Trailer power assist

[roverman]

NOT sports car-but, we like engineering-right ? I want to launch a 28' pontoon boat, on a "marginalized" ramp. No place to winch to. Considering something like a Kawasaki "Mule" to move/launch boat/trailer. Still likey to have "stuck" problems. What kind of simple power assist for 2-4 of the trailer wheels ? Two miles/hr. max ?  Air motor via CO2 bottle ? Hz seems too complicated. Ideas please ?  Thanks, roverman.

[BlownMGB-V8]

How about a hydraulic motor on a tag axle lowered by a hydraulic cylinder with a hydropack and battery in the tool box? Might get some parts from an old Bobcat.

Jim

[roverman]

I dunno, got sketch ? "Maybe" gear reduction starter motor(s) ? They only need "forward", working in concert with 4WD truck. "Maybe" higher floatation tires, on the trailer ? Only need 400 ft./max., beyond the concrete ramp. Thanks, Art.

[rficalora]

Only need 400 ft./max., beyond the concrete ramp.

Sounds to me like what you really need is just some rain!!

I feel for you though.  Our lake is full again, but for a few years, I had a beach that extended about 40'.  Luckily I got my boat off the lift & on the trailer before it was too late and there was a ramp not too far from me that was still in the water.

400' is a long way.  If the ground is dry up till the last 10'-12' or so, consider making some wooden ramps out of some 2x12's & plywood.

[roverman]

This is Salton Sea, so about 3"/year, counting on rain for help...not going to happen. Launch was built when level was above normal, via tropical storms in 76' and 77'. 300+ square miles of class 1 recreation water, with NO boats on it ! Boats would help aerate oxegen into the water, a dire need.  PBA used to race here, 227' below sea level, so fastest water and densest air, in the West. Estimated 20million  tilapia, too much salt content, and not enough oxegen.  Cheers, Art.

[Dan B]

Low tech...Use a winch to pull the trailer out.

[waterbucket]

I am with Jim on this one, I have used hydraulic motors on all sorts of machines (agricultural) from little 2 or 3 hp ones to 65hp on hedge trimmers. You can get various types ie slow or fast turning variations as well as different operational types. Most of these have been driven by the hydraulic system on the tractor but it is easy to calculate the size pump that you need from the motor spec, ie a motor requiring 100cc a revolution revolving 200 rpm will require a 20 litre a minute pump. Motor speed can be controlled by a needle valve . How you get the drive to the wheels is the only problem, but I assume a tag axle is an additional axle which is lowered when needed. I would used a small engine (Briggs and Stratton) driving the pump with the motor connected directly to the diff input on the axle. I would use a low rpm (high torque) motor rather than trying to gear down a high speed one though.
At the moment there are two hydraulic power units on ebay for $100 each, just need converting from electric to gas engine but New Hampshire is a long way from California

[roverman]

For the sake of simplicity, I'm giving a second look to gear reduction starter(s). The boat will have 2+ deep cycle group 27 batteries, so enough power available. Cheap, available and hi-tork.  Perhaps a flexplate could adapt to the back of the brake drum ? The starters would assist until trailer speed exceeded starter speed and bendix would unload.  What if ?

[MGBV8]

Start a petition to have the ramp extended.

[joe_padavano]

Google trailer mover. There are dozens of these out there commercially plus a whole bunch of homemade ones.

https://www.youtube.com/watch?v=C_OEzuKOoFE