Tuesday, July 3, 2018

Aft mast boom modifications

To safely lift the dinghy onto the deck cradle required a modification of the boom (that I should have done when I thought of it while we were building the mast/boom parts). The boom is 12' long and does a nice job reaching over the side of the boat for a pick from the padeye at the end of the boom. Once the load is in the air, you need some alternative pick points closer to the mast to transfer the load inboard and onto the aft deck. While I was building the new dinghy cradle, I pulled the boom off the boat and added a length of  3/8 x 1.5" flat bar to the underside, stitched 50/50 to the boom, and drilled every 12" for a shackle.

This allows for multiple pick points along the length of the boom for transferring the load in and out using a pair of 6:1 tackles. The flat bar stiffens the boom considerable and as long as we don't go too crazy with the weight, it should hold up fine with the additional mid-span loading. So far it works great for moving the dinghy and motor around. If we needed to hang some serious weight from the middle of the boom, we would move the topping lift to directly above the pick-point we are using on the boom. I don't have any good pics of using the rig for lifting (was too busy keeping track of things the first time around) but I'll post some more detailed pictures of lifting and moving big heavy stuff with this rig at some point.

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