Legend 35.5 - Crack under compression post

[Terry Cox]

If it were my boat, I would hire a certified marine surveyor to determine how serious of an issue, potential repair options, etc. Depending upon their findings and recommendations, I might defer the repair to a qualified FRP shop.

 

[Jan_H]

You're getting some good suggestions Wilburleft. A plate (SS or Al) over the top will do little to help, although an inverted channel section is heading in the right direction. Based on how the crack has run, it looks like the cross beam is an inverted U section with a step in the sides to support the floor. The highest bending stress in this configuration will occur along the lower edge of the sides, which is unfortunately where the hole is. Reinforcing the lower edges of the channel would be the preferred solution.
If there are no signs of deck depression under the mast step, then the easiest solution may be to slacken off the standing rigging (or unstep the mast), reroute the split loom wiring underneath the cross beam, and reinforce the lower sides of the cross beam 10cm or so either side of the hole with say 6mm thick woven cloth and epoxy. A relatively easy repair, and if it fractures, then it's time for some more serious engineering analysis.
Jan

 

[wilburleft]

Thanks for the advice Jan_H. I started having doubts about the steel plate option this afternoon for various reasons. Repairing and strengthening the original design, as you suggested, is probably the best course. I will look at rerouting possibilities for the wiring that runs through the hole. Also plan to consult with and engage a marine fiberglass repair person.