Build a Hydraulic Ram Pump

Follow our directions to make an inexpensive but effective hydraulic ram pump.

| May/June 1979

057 hydraulic ram pump - cover photo.jpg

The completed hydraulic ram pump is a simple device.


The search for a "perpetual motion" machine is just about as old as civilization itself. And though we all know that such a gadget probably doesn't exist, there is a piece of equipment that comes pretty close: the hydraulic ram pump.

The water ram (also known as a trompe) has been around for quite a while and was a widely used means of pumping water before electricity became common in rural areas. Strictly speaking, the ram pump doesn't create its own power but draws energy from the force of a moving column of water, usually fed through a pipe from a point more than 18 inches above the trompe.

Although the hydro ram won't operate without a fluid power source, it will work indefinitely when water is present. And, except for an adjustment every few months, the device requires no maintenance whatsoever!

It's a Bargain at 1/10 the Price...

Quality hydraulic rams are available commercially for anywhere from $400 to $800, complete. These are excellent units, designed to last for many years. However, most folks simply don't have that kind of money to spend, so MOTHER EARTH NEWS' research team came up with a pump that delivers the same reliable performance as its store-bought cousins but only costs about $60! Better yet, our version can be put together in less than an hour using off-the-shelf plumbing supplies.

Most of the components of our pump are fabricated from PVC pipe, the same conduit that's used throughout the country in residential and industrial plumbing systems. Polyvinyl chloride is tough, easy to work with, and readily available. The moving parts of the trompe consist of a standard check valve, a steel rod, a spring, and a rubber bathtub stopper.

NOTE: If you wish, you may substitute Schedule 40 black pipe (of comparable dimensions) for the flexible polyethylene used at the drive and delivery ends of the system.

10/21/2014 5:06:14 AM

I have seen other designs that have adjustable versions of the swing check valve. This lets you determine how fast the water must be flowing before the valve activates, and thus how much pressure you build up. Here this element can be slightly adjusted by rotating the pump along it's long axis, changing the force of gravity on the swing check valve.

9/22/2009 3:53:54 PM

Reading articles from time to time about the ram pump and actually getting a working plan is something else. Is there a actual step by step plan in english showing how to build one ?

8/5/2009 2:29:46 PM

Would it be possible to use a ram pump in conjunction with a gravity water system to power a hydro electric system? In other words. If you set up a gravity water system with a ram pump to continually return the water back to the top, could you insert a hydro electric system and use it to create electricity?

8/5/2008 7:35:20 PM

I wouldn't think that a PVC rampump is going to last as long as a well engineered commercial pump, since the pump is constantly exposed to water and gets hammered non-stop it's entire life. Good commercial pumps (eg here in the Waikato) are built out of stainless steel with high-impact polymer valves and can run for years at a time without needing repairs.

3/4/2007 4:46:25 PM

I appreciate and enjoy these articles very much. However.... A very important image is missing from this article. I have the original print article, which includes a view of the assembly in exploded assy format. This is probably the most important part of the article. What's more disappointing is that the exploded assy view is also missing from the archive CD I received as a gift. RIP OFF!

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