Trailer support - Bunks vs Cradles

[Carl Simmons]

I just noticed that most Trailers used for carrying Lightnings use two cradles (chine to chine). The new Shorland'r trailer I picked up uses bunks that support the boat lengthwise. It seems to me that cradles could fall in between frames and overtime deform the hull. Bunks that run lengthwise would fall under several frames. So what gives why are most trailers using cradles vs lengthwise bunks? What am I missing? Is there a long term problem using either?

Carl.

[imported_Sean]

I can't see why anyone would'nt use bunks in this situation. I should think they would work on most boats under a ton or so and like you say, they should distribute load better.

[shadow99]

I had a trailer with the cradle set-up, I found that it's only advantage was when winching the boat back onto the trailer, it provided a means of self-centering the boat, within the confines of the 3 cradles. The disadvantage is after long periods of storage on the trailer, I noticed the planks puckering in certain areas. The cradles were not in line with the main bulkheads and caused the planks to colapse in.
After fixing the boat, I removed the cradles in favor of 3 lengthwise bunkers. 1st pair at the garboards, 2nd at the chine, and 3rd as sideboards. This gives 100% support to the boat on the trailer, and still makes it easy to winch the boat onto the trailer on windy days.

Rick

[Wayne Jeffers]

Either way, it seems to me the first priority should be to ensure that the cradles or bunks 1) hit frames or stringers, not weak spots in the bottom of the boat, 2) are wide enough so as to avoid concentrating the weight too much on a small area, and 3) conform to the shape of the hull.

For my plywood skiff, I used wide bunks set near the chines. Bending them to the curve of the rocker was a pain, but they've worked well.

My Comet came with a trailer fitted with 2 cradles cut from 2 X 6 on edge and lightly padded. With the close frame spacing and 5/8" planking, I've seen no sign that they caused any deformity in the hull.

I think proper placement and support are the real concerns, not the choice of bunks or cradles.

Wayne