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July 2018

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Rig Survey, Part 3: Surveying the Components

Rig Survey Part 3: Surveying the Components

 

Cracked swages, chafed rope, corroded fasteners, deformed shackles, these are the kinds of things that most people – and I think most surveyors – think of when you say “rig survey.” In this view the rig is a series of components, and it is the job of the surveyor to hunt through it, and winnow out anything that is faulty.

It can be great fun, a thrill-of-the-hunt experience, and you get a lovely wash of endorphins when you find something, but that same wash tends to shut down your peripheral vision, tends to keep you from seeing the roots of the problem, as well as related failures in other components. Let’s take that cracked swage. Why is it cracked? It might be from internal corrosion, or fatigue, or an out-of-spec swaging machine, or bad metal, or any combination of those and other factors.

If the crack is vertical, then it is most likely a product of corrosion, because corrosion always entails expansion of the material, and this will try to blow the swage apart, creating vertical cracks. But then it makes sense to ask why is it corroded? Get out a magnet and put it on the wire. If it sticks, the wire is type 302/304, which is less corrosion-resistant than type 316. And then it makes sense to ask how old is this wire, and where has it been living? If the answer is, oh, 4 years and Hawaii, then we have a piece of rigging that was not suited to the environment it was sent to. And then we must wonder what else in the rig might have been ill-suited to that environment. You will start looking more closely at the quality of the chainplates, and how well they were sealed. You will get obsessive about checking all fasteners for galvanic corrosion, and all running rigging for UV damage. In other words, you will use that crack, not as a trophy, but as a window into the rest of the rig.

Your follow-up actions will change accordingly. Instead of recommending replacing the component, you will specify the better alloy, and maybe recommend that the client finds a shop that dips its wire ends in sealant before swaging, to prevent the internal corrosion that can happen even to that better alloy.

Similarly, a deformed shackle might lead you to consider that whoever rigged this boat might not have been real enthusiastic about calculating loads. If the shackle was on a halyard, you would determine the loads on that halyard (ideally from windspeed and sail area calculations, but at least from ropemaker’s recommendations) and see how the current halyard stacks up. Let’s say it is the proper size, strength, and degree of inelasticity. You would still follow its path, making sure it fits the masthead sheave, that if it goes through a rope clutch that the clutch is up to those loads, and that if it goes aft that the deck turning block is up to taking a load that is almost 1 ½ times that on the halyard, and that the winch won’t require grunting-level exertion to tighten the halyard.

Especially if you find inadequate components – or even overbuilt ones – in the halyard’s run, you might cast the same load-sensitive sensibility on mooring lines, traveler car, spinnaker pole, jib furler, and anything else in the rig that needs to be scaled to the loads it will see. Hint: that means everything in the rig.

If you are sure of the condition and suitability of your components, check the movable bits. Are the clevis pins and turnbuckle studs cottered? Are screws  and shackle pins stuck/backing out/stripped/bent/broken? Do the winch pawl springs spring? Do the sheaves rotate? Components in sailboats have sub-components, and those sub-components are generally receptive to attention from human beings. Also vengeful if they don’t get that attention. Survey is a way to participate in the rig, to be a component yourself.

Finally, what  do you do if a component is in perfect condition? What if it is new, of a strength commensurate with the load (times a safety factor), made from durable, corrosion-resistant materials, and securely installed. What could be wrong with it? How could it possibly be of concern to a surveyor? This is not a rhetorical question, because all of those virtues can be utterly undone unless they possess optimal vectoring and positioning, what the old salts called “fair leads.”

If a jib furler line doesn’t exit the drum at a 90 degree angle, if a reef clewline has too much outhaul and not enough downhaul effect, if  a Genoa sheet interferes with deck traffic, if your mainsheet boom blocks can twist, or if any line has to make a sharp turn when it exits a rope clutch, then you don’t have fair leads. If a deck padeye isn’t oriented for maximum strength, if chainplates don’t line up with their shrouds, if spreaders don’t bisect the angle of the shrouds that pass over them, or if a winch regularly overrides, you don’t have fair leads.

To sum up, then, surveying rig components is a matter, not just of assessing condition, but also determining suitability and quality,  checking for harmony with other rig components, and seeing if what you are looking at is conforming to the needs of geometry and common sense.

 

After this post, I will be taking a break for a while. Yet another ankle surgery is in my immediate future, and I expect it will wreak havoc with my writing schedule, among other things. I intend to concentrate on getting the Falling book published, and will be posting notifications, so please stand by for that.

Thank you to all those who have been so supportive of my attempts at writing. I hope to have more for you soon.

In the interim, there are lots of articles and puzzles to enjoy in the back issues of this blog, and our online store is, as always, open for business.

Fair leads,

Brion Toss

 

Breaking things 2 picture

Weird Wire Puzzle: the Answer

 

Last week’s rigging puzzle was about breaking stuff. Here is how it went:

The manufacturers of a new type of wire rope terminal conducted a destruction test. This test resulted in the sample of wire rope breaking at exactly 10,000 lbs. The wire broke right next to one of the terminals. The rated strength of the wire rope was also 10,000 lbs.

“That’s great!” said the manufacturer, “This means that our new terminals are 100% efficient!”

“Probably not,” said the testing machine operator. “It is much more likely that those terminals weakened the wire, maybe by as much as 15 or 20%.

The testing machine was calibrated correctly. Why did the operator think that the terminals weakened the wire?

This is an obscure one, so here is what I hope is a large hint: wire rope must meet, within very narrow tolerances, a minimum breaking strength, or it cannot be sold. Bonus points if you can tell what detail in my description of the test might have made the technician skeptical.

The solution lies in the term “rated strength.” By international standards, average strengths, as tested to destruction, must be not more than 2.5% weaker than the published rated strength (more on this later). Since break strengths can vary significantly from batch to batch, manufacturers will see to it that their wires are significantly stronger than the official requirement, sometimes by as much as 20%.

So when the tests on the new terminal were right at the official strength, the technician was suspicious; if the terminal really was 100% efficient, one would expect the samples to break well above the rated strength.

The puzzle’s bonus points answer was the fact that the wires broke right at the terminal. This usually only happens when the terminal creates a stress riser, weakening the wire so that it breaks adjacent to that stress riser – the terminal itself. With a truly efficient terminal,  the wire might be expected to break at least 2.5” away from the terminal, or “in the clear.” Where the wire broke confirmed the technician’s suspicions.

This puzzle has real-world significance. For instance, Norseman terminals were for years touted as being at or near 100% efficient, based on tests just like the above. But when the actual strength of the wire was known, they struggled to achieve, you guessed it, 80% efficiency. Happily, those terminals are no longer being made.

If you would like to see some destruction test results for sailboat terminals, based on actual wire strength, I can recommend the tests carried out by yours truly for Practical Sailor. The article is for subscribers only, but it is worth the subscription fee, and not just for that one article. Sign up here: https://www.practical-sailor.com/

For those of you who would like a more technical description of terminal efficiency, you might enjoy this information-dense entry by longtime reader and entrant Mike Madden:

If the manufacturer breaks x samples of his new wire rope, the result must surely be x different breaking strength values normally distributed (probably) about a mean . However, the minimum accepted strength can only be 2 1/2% lower than the published nominal breaking strength*. That is 2 standard deviations (SD) below the mean breaking strength of the wire rope. Since 6 SDs includes 99.9% of values, that suggests that the highest breaking strength found during testing would be about 5 SD above the published minimum. I couldn’t find any wire rope breaking strength data that included Sds, but in a thread in a Sailing Anarchy forum, a test of Dyneema break strength test found that the SD of the sample breaks was 3%. Using that value, 3% of 10000 llb is 300 lb, so 5 SD above 10000 lb would be 11500 lb. Whew! 

Anyway, given that series of guesstimates, 10000 lb is 15% lower than the tested maximum breaking strength of the wire, which is what the testing machine said. Since break tests for wire rope are only valid if the break occurs 2 or more inches from from the ends, and this break occurred at the terminal, the testing operator suspects the terminal as the cause of the failure. 

Ain’t statistics grand? Mike also included a link to a website describing the formal standards behind rated wire rope strengths: http://vernoncorp.com/products/black-diamond-wire-rope/design-factors-breaking-strengths/.

Worth a read.

We got some splendid entries to this week’s puzzle, and most of you got the basic answer and the bonus question. But there can only be one winner, chosen at random from the pool of correct entries, and this week that winner was … Tim Omlor! Congratulations, Tim, you have just won my new E-Book, Falling, a series of essays on the topic of, well, falling. We are in the final stages of editing, but I hope it will be ready to send in less than a month. Be in touch to remind me, please.

If the rest of you are interested Falling, we will be posting a pre-order opportunity in the near future. Stand by.

Meanwhile, if you enjoyed this puzzle, you might enjoy all the other ones we’ve posted, and maybe even the now-considerable number of essays that have accumulated on my blog. To find and binge-read, see: Our Blog

As always, I recommend that you visit our splendid Online Store, for the best in rigging services, tools, materials, and educational opportunities.

If you are reading this on Wednesday morning, it is because you are a subscriber to this blog, and you get to see it a day ahead of everyone else. If you are not yet a subscriber, consider scrolling to the bottom of this page, and signing up. It’s free.

Next week’s rigging puzzle: Problematic Padeyes.

Fair leads,

Brion Toss

 

 

 

 

Guest Essay: Time Out of Time

I will continue the Rig Survey series next week.. Meanwhile I urge you to take a break from all things nautical, and join philosopher and gonzo naturalist Jacob Haverfeld, on an adventure in the Southwest.

 

How I spent my days at the Grand Canyon.  Late March on the south rim is a cold place.  We stopped for provisions in the town of Williams on the drive in, an hour away from the precipice of eroded time. It was a strange scene.  Inside the car was a still-contained Mojave microclimate: zero moisture; dry-warm dusty air; arid and scented with sage.  Upon opening the doors we were greeted to a blast of chilling winter wind, comparatively wet, though perhaps not by Pacific standards.  Still, it was a shock.  Ponderosa pine smell in the crisp air, snow on the ground and a howling, moist wind.  The faces of people hurrying across a Safeway parking lot were wind-burned red, noses and ears bright and inflamed.  Clearly half of everyone in town was suffering from some severe lingering bronchial infection.  Everyone was coughing thickly.  “Plague town” the place immediately became in my mind.  I didn’t feel like lingering, and my mind dropped back in time to days of horse travel, and I pictured our short stay resulting in my companion Cassidy dropping my body into the cold rocky ground and erecting a crude and temporary monument before heading on down the trail.

 

We went when we did because our friend Emily was finishing up a job there, cooking for the Society for Creative Anachronism (SCA).  The scene when we arrived was, I admit, less than I might have imagined.  Perhaps because of having left one season and traveled “back in time” to a colder climate on the rim, there was an exaggerated sense of archaic human history.  Primitive tent, freezing weather, and a strange 1850’s work-camp feel about the place.  We ate with the group in the dark, huddled over our food, shifting on our feet in the cold.  Talk was truncated the first night, partly by darkness and cold, though more by cultural clash than anything else.  The SCA leaders and their flock of youth greatly resembled a kind of religious camp, with self-congratulatory and guilt-ridden environmental themes of salvation and purpose.  Strange songs were sung, and conversation was riddled with a discomforting sense of unhumorous fundamentalism.  Cassidy and I were as strange as two opposable thumbs.  It was a “dry” camp, so we took our bottle of JB to the slightly warmer, tiled floor of the men’s room, and sang songs of the day’s travel.

 

The wind was altogether more entertaining.  A sally to the rim before supper to catch sunset revealed a blasting updraft ripping through the woods.  A conspiracy of ravens performed fantastic aerial feats together out in the vast empty space of the canyon.  Spiraling downwards, thrown across the sky, traveling hundreds of meters upside-down down and backwards.  One can only say laughing, for there really is no other word for what they were doing.

 

On a whim, Cassidy threw his hat over the cliff and we watched it sail briefly out over the abyss and then shoot upward, lofted by the updraft over our heads and tossed 80 yards behind us into the woods.  For half an hour we completely forgot our cold in the manner of entertained children ― who can endure any temperature provided they are having a good time ― and threw everything we could find or break off over the cliff.  Enormous pine branches as tall as I were thrown out into space, only to be rejected by the void, and against all comprehension flung upward 50 feet into the air to arc over our heads.  This game was endlessly iterated until darkness.  Naturally my hat ended up high in a tree.  Small rocks thrown down into the canyon rose, miraculously and hilariously, and after stuttering in the wind were fired back at the thrower.

 

We spent two days down inside the canyon, where temperatures were much more pleasant and warm.  We walked down trails that when seen from below defied reason. The making of them is very much in question as a logical undertaking.  Flowers blooming, small silvery-green lizards skittering.  The alien formations of yucca stalks.  Exploration of old mines, we were informed by a small sign, was forbidden due to buildup of radon, a colorless, odorless gas – a natural but radioactive gas formed by the decay of radium.  The ground was littered with strange green and blue and red rocks.  Naturally bats lived there. A song about the restorative properties of Radium Springs was carried down the trail a ways.

 

Inside the chasm:  Spotted Towhee; flock of bushtits; turkey vultures (wobble hawks); canyon wrens; rock wrens; Say’s Phoebes; black-throated sparrows; white-throated swifts; peregrine falcon.

On the rim:  Western Bluebirds; white-breasted nuthatches foraging like small upside down ninjas; pygmy nuthatches; juniper titmice; gray-backed juncos;  mountain chickadees; cayotes; ravens.

 

We camped on a high plateau about halfway down.  Somewhere far above us the origins of mammals, somewhere in the most recent few layers of time high above.  Roughly 2 billion years down to the bottom, down past the great unconformity, down past countless layers of silted deposits of ancient oceans and ancient life forms embedded in the rock.

 

We spent the day together and alone, wandering the rim, forming theories and conclusions, attempting to comprehend, and failing pleasantly each time, staring blankly or sleeping on warm rocks before rising to attempt comprehension again.  At perhaps eleven at night, long after a very shadowed moon melded with the rim above us, after glassing the sky’s vastness with binoculars for a few hours and watching satellites traverse the cold sky, I wandered alone to the edge of the rim, and standing in the warm wind thought to call Piper.  My cell phone sparked to life.  The time was wrong: it read 12:00 a.m. which was unlikely. My eyes glanced over to the date and I was surprised to see that it read Jan. 6, which of course it was not, this being March.  But as my eyes slid across the line of text I was still more shocked to encounter a complete reading of Jan 6, 1980 12:00 am. This was, I will say, briefly and staggeringly weird.  On a sunny afternoon, perhaps standing on a sidewalk, surrounded by people and buildings, if a man looks down at his watch and it reads an incorrect time he is not much more than annoyed, and certainly is not thrown into a temporary dislocation of time and space whereby everything he knows suddenly falls away as if the appropriate time were the gravity holding everything together.

 

However, standing on stone deposited before the birth of mammals is another matter. Suspended, as it were almost floating in darkness, on a precipice of time, surrounded by lethal vertical vastness and stars, my tender human mind experienced an inexplicable plummet into space. I fell into the stars. For in that moment it was evident first that the person I hoped to call on my phone, by the phone’s telling of time, was not even born yet.  And I was not even an idea in the minds of parents whose youth and location in the world I could not ascertain; they certainly wouldn’t know me yet.  In fact, practically everyone I knew didn’t exist.  “Cassidy,” I said, “can I show you something?”

 

I can tell you that the experience of time-travel is not at all like in the movies. Your first thought is not that you will accrue enormous wealth by betting on all the baseball games which haven’t been won yet, or the stocks which haven’t yet skyrocketed in value. In fact, money is pretty well a meaningless concept to someone who has just lost all reference points. Perhaps you would become a mystic, or more likely end up institutionalized. Traveling backwards in time to a place before your own birth is probably the closest thing I can think of to experiencing true impermanence and living to tell about it. You are cosmically alone.  Free and unformed. A dim cloud of stars on a drifting trajectory, a bubble of spacious laughter and dust, all your friends and loved ones smiling conspiracies of stars themselves, timeless, without trouble. There is nothing to be saved, sadness a misperception of time and space itself.

 

Next time you see me ask to hear the sounds my phone plays when turned on or off; it will seal the story nicely for you (it hums a phosphorescent series of utterly alien alternating harmonic pitch changes and whispers “time, time, time” in a faint breathy female ethereal voice – I shit you not).

 

The above was part of a letter written by my dear friend Jacob Haverfield. You can see more of that letter in a previous post, .Difficult Feats, Pointless Tasks. Worth a look.

Also maybe worth a look: the last many month’s worth of essays and puzzles here on my Blog. I am so happy that our site stats indicate that we get a lot of binge readers.

The current rigging puzzle is called “Weird Wire,” and you can find it http://briontoss.com/index.php/2018/07/18/breaking-strength-2-weird-wire/.

If you would like to get notifications of new posts a day ahead of the general public, please scroll down and start a free subscription.

Let’s see, oh yes, please wander through our http://briontoss.com/index.php/shop/, for a look at some fabulous rigging gear and educational materials, along with how to reach more for rerigging, consultation, and survey work.

Fair leads,

Brion Toss

 

Breaking things 2 picture

Breaking Stuff Puzzle 2: Weird Wire

The manufacturers of a new type of wire rope terminals conducted a destruction test. This test resulted in the sample of wire rope breaking at exactly 10,000 lbs. The wire broke right next to one of the terminals. The rated strength of the wire rope was also 10,000 lbs.

“That’s great!” said the manufacturer, “This means that our new terminals are 100% efficient!”

“Probably not,” said the testing machine operator. “It is much more likely that those terminals weakened the wire, maybe by as much as 15 or 20%.

The testing machine was calibrated correctly. Why did the operator think that the terminals weakened the wire?

This is an obscure one, so here is what I hope is a large hint: wire rope must meet, within very narrow tolerances, a minimum breaking strength, or it cannot be sold. Bonus points if you can tell what detail in my description of the test might have made the technician skeptical.

If you think you know the answer, send it to  puzzle@briontoss.com. We will randomly select a winner from the pool of correct entries, and that winner will recieve as a prize a copy of a book that I will be publishing soon. Details in the coming weeks.

Submit your entry by noon, Pacific Time, Monday, July 23. The winner will be announced on Wednesday, July 25.

Note that subscribers to this free blog receive posts a day before everyone else, so scroll down and sign up if you like to get a jump on puzzles and prose.

Be sure to binge-read all my fascinating blog posts Here, and to take a look around our .Online Store

Fair leads,

Brion Toss

There is a book coming soon

This is an advance notice, being sent only to subscribers, that I will be publishing an e-book very soon, called “Falling.” It contains stories, many of which first appeared in the blog, on the topic of working aloft. It will be available to our subscribers, at a discounted price, before it is offered to the general public.

This letter is a way of testing the waters. Are you intrigued at the idea? Might you be interested in buying a copy? You can reply here, in the comments section, or you can email me directly: rigging@briontoss.com. I would be grateful for any and all feedback.

Fair leads,

Brion

Wallace_Carothers,_in_the_lab

Rig Survey, Part 2: Surveying the Materials

It is 1934. Wallace Carothers, a chemist for DuPont, is at work in his laboratory. He is lean, intense, bespectacled. All around him are beakers and flames and retorts. His boss comes into the room and says, “Carothers, I want you to develop the worst possible material for mooring lines.”

The chemist immediately starts listing properties that might meet this demand. “Let’s see, he says, we could make it vulnerable to UV degradation, because mooring lines are out in the sun all the time.”

“Good, good, what else?”

Well, let’s make it easy to chafe. Mooring lines see a lot of chafe.”

“Excellent.”

“And maybe we could come up with something that would chafe itself internally under extreme loads, so you couldn’t tell that it was about to fail. Oh, and let’s make it out of something that is weaker when it is wet!”

“Carothers, I knew you were the right man for the job. I look forward to seeing the –”

“Wait, I though of something else. Let’s make it so that, when it breaks under high load, it snaps back at you at, oh, about 600 feet per second!”

 

This is a somewhat, um, fictionalized account, but Carothers was a real person, and he really did invent a fiber with all of the properties listed above. We call it Nylon, and the odds are very good that your mooring lines are made out of it because, despite all of its drawbacks, it provides us with one crucial property: elasticity. It stretches, taking up the shock loads that mooring lines (and anchor rodes) must endure as a matter of course. Without this elasticity, it is very hard to avoid ripping hardware off of docks and decks, and without causing the crew to stumble about quite so much every time a wake goes by, so we put up with all the material’s drawbacks in order to take advantage of its singular virtue.

Similar tales could be told about every other component of a vessel’s rig. Stainless, to take another example, is obviously the worst possible material to make chainplates out of (only corrodes where you can’t see it, stays deceptively shiny, gets brittle as it ages, etc.), but again, we forgive it its shortcomings because it possesses a great combination of relatively high strength, ease of machining, and overall corrosion-resistance. So we use it.

It is obvious, then, that one cannot be an effective surveyor, of rigging or anything else, if one does not understand the properties of the materials that one is surveying.

If I am surveying a carbon fiber mast, I had better know that it is far more noble, galvanically, than stainless steel. If I don’t know that, then I might not check the fasteners that might have been put into it, to see if they have been properly isolated. If they haven’t been, the carbon fiber might be reducing the fasteners to dust.

If I am surveying an aluminum mast, I had better know that it is far less noble than those same fasteners, which therefore might be eating the mast.

If I am surveying a high-modulus (HM) halyard, I had better know that almost anything but a proper eyesplice will weaken that line by at least 60%. If a boat has a knot in the end of its Spectra halyard, and it hasn’t broken, then it is either scarily close to breaking, or expensively oversized, or possibly both.

And if I am surveying some of those aforementioned stainless chainplates, I had better know that the only way I can be sure that they are not crevice-corroding in the deck is if I remove them and put a microscope on them. Surveyors consistently fail to recommend this, which might be why the leading cause of dismastings, according to Boat U.S. statistics, is chainplate failure.

Once we understand the materials we are working with, we need to consider them in context. A nylon halyard, even in excellent condition, is still a lousy tool for that job, because its inherent elasticity makes for inconsistent sail shape. Likewise a Spectra anchor rode, no matter how pristine the rope is, might be counted on to tear the windlass off your deck, because of shock loads. Chain is similarly inelastic, but it is also heavy enough to produce a catenary, which provides some degree of gradual takeup of load, and this catenary can be further complemented by rope snubbers.

This brings us to considering the possibilities of materials. If we can work out a way to insert snubbers into the length of a Spectra rode, we could have a rode that is far lighter, stronger, and likely cheaper than chain, and this is exactly what some companies are working on. By understanding Spectra’s virtues, and understanding the specific demands of the context of anchoring, we can work to adapt the material to new uses. Surveying isn’t just a matter of noticing that something is breaking; it is the search for rig optimization.

Next week: Surveying the Components

 

This is the second in a series on rig surveying. To see the first part, along with a dense backlog on all sorts of topics, visit Our Blog.

If you want to get a look at new content a day ahead of the general public, scroll down to the bottom of the page and subscribe.

Also be sure to visit our Online Store, for all sorts of rigging tools, gear, materials, and educational content.

Wander around the site a bit for information on consultations and rig surveys, as well as actual rigging of boats (yes, I still do that, too).

 

Fair leads,

Brion Toss

Winch Winge, the Winners!

Hello all,

The puzzle was dormant for a bit, but re-emerged with “Winch Winge.” Here is how it went:

Photo courtesy of Scott Wilson

Stage One: In the picture above, there is something very wrong, as in could-cause-serious-injury wrong. What is it?

Stage Two: Hang on a moment, it is possible that things are not as bad as we think. What other (obscure) explanation is there that would reduce the problem to an annoying installation error? Hint, old-time racing sailors and their cruising contemporaries will have an advantage in figuring this one out.

The first-stage answer, obvious to many of you, was that the line on the starboard winch was wound on counterclockwise, which is really, really dangerous if the winch rotates clockwise. And nearly all winches do. Winding lines on  backwards means that, if any load comes on the line, there will be no snubbing action. Among other ghastly possibilities, this means that anyone hanging onto that line risks getting sucked into the winch.

A correct “normal” winding would look like this, with both lines winding on clockwise:

The second-stage answer is that not all winches rotate clockwise. If, in the first picture, the starboard winch rotated counterclockwise, and the port one clockwise, then the arrangement was correct. Sort of. See, one of the big reasons to have a “backwards” winch is so that you get a lead to the winch from the outboard side. This makes for cleaner leads from car to winch, because the line doesn’t have to cut across the coaming or dodger. Look again at that “normal” picture, above. See how the line has to cut inboard to get onto the winch? This might not seem like a big deal, but it frequently makes the difference between a fair lead and the need to install metal chafing strips, to keep the sheet from grinding a groove into your boat.

So the second-stage answer is that, if both winches in the top picture were wound correctly, they were both installed on the wrong side. Have them  switch places, and you will get this:

Now they both lead from the outside. Ahh.

You might be wondering why, if the resulting leads are so clean, this is not the standard way of doing things. One reason not to is that it adds a layer of complication to fix a problem that is minor or nonexistent on most boats. Another is that owners have to keep track of opposite-rotating parts. But the biggest reason is that most people reflexively wind every line onto a winch clockwise, and this has historically led to an appallingly high incidence of injuries aboard boats with counterclockwise winches.

If you have this setup, you probably already know all this, and have established a protocol to make sure that the whole crew knows how to do things right. On some boats, including many old racers and cruising vessels, opposite-winding winches are the only way to get clean leads. So if you find yourself aboard a boat like that, check which way the winches turn.

The winner of stage one, drawn at random from the list of correct entries is … Roger Briggs!

And the winner of stage  two is … Keith Quigley!

Congratulations, you two. Be in touch to arrange for us to send you your fabulous prizes.

For everyone else, brace yourselves for next week’s puzzle: Breaking Stuff, Part 2.

In other news, last week I posted the first of a series on rig surveying. You can find it Here. The second installment will be delivered to subscribers on the 13th, and to everyone else a day later. Subscribers are also seeing this post a day early.To subscribe, just scroll down this page, and sign up.

As always, I invite you to read every single blog post I have ever written, something a gratifying number of you actually seem to have done. You’ll find all those posts Here.

Also, please do cruise through our Online Store, for the best in tools, materials, and rigging education.

Fair leads,

Brion Toss

 

Rig Survey Part 1: Surveying the Design

,

As surveyors, our work is based on the skills and knowledge of others, on lessons learned, often at great expense, given as a gift to us. A surveyor is the holder of a template, a vision collated of the ideal and the practicable, a filter through which to view our subjects.

This template, in order to be valuable, must be firm and certain enough to provide a foundation for standards, and yet plastic enough to allow for changes wrought by new technologies, new theories and perspectives, and new data from the field. It must allow us to make our own contributions, our own gifts, and to provide a way for the surveyor to keep the forest in mind while examining individual trees, and even individual leaves. Concerted study and analysis is indispensable if one hopes to be a good surveyor; the creation of such a tactically and strategically all-encompassing template is clearly beyond the abilities of any one individual. We must, as in any other worthwhile endeavor, stand on the shoulders of giants.

Surveying is often seen as the process of noticing decay, and this is a big part of the art; fractures, corrosion, dents, and other flaws can compromise a rig, making it unsuited to face the demands placed on it by the sea. But meaningful survey is also about design, for how can we know how serious a problem is if we don’t understand how the problem affects the system? Design is abstract, but it has real consequences. Here’s an example:

Hunter sailboats feature the B&R rig, a brilliantly innovative take on the standard Bermudian rig. Because it is innovative, it is often misunderstood, especially in the matter of tuning; the loads interact and accumulate much differently than they do in a standard Bermudian rig. A well-tuned B&R is a marvel of forces resolved in three dimensions, an exquisitely balanced cascade of tension and compression. A poorly-tuned B&R is an ungainly assembly of wires and struts that are at war with one another. Most B&R’s are not well-tuned. I learned about this from Lars Bergstrom, the “B” in “B&R”. I came to the conversation with a dim-but-serviceable grasp of the principles of geometry, and a notion of how to apply those principles to a sailing rig; He gave me an appreciation for the variables of load paths that clarified how his rig works – and in the process he gave me a better idea of how standard rigs work. I was able to bring this information into the category of surveying because Lars’s ideas accurately predicted that mistuning a B &R rig can, among other things, tend to accelerate fatigue on the lower shrouds. I won’t go into the details here, but the short form is that, if you proceed carelessly, the wires at the middle and top of the mast can add loads to the already-loaded lower shrouds.

If B&R rigs were more common, it is likely that the knowledge of how to treat them would be more common. As it is, they are rare, and confined almost exclusively to boats made by Hunter; they have become something of an identifying symbol for that one manufacturer. In terms of general perception, how to tune them, much less how their characteristics relate to the hull form, matter less than that they are a distinct, somewhat quirky visual cue that says, “Hunter.”

This rig has evolved over the years. Some early ones were masthead rigs, whereas nowadays fractional is the rule. Hunter’s used to have standing backstays, which became gradually vestigial, until they were discarded altogether. Over the same period the spreaders swept further and further aft, so that the shrouds incrementally took over the backstay’s function.

Over the same period, Hunter owner demographics evolved into a group that in general has no interest in furling a big main the old-fashioned way. That’s why you now have to special-order conventional mains’l furling; in-mast furling is now standard. This mains’l furling fact is crucial to riggers, and thus rig surveyors, because for in-mast furling to work efficiently, mast bend must be minimized, ideally not exceeding 2”, according to the specifications of Selden, the builder of these excellent masts. Otherwise the luff of the sail, instead of floating relatively freely in the cavity of the mast, bears on one spot, at the point of greatest mast bend, inducing unacceptable amounts of friction when furling and setting. Fair enough, but Lars Bergstrom had in mind a rig that was emphatically meant to be bent, and which was stable and efficient with a strong bend in it. It is a mast that won’t wander about, a mast that can be shaped to an exquisite degree, to get the most out of the main. This is important, because in this boat, as with any fractional rig, the jib is relatively small, and acts to deliver energy to the powerhouse that is the main. The aft sweep of the spreaders, in addition to pulling the masthead aft, produces compression that pushes the spreaders forward, and this facilitates getting a strong bend. Tuning the bend to within 2” or so of straight, without producing uneven stresses in the rig, takes serious skill, because you have to defang all that spreader compression; judging by all the problems we see related to tune in these boats, some riggers do not possess this skill.

The B&R rig is notable for its sharply aft-swept spreaders and in-mast furling, but other manufacturers produce similar rigs. A popular and very nice example is imported from France by Sparcraft, and in the American version of the manual the instruction is to tune the mast with no bend at all. But as with the B&R, the angle of the spreaders means the mast really wants to bend, and making it absolutely straight is just about impossible without some serious tuning distortions. After trying and failing, on one boat, to get a straight mast without imposing weird rig loads, I tried easing things off, and went for the same 2” bend that Selden recommends. It was as if the rig breathed a sigh of relief, and there was no increase in furling difficulty. I checked with Sparcraft on this, and they very kindly referred me to the French engineer who had designed the rig. He emphatically agreed that the 2” bend was the only mast shape that made sense, given those swept spreaders. But because the American manual remains unchanged, a good rig survey will frequently turn up unhappy loads — with resultant fatigue and performance issues — in these rigs.

This is just one example of how design can have an impact on rig survey. Other examples include the evolution of shroud staying angles, loading of components in discontinuous rigs, hardware failures inside single-line-reefing booms, and primary winch leads on center-cockpit boats, to name just a few. Rig survey, then, isn’t just about the strengths and weaknesses of materials, but the strengths and weaknesses of the surveyor’s understanding of the design.

 

In the next installment, we will look at Surveying the Materials. Meanwhile if you would like more information on this topic, see the pertinent sections in The Rigger’s Apprentice, and in my Rig Tuning video. You will find those and lots of other DVD’s, books, tools, and supplies in our online Store .

If you are in the mood for a good rigging puzzle, you can find the current one Here. It’s about winches.

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Fair leads,

Brion Toss