Ram Pumps

A ram pump uses the momentum of falling water to push a smaller volume of water to a greater height. Water drops through a drive pipe, slams a waste valve shut, and the pressure spike that follows forces a fraction of that water through a check valve into an air chamber, which then pushes it up the delivery pipe. The cycle repeats several times a second, on its own, indefinitely.

The efficiency is poor — you might deliver ten percent of what enters the drive pipe — but the input costs nothing and the fuel is gravity. For a property with a year-round drop and a need to move water to the uphill fields, there is no cheaper machine.

Our installation uses a cast-iron ram rated for roughly forty feet of head and a delivery rise of about sixty. The drive pipe runs two hundred feet down the wet corner; the delivery line is buried at eighteen inches to keep it from freezing and rises to a stock tank at the top of the south pasture.

The air chamber needs recharging about once a month, because air dissolves into water over time. That is the entire maintenance schedule, and it takes a bicycle pump.

The pump is a small argument made physically: a property can move its own water without a solar array, a battery bank, or a grid connection. It will still work when the power is out, and it will still work when we are not here to switch it on.