Pumping water on the river

[Chagrin]

The question is: how do you pump water with no head, not enough current, and as cheaply as possible? Well, here's the answer I'm going to try:

The float is missing on the end of the arm, but basically I'm going to try to harness river waves (mostly generated by boats on the river) to activate the homemade PVC pump in the picture. At the top of the pump you will see two check valves - one for intake and one for outtake. A small piston inside the cylinder (a single O-ring) will hopefully keep the seal.

The water will be used for a nearby garden. I figure that if I can get even five gallons a day I'll be doing great.

[Norm]

  Yes they work I've seen bilge pumps that work by the rocking of the boat....quite a bit of power in waves....now if you've got a big enough float a double acting pump......

             Have Fun!

               ( :>) Norm.

[Chagrin]

I was able to get this up and running last Sunday. Appears that the theory is sound, it's the details that get ya: very difficult to make everything rigid enough that you don't lose a lot of power with the poles swaying around. I was still able to pump about three gallons over an eight hour span with uncustomarily low boat traffic. Still, that's decent for my garden-watering purposes.

I have a floating dock nearby and plan on building a shorter, fatter piston and cylinder to attach between the floating dock and the poles pounded into the river bed that keep it in place. Seems that these floating dock pieces toss around quite a bit even without any waves evident and I should be able to increase water volume quite a bit.

[Norm]

  Put an eight foot pole on the floating dock and attach a pendulum with a 50 lb. weight and consider the power of that swinging weight.....hmmm?

                   ( :>) Norm.

[Chagrin]

That's an intriguing idea as it would allow for the entire apparatus to float and negate any issues with the river stage increasing/decreasing. The devil is still in the details though - anything large enough to swing a 50lb weight would be ... quite large.

[Norm]

 anything large enough to swing a 50lb weight would be ... quite large.

  Not necessarily...just a  couple of floats

small drums with an 8 foot span 4 foot high for

the pendulum to swing.

                  ( :>) Norm.