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Entending trailer bunks

PostPosted: Thu Apr 23, 2009 8:49 am
by rjbachmann
I am currently restoring my 1965 18' Thompson by Chris Craft. In the process, I am also re-working the trailer bunks. I am planning on extending them to the transom, but have a concern about the unsupported portion of the bunk. There will be approximately 23" of bunk past the last bracket. Is this a reasonable concern? If so, I would appreciate the collective expert advice on how to support the bunk.

Thanks in advance

PostPosted: Fri Apr 24, 2009 6:46 pm
by txcaptdan
You should have trailer bunks that extend past transom so that transom is always supported. Keel can rest on rollers but transoms should always have a base support.

PostPosted: Sat Apr 25, 2009 3:53 pm
by John Hart
Does your boat extend 2 feet past that last trailer cross member?.... Can you add brackets to what you have already...

My transom is about flush with the last trailer member.. I added a bunch of extra brackets to support additional bunks..



PostPosted: Sat Apr 25, 2009 7:29 pm
by rjbachmann
Yes, the boat extends about 23" beyond the last vertical bunk bracket. So I extended the bunk the same distance, so all of the transom would be supported. However that last 23" (of bunk ) is not supported. I thought about a diagonal support from the end of the trailer to the end of the bunk. Do you think this last 23" needs to have a support under it?

PostPosted: Sun Apr 26, 2009 7:04 am
by Phill Blank

Yes you need to gat some type of structural support for the 23" beyond the last support. The ransom is carrying the weight of the motor and if the last 23" are not supports somehow in time the bunk, unless it is made of steel "C" channel or has a steel "L" angle that will support the boat and mottor weight backing it up, will tend to bow downward due to the weight and the hull can hog.

Look at the way the supports are on John trailer above and work out something like you see there.

Good Luck,