Bow Thruster Cables

[CDK]

Mat-C's question was whether or not he could use the existing AWG 0 cable, not if it would be wiser to abandon the idea, how to moor without a thruster etc.

I calculated a 1.5 V drop for 100 ft. of AWG 0 in post #4.
The actual length is 65 ft., so the drop will be 0.975 V; should AWG 00 be used, the voltage drop would be 0.78 V, all based on 150 A being drawn by the thruster.

To assess the danger of overheating, we must look at the dissipation in the cable.
That is 146 W for an AWG 0 cable, or approx. 2.25 W per foot (1.8 W for AWG 00).
It is safe to say that in both cases this is a very light load and the cable will not warm up noticeably during normal use of the thruster. It would take hours of continuous use for the rise in temperature to become significant.

The dissipation in the thruster motor is 1650 W: prolonged use can and will quickly lead to overheating there. For that reason the manufacturers state a duty cycle of max. 5% and a maximum duration of just a few minutes.

[Submarine Tom]

Okay, we now have some information about if it is really necessary and it appears to be.

Is it sized properly for the job (windage)? Lets hope so.

I agree with CDK's logic. Go for it.

-Tom

[FAST FRED]

A 6-8 HP outboard doesn't weigh much make up a bow bracket and simply plop it in the water 90deg to the keel,before docking.

FWD is Right , Reverse is Left . Electric start or pull , your choice.

IF the boat is a real nightmare a 40hp could be used.

FF

[Submarine Tom]

That's what I've done on the bow of my houseboat. A Merc 3.5 with built in fuel tank simple installed "backwards" on the bow. I never use reverse, just position it as necessary and work it against the Merc BigFoot 25 on the stern. I have a bow steering station by rope and tiller for the transon mounted 25. It works great and it's nice to have a spare motor onboard too.

-Tom

[Landlubber]

Fast Fred and Sub Tom...you guys need a life fellas....I am surprised that you do not start the motors with a crank handle....

[mydauphin]

Originally Posted by Landlubber

Fast Fred and Sub Tom...you guys need a wife ?

Does she operate bow outboard when docking?

[Submarine Tom]

"Happy wife, happy life"

-Tom

An old rope pull outboard is all that is really required to more your boat.

Actually a true Sailor would not need an engine at all.

The Salty method is to develop as much headway as possible and then unleash your BoomVang and push the Boom into the wind oppisate of the direction that you wish to sideslip. Be sure to hard over your rudder anticlockwise and dogg off the cleat.

Try this method in a crowded commercial harbor for best learning satisfaction. Other Yachtsman and Tug Captain will let you know if you have a learning curve to overcom.