Turning the craft with controllable ball valves

[jdibenedetto]

Good afternoon,

I am designing a marine propulsion system for a search & rescue tether operated vehicle. I intend to limit cost by using only one bilge pump to move the vehicle in water. Can this be accomplished by installing two pipes @ 45 degrees to the parallel at the rear of the craft?

Ball valves attached to the two pipes will allow the end user to turn the craft by opening & closing water flow into each pipe. The central output used for foward motion would be closed while the vehicle is turning. The two other side outputs on the "exhaust" would remain closed during foward movement to keep acceleration swift.

Does this idea seem feasible? I am not sure how I can open/close the valves from the shore. All suggestions are sincerly appreciated! I am also considering using additional outputs to control depth, but I think I should tackle this challenge first.

Being able to cut costs by only using one bilge pump for marine propulsion is vital as I also need to build a land transportation method and object/people recovery system.

Thanks in advance,

J

[thegadgetguy]

You could probably do it, but in my opinion, the mechanisms to control it would cost significantly more than the 20-30 dollars it would cost to add another pump.

[jdibenedetto]

@gadgetguy, Thanks for the quick reply. I researched PVC ball valve actuators, and they are certainly too expensive for my budget. I believe these cheap solenoid valves ($7) on ebay would work but my current design requires at least 3 valves.

http://www.ebay.com/itm/Electric-Soleno ... 3a780349c1

Since an additonal pump cartridge would cost me as much as three valves, I might as well utilize the added power of two independent thrusters. It's just a shame that I can't turn this vehicle with one thruster, as it will most likely fit within a cubic foot upon completion. Does anyone think that three modified bilge pump thrusters with propellers would be unstable on a craft of this size?