AGRICULTURE REPORT - Treadle Pumps
By Mario Ritter
This is the VOA Special English Agriculture Report.
In many places, farms require a system to move water to fields where it is needed. For many small farms, a treadle [TRE-dul] pump may be the answer. A treadle pump uses leg power to force water up from the ground. Treadle is spelled T-R-E-A-D-L-E. Here is how it works.
A treadle pump is designed kind of like the engine in a car. Pistons move up and down inside cylinders to create suction force. With a treadle, this force pulls water from one place and moves it to another.
There are many different designs for a treadle pump. But all have two cylinders. These can be made from lengths of pipe. The surface of the sliding piece inside can be made of rubber or leather. A stick is attached to move the piece up and down. The piston must fit closely inside the pipe, but must also be able to move along its length.
Two openings are cut into the bottom of each pipe. These openings control the force of each piston. Valves are placed in the openings. Valves are like doors that open only one way. When the piston goes up, one valve opens. The force of suction takes water into the pipe. When the piston moves down, it forces the water out of the pipe. The same force opens the other valve and carries water to where it is needed.
The easiest design is to use two long pieces of wood to stand on to operate the pistons. The operator stands above the pump and pushes down on one piston with one foot while the other piston rises. This movement is much like walking.
Treadle pumps can be made with common parts. Companies in many countries also sell them for prices between ten and twenty-five American dollars.
These human-powered pumps can lift water several meters. They can pump water from underground supplies or lift water from rivers to higher ground. But treadle pumps do have limits. They cannot lift water from deep underground supplies. Also, treadle pumps lose about ten percent of their power for every kilometer above sea level. So they are not effective in high mountain areas.
Still, for many small farms, treadle pumps can increase production with less effort. The Food and Agriculture Organization of the United Nations says treadle pumps can help farmers improve crops and increase profits.
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