Tansom extension (how to?)

I have a 1974 Cal Cruising 35 with a lot of modifications by previous owners. One of these includes a diesel generator shoe-horned into the aft port corner of the boat under the cockpit seat. While it fits the location perfectly, it is the worst place to concentrate that much weight. I would like to add a transom extension to help minimize the impact of this generator and give myself a better place to mount my propane bottles and fenders.

Not my boat, but a good picture of the stock stern profile:
Botany Bay


I have seen similar to what I want done on this same model, though their extension is a sugar-scoop while mine might not be. I have asked them about this and have not yet received a reply on how they went about building the extension:
Windfall

 

It will weigh more than the generator .

 

No it wont but as its all above the waterline its not going to help offset the weight of the generator,it just adds to it, get rid of the genset.
Steve.

 

Steve , it will way nothing, because it is out of the water . No it will weigh 200lb.

 

Exactly, the extension would need to be immersed enough to pick up enough bouyancy to offset its own weight as well as the generator to not be adding to the problem , i suppose you could make it weigh 200lbs if you tried but shouldnt be more than half that if built by a boatbuilder. Hanging up in the air like the one in the photos (which is the only way it can be) it would just aggravate the problem. I dont have any idea really what size generator were talking here but i would be very suprised if it was less than a well designed transom extension. That extension looks good btw, i would throw out the genset and do the extension, but then i hate those things.
Steve.

 

Hi,
Some friends of mine used to own Windfall and cruised Mexico for several years with their two kids before selling her and moving up to a bigger boat in January 2010. Tim and Mary did not do the transom extension. It was done by a prior owner. I have looked at the extension and it appeared to be a nicely done, professional job. There are storage lockers built into the extension. Underway the boat settles and the effective waterline goes almost to the end of the extension. I have observed this several times.
Boats out cruising tend to be stern heavy because it is so easy to cram stuff into the stern lockers and you hang your outboard, BBQ's, propane tanks. etc. off the stern pulpit. It just goes with the territory.
I have other friends with a Dickerson 41 who added a stern extension and just love it.
My Gulfstar 37 squats under power for a variety of reasons and one of my projects this fall is to add a transom extension. I'll let you know how it comes out.
Chuck

 

I plan to make my living while cruising as a mobile TIG welder, so the generator needs to stay. It's a NextGen, either the 3.5KW (160lbs) or 5.5KW (230lbs) model (will have to look at the literature but I believe it is the former.

Under way, when my transom submerges, the extension would only have to displace 3 cubic feet of water to carry itself, and its leverage of being aft of the generator should help to support that as well. Let's say 250lbs for the extension and some gear stored in it (2 10# propane tanks and my fenders) still only requires 4 cubic feet of displacement to support it.

Valid points all around though and food for thought. I'll take a closer look (and maybe some pictures) of the transom in action when I move the boat to a new anchorage this week.

 

That is an interesting costume , but each to his own .
Cant see how you get more buoyancy out of the extension, seeing as its out of the water .

 

Even if you do pick up some bouyancy when heeled it doesnt look like it would help while motoring, i can see why you need the genset now,i just have a bad attitude towards those things as i just cant see where you use them without being inconsiderate to others.
Steve.

 

If it was in the water it would increase water length and speed , it would also weigh nothing as it would be floating. Gens are important for the Air conditioning.