single engine electric backup drive

I've read that there are generator powered backups (to the main shaft) for single engine boats, but can't actually find any brand names, products, or links for them. I've tried searching on this site, but can't find any solid leads.

Any help? Anyone actually have one? Are they an electric motor, hydraulic, and/or gear driven?

A wing engine is often found on larger passagemakers as an alternative to dedicated twins. The wing can be connected to the main shaft electrically, hydraulically, mechanically, or may drive a separate shaft with a folding prop.

Many single engine boats use the gen set that powers a hydraulic pump that drives the main shaft. I don’t think there is any specific name brand as most are special one off. On the Eagle the gen set power hydraulic pump also drives the hydraulic bow thruster. I have modified the Eagle hydraulics several times. The biggest modification was charging the hydraulic pump to a variable PSI pump with an electric clutch, and increasing the gen sets pulley so the PSI can be 0 to 1800 psi, which is 75% max. The present limiting factor is the hp of the gen set Perkins engine.

I would recommend for single engines the gen set rating should be by HP not KW if the gen set is going to be use as a get home.

Check here the company is Wesmar APU

windmill29130 said:

Check here the company is Wesmar APU

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Exactly the type of information I was looking for. I was surprised at the $12,000 price tag. Any others?

mikesacs said:

Exactly the type of information I was looking for. I was surprised at the $12,000 price tag. Any others?

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E motion Hybrids Home

www.thrusters.com

www.keypower.net/

www.steyr-motors.com/marine

My 1974 Defever 34' came to me with a get home system that runs off my Perkins 4-107 generator.Its a hydraulic unit and worked when I took it off the boat.It is A Vickers Vane Pump motor and it has a two piece chain coupling that is machined to the shaft.Its complicated in that one has to bolt the power take off to the front of the Perkins engine and then install a chain that looks like it came off the Battleship New Jersey.Only then do you start the Perkins,make sure the M/E transmission is in neutral and then engage the pump.......and thats why it sits under my garage.Boat US is much easier.

If you are going to use the gen set most are hydraulic There cheap/simple or expensive/comex ways. The Eagles connection to the main shaft is similar as explained be low. How ever the gen set does not have enough hp to go very fast. May be some head way.

So I view it as a small spare tire for a vehicle, and hopful never used, as I maintain the main 671 so it does not fail. Most of the commercial trawler do to have a get home as the maintain the main engine and care spare parts and know how to fix them. Worst come to worse the call coast gaurd or other trawlers for a tow.

Alot depends on the rating reliability of the engine. So its more of a peace of mind, its there if needed.

Mikesacs

Surprised at $12,000 you say, just wait until you get it installed and working right for the final price to be realized. Boating (away from shore connections) isn't cheap.

A big wing engine or twins will provide nearly 100% peace of mind. The hydraulic drive "standby" setups on Selenes, Northern Marines and others I've seen are low HP very light duty. As mentioned, if you don't stray from Boat US waters and remain within cell range of help (probably 90+% on this Forum), don't worry, be happy with a well maintained single.