It's been a while since I posted, but that 's what happens in the summer. So many things to do, and I would rather be on the boat than writing about it. But, I did promise to explain the final davit layout, so here it is. Once the boat comes out of the water next week, I'll begin another round of posts, explaining the latest in the restoration.
The davits, as designed, worked extremely well, with one notable exception: in a following sea, or when coming off plane, the stern wave would lift the dinghy off the rails, and push it towards the stern. After watching this occur several times, two possible solutions came to mind. The first, which is what I usually see, is to simply change the strapping arrangement to provide for more downforce - crossing the straps under the dinghy, strapping in an "X" configuration, etc. However, these arrangements all put a lot of stress on the dinghy bottom and davits, and use strap tension to maintain the dinghy position. It works, but it's not good for the dinghy, and places a lot of stress on the strap mounting points.
The other solution was to re-shape or add to the existing davits, to provide a degree of restraint to the dinghy motion. This is the solution I used:
The curved plastic rails are 1" thick HDPE, carefully shaped to match the dinghy, and thru bolted to the davit rails. Now, the dinghy is well secured, and positively located, with very little strap tension. Also, I don't have to cross the straps, so it is very easy to load and unload the dinghy. I can launch in less than 2 minutes, and retrieve almost as quickly. It's done - next project.