The case of the missing chainplate
The importance of chain plates cannot be over emphasized, because when they
fail, disaster is eminent.
Many sail boats have accessible chain plates which are easy to inspect. Some,
especially older models, 60,s and 70,s vintage, have port and starboard chain
plates which are secured to plywood which is laminated and then secured to the
structure. Many companies used plywood which is sandwiched between layers of
woven roving and secured to the hull with woven roving. This technology would
be great if, over time, water did not leak through the deck penetration and
saturate the plywood. Once the plywood is wet, rot begins to set in, and it does
not take long before the chain plate supporting plywood is rotted away
completely. In order to check these types of secured chain plate supports they
must be sounded and in some cases core sampled. Also, the securing bolts may
be loose if the wood has rotted away.
Another situation that is rare but serious, I will call the “Case of The Missing Chain
Plate”.
All boat owners are not created equal, as interior decorating to some owners may
be more important to those darn things that stick out over there, (chain plate
supports).
I received a call one day from a judge who was having trouble collecting a
settlement from his insurance company after a dis-masting during his first race. I
arrived at the vessel with the judge and was informed that the judge had been
working on the vessel for the past year and had made serious modifications to
the interior so that it was very comfortable, and just a great live aboard and
summer home. The judge explained how the dis-masting occurred during his first
race while he was on a broad reach with winds about 25 knots. He then
explained how his crew brought to his attention that the deck, amidships, right
along the starboard side was beginning to lift, a couple of inches at first and then
a foot during the next minute or so. As luck would have it he said “a slight gust
came along” and off went the mast to port. The mast was keel stepped and broke
off clean at the deck and departed to the water with all attached gear and sails.
Luckily no one was injured and the vessel was towed back to port.
The good judge’s racing career was temporarily put on hold. How was this
possible on such a large, well designed, contemporary sloop? The good judge
hired a crew to remodel the main salon in order to make it more spacious. The
crew, he thought, was great as they had done a wonderful job on his new kitchen
at home. As you might expect the crew had no knowledge of vessel maintenance
or structures and simply removed anything they could to make the main salon
more spacious. They removed the chain plates, modified them and re-secured
them to the underside of the deck. A new head liner was installed and everything
looked great to the judge when the crew departed.
The bottom line is the insurance company declined to pay the claim because of
the modifications which were made to the chain plate supports caused the vessel
to be unsafe. As removing chain plate supports because there were in the way is
not acceptable. In my sailing experience, I have observed more than a few dis-
masted older Pearson’s and Bristols towing their standing rigging back to port
and those were the lucky ones. A dis-masting under the right conditions can be
fatal to the vessel and its crew. Typically the bow and stern plates are visible as
they are usually bolted right to the hull in plain sight and any defect should be
obvious. Over the years I have observed vessel owners tuning their rigging in
preparation for a race. In one case the owner said to me, “this stay was tight a
few minutes ago, I tightened it just a little more to be safe, and now it’s loose”. A
few minutes later he and his crew sailed off for the Wednesday night club race.
This owner had tightened the rigging to the point of collapse, and he actually
separated the plywood mounted chain plate from the hull. I could not believe he
was sailing away. Fortunately there was very little wind for the race that night and
he made it back to the dock still unaware of what might have happened.