of imaginary boundaries, enclosing a building site, that regulate development in relation to the sun's motion -- which is predictable throughout the seasons for any place on Earth.

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Buildings within the solar envelope do not overshadow neighbouring buildings during critical energy-receiving periods of the day and the year

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Buildings within this imaginary container do not overshadow neighbouring buildings during critical energy-receiving periods of the day and the season, and assure solar access for both passive and active solar systems. On the one hand, the solar envelope allows architects to design with sunlight without fear that their ideas will be cancelled out by future buildings. On the other hand, the solar envelope recognizes the need for development and high population densities, by defining the largest container of space that would not cast shadows off-site at specified times of the day.

Knowles and his students have reached densities that are far above the average in European and American cities (See part 3), with the exception of high-rise centers such as Manhattan.

Modification of traditional zoning practices

The solar envelope is actually a relatively simple modification of existing zoning practices, which also set imaginary boundaries that enclose a building site -- determining the maximum height, width and depth of future buildings. The most rigid approach in conventional zoning prescribes maximum building heights, set in feet or metres, number of floors, or both. A second, more flexible approach, sets limits based on a ratio between developeable land and floor area within the building on that site. For example, a floor-to-area ratio (FAR) of 6 means that architects can develop 6 times the developeable square footage of land within the setbacks. They could cover the entire site with 6 stories, or cover only half of the site with 12 stories, for example.

Although both zoning methods offer a certain degree of solar access in a city, they are far from optimal. The main problem is that they do not design building orientation with its solar impact in mind, which can be as critical as building height. For example, a skyscraper with its broad flat sides facing east and west will cast a relatively small midday winter shadow, while one oriented with its broad flat sides facing north and south will shade a much larger area during the sunniest periods of the day (illustration above). Taking orientation into account would greatly improve solar access for surrounding buildings, without sacrificing housing density.

The geometry of the solar envelope

Compared to conventional zoning practices, the solar envelope produces a different geometry -- the limits of the envelope derive their vertical dimensions from the sun's daily and seasonal movements. Thus, while conventional zoning envelopes are shaped like a box, the solar envelope has both vertical and sloping spaces.

Solar envelopes on the Spanish street grid system in Los Angeles. Ralph Knowles.

As a result, the buildings and city blocks that fill these imaginary solar envelopes are more likely to have unique shapes. One side of a building would not look like the other, nor would each side of the street. In the northern hemisphere, development would tend to be lower on the south side of a street than on the north where a major southern exposure would be preserved. Streets take on a directional character where solar orientation is clearly recognised.

Buildings within the solar envelopes shown above. Ralph Knowles.

Adjacent buildings can meet each other gently, rather than abruptly, across property sidelines. Tall buildings would group together at the site's southwestern end, and those of moderate height at the northeastern end, with the shortest buildings taking up the site's midsection. Buildings on corner lots will be taller because their shadows can extend accross the street in two directions instead of one.

Building designs under the solar envelope are characterised by roof terraces, courtyards and clerestories. Ralph Knowles.

Within the solar envelope, certain architectural characteristics have great consistency. For instance, roof terraces appear where the sloping sides of the envelope intersect the rectilineair geometry of buildings. Courtyards are another crucial element, as they introduce sunlight and heat to deep interiors. Clerestories allow for the penetration of winter sun down stairways to enliven otherwise darker, lower floors. Sunscreens and porches are everywhere, keeping the sun out in summer.

Defining solar access

The solar envelope is not only defined by the path of the sun, but also by fixed parameters set by the designer. Choosing these will determine the balance between solar access and development potential.

The most important choice is the definition of the hours during which we want to avoid casting shadows on adjacent land -- the 'cut-off times'. The longer the period of daily solar access, the smaller the developeable volume under the envelope. Obviously, setting the cut-off times as equal to the period between sunrise and sunset would not work, because in that case few or any buildings could be constructed. For passive solar design, a minimum of 4 to 6 hours per day in winter is considered practical, depending on the climate.

The duration of solar access could also be set by a minimum percentage of available energy instead of determining a minimum hours of sunshine. In that case, cut-off times would change over the course of the year. Another parameter to be set is the 'shadow fence'. It determines the minimum height to which solar access has to be assured; for instance zero, 3 or 6 metres above street level. For example, one can choose to allow shadowing of garages and shops in order to improve the density under the solar envelope.

What about existing buildings?

Solar envelopes can be designed for individual buildings or as a single envelope for a group of houses, a neighbourhood, a district or even an entire city. This is a rather straightforward process when a site is being designed from scratch, but often current buildings will complicate the generation of a solar envelope. When the solar envelope is applied in line with existing buildings, new construction would always be shaped and proportioned with reference to the old. Each new phase of development changes the surroundings and thus the context within which the next envelope is generated.

A solar envelope casting its maximum shadow in winter. The smaller, previously built houses retain their solar access. Ralph Knowles.

One of the building designs within the solar envelope shown above. Ralph Knowles.

It is important to note that the solar envelope only protects neighbouring properties. It is the architect who must ensure solar access to the buildings within the envelope, tackling problems of overshadowing within the envelope itself. For larger sites, the volume of a solar envelope is therefore larger than the volume of the buildings that actually fill it, at least when solar access is assured to all dwellings on site.

Solar oriented cities in Antiquity

Knowles' research draws on ancient knowledge, most notably the solar planned cities in Ancient Greece and the solar communities of the Ancient Pueblo People in what is today the Southwestern United States. The Ancient Greeks built entire cities which were optimal for solar exposure.

In the fifth century BC, for example, a neighbourhood for about 2500 people was built in the city of Olynthus. The streets were built perpendicular to each other, running long in the east-west direction (the horizontal streets shown in the plan), so that all houses (five on each side of the street) could be built with southern exposure.

A gridirion street plan oriented at the cardinal points was not new at the time, and neither is it proof of a design aimed at maximum solar exposure. But the Greeks did more. In "A Golden Thread: 2500 Years of Solar Architecture and Technology", Ken Butti and John Perlin note that all houses were consistently built around a south-facing courtyard:

"The houses that faced south on the street and south to the sun were entered through the court, straight from the street. The houses that faced north to the street and south to the sun were entered through a passageway that led from the street through the main body of the house and into the court, from which access was gained to all other spaces."

In keeping with the democratic ethos of the period, the height of buildings was strictly limited so that each courtyard received an equal amount of sunshine:

"In winter, rays from the sun traveling low across the southern sky streamed across the south-facing courts, throgh the portico, and into the house - heating the main rooms. The north walls were made of adobe bricks one and a half feet thick, which kept out the cold north winds of winter."

Another obvious example of Ancient Greek solar planning was Priene (illustration above), rebuilt in 350 BC and located in present-day Turkey. The city had about 4000 inhabitants living in 400 houses. Its buildings and street plan were similar to those in Olynthus, but because the city was built on the slope of a steep mountain, many of the fifteen secondary streets (running north-south) were actually stairways. The seven main avenues were terraced on an east-west axis.

Native Americans

The Ancient Pueblo People or "Anasazi" built a number of sophisticated solar oriented communities during the 11th and 12th centuries AD in what is now the Southwestern United States: Long House at Mesa Verde, Pueblo Bonito in Northern Mexico and the "sky city" of Acoma.

Illustration of Acoma Pueblo, by Gary S. Shigemura (from "Energy and Form", Ralph Knowles).

These communities followed a different building style than that of the Greeks. The Ancient Pueblo People constructed terraced buildings of up to three floors high. These were buildings that would fit perfectly in a solar envelope with slanting lines. Acoma pueblo (illustration above) is one example of these orderly, solar planned communities. It consists of three rows of houses built along streets running east and west, so that each building faces south. The streets that separate the houses have a width that allows winter shadows to cover the whole of the adjoining street, stopping just before the following row of buildings.

Heliodon

Knowles' research combines the best elements of these historical designs and incorporates modern technology that greatly facilitates the generation of a solar envelope. The heliodon, invented in the 1930s, is a contraption that creates a geometrical relationship between an architectural scale model and (a representation of) the sun. More recently, software versions of the heliodon have made the technology much more affordable, while allowing for the fast generation of even very complex solar envelopes.

On larger sites in particular, and when already existing buildings complicate the generation of a solar envelope, the available computer software saves time and can result in more building volume.

Continue reading: 1 / 2 / 3.

Kris De Decker (edited by Deva Lee)

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The art of producing sustainable consumer goods: basketry

2012-02-24T14:03:54+01:00

This is a guest post by Brian Kaller, who blogs at Restoring Mayberry.

Baskets have been replaced by plastic and other kinds of factory-made containers in almost every area of life, appearing today mainly as twee Easter decorations. Making them has become synonymous with wasting time – “basket-weaving” in the USA is slang for an easy lesson for slow students.

The craft of basketry, however, might be one of our species’ most important and diverse technologies, creating homes, boats, animal traps, armour, tools, cages, hats, chariots, weirs, beehives, shelters and furniture, as well as all manner of containers. Basket weaving makes use of fast-growing biodegradable materials -- branches, twigs or shoots -- that requires the forest to be cultivated rather than cleared. Basketry allows almost anyone, with little or no money and few tools, to create a large variety of useful goods in a way that is one hundred percent sustainable.

Picture: Big burden basket by Joe Hogan Baskets.

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We tend to think of technology as rock and metal – from the Stone Age to the Iron Age, from pyramids and statues to Viking swords and pirate cannons. We think of the things that survive to be placed in museums, in other words, and tend to neglect the early and important inventions that ordinary people used every day but whose materials did not survive centuries of exposure.

Picture: Joe Hogan Baskets.

29,000 years of history

Virtually all human cultures have made baskets, and have apparently done so since we co-existed with ground sloths and sabre-toothed cats; for tens of thousands of years humans may have slept in basket-frame huts, kept predators out with basket fences, and caught fish in basket traps gathered while paddling along a river in a basket-frame boat. They might have carried their babies in basket papooses and gone to their graves in basket coffins.

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Some of the first agriculture might have been to grow basketry crops, not food crops

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The earliest piece of ancient basketry we have comes from 13,000 years ago, but impressions on ceramics from Central Europe indicate woven fibres -- textiles or baskets –- up to 29,000 years ago. (1) We have clues that the technology might be far older than that; in theory, Neanderthals or some early hominid could have woven baskets.

Picture: Joe Hogan Baskets.

“The technology of basketry was central to daily living in every aboriginal society,” wrote ecologist Neil Sugihara, and baskets “were the single most essential possession in every family”. (2) Early humans must have regularly cropped basketry plants as they would edible plants, and burned woodlands to encourage their growth, according to anthropologist M. K. Anderson. Anderson even proposes that some of the first agriculture might have been to grow basketry crops, not food crops. (3)

Main basket types

Baskets come in several main types. Coiled baskets appeared early, created by winding flexible plant fibres from a centre outward in a spiral and then sewing the structure together. Their spiral nature, however, limits them to circular objects; beehive containers, called skeps, were built this way for hundreds of years, and straw hats still are today.

The earliest American baskets were twined; fibre was wound around a row of rigid elements like sticks – wrapped around one, twisted, wrapped around the next one and twisted again. The sticks would seem to limit this approach to flat surfaces like mats, but bending and shaping the sticks allows twining to create a variety of containers and shapes.

Basketry high sleeper, by Coopérative Vannerie de Villaines.

Still others were plaited, with flexible materials criss-crossed like threads through cloth. The Irish flattened and plaited bulrushes for hundreds of years into mats and curtains. Here too, the approach would seem to limit plaiting to flat surfaces, but as the rushes must be woven while green and flexible and harden as they dry, they can be plaited around a mould to create boxes, bags or many other shapes.

Wicker, however, probably remains the most versatile technique, weaving flexible but sturdy material like tree shoots around upright sticks that provide support. Wicker is the form used for fences, walls, furniture, animal traps and many other advanced shapes, and when you picture a basket, you’re probably picturing wicker too. (4)

Picture: Seven-band backpack baskets by Hiroshima Kazuro.

Hurdle fences

Once early humans mastered the technique of fashioning wicker, they began using it for a variety of purposes beyond carrying and preparing food, and shelter probably came next. Wattle fences were made with a row of upright poles with flexible wood cuttings woven between them, a basket wall. Unusually, they could be made in modular, lightweight pieces a metre or two high and a metre or two across – hurdles -- and then uprooted, carried to a new location, and stamped into the ground where needed.

The uprights, sometimes called zales or sails in Britain, were typically rounded at the end and placed in a wooden frame, sometimes called a gallows, to hold them in place. Then withies – slim cuttings of willow or hazel – were wound back and forth around the uprights. At the end of the hurdle the withy would be twisted for greater flexibility, wound around the last zale, and woven back in the other direction. Usually a gap would be left in the middle of the hurdle, called a twilly hole, which allowed a shepherd or farmer to carry a few hurdles as a time on his back.

Hurdle fence, source: Windrush Willow.

According to author Una McGovern, hurdle fences were vital to medieval agriculture; by keeping sheep confined without the need for permanent infrastructure, they allowed tenant farmers to graze sheep on a patch of land, letting them manure the fields one by one and deposit the fertilisers necessary for cereal crops. (5)

Basketry buildings

The same technique could form the walls of a house, once a log or timber frame was built and the wattle filled in with a “daub” plaster for insulation and privacy. The daub often contained clay, human or animal hair and cow dung, and hardened around the wattle like concrete around rebar. The resulting structure could last for centuries, and even now restoring or demolishing old buildings sometimes reveals wattle inside the walls.

Wattle and daub wall of a 1905 house in Belgium (source).

Similar techniques were used by cultures around the world, from Vikings to Chinese to Mayans. While their cheap and easily available materials made them an obviously popular and practical building method, not all builders loved it. The Roman architect Vetruvius, in the first century AD, moaned about the hazards of such cheap material in his Ten Books on Architecture:

“As for ‘wattle and daub’ I could wish that it had never been invented,” Veruvius wrote. “The more it saves in time and gains in space, the greater and the more general is the disaster that it may cause; for it is made to catch fire, like torches. It seems better, therefore, to spend on walls of burnt brick, and be at expense, than to save with ‘wattle and daub,’ and be in danger. And, in the stucco covering, too, it makes cracks from the inside by the arrangement of its studs and girts. For these swell with moisture as they are daubed, and then contract as they dry, and, by their shrinking, cause the solid stucco to split.

But since some are obliged to use it either to save time or money, or for partitions on an unsupported span, the proper method of construction is as follows. Give it a high foundation so that it may nowhere come in contact with the broken stone-work composing the floor; for if it is sunk in this, it rots in course of time, then settles and sags forward, and so breaks through the surface of the stucco covering.” (6)

Woven boats

Improbable as it sounds, basketry has long been used to make boats. How long we don’t know, but humans appeared in Australia 40,000 years ago, even though it was separated from Asia even in the Ice Age. They might have built wicker boats covered in animal skins, but even if they merely tied logs together into rafts, they must have had the related technology of making fibre and tying it into knots.

The Irish used woven boats, or coracles, for hundreds – and probably thousands -- of years; they are mentioned in medieval Irish literature and are still made by aficionados today.

Irish coracles. Source: Guy Mallison Woodland Workshop.

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The coracle’s small size and lightweight construction ensured that, after the occupant had paddled across rivers, lakes or marshes, he could pick up his boat and walk across country with ease

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All were woven from willow or hazel and covered with a hide – usually cow hide, but horse-hide and sealskin were also used – and supposedly waterproofed with butter. All of them were alarmingly tiny crafts in which a person sat cross-legged and sat carefully upright to avoid tipping over, like a bowl-shaped kayak. The coracle’s small size and lightweight construction ensured that, after the occupant had paddled across rivers, lakes or marshes, he could pick up his boat and walk across country with ease.

Building a coracle, first step. Source: Guy Mallison Woodland Workshop.

To take to the sea, the Irish wove curraghs -- larger and oval-shaped to navigate across choppy waters, but still no larger than a rowboat. Documentary footage from 1937 showed men constructing a Boyne curragh; first planting hazel rods in the ground in the desired shape, and weaving a tight frame between them along the ground – what would become the gunwale, or rim, when the frame was flipped over. Then the hazel rods were twisted together to make a wicker dome, and the frame was uprooted and turned upright and a hide placed around the frame and oiled. (7)

Traps for river crabs, made by Hiroshima Kazuro.

Fish traps

One common use of such craft was to set and gather fish and eel traps from rivers and lobster pots from the sea – also made, of course, from wicker. Such foods were an important source of protein, especially in Catholic countries where meat was sometimes forbidden. The traps operated on a simple principle; a bit of bait could lure an animal into the trap but, if it were shaped properly, they would be unable to escape.

'Lowering the Eel Bucks ' - From 'Life on the Upper Thames' by H.R. Robinson, 1875 (source)

Hundreds of plant species

Baskets can be woven with any one of hundreds of plant species, depending on whatever was available. In more tropical climates people used cane or raffia, while in temperate areas like Europe a wide variety of branches and plants were available: dogwood, privet, larch, blackthorn and chestnut branches; broom, jasmine and periwinkle twigs; elm, and linden shoots; ivy, clematis, honeysuckle and rose vines; rushes and other reeds, and straw.

Field of Brittany Blue willow in Kildare, Ireland in February. Picture by Brian Kaller.

Perhaps the most popular, however, was willow -- sallies or silver-sticks here in Ireland, osiers in Britain, vikker in Old Norse, the last of which became our word “wicker.” They are highly pliable when young or wet, lightweight and tough when dried, and grow so quickly that a new crop of branches up to three metres long can be harvested each year. As one of the earliest trees to grow back after an old tree falls and leaves a gap of sunlight in the forest, or after a forest fire razes an area, they are perhaps the tree closest to a weed in behaviour.

'Osier Cutting', from 'Life on the Upper Thames ' by H.R. Robinson, 1875 (source)

Their roots spread rapidly under the surface of the soil, making them an ideal crop to halt erosion. Their fast growth makes an excellent windbreak, the basis of most hedgerows, and makes them particularly useful in our era for sequestering carbon and combating climate change. In addition, the bark of the white willow (Salix alba) can be boiled to form acetecylic acid, or aspirin.

Cleaning the soil

In addition, the common variety Salix viminalis or “basket willow,” has been shown to be a hyper-accumulator of heavy metals. Many plants help “clean” the soil by soaking up disproportionate levels of normally toxic materials, either as a quirk of their metabolism or as a way of protecting themselves against predators by making themselves poisonous. Many plants soak up only a single toxin, others only a few; Viminalis, it turned out, soaked up a broad range, including lead, cadmium, mercury, chromium, zinc, fossil-fuel hydrocarbons, uranium, selenium, potassium ferro-cyanide and silver. (8) (9) (10)

Willow harvested stools in front, standing crop at rear, source: Joe Hogan Baskets

Many hardwood trees can be coppiced, cut through at the base, or pollarded, cut at head-height, and regrow shoots on a five-to-twenty-year time scale. Willows, however, do not need to grow to maturity, and continue to thicken at the base and grow a fresh crop of shoots each year. Basket-weavers here harvested willow as a winter ritual – ten tonnes to the acre – from fields of large century-old stumps that had never been mature trees. (11)

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Out of hundreds of traditional crafts, none has so many everyday applications

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Once the willow is cut it could be dried with the bark on, or the bark could be stripped off. Stripping was a tedious task but it made the willow easier to quickly prepare and use, reduced the risk of decay, and it gave the willow a valued white colour. To strip the bark a large willow branch was cut partway down its length, with metal strips attached to the inside of the cut; the weaver could hold the branch between their legs and use it as we would use a wire-stripping tool to remove insulation. When cuttings were too thick to manipulate, a special tool called a cleve was used to cut them three ways down their length.

Basketry banisters by Coopérative Vannerie de Villaines.

Withies were typically dried for several months and kept indefinitely before soaking again for use. Willow can be woven straight from the tree, but as it dries it loosens and the weave shifts and rattles, which is seldom desirable. To a novice, preparing the materials presents as much of a challenge as the actual weaving, as the willow must be dried but re-soaked, kept wet without rotting, and used before becoming dry and brittle again.

Everyday applications

Today a small but growing movement of people around the world tries to rediscover and re-cultivate traditional crafts and technologies. Many such techniques deserve to be revived; but some require substantial experimentation, skill, training, infrastructure or community participation. Not all low-tech solutions can be adopted casually by modern urbanites taking their first steps toward a more traditional life.

Basket weaver. Source: Roule ta bosse!

Basket-weaving, however, requires no money other than that needed for training and possibly materials. It uses crops easily found in almost every biome on Earth, and requires few if any tools. Highly skilled weavers can create works of art, but simple and practical weaves can be done by almost anyone. Out of hundreds of traditional crafts, none has so many everyday applications.

Brian Kaller

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Brian Kaller is a journalist living in rural Ireland. He interviews elderly Irish about traditional ways of life, and writes a weekly column about the Long Emergency for his local newspaper. Brian blogs at Restoring Mayberry. Some of his posts there were previously highlighted at No Tech Magazine:

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Citations:

(1) Archeologické rozhledy, 2007, Baskets in Western America 8600 BP: American Antiquity 60(2), 1995, pp. 309-318.

(2) Fire in California's ecosystems, By Neil G. Sugihara, p. 421

(3) Anderson, M.K. – The fire, pruning and coppice management of temperate ecosystems for basketry material by Californian Indian tribes. Human Ecology 27(I) 79-113. 1999.

(4) The Complete Book of Basketry Techniques, Sue Gabriel and Sally Goyner, David and Charles 1999.

(5) Lost Crafts, Una McGovern, Chambers 2009

(6) Ten Books on Architecture, Vetruvius, Chapter 8, Section 20. Circa 20 BCE

(7) Hands, RTE documentary by Sally Shaw Smith, episode 29, “Curraghs.”

(8) Phytoremediation. By McCutcheon & Schnoor. 2003, New Jersey, John Wiley & Sons, page 19.

(9) Enhancing Phytoextraction: The Effect of Chemical Soil Manipulation on Mobility, Plant Accumulation, and Leaching of Heavy Metals. By Ulrich Schmidt. In J. Environ. Qual. 32:1939-1954 (2003).

(10) The potential for phytoremediation of iron cyanide complex by Willows. By X.Z. Yu, P.H. Zhou and Y.M. Yang. In Ecotoxicology 2006.

(11) Bulletin of the Bussey Institution, Vol. II, Part VIII. p. 430. Published 1899. C. D. Mell’s 1908 book Basket Willow Culture urged farmers to grow willows as a cash crop to feed the continual demand of weaving material, maintaining that “the demand for basket willow rods is very great and every year many thousands of bundles of rods … are imported from France, Germany and Holland.” Incredibly, it seemed that as highly valued as baskets were in the USA, the then-sparsely-inhabited country was still importing willow from comparatively small and crowded Old World countries.

(12) Basket Willow Culture, C. D. Mell, Report Publishing Company 1908

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Related articles:

How to tie the world together: online knotting reference books The sheer number and diversity of knots that was once in use would be bewildering to the modern city-dweller. About 4,000 different knots are described, ranging from the very simple to the extremely complex.

Lost knowledge: ropes and knots They are among the most ancient and useful technologies ever developed by man, predating the wheel, the axe and probably also the use of fire. Today, ropes and knots are fast on their way to become an obsolete technology.

Parabolic basket for a tin can solar cooker The structure of a parabolic solar cooker can be made using traditional basketry construction methods. The same goes for other solar concentrators such as the Solar Fire P32, described in the article on solar powered factories.

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How to downsize a transport network: the Chinese wheelbarrow

2011-12-29T02:26:30+01:00

For being such a seemingly ordinary vehicle, the wheelbarrow has a surprisingly exciting history. This is especially true in the East, where it became a universal means of transportation for both passengers and goods, even over long distances.

The Chinese wheelbarrow - which was driven by human labour, beasts of burden and wind power - was of a different design than its European counterpart. By placing a large wheel in the middle of the vehicle instead of a smaller wheel in front, one could easily carry three to six times as much weight than if using a European wheelbarrow.

The one-wheeled vehicle appeared around the time the extensive Ancient Chinese road infrastructure began to disintegrate. Instead of holding on to carts, wagons and wide paved roads, the Chinese turned their focus to a much more easily maintainable network of narrow paths designed for wheelbarrows. The Europeans, faced with similar problems at the time, did not adapt and subsequently lost the option of smooth land transportation for almost one thousand years.

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Transport options over land

Before the arrival of the steam engine, people have always preferred to move cargo over water instead of over land, because it takes much less effort to do so. But whenever this was not possible, there remained essentially three options for transporting goods: carrying them (using aids like a yoke, or none at all), tying them to pack animals (donkeys, mules, horses, camels, goats), or loading them onto a wheeled cart or wagon (which could be pulled by humans or animals).

Carrying stuff was the easiest way to go; there was no need to build roads or vehicles, nor to feed animals. But humans can carry no more than 25 to 40 kg over long distances, which made this a labour-intensive method if many goods had to be transported. Pack animals can take about 50 to 150 kg, but they have to be fed, are slightly more demanding than people in terms of terrain, and they can be stubborn. Pack animals also require one or more people to guide them.

When carrying goods - whether by person or by pack animals - the load is not only moved in the desired direction but it also undergoes an up and down movement with every step. This is a significant waste of energy, especially when transporting heavy goods over long distances. Dragging stuff does not have this drawback, but in that case you have friction to fight. Pulling a wheeled vehicle is therefore the most energy-efficient choice, because the cargo only undergoes a horizontal motion and friction is largely overcome by the wheels. Wheeled carts and wagons, whether powered by animals or people, can take more weight for the same energy input, but this advantage comes at a price; you need to build fairly smooth and level roads, and you need to build a vehicle. If the vehicle is drawn by an animal, the animal needs to be fed.

When all these factors are taken into consideration, the wheelbarrow could be considered the most efficient transport option over land, prior to the Industrial Revolution. It could take a load similar to that of a pack animal, yet it was powered by human labour and not prone to disobedience.

Compared to a two-wheeled cart or a four-wheeled wagon, a wheelbarrow was much cheaper to build because wheel construction was a labour-intensive job. Although the wheelbarrow required a road, a very narrow path (about as wide as the wheel) sufficed, and it could be bumpy. The two handles gave an intimacy of control that made the wheelbarrow very manoeuvrable.

East and West: a very different story

The wheelbarrow tells a very distinct history in both the Western and the Eastern world. Although to this date its origins remain obscure, it is clear that the vehicle played a much larger role in the East than in the West. While in recent years there has surfaced some evidence that the wheelbarrow might have been used on construction sites by the Ancient Greeks at the end of the fifth century BC, there is no mention at all of wheelbarrows in Ancient Rome (although that does not exclude the possibility that they in fact did use them).

The first sound evidence of the wheelbarrow in the Western world only emerged in the early thirteenth century AD. In China, their use is documented extensively from the second century AD onwards - more than a thousand years earlier. It is interesting to note that the wheelbarrow appeared at least 2,000 years later than two-wheeled carts and four-wheeled wagons.

Handbarrow

When the wheelbarrow finally caught on in Europe, it was used for short distance cargo transport only, notably in construction, mining and agriculture. It was not a road vehicle. In the East, however, the wheelbarrow was also applied to medium and long distance travel, carrying both cargo and passengers. This use - which had no Western counterpart - was only possible because of a difference in the design of the Chinese vehicle. The Western wheelbarrow was very ill-adapted to carry heavy weights over longer distances, whereas the Chinese design excelled at it.

On the European wheelbarrow the wheel was (and is) invariably placed at the furthest forward end of the barrow, so that the weight of the burden is equally distributed between the wheel and the man pushing it. In fact, the wheel substitutes for the front man of the handbarrow or stretcher, the carrying tool that was replaced by the wheelbarrow (illustration on the right).

Superior Chinese design

In the characteristic Chinese design a much larger wheel was (and is) placed in the middle of the wheelbarrow, so that it takes the full weight of the burden with the human operator only guiding the vehicle. In fact, in this design the wheel substitutes for a pack animal. In other words, when the load is 100 kg, the operator of a European wheelbarrow carries a load of 50 kg while the operator of a Chinese wheelbarrow carries nothing. He (or she) only has to push or pull, and steer.

The result was an extremely powerful and agile vehicle. In 1176 AD, the Chinese writer Tsêng Min-Hsing noted enthusiastically:

"The device is so efficient that it can take the place of three men; moreover, it is safe and steady when passing along dangerous places (cliff paths, etcetera). Ways which are as winding as the bowels of a sheep will not defeat it."

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The large central wheel of a Chinese wheelbarrow takes the full weight of the burden with the human operator only guiding the vehicle

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The Chinese wheelbarrow - which was also widely in use in present-day Cambodia, Vietnam and Laos - originally appeared in two basic variants. One was originally termed the "wooden ox" ("mu niu"), which had the shafts projecting in front (so that it was pulled), while the other was termed the "gliding horse" ("liu ma"), which has the shafts projecting behind (so that it was pushed). A combination of both types was also used, being pulled and pushed by two men. From these two basic types, many variations evolved. Later, the Chinese also used western-style wheelbarrows alongside their own design.

Western praise

The characteristic vehicle stupefied Western foreigners who visited China during the early modern period. In "Science and civilization in China", Joseph Needham quotes the Dutch-American merchant Andreas Everardus van Braam Houckgeest, who visited the country in 1797 and gives an excellent description of the contraption:

"Among the carriages employed in this country is a wheelbarrow, singularly constructed, and employed alike for the conveyance of persons and goods. According as it is more or less heavy loaded, it is directed by one or two persons, the one dragging it after him, while the other pushes it forward by the shafts. The wheel, which is very large in proportion to the barrow, is placed in the centre of the part on which the load is laid, so that the whole weight bears upon the axle, and the barrow men support no part of it, but serve merely to move it forward, and keep it in equilibrum."

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A Chinese traveller sits on one side, and thus serves to counter-balance his baggage, which is placed on the other

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"The wheel is as it were cased up in a frame made of laths, and covered over with a thin plank, four or five inches wide. On each side of the barrow is a projection, on which the goods are put, or which serves as a seat for the passengers. A Chinese traveller sits on one side, and thus serves to counter-balance his baggage, which is placed on the other. If his bagage is heavier than himself, it is balanced equally on the two sides, and he seats himself on the board over the wheel, the barrow being purposely contrived to suit such occasions."

Wheelbarrow trains

"The sight of this wheelbarrow thus loaded, was entirely new to me. I could not help remarking its singularity, at the same time that I admired the simplicity of the invention. I even think, that in many cases such a barrow would be found much superior to ours."

The American soil scientist F.H. King shows himself equally impressed in his 1911 publication "Farmers of Forty Centuries":

"We had observed long processions of wheelbarrow men moving from the canals through the streets carrying large loads of [crops] in bundles a foot long and five inches in diameter. These had come from the country on boats each carrying tons of the succulent leaves and stems. We had counted as many as fifty wheelbarrow men passing a given point on the street in quick succession, each carrying 300 to 500 pounds of [crops] and moving so rapidly that it was not easy to keep pace with them, as we learned in following one of the trains during twenty minutes to its destination. During this time not a man in the train haltened or slackened his pace. This same type of vehicle, too, is one of the common means of transporting people, especially Chinese women, and four, six and even eight may be seen riding together, propelled by a single wheelbarrow man."

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This description would not be complete without mentioning the squeaking of the unoiled axle, a nightmare to foreigners, which does not bother the Chinese in the least

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Rudolf Hommel, in his 1937 book "China at work" (based on a 1921 travel through the country), seems to be most intrigued by the ingenuity of the low-tech design, going into technical details:

"While there are many kinds of wheelbarrows, the one shown [here] is typical of them all; the principle always being the same, i.e. one large wheel surrounded by a framework, guarding the upper part of the wheel from contact with merchandise or persons transported. The two long shafts, held at a proper distance from each other by two crosspieces, terminate in the handlebars, and form the basis of the whole vehicle. Into them is mortised the lattice work which surrounds the wheel. On each side a carrying frame is formed by curved bars attached to the main shafts by crosspieces."

Low-tech masterpieces

"The wheel, about 3 feet in diameter, is made entirely of wood and has two iron bands around the hub, and an iron tire. The axle is made of some very strong wood. From the frame of the wheelbarrow two pieces extend downward with the bearing holes for the axle. This looks rather precarious, and yet these pieces stand up splendidly under the heavy strain of immense loads and the considerable bumping over the miserable roads. These wheelbarrows are masterpieces of joinery and special care is bestowed on the selection of the best grades of hard wood for all parts. This description would not be complete without mentioning the squeaking of the unoiled axle, a nightmare to foreigners, which does not bother the Chinese in the least."

Just as other Western observers, Hommel watched the vehicles pass by in admiration:

"Besides transporting goods with these wheelbarrows, the Chinese use them also for passengers. I have seen as many as six people on them, three sitting on each side with their feet dangling down. If only one person is conveyed the driver balances the wheelbarrow skilfully with the wheel tilted at a considerable angle from the vertical. If a peasant wants to take a pig to the market, he saves himself all the trouble of guiding the recalcitrant beast, by tying it upon the wheelbarrow and wheeling it to the market."

Mobile forts

As so many other innovative technologies, the Chinese wheelbarrow was orginally developed for military purposes. The first records mention its use for supplying food to the army. The wheelbarrow gave the Chinese armies such an advantage in moving goods that it was kept secret - early Chinese writings talk about wheelbarrows in code. True to its origin, the wheelbarrow remained in use for military operations, though not only to supply food to soldiers. In 1176, Tsêng Min-Hsing alluded to the military use of the wheelbarrow in forming protective layers.

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The Ancient Chinese used their wheelbarrows as a defence against the onslaught of cavalry, a tactical system that remained in use during later times using two-wheeled carts

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His words are quoted by Joseph Needham:

"Not only is it useful for transporting army rations, but at need it can be employed as a defensive obstruction against cavalry. Since the digging of trenches and moats, and the building of forts, take time, the wheelbarrows can be deployed round the perimeter so that the enemy's horses cannot easily pass over. This kind of vehicle can readily go forward and withdraw, and can be used for any purpose. It might well be called a 'mobile fort'."

Watching the Vietnamese wheelbarrow pictured above, the defensive use of the vehicle is easy to imagine. According to Needham, it was the Chinese with their wheelbarrows who pioneered the use of 'laagers' or 'mobile forts' as a defence against the onslaught of cavalry, a tactical system that remained in use during later times using two-wheeled carts.

Animal traction

A remarkable feature of the Chinese wheelbarrow was the combined use of human and animal traction, which became common from an early date on. This practice can be seen in a 1126 painting by Chang Tsê-Tuan, which is described by Joseph Needham:

"The painting depicts the popular life of the capital Khaifêng at the time of the spring festival. Many wheelbarrows are moving or stationary in the streets of the city. All but one have the large central wheel and some are very heavily laden. During the loading and unloading the wheelbarrows rest on the side-legs. One is being pushed by a single man, and in all cases the porter steadies the vehicle by the shafts behind, while traction is effected either by one man in shafts and one mule or donkey with collar-harness and traces, or by two animals side by side similarly attached."

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The use of auxiliary power from animals and wind (the two were sometimes combined) made it possible to design larger wheelbarrows that could take more cargo

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The latter configuration is shown again in a picture in the Thien Kung Khai Wu (1637), where in the text we read:

"The northern one-wheeled barrow (tu yuan chhê) is pushed by one man from behind, with (one or more) donkeys pulling it from the front; it is hired by those who dislike riding (on horseback). The travellers sit on opposite sides to balance it, and a mat roof shields them from sun and wind. This kind of conveyance goes as far north as Chhang-an and Chi-ning, and also comes to the capital. When not carrying passengers these barrows will take as much as 4 or 5 tan of goods [about 6 cwt or 300 kg]. The one-wheeled barrow (tu lun thui chhe) of the south is also pushed by one man (but without animal aid), and carries only 2 tan. When it meets pot-holes (in the road) it has to stop; in any case it seldom goes more than 100 li [50 km]."

Wind powered wheelbarrows

An even more surprising method to augment human power in moving the wheelbarrow was the use of sails. The date of the introduction of the sailing wheelbarrow is unknown, but Joseph Needham notes that this contraption (the chia fan chhê) was still widely used in China at the time of writing (1965), notably in Honan and in the coastal provinces such as Shantung. Rudolf Hommel and F.H. King also spotted and described the vehicles. While some sails were very simple pieces of cloth, others were perfect miniatures of the ones used on a junk (a Chinese sailboat), easily adjustable by the driver.

The use of auxiliary power from animals and wind (the two were sometimes combined) made it possible to design larger wheelbarrows that could take more cargo. Again, it is worthy to quote Andreas Everardus van Braam Houckgeest, writing in 1797:

"Near the southern border of Shantung one finds a kind of wheelbarrow much larger than that which I have been describing, and drawn by a horse or a mule. But judge of my surprise when today I saw a whole fleet of wheelbarrows of the same size. I say, with deliberation, a fleet, for each of them had a sail, mounted on a small mast exactly fixed in a socket arranged at the forward end of the barrow."

"The sail, made of matting, or more often of cloth, is five or six feet [1.5 to 2 m] high, and three or four feet broad,, with stays, sheets, and halyards, just as on a Chinese ship. The sheets join the shafts of the wheelbarrow and can thus be manipulated by the man in charge."

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While some sails were very simple pieces of cloth, others were perfect miniatures of the ones used on a junk (a Chinese sailboat), easily adjustable by the driver

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"One had to grant the apparatus was not a freak, but an arrangement by which, with a favourable wind, the wheelbarrow porters could be greatly assisted. Otherwise such a complicated thing would have been only a bizarre curiosity. I could not help admiring the combination, and was filled with sincere pleasure in seeing twenty or so of these sailing-wheelbarrows setting their course one behind the other."

Wheelbarrows on rails

The Chinese wheelbarrow kept evolving even after the arrival of the Industrial evolution, adapting modern materials and wheels. Another noteworthy example of this is the so-called 'piepkar', which showed up on the island of Billiton at the coast of Sumatra at the turn of the twentieth century. There, a Dutch tin mining company was faced with very bad roads. The solution? A great example of combining Eastern and Western knowledge; wheelbarrows equipped with very narrow wheels, guided by iron rails. The technology - which was in use from the 1880s to around 1920 - reminds of the horse-drawn rail cars that became popular in Western cities at the time.

The decay of the Chinese road infrastructure

The importance of the Chinese wheelbarrow can only be understood in the context of the Chinese transportation network. Prior to the third century AD, China had an extensive and well-maintained road network suited for animal powered carts and wagons. It was only surpassed in length by the Ancient Roman road network. The Chinese road infrastructure attained a total length of about 25,000 miles (40,000 km), compared to almost 50,000 miles (80,000 km) for the Roman system.

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The importance of the Chinese wheelbarrow can only be understood in the context of the Chinese transportation network

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The Chinese and Roman road systems were built (independently) over the course of five centuries during the same period in history. Curiously, due to (unrelated) political reasons, both systems also started to disintegrate side by side from the third century AD onwards, and herein lies the explanation for the success of the Chinese wheelbarrow. As we have seen, the one-wheeled vehicle appeared during this period, and this is no coincidence. Increasingly, it was the only vehicle that could be operated on the deteriorating road network. As F.H. King observed: "For adaptability to the worst road conditions no vehicle equals the wheelbarrow, progressing by one wheel and two feet".

In 1937, Rudolf Hommel goes on complaining about the Chinese roads:

"In olden times, excellent wide roads were in existence in China, suitable for chariots, coaches, and wagons of many descriptions. Present-day conditions show a different picture, especially in Southern and Central China where the two-wheeled cart is not known. The splendid roads are gone, and in their place, we find only narrow paths, scarcely wide enough for foot passengers and wheelbarrows. The two-wheeled cart survived only in North China under the sway of the court of Peking, where the important business of victualizing the capital was sufficient urge to keep up the roads."

"The Chinese peasant, ever intent to gain more ground for the cultivation of his crops, has gradually reduced the width of former highways, unhampered by a watchful government. In fact, the greedy officials winked at such encroachments, as long as they have been thereby enabled to exact increased contributions in taxes from the hardworking peasants. It is only within the last five years that an extensive program of road building has been carried out."

Pathways designed for wheelbarrows

However, it seems that Rudolf Hommel got it wrong, and was looking at the Chinese roads with a Western bias. Joseph Needham tells a more positive story, noting that the network of wide roads was gradually replaced by an informal, low-tech infrastructure that was not less ingenious than the wheelbarrows that operated on it (see his pictures on the right and below). The Chinese answer to a decaying road infrastructure went much further than the adaptation of their vehicles:

"In many periods the government was interested primarily, and sometimes exclusively, in those roads and water-ways which were significant for tax-grain transportation and the conveyance of official messages. The upkeep of a multitude of local roads and paved pathways devolved, therefore, upon the people themselves, acting in their co-operative capacity under village elders and small-town worthies. In this context, religious associations, such as the Taoists Yellow Turbans about 180 AD, later so politically important, or the Buddhist fraternities afterwards, played a significant part. Making good roads was nothing less than a pious duty."

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The network of wide roads was gradually replaced by an informal, low-tech infrastructure that was not less ingenious than the wheelbarrows that operated on it

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"Thus in the course of time, quite apart from the Ancient and medieval imperial highways, China's landscape became shot through with millions of miles of well-paved paths, suitable chiefly for pedestrians, porters with carrying poles, pushers of wheelbarrows, and men carrying litters. Rough unpaved cart-tracks predominated only in the Eastern plains. Those who, like the author, have followed these paved ways past woods and rice-fields for many a mile cannot think of them without intense nostalgia. There was a long tradition of such privately initiated roads going back to the Han or even earlier, and their total mileage far outstripped that of the government main roads as the ages passed."

Interestingly, the modern, twentieth-century road network that appeared in China, and that Hommel was alluding to in 1937, did not immediately gave way to the automobile, but to another low-tech vehicle that is a worthy competitor for the wheelbarrow: the bicycle, a product of the Industrial Revolution that is even more efficient. It will probably take us (and the 21st-century Chinese) another few decades before we realise how smart the Chinese transport infrastructure was.

The decay of the Western road infrastructure

The use of wheelbarrows in combination with specially designed narrow pathways made land transportation in China considerably more efficient than in Europe for a period of almost 1,500 years. Today, critcism on the omnipresent automobile is often ridiculed by saying that we cannot go back to horses and carts, without realizing that the combination of horses and carts is far from evident and not as low-tech as it seems. History clearly shows that an extensive road infrastructure is a very vulnerable thing.

Europe was also left with a deteriorating road network after the demise of the Roman Empire, though the Europeans could buy some time. Because it was sturdier (using piles of stone and concrete rather than the early form of asphalt applied by the Chinese), the Roman road infrastructure remained relatively useful until about the 11th century AD, after which it was largely abandoned. But even before that time, the destruction of bridges and road facilities by the barbarians - or by the locals in order to defend themselves against the barbarians - gradually dimished its usefulness. Lack of maintenance and the plundering of paving stone did the rest. Moreover, the appearance of new towns and capitals (such as Paris) required new routes that did not always coincide with the existing Roman roads.

Contrary to the Chinese, the Europeans did not develop a new vehicle and appropriate infrastructure of paths to make up for the loss of the Ancient highways. New roads appeared during the economic revival of the late Middle Ages, but these were not paved or hardened in any other way. This made them at best inefficient in good weather and nearly impassable when (and after) it rained. Furthermore, because of the absence of foundations, soil erosion caused by heavy rains could wash entire roads away. As a result, the use of carts and wagons all but disappeared in medieval Europe, while nothing else came in place. For people, the options of land transportation again became limited to walking or - only for the rich - horseback riding.

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In most European countries, smooth wheeled traffic only made a comeback during the nineteenth century

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Cargo was most often transported by pack animals (mostly donkeys and mules, sometimes horses), or simply by carrying it. With the exception of England, where wheeled traffic resurged from as early as the 14th century in some places, and France, where some sturdier roads (unpaved but with foundations) appeared in some regions during the late 16th century, smooth operating wheeled traffic only made a comeback in Europe during the nineteenth century - at the same time as the first railroads appeared.

Ox drawn carts

Carts and wagons drawn by oxen remained in use throughout the centuries in Europe, for heavy or large-sized loads that could not be transported by rivers or by sea. However, road conditions often required large spans of oxen, which made wheeled transportation of heavy loads ridiculously expensive and limited to very short distances. Because of friction, the nature of a road surface greatly determines how efficient wheeled transport will be. In "Energy in world history", Vaclac Smil writes: "On a smooth, hard, dry road, a force of only about 30 kg is needed to wheel a 1 tonne load. A loose, gravelly surface may easily call for five times as much draft. On sandy or muddy roads the multiple can be seven to ten times higher."

This had important consequences, as we have seen in the article about the pre-industrial use of fossil fuels. Many countries could not capitalize on most of their energy resources, be it wood or peat or coal, because transporting them over land took more time and energy (in terms of animal feed) than they could afford. If they would have been aware of the Chinese wheelbarrow, the Europeans could have followed a similar strategy as the Chinese, using their limited resources to construct and maintain smooth but narrow pathways (and bridges) while downsizing their vehicles. As was noted in several of the historical sources mentioned above, the Chinese wheelbarrow, aided by a second man, an animal, or wind power, could transport up to 300 kg of cargo. This was almost as much as the maximum allowed cargo for horse and ox drawn carts in Ancient Rome (326 kg and 490 kg respectively).

Lessons for the future

Of course, it was not only the wheelbarrow that kept Chinese communication running after the second century AD. At least as important was the impressive network of artificial canals that complemented it. This infrastructure became ever more important after the detoriation of the road network. For example, the Grand Canal, which ran from Hangzhou to Bejing over a distance of 1800 km, was completed in 1327 after 700 years of digging.

In Europe, the first (relatively modest) canals were only built during the 16th century, and most of them only appeared in the eighteenth and nineteenth centuries. The Chinese wheelbarrow alone could not have given Europe an equally effective transport infrastructure as the Chinese, but there is no doubt that it could have made life in medieval Europe a great deal easier.

The story of the Chinese wheelbarrow also teaches us an obvious lesson for the future. While many of us today are not even prepared to change their limousine for a small car, let alone their automobile for a bicycle, we forget that neither one of these vehicles can function without suited roads. Building and maintaining roads is very hard work, and history shows that it is far from evident to keep up with it.

In this regard, it is important to keep in mind that we won't be as lucky as the medieval Europeans who inherited one of the best and most durable road networks in the world. Our road infrastructure - mostly based on asphalt - is more similar to that of the Ancient Chinese and will disintegrate at a much faster rate if we lose our ability to maintain it. The Chinese wheelbarrow - and with it many other forgotten low-tech transportation options - might one day come in very handy again.

Kris De Decker (edited by Shameez Joubert)

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Sources:

"Science and Civilisation in China, Volume 4: Physics and Physical Technology, Part 2, Mechanical Engineering", Joseph Needham, 1965 (the wheelbarrow)
"Science and Civilisation in China, Volume 4: Physics and Physical Technology, Part 3: Civil engineering and nautics", Joseph Needham, 1971 (the road network)
"Hommel: China at Work", Rudolf P. Hommel, 1937
"Farmers of Forty Centuries, or, permanent agriculture in China, Korea and Japan", F.H. King, 1911
"The medieval wheelbarrow", Andrea L. Matthies, in "Technology and Culture", Vol. 32, No.2, April 1991
"The origins of the wheelbarrow", M.J.T. Lewis, in "Technology and Culture", Vol.35, No.3, July 1994
"Roads and pavements in France", Alfred Perkens Rockwell, 1895
"Voyager au Moyen Age", Jean Verdon, 2007 (original edition 1998)
"Histoire générale des techniques" (Tome I / Tome II), Maurice Dumas, 1962
"Horse hauling: a revolution in vehicle transport in 12th and 13th century England", John Langdon, 1984
"A social and economic history of medieval Europe", Gerald Hodgett, 1972
"Science and Technology in Medieval European Life", Jeffrey R. Wigelsworth, 2006
"Medieval sourcebook: Richer of Rheims: Journey to Chartres, 10th century", Michael Markowski (webpage)
"Inland transportation in England during the fourteenth century", J.F. Williard, 1926
"The use of carts in the fourteenth century", J.F. Williard, 1932
"Energy In World History", Vaclac Smil, 1994
"The Subterranean Forest", Rolf Pieter Sieferle, 2010
Coming home with riches: the wheelbarrow as an auspicious motif in popular Chinese prints, Antje Richter, 2004
The wheelbarrow, Engines of our ingenuity, John Lienhard
Institut d'Asie Orientale: pictures (overview).
Lantern slide collection, Art, Architecture and Engineering Library.

More low-tech transportation:

Cargo cyclists replace truck drivers on European city streets
Aerial ropeways: automatic cargo transport for a bargain
Wind powered vehicles
Trolley canal boats
Wood gas cars: firewood in the fuel tank
Gas bag vehicles
The velomobile: high-tech bike or low-tech car?
Electric velomobiles: as fast and comfortable as an automobile, but 80 times more efficient
Piston-powered aircraft
The status quo of electric cars: better batteries, same range
Cars, out of the way
Water powered cable trains
Get wired (again): trolleybuses and trolleytrucks
Electric road trains in Germany
Cargo ships, then and now
The age of speed: how to reduce global fuel consumption by 75 percent
Life without airplanes: from London to New York in 3 days and 12 hours
A world without trucks: underground freight networks
Low-tech cars

More articles related to Chinese technology:

Recycling animal and human dung is the key to sustainable farming
Lost knowledge: ropes and knots
Boat mills: water powered, floating factories
Medieval smokestacks: fossil fuels in pre-industrial times

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Gas Bag Vehicles

2011-11-13T22:50:24+01:00

Wood gas cars were not the only answer to the limited supply of gasoline in World War One and Two. An even more cumbersome alternative came in the form of the gas bag vehicle.

The old-timers on these pictures are not moving furniture or an oversized load. What can be seen on the roof is the fuel tank of the vehicle - a balloon filled with uncompressed gas.

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Gas bag vehicles were built during World War One and (especially) World War Two in France, the Netherlands, Germany and England as an improvised solution to the shortage of gasoline. Apart from automobiles, buses and trucks were also equipped with the technology. The vehicles consumed 'town gas' or 'street gas', a by-product of the process of turning coal into cokes (which are used to make iron).

Today, vehicles powered by compressed natural gas (CNG) or liquified petroleum gas (LPG) are quite practical. The fuel tank needs to be roughly twice as big as a gasoline fuel tank in order to get the same range. But the fuel used for gas bag vehicles during the World Wars was generally not compressed and had a much lower energy density than LPG or CNG. To replace one litre of gasoline, two to three cubic metres of gas was needed.

The only way to get a somewhat practical range, was to use an extremely large 'fuel tank'. Buses were better suited for this than automobiles - they had a full-length gas storage bag on a roof rack. It could be enclosed in a streamlined fairing but most often it was not.

Private automobiles were equipped with a wooden framework which was fastened to the roof and the reinforced bumpers of the vehicle. It was hard to overlook a gas bag vehicle passing along.

The Dutch old-timer on the pictures above carried a gas storage bag of 13 cubic metres, an installation that gave it a range of approximately 50 km (30 miles) at an energy consumption of 13 litres per km (22 mpg). The aerodynamics of gas bag automobiles were disastrous, so fuel economy was far from optimal.

Easy repair

Witnesses to the vehicle passing by could easily see how much fuel was left: the gas bag was fully inflated at the start of a trip, and it deflated with every mile that was driven.

The gas storage bags were made of silk or other fabrics, soaked in rubber (Zodiac was one of the manufacturers). These bags were (and are) much cheaper and easier to build than metal tanks. They could also be repaired in a similar way to bicycle tyres. The bag was anchored to the roof using rings and straps. Some gas bag vehicles could operate alternatively on gas or gasoline. Switching between the two options could be controlled from inside the vehicle.

Compressed gas

Although it was technically possible to compress town gas or street gas, this did not happen because of two reasons. Carbon monoxide, one of the components of town gas and street gas, disintegrates quickly when compressed, while hydrogen gas, another component, leaks away through steel tanks when it is compressed.

The only exception was the use of gas cylinders in France during World War Two (picture above), allowing for a smaller fuel tank or a better range. Natural gas was used in this case, which could be compressed without the drawbacks of compressing town gas. However, this configuration turned out to be more expensive and more dangerous.

No smoking

It will not surprise anyone that gas bag vehicles had their risks. One obvious risk was fire, which could cause a gas explosion. As a result, people waiting for the bus were urged not to smoke (See pictures: "Autobus-Haltestelle" = "bus stop" & "Rauchen verboten" = "smoking prohibited").

Bridges

Another risk were bridges and other overhead obstacles. The driver needed to know the exact height of his vehicle and of the bridges that he planned to drive underneath.

Excessive speeds were not a good idea either. It was advised not to surpass a speed of 50 km/h (30 mph), not only to maintain a decent range but also to make sure that the fuel tank would not fly off the vehicle. Strong side winds could present hazardous situations, too. Gas bag vehicles also suffered from carburator fires, loud bangs and engine damage.

Gas bag buses could still be seen in China in the 1990s, notably in the municipality of Chongqing where they were developed in peace time as a cheap public transportation option. The picture below (credit) shows at least six operating gas bag buses in Shawan ("Sandy Bay"), Shandong, China, in 1965.

Kris De Decker. Edited by Deva Lee. Thanks to Dutch John.

Sources:

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Sailrockets & kiteboats
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Low-tech cars at No Tech Magazine

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