Chain plate / bulkhead structure

[Tony Allport]

The boat is a 1969 Santana 37, it has seen better days but seems to benefit from the heavy layup typical of boats of that vintage. The chain plates have leaked where they penetrate the deck and the plywood bulkheads that they attach to are deteriorated in way of the tabbing that bonds the bulkheads to the hull. Three out of four bulkheads have been compromised. I typically consider this a serious failure but in this case there are also heavy diagonal cables tying the chain plates to the mast step. The mast step is a massive assembly of I-beams. My read on this structure is that the deck and bulkheads are acting more like spreaders in compression rather than anchoring points on the hull, and that the mast step is carrying the rigging load. This leaves me wondering if the dis-bonded bulkheads are less serious in this case.

Tony Allport