Modifying T type dinghy trailer for SIB use - Page 2

chipko · 23 May 2022, 21:32

Overkill, yes. Your first pic with the bunks under the floor and adjacent tubes will be perfect for the cat hull. The tubes will come to no harm unsupported.

We keep our Elling on a launch trolley all season with the bunks in exactly the same position.

Steve509926 · 23 May 2022, 21:37

Don't think it's overkill, but wi the tubes be supported enough?
An alternative would be to have the bunks support the length directly under the tubes and have smaller secondary bunks under the transom.

Mattster · 23 May 2022, 21:39

Thanks Chipko, yes - inclined to agree. I'm just over thinking whilst I wait for the bits to arrive (and the time to fit them). Weight on the trailer is going to be nothing at all really - it wouldn't even be that much with the engine on, which it won't be. In fact I'm sure the seams along the tubes would get more of a beating during an average day on the water.

Mattster · 23 May 2022, 21:41

Quote:

Originally Posted by Steve509926

Don't think it's overkill, but wi the tubes be supported enough?
An alternative would be to have the bunks support the length directly under the tubes and have smaller secondary bunks under the transom.

I think if you get it exactly right (angles, heights) then it could provide support to the tubes - and would certainly "lock" the boat into position on the bunks. Then again just the horizontals would do that pretty well. I'll start with those, and additional bunks attached to the main ones would be a fairly easy, non destructive future mod if needed I guess.

TmMorris · 24 May 2022, 07:26

Personally, I'd ensure the bunks were supporting the inside of the tubes as opposed to putting any weight on the floor material.

chipko · 24 May 2022, 07:55

In all fairness the floor material is not being stressed at all. Directly above and in contact with the floor membrane is the high pressure floor which locks under the curve of the tubes.

If you want bunks to fully support the tubes you would need twin bunks positioned at twenty past and twenty to centrally under each tube.

Mattster · 24 May 2022, 08:01

Good point again Chipko!
Supporting the tubes directly is definitely a trickier proposition bunk wise - this is why I mentioned the possibility of transverse bunks in an earlier post. Either more or less a cradle arrangement as you describe, or perhaps a single bunk (each side) at an angle to meet the tubes on the inside - although perhaps this would bring its own issues of pushing out on the tubes etc. I think I will start with 2 x flat bunks under the floor and assess. Again, worth noting that there is very little weight involved here, and also bunks will be under transom and boat supported again at front.

Mattster · 13 June 2022, 16:11

Well all done, finally - took a bit longer than expected as most things do, mostly due to other commitments. Mudguard connection is a bit Heath Robinson but works. Fair to say there isn't that much left of the original trailer..

Boat sits well on the two bunks and, as Chipko said, once the floor is in the underside is solid as a rock so no real concerns there. Still need to cover the front support with something - didn't get enough carpet to do all three. So far, boat seems to be easy on/off solo, just lift and push until wheels hit the ground then becomes even easier. Boat cover from Ducksback is a near perfect fit (3.5m inflateable model) and definitely worth the outlay, which frankly isn't much more than a quality tarp. The heat reflecting properties seem excellent as well, with the boat more or less cool inside even when sitting in bright sun.

Now to get it wet - with any luck a quick session over the next few days now this persistent wind is finally dropping out..

Steve509926 · 13 June 2022, 16:20

Nice job, looks very neat.

chipko · 13 June 2022, 16:35

Looking like a proper catamaran trailer now.
Excellent work, very impressed.

Enjoy your maiden voyage.

topshelf · 30 June 2022, 13:57

Hi, So this is what I have done with my Bramber trailer, I did not want to alter the trailer by drilling holes or welding to it. Place a length of 4 inch timber on the base rail to support it falling off, bolted 2 brackets to the mudguard fixings, then made a cross beam and screwed it to the base piece . it is stable and just needs the end section moving out a touch. I have an electric welder and got the steel box section from a local steel supplier out of the damaged section 3m . used plates from toolstation and tacked it together until I got a fit then buzzed it up, hopefully photos will come with this post

Steve509926 · Yesterday, 12:45

Looks good, but are those mudguard fixings strong enough to take the extra weight?