I originally wanted to call this section "Pieces of
string too short to save", after the punch line of
a Maine story about a
notable packrat, who had a box in his attic with
that label on it. The
idea is that you don't throw things away just
because there's no apparent
use for them. In this context, there are a whole
bunch of items that we
don't sell, and ideas that aren't in any of our
books or tapes, and even
things that have nothing to do with rigging at all,
but are too nifty or
unusual or odd to ignore.Back to Fairleads Index |
February 1999 |
One of the most often-asked questions we
get here - besides
"Can you have it by Tuesday?" - is, "How often should I
replace my standing
rigging?" This is a very important question, touching as
it does on matters
of both safety and expense, and it is my humble opinion
that typical
responses to this question, from ostensibly knowledgeable
experts, are so much
hooey. For instance, there's the "Oh, don't worry, it'll outlive you" response. Or the "Every six (or seven, or whatever) years" response. Or the "As soon as it shows broken yarns" response. None of these addresses the problem in a remotely complete or logical manner, and any of them can result in either needless rig replacement or avoidable rig failure. But all of them have the compelling advantage of being short, and requiring minimal thought on the rig owner's part. But the truth is that there is no simple answer, and that if you want to know when it is time to replace that gang, you must open a small can of variables. For starters, how old is the wire? This question is obvious, but meaningless by itself. Just find out and keep it in mind. If you don't know how old the wire is , then ask, what is the oldest it could be? Best to err on the old side. Next, where has this boat been? Up here in the Northwest, it is common to find rigs 15 or more years old that are in good shape. But it is relatively cool up here, so corrosion isn't so intense as it is further South. Bear in mind that the speed of a chemical reaction doubles for about every 20 F of temperature rise. And wire corrosion is always at least in part a chemical reaction. Next, how much has the boat been sailed, and in what conditions? That is, are we dealing with a daysailer from Seattle, a cruiser going around the world the hard way, or a party boat in Rhode Island, that only leaves its slip to pump the holding tanks? Next, has this boat been kept well-tuned? Even a lightly-sailed vessel will wear its rig out in a hurry if the wires are way tight or way slack. Next, who made that wire, and of what alloy? Market pressures seem to have brought the worst manufacturers up to speed in recent years, so you don't often see yarns breaking as the wire comes off the spool any more. But there is still a great range of quality out there. For years, I plugged U.S. wire made by almost anybody, as it consistently outperformed imports. And much of it is still good. But lately I've seen wire from previously trustworthy makers that had proud yarns or poorly cleaned yarns, bad enough I've had to return whole spools. The best wire I can find at the moment is a brand from, of all places, Korea, source of some of the worst wire in the world as well. The point here is that you have to know the quality of the wire as part of your rig longevity calculations. Next, is this the right wire for the boat it's on? Wire that is too small for the job will wear out exponentially faster than the right stuff, while wire that is too big for the job will be likely to wear out everything else - just getting the slack out of it imposes intense loads on tangs, mast, chainplates, and hull. So figuring wire life is in part a design question. Which brings us to the final consideration: How good are the terminals? The other day I surveyed a gang that had beautiful type 316 wire, stuffed into cheap alloy, banana-shaped swages. This is like asking Michael Jordan to play in plastic huaraches, except of course that he could still beat anyone else on the planet. But this wire, through no fault of its own, had to be replaced, because the swages were corroded and cracked. Given all those considerations, take a good, jaundiced look at the rig on your own boat and ask yourself how confident you feel about it. Bear in mind that stainless gives much subtler physical indications of failure than galvanized, so this "intellectual survey" that you are conducting is at least as important as a physical one. Visualize a steadily declining factor of safety, with the chances of component failure increasing with the passage of time. Imagine your embarrassment if your mast ends up on deck. Whatever works. It may sound as though I'm trying to induce paranoia, and maybe I am, but in a worthy cause; rigging is invisible to most people, a system whose principles are somewhat alien, and therefore to be ignored. Many times over the years I've told people that, based on the above factors, they needed new wire, only to be met with some variation of the response that, "It hasn't broken yet, so why replace it?" These same people will religiously change their engine oil after a given number of running hours, even if the engine hasn't actually seized up yet. And they'll replace substandard wiring, even though it hasn't actually burned their boat to the waterline yet, because why take chances? But rigging, that's different, maybe because it's so nice and shiny. Do I sound bitter? To get back to the original question, let's go through a sample scenario. The standing rigging aboard the "Christian Radish" is 8 years old. The vessel has spent its entire life in Puget Sound, mostly tied up to a dock, but with several trips to Alaska, and one to Hawaii. The wire is a good grade of type 302 stainless, with Sta-loks all around. Good tune its whole life, and appropriate size. The owners are contemplating a prolonged South Pacific sojourn. Should they replace the wire? Well, right up to that last detail, the answer would probably have been "no". But a warm climate is going to kill that already-somewhat-used wire in a hurry, and replacing it in some island paradise might cost more, just for shipping and duty, than the entire job would here. So at the very least I'd urge taking new wire along, with a plan to fabricate a new gang before the old one was dangerous say 2 years at the most. And in addition, I'd take apart a few of those Sta-loks for inspection. These are my favorite mechanical terminals, but they can be put together, let us say, creatively. The wires might be badly-formed inside them resulting in weakening and fatigue, or there may be insufficient goo to keep water out leading to corrosion of both the wire and the terminal, or the threads may be galled, so the terminal is welded together. Any of these problems will render the terminal useless for new wire, and compromise safety meanwhile. Every boat will have a different story, and thus a different answer to the question. If the same boat had been sailed exclusively in fresh water, especially North, it would only have suffered mild fatigue, and possibly only negligible corrosion. Or it might have spent those same 8 years in St. Thomas, out often, sailed hard, and just about to break. Variables. With all that said, it is very easy to have a solid reliable rig, with a known, ample safety factor, the kind of gang that will let you sleep nights, and whose every component can be inspected by you, and replaced when the time comes. Next month: Things that can go wrong, Part One. Fair leads, Brion Toss
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