Trailer Transom Bunk Supports

[tboltmike]

I'm transitioning from rollers to bunks.

The trailer cross beam is a 3 inch tall channel with legs facing toward the front of the trailer. The 12 inch wide transom roller brackets were U-bolted to the cross beam.

I am planning on using 4x4's as the transom bunk, one either side of the keel. The simplist support would be the channels U-bolted to the cross beam with the bolted on angle tabs to screw into the bottom of the bunks.

Is this a good idea? Will they give good longitudinal support to resist the boat sliding on and off the trailer? The bunk span will be 16 inches, How many should be used?

The boat is a trihull with 12" wide keel and a vee shape up from there. The surfaces of the Vee are straight. The bunks will engage the Vee. The boat is 1100 lbs with a 390 lb engine.

Thanks, Mike

 

[LippCJ7]

Re: Trailer Transom Bunk Supports

ugh, I can't see it mike can you take pics? I think 4x4's are overkill but who knows.

Post some pics if you can, I just can't visualize the boat hull and what your trailer looks like

 

[tboltmike]

Re: Trailer Transom Bunk Supports



The bunks will replace the angled aft rollers and a piece will bridge between the angled bunks to support the flat keel.

 

[LippCJ7]

Re: Trailer Transom Bunk Supports

ok If I am reading this right you want to replace the rollers you have with 4x4's(I'm assuming you are planning on covering the 4x4's with marine carpet) and using the existing roller braces to mount the 4x4's? Your probably thinking that the 4x4's will make up the difference in height to extend passed the steel that mounts the rollers?

If it were me I would probably remove the vertical steel roller mounts that Ubolt to the trailer cross member and use these

http://www.iboats.com/Adjustable-Bo...39272661--session_id.205191360--view_id.40421

Then I would use 2x4 or 2x6, these bunk brackets allow you to swivel the bunk to meet the hull, you will also save weight and space, you could then add another bunk out side to hold your boat even more and make it almost a self centering trailer.

That trailer looks like a beast by the way!

 

[tboltmike]

Re: Trailer Transom Bunk Supports

Thanks for the input. I was curious if this type of bracket would give good load distribution to a 2x4.

Good "beast" or bad "beast"?? I like he catwalk.

 

[LippCJ7]

Re: Trailer Transom Bunk Supports

well thats why I say you can always add another 2x4 outboard of your first one on the keel which should make your trailer center the boat while loading, I'm not saying you need it but it would make it easier, I have seen heavier boats on much less.