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The 27th Comrade


Chris, you the best.

I just had to tell you that your magazines—Low-Tech and No-Tech—are really just such a whole lot of collected ingenuity. I can’t say enough “thank you”s.

Darkest Yorkshire


If you want to do this in the modern world then compressed air would be a better option. It is already widely used in industry and can operate a large range of tools, machinery, vehicles and refrigeration. The heat generated during compression can also be recovered and used. A much greater advantage is that compressed air can be stored as well as transported, decoupling production of energy from its use. This system has huge potential as wind and hydro sites not fast, powerful or consistent enough to generate electricity can still compress air. This is the most promising future for developing industrial windmills and watermills.

Jan Steinman


Darkest Yorkshire, can you transmit compressed air over a kilometre via wood?

I'd guess the transmission media for compressed air is probably two orders of magnitude more energetically expensive than that of wood, or even that of steel cables. It would be interesting to see a good emergy analysis comparison of the two.

Kris De Decker


@ Darkest Yorkshire & Jan Steinman: compressed air will be discussed in a forthcoming article. It has its own merits, but for oil pumping jerker line systems turned out to be the better choice. Some compressed air systems operating oil pumps were built, but they were exceptional: http://digital.library.unt.edu/ark:/67531/metadc12407/m1/123/

@ The 27th Comrade: you're welcome.

Darkest Yorkshire


Kris, I should have been clearer. I was not suggesting compressed air just for pumping oil but as a way to store and transmit renewable mechanical energy for industry in general, in the same vein as your windmill and solar factory articles. Looking forward to your thoughts on the subject.

Jan, compressed air cannot be transported over a mile by wood, but it can be by metal pipe, and be far more versatile when it gets there (think of the range of air tools available). Compressed air is a notoriously inefficient energy storage medium, but this is only a problem when it is generated by fossil fuel electricity. If it is generated directly by wind and water then after the initial investment it is largely free energy. In my opinion the combination of energy storage and flexibility of use more than makes up for the inefficiency. Having said that, a jerker line may be the best solution in some situations and a windmill/watermill and stangenkunst combo would be beautiful and hypnotic in an ecovillage, I just don't expect to see them running through industrial estates.

Michael Buck


The elementary school I went to had a rider powered merry go round. I have been looking for many years for the mechanism that allowed the reciprocating bars to transmit the rider's pumping to the center post making the thing spin. I recognize that mechanism in the photo at the top of this post. Can you provide drawings or details about that mechanism? I want to reproduce this merry go round for my friends, well, for myself to spin myself sick like the old days. Any help is so appreciated!



In Switzerland cables and belts have been used to power textile factories. The energy flow is constant with a continuously moving endless cable. Different machines could have different speeds by simple gearing.
One huge problem with moving power transmission is safety. There where many accidents because an arm was bought in the diving mechanism. With todays safety levels the transmission would net to be completely enclosed. Also with electricity an emergency stop is ready to implement.

Kris De Decker


@ Matt: Correct. Those systems are the subject of part 3, which is still to be published.

@ Michael: Unfortunately, I have not more drawings other than those shown in the article. You could check out "Surface Machinery and Methods for Oil-Well Pumping" (the first link in the sources) for more details on the technology. However, technical information on jerker line systems is extremely rare. Historians never gave them much attention.

Kris De Decker


More comments at Metafilter and Hacker News:



Peter Allen Sharp


Excellent article. I'm developing an unbalanced, single-blade, vertical axis windmill (called the Bird Windmill) that will reciprocate cords to transmit energy via a jerker line. Many such small-scale windmills will be able to concentrate power at a single location to drive a wide variety of devices, including a generator or air compressor (perhaps using the LightSail system for conserving the energy of compression). My goal is to provide off-the-grid farms and villages with reliable, low-cost power. The system may prove to be cheap enough to compete with conventional, large-scale wind turbines, but it's too soon to tell. I'm still at the model stage. Here is a video showing me testing a very cheap blade:

John Hewat


I saw this and said 'I don't believe it!'
Human ingenuity. Brilliant!



Agreed: this is brilliant. Though, it occurs to me that ordinarily, reciprocating motion applied to mass has an inertial loss at each end of each stroke. What means if any, were used to compensate for that? Or is the system sufficiently economical to operate, that the inertial losses don't matter?

If the field lines were suspended from pendulums hung from pivots above the lines, that would partially compensate: As a stroke reached the end of the arc of the pendulums, inertia would be working against gravity, thereby effectively absorbing energy and storing it as the lines were raised by the pendulums at the ends of their swing. As the stroke in the opposite direction began, gravity pulls the lines down and partially compensates for the inertia of getting them started back in the opposite direction.

This is a bit of a wild long shot, but: What about optimizing for, and taking advantage of, the resonant frequency of a system? If a mechanical transmission system is built with elements of the correct size and mass, operated at the correct frequency of reciprocation, it should theoretically develop a resonance that improves the efficiency of the output. Each installation would need to be carefully calculated for this, but the variables are pretty well known and understood.

Jim of Olym


I remember such a system in Los Angeles, in the Bunker Hill area where there were old oil wells which worked from a central cable system. Used to see them from the streetcar from Glendale. (back around 1950) Remember streetcars? they were electric, until GM forced them to get busses.



I am in the process of building an off grid home with a 150 foot well. A 12 volt well pump is about 1500 dollars for a good one. After living on a sailboat for most of my life, I learned not to depend on anything electrical, so that leaves mechanical. I saw one mechanical pump on the internet for around 600 dollars plus the pipe. Still probably about $800 to $1000. The other one is about $7,000, ain't gonna happen.

I went to the oil industry for a pump design because that is the most extreme pumping conditions. The most obvious way to power it has already been figured out by GUESS WHO ? The oil industry. While studying pump jacks I found this page. Low and behold I will have a gas generator a hundred feet away.

Gear it down to 6 rpm
jerk line
pump jack

That's it, maybe $300. Manual, freeze proof, can be operated with gas engine running on waste motor oil, gas, diesel, propane, wood gas etc etc etc.

The biggest problem with gas engines is the carburetor. All those sources of fuel do not require a carburetor. Now I have a much more reliable source of power.

Thank you oil industry



Thanks for the read. The land I bought a while back had one of these wells and I wasn't sure what it was! We still get oil and house gas off the wells.

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