T-Pain Is On A Boat: RE: [Electric Boats] Re: Newbie Question- Converting a 45' catamaran

Thursday, March 1, 2012

RE: [Electric Boats] Re: Newbie Question- Converting a 45' catamaran

Chris,

The guy who designs the Coral Coast catamarans in OZ has done this on his CC 27. I wrote to him a couple of years ago about it. The setup was pretty simple, just a tractor style U-joint and a strut close to the prop to lower the prop and shaft. He actually had a copper tube on the strut for the cooling water, and an electric pump to lift it to the engines raw water intake so no through hulls. I think a little better arrangement might be a keel cooler combined with one or two of the constant velocity joints. That way you could bed the motor on soft rubber mounts and kill some of the noise and vibration. Pro Boatbuilder had a good article about this maybe a year ago.

Jerry Barth

From: electricboats@yahoogroups.com [mailto:electricboats@yahoogroups.com] On Behalf Of chris Baker
Sent: Thursday, March 01, 2012 1:23 AM
To: electricboats@yahoogroups.com
Subject: Re: [Electric Boats] Re: Newbie Question- Converting a 45' catamaran

Andrew et al

I've now put up some photos in an album called Long Tail Cat, which is no doubt is some kind of rare and endangered feline not to be trifled with. But this album is really about a type of shaft drive reminiscent of the long-tail boats of Thailand. There's plenty of photos with details about how Owen Easton sets up his cats using this kind of shaft drive.

Cheers

Chris

On 29/02/2012, at 5:23 AM, And&Hanna wrote:

Hi Chris. I think this is an absolutely beautiful idea. I have been thinking along these lines for a long time. I desperately wanted diesel outboards for my catamaran, but could not find anything remotely suitable.

The advantages of this mid-bridgedeck long-tail arrangement are many: Compared to outboard motors, with this arrangement you get the economy of diesel, the battery charging capability of a full alternator, can put a big pushing propeller on the engine and put the propeller as deep in the water as you wish to have it. The central weight distribution is also better than the normal aft-engine arrangement. The regular marine gearbox that you use on the engine is a lot cheaper than the sail-drives that are normally used on catamarans.

And then you get most of the advantages of outboards - you can lift the prop out the water when you are sailing or at anchor, you can drop the engine off the boat for major work without having to pull the boat out the water (although with a cat you can beach it reasonably easily anyway - but still on conventional diesel installations prop and shaft work has to be done between tides) and there are fewer holes in the hulls - just need a through-hull if you wish to suck the cooling water up through the hulls. Unfortunately the layout of my bridgedeck and saloon was already done and did not allow for an easy conversion to this arrangement of engines. But glad to see that someone has actually done it this way.

Cheers

Andrew