My Oday 272LE recently experienced a fairly catastrophic failure of the chain plate attachment to the bulkhead. Fortunately the failure occurred at the dock after a rigging tune-up in which I obviously overtightened the shrouds beyond their capacity. The root cause of the failure was probably three-fold: 1) Poor design. As many of you know, the chain plates bolt to the marine plywood bulkhead (that is in turn attached to the hull) via a hardwood "spacer block" about 2 1/2" thick. It is located fairly close to the top edge of the bulkhead (too close in my opinion). The tension on the chain plates doesn't result in a pure "pull" force being transferred to the bulkhead; because of the offset, the spacer acts as a lever and also applies a torquing force to the plywood. The result was that it simply ripped a square chunk out of the bulkhead near the top! 2) Poor maintenance. I failed to pay attention to bedding around the chain plates. Water had seeped in and partially rotted the top of the bulkhead. 3)AS stated above, I probably overtightened the shrouds. Fortunately, the spacer block just stopped when it pulled up tight against the underside of the deck and the mast stayed upright. My questions to you all are: 1) What is the proper inner and outer shroud tension for the 272LE? I have access to a fairly good rigging tension guage. 2) Has anyone out there had to repair a failure of this kind? My typical response is to (hopefully) over-engineer the repair so it never happens again. Currently I plan to put fairly large SS backing plates on both sides of the bulkhead and replace the wooden chain plate spacer with a longer aluminum one that will spread the torquing force over a much larger area. I'll also through-bolt the backing plates to the fiberglass hull tie-ins and the bulkhead at numerous points. Is this total overkill? Does anyone have a simpler idea that would effect a sound repair?
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It definitely is not the most intelligent move ...
to run a block out from the bulkhead and then attach the chain plate to it, like they did in the 272 ... but on the other hand it did keep the chain plate from blowing out of the deck. I had a spot of rot under the block outside the closet of the john. I added a 15x10+ in. backing board of 5/8 marine plywood flush up against the rugged bottom of the deck inside the closet (used 5200 as glue), and put longer bolts holding the block to the bulkhead. This was five years ago. Last year when Charlie came up the Gordon River, I thought for sure they were going to fail. Someone in the condo next to the dock took pictures of Seven hobby horsing in very short 4-5 ft waves and 70 mph wind. This was right near Tin City for you Naples knowledgeable people. The action was strong enough to bend the windex through whiplash effect, but the repair was solid as a rock. There seems to be no really definitive tension for the 272. And actually I think the manual said that the leaward inner stays are actually supposed to be pretty loose in a decent wind. As long as the mast isn't bending out of shape. This is no J24. Actually, I had no damage to Seven from Charlie even though the dock broke up and Seven sat there only with my bow line attached to the center pier. The 30 ft. piece of T dock was nicely attached to my boat but completely broken off the center pier. I didn't really have too great an opinion of the 272 before that. But have changed my mind for the lightweight 272. Vic "Seven"
to run a block out from the bulkhead and then attach the chain plate to it, like they did in the 272 ... but on the other hand it did keep the chain plate from blowing out of the deck. I had a spot of rot under the block outside the closet of the john. I added a 15x10+ in. backing board of 5/8 marine plywood flush up against the rugged bottom of the deck inside the closet (used 5200 as glue), and put longer bolts holding the block to the bulkhead. This was five years ago. Last year when Charlie came up the Gordon River, I thought for sure they were going to fail. Someone in the condo next to the dock took pictures of Seven hobby horsing in very short 4-5 ft waves and 70 mph wind. This was right near Tin City for you Naples knowledgeable people. The action was strong enough to bend the windex through whiplash effect, but the repair was solid as a rock. There seems to be no really definitive tension for the 272. And actually I think the manual said that the leaward inner stays are actually supposed to be pretty loose in a decent wind. As long as the mast isn't bending out of shape. This is no J24. Actually, I had no damage to Seven from Charlie even though the dock broke up and Seven sat there only with my bow line attached to the center pier. The 30 ft. piece of T dock was nicely attached to my boat but completely broken off the center pier. I didn't really have too great an opinion of the 272 before that. But have changed my mind for the lightweight 272. Vic "Seven"
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