Monday, August 25, 2014

Should have paid better attention

Should have paid better attention in those engineering classes. Doh! The more I work on this whole 'rolling the boat over' challenge the more I realize I know absolutely nothing about what I'm doing. Trying to wrap my head around the forces that'll be applied to the whole structure and how to design/build it to meet those demands is a bit of a noodle bender.

So I've increased the size of the longitudinal beams (for lack of a better term) that'll I'll actually be tugging on to 2X6's. Screwed & bolted to the lifting frames.
Three of the four corners will have force applied to them at some point in the whole procedure so they'll all be built the same.
1/2' plywood backers on both sides of the beam. U-bolt is 1/2" 316 Stainless Steel with a SWL of over 17,000 lbs.
And on the other side. This is the beam that'll actually do most of the lifting.
I did a test pull with the electric winch just to take a strain on it so I could see how it would react. I noticed a lot of twisting in the 2X6 so I used the ratchet strap to connect it to the beam on the other side of the boat.
I need this beam to lift without twisting. Once I tightened up the ratchet strap it was fine. Originally I was thinking of diagonal bracing from the center of this beam to the rolling frames but the hull sticks out too far. I don't have a Plan B yet if this won't work.
The other side will definitely get some diagonal braces to help keep this beam from bending. It'll have a lot of force applied to it during the whole turning process. This beam will also be the primary point of lift on the second pull to bring the hull upright.

I'll have to climb up on top of the boat day after tomorrow and rig the third beam. Tomorrow is the run to Princess Auto and their 'End of Summer Sale'!  :-)