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Three Chainplates

It was a straightforward rerig, involving new wires, some assorted deck hardware, and the installation of new chainplates. The latter job was handled by the owners, who were hoping to save some money on this labor-intensive job. And of course we said "fine", as we commonly share the work with owners. It can make sense for the non-skill-intensive work, so the client doesn't have to spend as much money, and we are freed up to work on more complex and interesting details.

Of course, "skill" is a relative term, and we make a practice of checking the client's work as it goes along, just to be sure; after all, it will be our name on the finished job, no matter who actually did what.

In this case we weren't noticeably involved, because how hard could it be? These chainplates were held to the hull by one bolt each, and those bolts were down inside the cabin, where all of them were fairly accessible. Well, all but one, which required just a bit of yacht yoga to get at, including sticking your head into a little hole and craning around sideways to see the connection. Oh, and two of the chainplates also had little bolts to secure them against some plywood paneling. These weren't load bearing, just tidying fasteners.

So the chainplates are in and bedded, the mast is stepped, and it's time to tune. We're almost done, just coming up on the upper shrouds, and I'm thinking that they're not getting tight as fast as I would expect, and on the edge of wondering if somehow something is wrong, when one of the owners comes leaping, positively leaping up from below, and says, "Brion, we are totally screwed." At almost the same moment Sean, our senior apprentice says "Uh-oh", in a quiet, bleak, our-wings-just-fell-off tone of voice that commands immediate attention, and I turn to look at what he's looking at, which is the sight of the starboard upper/intermediate chainplate creeping up through the deck. This, in technical parlance, is what is known as a Very Bad Thing.

I run below, getting there in time to see the lower part of that same chainplate pop upwards an extra inch or so, tearing a gouge in that plywood panel as it does so. The lower throughbolt, the structural one, is not connected after all. Up on deck, thank God, my crew is slacking the uppers and intermediates as fast as they can.

A little aside of advice: should you ever find yourself in this situation, the first thing to do is to loosen all the wires. Yes, I know that the problem presenting itself is a loose wire or wires, but everything else in the rig is still tight, except for the mates to the now-chainplateless pieces. Those mates are going slack, too, but only because they are now unopposed, and are pulling the mast wa-a-ay out of column, leaving all the other wires to conduct a large-scale exercise in mast distortion. Wonderfully elegant force resolution vectors. Surprising, delightful shapes. But only if you are a mathematician.

As I write, that boat lies just a few yards outside the window, the rig intact, beautifully tuned, the owners as delighted by its improved performance as they were chagrined by their oversight. It turns out that it was just too awkward to look into the little space by the chainplate, so instead of looking at the connection they just felt the way, and by golly it sure felt connected.

All's well that ends well, but in the middle of the emergency, as everything slowed down and expanded the way things do in emergencies, I thought to myself, "0h, not again," and remembered how years before we had just stepped a mast on a boat that the owners had also installed the chainplates for. We had shown them how to bed and fasten the chainplates, then gone on about our business. When the mast went in, we hooked up just the four lower shrouds, because the uppers, jibstay, and backstay were to be cut to length and terminated in place; the lowers had a generous fore-and-aft spread to them, and provided ample temporary staying for the mast. Or would have if there had been any bolts in the port forward lower. But there weren't, so some time after the crane came off, I looked forward, saw that chainplate crawling out of the deck, saw the mast (it was deck-stepped, of course) start an inexorable-looking tip aft and to starboard, and heard that same unhappy "uh-oh" coming out of my own mouth. With a promptness and efficiency that startles me to this day, I somehow got hold of a halyard as I ran forward, and nearly launched myself off the port forward quarter as I sought to arrest the mast's fall. It actually worked, and the crew, owners, and I were able to secure a couple of other lines up there for insurance. This time it turns out that the owners had simply forgotten to put in the throughbolts. Much apologizing, much ebbing of adrenaline flow, and all turning out well in the end.

You would think I would learn. Well, maybe I do, but not as fast or as thoroughly as I would like. After the first unbolted incident, I never settled for just the lowers as temporary stays, and I shudder when I see boats with minimal temporary rigs. It is, for example, necessary to detach the backstay or forestay in order for boats to fit into many Travellifts. When we do this, it is always with extreme caution, because rigs hardly ever fall down at this point, but it can and does happen. So we always double-check all remaining attachment points, and sometimes lead halyards and such to points that will provide some staying, yet clear the lift, even though it means putting up with the snickers from our local colorful lift operators.We are just as cautious with keel-stepped rigs as with deck-stepped; sure, most keel-stepped masts will probably stand up with no standing rigging at all attached, but they can be damaged, even without the help of the odd passing wake. Every once in a while we get confirmation that our precautions are a good idea: just a few months ago, a mast in a local yard went down because the temporary stays were a little too temporary.

Boat U.S. research, as I never tire of telling my survey clients, shows that fully 1/3 of all dismastings are directly related to chainplate failure, and that's not even counting problems with bulkheads, hulls, or railings.

But it seems that I still have a childlike faith in chainplates. They're so solid, so primally connected. I still feel a little bit, well, almost betrayed when I find one that is dying from crevice corrosion or fatigue. I want to trust them. More than that, I assume that everyone feels the same way, so they will be obsessive about preventing deck leaks, drilling attachment holes true, using the right bolts, angling for a fair lead, etc., and certainly that they will at least manage to attach them to the hull.

A few weeks ago we did a rig survey, on a boat that has a two-part chainplate configuration: the upper portion is the deck piece, with holes for the turnbuckle clevis pins. This is inserted into the deck, and throughbolted there. These throughbolts are not meant to take sailing loads, just to locate the piece securely in the deck. A second piece, the load-bearing part, is threaded up into the deck piece from inside the boat. This second piece is a tie rod, with its own built-in turnbuckle. The tie rod is anchored to a strong point on the hull. It's a clever arrangement, which allows for a relatively easy install, and can accommodate different hull shapes and sizes. On this boat, only two shrouds come to deck per side, and both of them go to a single chainplate per side.

One of the things we noted on the survey was that, even with the mast out, those tie rods were tighter than necessary, so they received a needlessly high total load when the rig load was added to their own. A minor point, but one I thought was worth making. The owner promised to slack them a bit, just a bit, and I went on my way.

Some time later the owner asked us to do some work on the boat, including work aloft. Our then-newest apprentice took her first trip up a mast for us that day, to do the work. All went well. The next day, the owner calls up and says, "Have you done that masthead job yet?"
"All taken care of," I reply.
"Oh. Well I meant to tell you sooner, but I actually disconnected the starboard tie rod."
"....."
"Hello?"
"....."
"Brion, are you there?"
"You what?"
"Yeah, um, I just thought I'd clean it up some. Finished the port one and put it back in, but it was getting late before I could finish the other."

I paused again, thought of Elize up there at the top of a 40-some-foot mast, her life depending on those relatively flimsy deck bolts. Then I looked out the window and saw that the wind was gusting over 30, from the unconnected tie rod side. "Talk to you later," I said, hung up, and raced to the boat. I feared - knew - that I would find the mast lying on the ground, a hole in the deck where that chainplate used to be. Simultaneously, I was castigating myself for not checking those tie rods, even though another part of me knew that no one could have anticipated this level of goof. I got to the boat, where the mast was still standing, hooked up the damn tie rod, and went back to the shop.

I still trust chainplates, but now I like to think that I don't trust them too much. They are now the first thing we check when we do a rig survey, and they used to be the last. Done right, they are an especially stout, reliable, fabulously strong rig component. But what these three chainplates have shown me is that they are also about people, good old fallible people. The things we count on most are the things that count on us the most.

Fair leads,
Brion Toss