CSAW,
A ram pump is simply a bunch of pipe, several diferent valves and an air compression tank. I will TRY to explain how it works. You have a length of pipe, in our case it was 3" steel, and if I remember correctly was 30 feet long, it all depends on the amount of flow you have in the creek and the fall, I think we had 7 or 8 feet of fall. At the end of this is a gate valve then the pump itself, which is just a valve that Dad made with a piece of pipe, a T fitting on the end, one leg off of the T was the valve which was on a leaf type spring adjusted so that it let the water run out until the flow of water pushed the valve closed, which caused a water hammer effect, this compressed the air in the air tank which was simply another length of pipe situated past the valve and vertical, which had a small hole and key in it to let it draw a little air each time, the pipe was capped off which made the air compression tank, I think it was around 4 feet tall. On the bottom of the air tank we had a one way valve which was hooked to the outlet line which went to the house, this valve was to keep the water in the line from backfeeding into the pump. Now, all of the measurements are custom fit to the water source and everything has to be adjusted just so, it is not hard once you know what you are doing, all you do is open the first gate valve to let water to the pump and while the water is running out the clapper valve adjust the tension of the spring with a bolt placed for the purpose, and another bolt to adjust the stroke length ( how far the valve can go up or down) adjust the tension until it starts pulsating by itself, you might have to lift it by hand once or twice to start it, once it is running adjust until you get the best water flow for your situation, ours was one pulse per second. Now as long as it doesn't get clogged with a fish or other trash it will run until it beats itself apart with no further attention, no fuel no cost, nothing, use the absolute best pipe, bolts and valve material ( hard rubber washer or something similar ) and it will last a long time, a neighbor of ours has had his running nonstop for ten years trouble free.
Now you have a real surprise to show everybody who comes by, we never got tired of seeing peoples faces when we showed them!, they couldn't believe it!
One thing more, it must be tied down to the ground somehow, very well or else it will beat itself out of position down the creek, it has an amazing pound, The neighbor had to finally cement his in and bury the lines because it broke all of the pins or anything else he tried, it finally broke the cement, he just put on more cement and it has been working fine. They pack an amazing punch!
I didn't explain it very well, I hope you get the general idea, I wish I had a picture to post
I would be happy to try to describe it better if you need, Christopher