Dock walk:  rigging fails

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We’re rarely in marinas, but in South Africa’s harbors tying up is the norm. Jamie and I have fun walking the docks, checking out other boats; I always have something to learn from the critical eye of my sailmaker/rigging-savvy husband. Most often, it’s the condition of sails; on a blustery day in Durban, rigging mishaps were the theme.

-stanchion bent-lifelines stretchedThe first one that stood out was just across the dock from Totem. It’s a perfect example of why sailors shouldn’t be tempted to tie fenders to the lifelines, although many persist in the habit or don’t seem to know it’s a bad one. Toe rails are much stronger and often have a convenient opening to tie into. What’s the problem:?  Tying to lifelines sets up a couple of problems, as seen here. When a fender gets pinned to the dock when the boat rolls, it puts tremendous force onto the lifeline. This can break the fender, but that’s the least of the problem. It weakens lifelines (work hardening the stainless steel) and can eventually break them, and bend the stanchion.

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classic “banana” swage

Here’s a swage to wire stay that’s “banana-ed.” The swage is poorly executed, and bent into a curved, banana-like shape. Because the swage isn’t straight, under load it tries to pull straight, and this work hardens both the swage fitting and the wire—shortening their lifespan.

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What’s wrong with these chainplates? The original, longer part (painted white alongside the hull) was cut off; the stainless part of the chainplate is the current load-bearing portion. But that’s just ONE BOLT carrying the entire load, tying it to the old chainplate… way too prone to failure.

DSC_1254Whoops…someone didn’t measure the rig very well! See that big gap inside the left-hand turnbuckle? It shows that the wire is barely long enough to screw it on. Oh, and up by the arrow, if you look closely… the top threaded stud is missing a cotter pin. Yikes!

Moving right to that middle turnbuckle, now the wire is clearly way too long. There’s no wiggle room to make any adjustment to tighten it further if needed.

You might get away with this if the rig is perfectly tuned. It was plain from a scan that the rig was not well tuned, and now there are limitations to what can be done because the wires are either too long or too short. Hopefully the owner didn’t pay too much for such sloppy rigging work.

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This sprit is bent, suggesting it’s under spec’d and not strong enough for the load it has to bear. Code Zeroes and other asymmetric sails that would attach to sprits like this can generate huge loads, especially shock loads, when sailing in a good breeze and/or lumpy seas.

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Hello, weak link: this sprit has a big eye on it, and then this dinky little shackle. The extension is fine, with square structure inside the relatively thin-walled round tube lending strength. The wee little shackle, however…

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No problems here! Jamie liked this sprit, which serves the same task as the one above. Jamie recommends that his customers buying an asymmetric / code zero / screecher install something similar to this; a number of companies make good, after-market sprits like this. They’re often not beautiful, but they’re very practical and simplify working with downwind sails.

We’ll leave you with that hallmark of developing countries: the good-ol bent rebar anchor.

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This post is syndicated on Sailfeed.

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11 Responses to Dock walk:  rigging fails

  1. Kevin (SailFarLiveFree) January 6, 2016 at 5:08 pm #

    And the original chainplates shouldn’t be painted either, right? Wouldn’t paint just trap moisture and increase the odds of corrosion on this all-important component of the rig?

    • Behan January 6, 2016 at 5:27 pm #

      That does seem to compound things doesn’t it? It’s possible to paint it right (acid etching, the right paint… not an expert here… fwiw, this is a steel boat), but yeah, that introduces other potential issues. Well spotted. 🙂

  2. Jason Hudson January 6, 2016 at 7:22 pm #

    Everything well spotted! Fun and scary!
    I’m gonna chime in on a couple things.
    The block on the sprit . Most manufacturers size the shackle to the breaking load of the block so the block is the weak link. The second shackle seems to be the same pin size as the block one so all good there. The question is whether the block is sized for the load. Also, upon zooming in I noticed that that block is cracked and should be replaced regardless of the classic full strap.
    Missing cotter pins (in turnbuckles only!) Are not that scary when you see what it takes for those to turn by themselves. I would only seriously worry if both the sage stud had no cotter pin and the upper fitting was a stem ball. This could potentially spin free even under load.
    Is that boat with the cut chain plates ferro cement?
    Cheers!

    • Jamie Gifford January 7, 2016 at 7:08 am #

      Hey Jason – regarding the weak link shackle. You’re right on paper, however practical experience tells me otherwise. Block and shackle strengths match when both are new, but shackles flex / hard-harden / fail (feature of stainless steel) or suffer crevice corrosion / fail (because SS on SS scrapes away its natural protective layer) or wears thin / fail much faster than issues that cause the block to fail. In 8 years on Totem we’ve had 1 block fail (Harkan high strength snatch block – shock load); and at least 8 shackles or similar stainless attachments fail – and in 40+ years racing/cruising I come up with roughly similar ratio. Better to use Dyneema, upsized strops/soft shackles. You’re right to questions the block size as well. Nice catch on spotting the crack, I missed it.

      As to the missing pin – again your right that it isn’t likely to spin out, but the rig was poorly tuned due to a bad rig job – Sailing in South Africa is challenging enough, why tempt fate over a $1 cotter pin?

      Chainplate boat was steel.

      The challenge with rigging is finding subtle clues of wear and weakness before failure. Some part of this is impossible, because you cannot inspect every surface (barring expensive testing). Much is possible, but takes a really keen eye. And a surprising amount is easy to spot with just a little knowledge.

      Last bit – I did a rig inspection on a big boat in Seychelles. It rushed and they had furling sails so could only go up on the spin halyard. I don’t normally do this, but… Anyway, I got to the top and the first thin I found was a hairline fracture in the spin halyard block shackle – I had a safety strop to the mast, but nearly had to change my shorts!

  3. Joe January 7, 2016 at 2:02 am #

    Curious? Did you pass on your gems of observations to the respective yacht owner and were they well received?

    • Behan January 7, 2016 at 5:44 am #

      None of the owners were around to share them with.

  4. Ken Newell January 8, 2016 at 12:18 am #

    Met one of your followers her in Galle named Ann Millen. We spent a nice lunch at their incredible colonial home that they have refurbed.

    Leaving for GOA in a day or two….see ya on the other side?

    Cheers,

    Ken

    • Behan January 8, 2016 at 6:18 am #

      Very cool, Ken! Ann has a WEALTH of experiences to share… lucky you go get to visit with her in Sri Lanka, missed during our stay.

      • Ken Newell January 8, 2016 at 8:32 am #

        Small world…turns out she is best friends with the mother of my crew. They all know each other from days in Dubai.

  5. Gene April 30, 2016 at 5:20 pm #

    Regarding the chainplate, without meaning to endorse the workmanship, technically the single bolt holding the two pieces together is no more a weaker link than the clevis pin above it, etc. The purpose of multiple bolts in a chain plate is to transfer the load to a weaker material hull such as wood, fiberglass, etc., which this still does.

    Likewise, painting the chainplates will certainly deny the stainless the oxygen needed to remain stainless and not rust, but that is already occurring on the backside which is bolted to the hull. Remove any stainless chainplate older than about ten years, and you probably won’t like what you find. Better to go back to bronze chainplates. No corrosion, lasts forever. That’s what I did. (Make them a little thicker because bronze has slightly less tensile strength than stainless)

    Just found your website today. Like it a lot. Thanks for giving back.

    • Jamie Gifford April 30, 2016 at 8:55 pm #

      Gene – your right about the single bolt. And it is much like the clevis pins connecting the rigging components above deck. There is a subtle difference that I think calls for more than 1 fastener though..The single bolt going through the chainplate, and hull in this case, is more likely to be oxygen deprived and a salt trap than the above deck clevis pin. I’ve seen far more chainplate bolts with corrosion issues, than clevis pins.

      And I agree that there’s a great case to be made for bronze chainplates. When I replaces ours, I did in 316 stainless, but to do now I think I’d go bronze. I’ll also consider hi-modulus line instead of stainless wire for standing rigging. Stainless is amazing material, but…. It has issues, and near impossible to inspect with certainty.

      Cheers,
      Jamie

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