Re: Trailer for Caledonia Yawl
I've never had problems towing boats with up to 20% of total/tongue weight, as above this weight is **critical** to stability when towing at high speeds. And remember that you may end up towing far further in the future, possibly with the boat loaded with gear, so I wouldn't rely too much on the current weight and towing distance.
The wobbly rollers and standing rollers for guide-on can be critical, as getting the boat back on the trailer by yourself or even with another person in crosswinds and currents can be tricky. So think of the rollers and bunks as having two functions -- guiding the boat on and off the trailer, and supporting the boat when on the trailer. Keel rollers are nice for taking most of the weight, but bunks are good for holding it in place and additional support. If you've gotten an axle rated for a much heavier boat (quite common), you should plan on the trailer doing quite a bit of dancing about and leaping under tow when you hit rough spots or a big lorry passes you.
Speaking of getting the boat on and off, keep the whole rig as low to the ground as possible. With the UK's tidal changes, you may find that you launched in plenty of wet stuff, but have to get it back on in a fraction of that amount and depth. Build it solid and steady, but resist the temptation to raise it any higher than necessary. Ditto for the length -- handy when you carry the mast on the boat rather than the roof of the car, but it can be limiting when manuevering to launch or turning around in a narrow lane.
Here's a few photos of the trailer I modified. It was foolish of me to use a non-marine trailer and axle, and I've paid the price to replace it since, but overall it worked reasonably well structurally.
Last edited by Thorne; 02-14-2012 at 10:11 PM.
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Doctor Jacquin to Lieutenant D'Hubert, in Ridley Scott's first major film _The Duellists_.