Move compression post on O'Day 23

[ClintonLakeSailor]

Hi all,

The port bulkhead was rotten from a leaking chainplate in the 23 that I purchased last year. I have removed the bulkhead, as well as the toilet. I likely won't replace the toilet, and am wondering if it is structurally sound to add a 4×4 horizontally under the mast and support the edges with two compression posts. This would allow me to increase the opening to the bow. My concern is that the mast will flex the 4×4, but it would not be a long run, basically just having the port bulkhead match the starboard. Other concerns are the support under the floor. Thoughts?

 

[agprice22]

I doubt there is good support in the floor pan for you to redistribute the compression forces closer to the sides and away from the keel. The compression post stands below the mast and above the keel. This directs forces down the center of the boat and into the keel. Additionally, that 4x4 could eventually sag, and your deck will crack, leak, and cause you lots of headaches. It will be too late when you see the cracks.
I would not do this.

 

[ClintonLakeSailor]

I know you are right, so I will stick with the original bulkhead design. Thanks for the advice.

 

[Ted]

If you properly size the structural members, this shouldn't be a problem. You can do what you originally described with a beam under the mast step with two columns carrying the load to another beam at the cabin sole level. The lower beam can be set to carry the mast and rig loads to the same place as the original design did. Then there would be no worries about placing loads in areas where they weren't designed to be. You can increase the strength of the 4"x4" beam by bolting stainless steel plates to the side of it. Or you could use two 2"x4"'s wood members with the plate sandwiched/through bolted between them. The only downside to this arrangement is that you'll have a beam at the floor which will most likely be elevated above the cabin sole. Basically you are redirecting the vertical loads to the columns and then back to the center of the boat by means of the lower beam where the load of the original compression post was located.