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

Sat, 02 Mar 2013 00:00:00 +0000

Wire rope transmission in Schaffhausen, Switzerland, 1886. Image: [Schaffhausen Foto Archiv](http://www.schaffhausen-foto-archiv.ch/moserdamm.html).

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.

Mechanical Power Transmission

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 Germany. Source: [Singen Industry](http://www.singen-hegau-archiv.ch/singen-industrie.html).

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 Germany. Source: [Singen Industry](http://www.singen-hegau-archiv.ch/singen-industrie.html).

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 ⁴.

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.

A wire rope transmission.

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.

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

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](http://www.industrieensemble.ch/), the only remaining wire rope transmission line in Europe. Image: [Peter Christener](http://www.egghof.com/weblog/seiltransmission.html).

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.

Different types of wire rope transmission.

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).

A wire rope transmission.

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.”

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

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. Image: [Schaffhausen Foto Archiv](http://www.schaffhausen-foto-archiv.ch/moserdamm.html).

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.

Wire rope transmission at Fribourg.

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.

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

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).

Wire rope transmission at Gokak, India.

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 ⁵. 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. [Image](http://www.industrieensemble.ch/wasser.wasserkraft.html#apDiv9)

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.

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

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%.

The efficiencies of different types of power transmission.

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%. ⁶

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 ⁷.

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. [Image](http://www.stadtarchiv-heilbronn.de/stadtgeschichte/unterricht/bausteine/muehlen/arbeitsvorschlaege/grundlagen/).

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).

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

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. Image: [Stadtarchiv Schaffhausen](http://www.stadtarchiv-schaffhausen.ch/Bild-Schaffhausen.asp?startSequence=1&level1_ID=9&level2_ID=19&level3_ID=122&level4_ID=1643).

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 ⁸. While this is far from reality at this point, we do have better ropes than 120 years ago, and we can run them faster.

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

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](http://www.stadtarchiv-schaffhausen.ch/Bild-Schaffhausen.asp?startSequence=1&level1_ID=9&level2_ID=19&level3_ID=122&level4_ID=1643).

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.

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

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.

The Schaffhausen wire rope transmission in 1896. Source: Stadtarchiv in Switzerland. Image: [Historische Werkstätte Gebrüder Giger Mulin, Schnaus](http://www.mulin-schnaus.ch/).

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.

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

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.

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.

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 ↩︎
. Pneumatic and hydraulic transmission will be discussed in a forthcoming article [^6]: Flather, 1900 ↩︎
Hunter, 1991 ↩︎
Beringer, 1886 and Unwin, 1894 ↩︎
AC Transmission Line Losses, Stanford University, fall 2010 ↩︎
Dave Santos, personal communication, February 2013 ↩︎

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

Sat, 02 Feb 2013 00:00:00 +0000

Field motor on steel frame with steel jerker rods on the James Field. Image: "[Conservation district study appendix](http://www.lambtononline.ca/home/residents/planninganddevelopment/Oil%20Heritage%20Conservation%20District%20Plan%20Documents/Forms/AllItems.aspx)", Oil Heritage Conservation District Plan, The Corporation of the County of Lambton.

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.

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.

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. Image: [Markus Wandel](http://wandel.ca/).

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](http://www.lambtononline.ca/home/residents/planninganddevelopment/Oil%20Heritage%20Conservation%20District%20Plan%20Documents/Forms/AllItems.aspx)", 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](http://www.lambtononline.ca/home/residents/planninganddevelopment/Oil%20Heritage%20Conservation%20District%20Plan%20Documents/Forms/AllItems.aspx)", 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](http://www.herculesengines.com/FlatRock/).

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](http://www.herculesengines.com/FlatRock/).

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.

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](http://www.loc.gov/pictures/item/pa3551.sheet.00003a/resource/).

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 below).

Eccentric motion jerker

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](http://www.loc.gov/pictures/item/pa3551.sheet.00003a/resource/).

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](http://www.lambtononline.ca/home/residents/planninganddevelopment/Oil%20Heritage%20Conservation%20District%20Plan%20Documents/Forms/AllItems.aspx)", 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](http://www.herculesengines.com/FlatRock/).

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. Image: [Old Iron](http://www.herculesengines.com/FlatRock/).

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.

Balancing a jerker line system

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](http://www.herculesengines.com/FlatRock/).

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.”

Images: Jerker line system supports.

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](http://www.herculesengines.com/FlatRock/).

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](http://wandel.ca/).

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](http://wandel.ca/).

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](http://wandel.ca/).

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.

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.

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

The Mechanical Transmission of Power (1): Stangenkunst

Wed, 23 Jan 2013 00:00:00 +0000

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

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.

Revival of the Mining Industry

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.

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](http://geomuseum.tu-clausthal.de/histoharz.php?section=43110&level=14&name=Huttaler%sp%Wasserregal&details=on&select=0&nr=0&art=) 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. Image: [Bengt Oberger](http://commons.wikimedia.org/wiki/File:Pershyttan_konstg%C3%A5ng_01.JPG).

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.

Hakenkunst by Polhem in the Falun copper mine. SOurce unknown.

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.

A man engine.

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.

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). Image: "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. Image: "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. Image: "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. Image: “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.

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