Stagger When You Anchor

rev. 8-14-2024

Sounds like I've either been drinking to much or sailing too long. But bear with me....

I'm convinced the average person cannot see in 3 dimensions when they look across the water. They can recognize right and left, and to some minor extent distance, but they cannot accurately relate what they see to a map-view.

Anchoring is the classic case. They move the boat to what seems like a good spot and lower the anchor,  without being able to visualize where the boat will be after they stretch out scope, or how boats may swing. They end up anchoring either very close in front of you or exactly beside you, neither of which they actually intended. They just measured wrong.

1. Calculate how much rode you will use, including an allowance for adding scope if a storm arrives. For example, if the water is 7 feet, you bow is 3 feet, and you like 7:1 scope, (7+3) x 7 = 70 feet.
2. Lower your anchor 1 rode length +1  boat length off the bow of your neighbor. This might be 1.5 to 2 mast-heights, a simple way to gauge distance if you are reproaching from astern of your neighbor. By the time the anchor tips, digs, and sets, particularly in softer mud, it will be off the beam of your neighbor.
3. Need to anchor in front?  You need to be about 2 rode lengths + 2 boat lengths (about 210 feet). Simple come up beside the boat, note the lon/lat, and move 0.039 minutes forward (a minute is 1 nautical mile, and GPS typically displays 0.001 increments). Or time the distance; 1-knot ~ 1.5 feet per second. At 3 knots, 210 feet will take about 45 seconds. The point is, do something better than just guess.

You have now achieved the optimum stagger, which will allow the maximum number of boats in a minimum space, with minimal need to visualize the geometry.

Simple.This, along with every detail of single and multi-anchor rigging that I could test, is described in "Rigging Modern Anchors."

Lazy Figures of Speach

We're all guilty of it (an example, right there!). Generalizations or truisms that contain little information are used to defend a position. False analogies and straw men that are use to tear a position down.

I'm going to stick to sailors. Politics would take a book.

Just a few from today's forum morning read:

• "I was taught to do it [this way]." I was taught that 2 + 2 = 4, but it did not become a part of my knowledge base until I was shown or figured out why it was true. I would certainly not tell you 2 + 2 = 4 unless I had some basis, other than I was told, that it was true. As you know, I do a lot of testing. That is NOT because I do not believe what I read. I always start with literature research, because many really smart people went before me. But they didn't go down every alley, not everything was published, and things do change.
• I've been [doing X] for 30 years, and [this] has always worked for me." Often used to resist something newfangled. An adding machine works, but an electronic calculator works better. A CQR anchor works, but a Rocna (or other new generation anchor) work better. This can also be used to defend practices that were never very good, but were good enough, since they were never tested in a real crucible.
• I've heard it said that.... This precedes and opinion offered without any support. The writer may not remember the reasoning, he may not have understood it, or it may not exist. We are offered no opportunity to examine the argument, and not convinced that the speaker reviewed it either. It is likely nothing more than parroting, unless followed by support.
• Non-corrosive, when what is meant is corrosion resistant. For example, this from ABYC standard relating to bilge pumps: "h. Hose connections shall be secured with a non-corrosive type of clamp."Standards are supposed to be written using the standard english meanings of words, and new words are only to be defined if you can't find it is a standard (Websters or Oxford) dictionary or if the meaning is necessarily different. Since all of industry refers to stainless steel as "corrosion resistant," this is sloppy writing. What it literally says is that the clamp should not corrode the hose, which is not what they mean.

How Long Should a Tether Be?

7-02-2016, rev. 8-8-2024

The 3' / 6' split has become a defacto standard, since these are the lengths in the ISAF standard. Well, sort of. What it actually says is that:

• 30% of the crew (or everyone if you single hand) must have a tether leg of no more than 3'.
• Every tether must be less than 6'6".

First off that means you can, and perhaps should have tethers less than 3'.

This tether is only 30 inches, is attached well in-board, and I'm well outboard. Of course, I had to climb over the high lifeline.

 At the mast in lump weather I sometimes go even shorter. How about a vertical jackline. Every boat should have these available in the form of halyards, though mine are fixed (they serve an unrelated tangle-avoidance function).

Additionally, I see no reason they cannot be longer in certain cases. My other leg is 8', bout right for the broad bow of a cat. I can imagine much longer on bigger boats. You just have to use the length intelligently.

What about smaller boats? I was fooling around on this 27' mono, using Amsteel jacklines, and concluded that the longest leg should be 3' and the shorter perhaps less than 2'. A 6' tether has no place on a smaller boat. If you would like a longer tether for the cockpit, then have a separate dedicated tether there.

I like custom sizes. I fabricate mine from 8mm climbing rope using sewn splices, but climbing webbing and knots will do nicely.

rev. 8-8-2024

The 3'/6' split is perfect for my F-24. The jacklines run along the inside edge of the tramp lacing and end 4 feet from the bow and 5 feet from the stern, and the large wing nets make it practical impossible to reach the edge. There are no lifelines, other than small sections at the bow and stern. 

 

 

 

High Lifelines

6-4-20216, rev. 8-8-2024

Standard lifelines are only slightly above the knee; helpful, perhaps, but not reassuring. For example, reaching over the side to add a sheet to a sail clew can be a little unnerving.

While researching jacklines materials I came a cross a lot of references to high lifelines, rigged to the shrouds. I poo-pooed the idea for years, but now that I have actually tried, it, I think I was wrong, at least for this boat. Yes, they are in the way just a bit, but they make going around the side without a jackline that much safer, they make it safer with a long tether, and they make it better when rough or for those with balance problems.

I used a length of old Kevlar genoa sheet (you want something non-stretch). I investigated all manner of fancy shroud attachments, but a clove knot worked best, with a little tape under it to prevent sliding. Attach it to the lifeline in such a way that the tension is carried by the lifeline, not the stanchion (it looks like I tied the forward end to a stanchion, but there is actually an eye for a gate). The aft end is tensioned with a lashing to another gate terminus.

Reaching out feels casual with a lifeline at your waist.That water is only 45F. Falling in under spinnaker, even on a calm day like this, could be life threatening. Note that I am also clipped to a short tether.

The high line makes a good handline that doesn't stress the stanchions.

Dynamic Tethers

 rev. 4-19-2014, rev 8-8-2024

Stitched Splice Warning. Based on limited testing we have found that nylon rope is much different to sew than polyester rope. Because of the extreme elongation prior to break, the stitching at the tail must carry nearly all of the load, while the stitching near the throat carries no load. It is rather like tug-of-war with a bungee cord; only the 2 men nearest the center can do any work.

Because of this difficulty, I strongly suggest all dynamic tethers be knotted rather than sewn. Climbing ropes have very high knot strength and are drop-tested with a figure-8 to attach the mass. A double overhand noose has also been drop tested. 

[Since this article I switched to a webbing retracting Proline tether by Wichard. I don't like the clips quite as well as the  Kong Tangos, but once you get used to them they are very good. The webbing has a bit more stretch than the prior polyester webbing and can pass the ISO drop test, but with a terrible jolt. After 5 years, the elastic is about shot, so the long tether droops dangerously. It has a quick release on the harness end, but I have mixed feeling about something that can release when I don't want it to. This winter I will either buy a new tether or build a new dynamic tether with Kong Tangos on for all three clips (On my F-24 we detatch the rope end as well, rather than leaving the tethers on the jacklines.]

This subject is a little too esoteric--for most sailors--and so magazines aren't much interested.   Fatalities due
to tethers breaking are rare. On the other hand, bruised ribs and back injuries are more common, but wrongly accepted as a part of rough weather sailing. However, if  we simply apply what we know from climbing about falling--lots or real world experience and lots of lab testing--it just doesn't need to be that way. Let's see if I can sweep away a few bits of conventional wisdom that are just plain wrong. Though you may never sail the Sydney/Hobart, capsize your boat and test the limits of  the human body, routine bumps against tethers don't need to hurt either. We can make our sailing experience more comfortable and safer at the same time. My tethers don't hurt.

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Dynamic tethers spliced from 8mm ice climbing rope. Knots would serve just as well. 10mm climbing rope works, but it is heavier and a little rolly if you step on it.

I started my investigation into soft tethers and impact forces years ago, but honestly, my boat is not the ideal
test bed; catamarans don't heel, I don't sail in big waves, and I'm not as willing to risk physical trauma as I used to be. I hold on and I don't fall. However, I've let myself slam into tethers intentionally a few times, just for testing, and I'm not happy with the current state of design. My back is too old.

Let's step back for a moment, before we charge forward, and state the limits of our investigation. We're not discussing jackline and energy absorption. I've covered that before and common experience indicates that a jackline will absorb enough energy to safely slow the sailor. I am discussing only the case of a sailor clipped to a rigid point.

While the Screamer/webbing combination is a huge safety improvement over the typical non-elastic tether, it is really engineered for a different purpose; to catch severe impacts in a survivable way for climbers and workers wearing hip or full body harnesses. Sailors, on the other hand, have a chest harness, which is lousy at distributing force. The screamer is just too hard.


A little backyard testing

I do NOT suggest this as you can easily hurt your spine. I've climbed enough to know what I was getting into.

• Anchor one end of the tether to an immovable object, in this case a large tree wrapped with non-stretch line.
• Create several tethers, 6 feet long from test materials: 1-inch nylon webbing,  1-inch webbing with Yates screamer, 10.4 mm dynamic rope (UIAA single), 8.2 mm dynamic rope (UIAA double).
• With increasing amounts of slack in the line, run at the end of the tether as hard as you can back first.

Results:

1-nylon webbing with Screamer. A very tough stop. With about 3 feet of slack I was able to just get the Screamer to trigger and it hurt. My back will complain for a few days.
10.4 mm rope. Firm stop. I didn't go further than 4 feet, not wanting injury. I'm sure I could have run from 6 feet with no harm, though it would be a jolt.
8.2 mm rope. Even at 6 feet and with a sore back, the stop was practically fun. It might take you off your feet, but was no harder than hitting a well padded couch. At 2-3 feet it was only amusing, with about 1-foot of stretch.
1/4-inch Amsteel. I was smart enough not to try. It would be worse than webbing without a Screamer.

General Observation. I wear my harness high, nearly in the armpits and definitely on my lats. If the harness had been worn lower, where catalogs show them or where combo PFDs fit, I would have injured my ribs.  Whiplash is also a problem. Wearing a harness down near the solar plexus and lower ribs, where so many are located, is plainly dangerous.

In the end, only the 8.2 mm rope felt good, thought the 10.4 mm was livable.


Data and Calculation

Is it strong enough? 8.2 mm line is not 5000-pound rated, but as we will see, it is far tougher (can absorb more energy) than 1-inch webbing.

What do we know from laboratory and real-world fall data? For new products....

• Webbing tethers are just adequate: They occasionally fail at forces near 4000 pounds. Rare, but we can use that as a design point. 
• 1-inch webbing can just manage a 6-foot fall with a 185-pound rigid mass; this is generally considered as equivalent to a 200-pound person, since the harness and body absorb some energy by deforming (data from DMM, a climbing equipment manufacturer).
• 10.4 mm UIAA single rope can manage more than 10 falls from nearly twice this distance.
• 8.2 mm UIAA double rope can manage more than 10 falls from nearly twice this distance with a 242 pound rigid mass (261-pound person) using 2 strands.
• 8.2 mm UIAA double rope can manage more than 10 falls from 6 feet with a 242 pound rigid mass (261-pound person) using 1 strand. Thus, it is more than 50% tougher than 1-inch webbing.
• 8.2 mm UIAA double rope can manage one fall from nearly twice this distance feet with a 242 pound rigid mass (261-pound person) using 1 strand. Again, it is more than 50% tougher than 1-inch webbing.
• 1/4-inch Amsteel is the worst material that could be used. While strong, its energy absorption capability is negligible. Its only advantage over chain or cable is light weight.

I created data using well-used products. Why used? Because they will become so, obviously. Less documentable and less repeatable by others--science is all about reproducible results, be they real-world or not--but ultimately more practical.
 

 Percent Elongation (left) vs. Pounds Stress, pounds (bottom)

Webbing is 3-5 times stiffer than dynamic rope. Amsteel is very stiff.

I took the samples and pull tested them up to 2500 pounds; I didn't feel like destroying my tether just yet. I used on-line data  to extrapolate out to the breaking point of each material. In dynamic situation, the breaking strength and the elongation to break is typically 30% less and energy absorption about 3 times less, but for blog post purposes, the above data at least allows comparison on an equal basis.

What matters is the area under the curve.

Static Energy Absorption, 6-foot tether, ft-pounds (left) vs. Stress, pounds (bottom) 

Static calculated energy values are greater than fall values for 3 reasons:

• Ropes are tested with figure-8 knot, weakening rope by ~ 40%.
• Dynamic testing does not allow for heat dissipation and reorientation of fibers.
• Dynamic ropes survive 8-12 falls, the webbing only 1 fall in our test data. Dyneema survived zero test falls.

Dynamic Energy Absorption, 6-tether, ft-pounds (left) vs. Stress, pounds (bottom) 

 At lower stress, 8.2 mm rope absorbs more energy for a given impact force, but eventually 10.4 mm rope has greater capacity. Both dynamic ropes have greater energy storage capacity than webbing. 8.2 mm rope is more than twice as tough as 1-inch webbing.

Both this data and UIAA drop data thus confirm the following:

• 11mm rope can absorb many fall factor 2 drops.
• 8.2 mm rope can absorb 1 fall factor 2 drop.
• 1" webbing can absorb 1 fall factor 1 drop.

What happens in a 6-foot test fall?

• 1-inch webbing: At 4000 pounds impact, 1100 ft-pounds energy. We know from fall testing, however, that 1-inch webbing can only absorb about 1100 ft-pounds (sometimes passes, sometimes fails), so we will use 1100 ft-pounds as the design point.
• 10.4 mm rope:  If we accept the design point only 1100 ft-pounds of energy, impact force is about 1400 pounds. New rope fall data indicated significantly less.
• 8.2 mm rope: If we accept the design point only 1100 ft-pounds of energy, impact force is about 1100 pounds. New rope fall data indicated significantly less.
• 1/4-inch Amsteel: Only 236 ft-pounds of energy were absorbed by the point 5000 pounds of stress were reached, and only 677 ft-pounds of energy were absorbed at the break strength of 8600 pounds. Amsteel will kill the sailor and pull the harness apart before surviving a 6-foot fall. This has been duplicated in real-world fall testing with spectra products; Dyneema is worse.

If we limit the fall to something more reasonable--a 2-foot fall is similar to wave strike and 6 knot stumble, and more severe than my backyard testing--the energy for me is only165# x 2' = 330 ft-pounds, which can be absorbed by a 500-pound impact; you'll feel it but not get bruises. With a webbing lanyard it would be 3 times that pressure and you will be injured. A Screamer will trigger but not be fully spent (though they are single-use).

How much energy can a Screamer absorb? About 270 foot-pounds according to several testing sources, or about 25% of a 6-foot fall; in combination with the stretch of the webbing, enough to reduce the impact force below 2000 pounds. And then you bottom out and the force goes up, though less so.

Other Factors. Does the extra stretch bother you? Probably personal. Is stepping on rope a greater hazard than webbing? For 8.2 mm rope, not much, but on a monohull (sloping decks) that may be more of an issue. Construction? Either knots (testing assumed figure-8 knots) or sewn eyes are practical.

A critical biometric factor, not easily relayed by a machine or simple data, is that a force that comes on gradually (the dynamic rope) allows the muscles time to tighten and resist. A sudden 500-pound kick before a screamer gives is painful and damaging, like a blindside blow, even at the same force level. You truly feel the difference. 

Dynamic rope or a screamer--The best solution? For smaller, more routine falls on the deck, the rope is
kinder. For that once in 100 sailors' lifetimes, torn from the cockpit by a rogue wave impact, the screamer/webbing combination is competitive, though the climbing rope tethers are still survivable without serious harness impact injury; both could have impact forces of 1000-1500 pounds depending on the force of the wave, and it would hurt, but not break ribs or vertebrate. A climbing rope, even 8.2 mm, has greater energy absorption capacity than a webbing/Screamer combination. Thus few climbers use Screamers, but they ALL use dynamic ropes.

The only disadvantage of rope over webbing is the  potential for rolling under foot. A dynamic webbing would be nice, but I could not find any. On a catamaran this is a limited problem (level decks), and the roll-under-foot potential is reduced by the small size of 8.2 mm line (5/16-inch).

What have I done? I've switched to 8.2 mm dynamic tethers. It is kinder on the back for minor falls and even over the edge. It is lighter than the webbing/Screamer combination and easier to hold on to.

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Where to get limited quantities of dynamic (climbing) rope?
MEC sells both single and half rope off spools, by the foot.
Half Rope,
Single Rope.

Testing of Stitched and Seized Eyes

11-15-2013, rev. 12-31-2013, rev. 8-5-2024

A few weeks ago I posted that stitching and seizing an eye was a viable alternative. I've had stitched eyes outlast the line and no failure, but given the high load on the genoa sheets, I though some back-up calculations were in order. I broke out and old rock climbing gear testing rig and did some breaking.

All testing with used 1/2-inch Sta-Set polyester double braid. All tension figures refer to a sewn or stitched eye. Stitching was hand work, round stitching with sail makers needle and doubled 50-pound waxed whipping twine, about 3/16" apart and about 25% of the distance to the rope centerline, staggered slightly. All seizings were hand tight (about 1-pound, allowing for slippage) and side-by-side, about 40 per inch. Three trials of each fabrication, the minimum of which was used for all calculations. The whipping twine was tested to confirm the 50-pound rating. The angle formed by each eye where it was slipped over a beefy eye was 20-30 degrees; certainly realistic. If for some reason a wider angle is needed, a sturdy throat whipping is in order, with sufficient thread count to keep the throat closed. On 1/2-inch line this should amount to about 25 turns, or a 1/2-inch whipping, just to be safe. However, we did not use a throat whipping during the stitched eye trials.

Rounds Stitching on the Outside Quarter. At 4500 pounds tension a maximum of 9 round stitches on each side (total of 18) of doubled 250 pounds per round stitch (2 passes of doubled twine) . At 2000 pounds 4 stitches on each side (total of 8) also carried 250 pounds per round stitch. This is with the end of the thread unsecured (I cut the last stitch with a razor knife) to simulate wear. Over 8 trials, the variation per stitch was less than 10 pounds. Each time the failure was abrupt, the line only slightly distorted around the stitches, and no line damage resulted even from repeated stitching and testing to failure. Thus, I have no reason to believe that the the eye should be significantly less than 100% line strength; probably 90% like most splices. I will test some smaller line to failure to confirm this.

This works out to 62.5 pounds per strand or about 125% of thread strength. Some of the load is carried by friction around the eye and some by line to line friction, while at the same time the angle of the stitches increases stress. Anyway, it all works out to 62.5 pounds per strand. Thus, 20 round stitches on each side of doubled 50 pound line should give a failure strength = 80 passes *2* 62.5 = 10,000 pounds. A nice safety factor. Hard to believe on a gut level, but watching those few stitches holding 4500 pounds set the mind at ease and proves the engineering.

Stitching Through the Core. This time I simply ran  a plain stitch through the core about every 1/4-inch. Over the course of 3 trials up to 2500 pounds, the result was the same; 50-60 pounds per strand. Advantages or disadvantages? On smaller line, 5/16-inch and smaller, this is easier and perhaps less likely to damage the line. However, the problem is the distance needed for the required number of passes. Assuming we sew two lines, rotating the rope 90 degrees, the maximum stitch count is 16 per inch of line or 800 pounds of holding per inch. The second pass can be difficult (the line is compressed) and could be damaging (the fibers are more likely to be cut by the needle, as they cannot move out of the way). Neglecting that factor and ignoring the last 1/2-inch or line....

• 1/4-inch, 2000 pounds:    3 inches
• 5/16-inch, 3000 pounds:  4.25 inches
• 3/8-inch, 4000 pounds:    5.5 inches
• 1/2-inch 8000 pounds:   11.1 inches

So for larger line this gets a bit impractical; my Warp Speed sheets I would need 28 inches of stitching! Of course, they can be combined. Sew the center line first, as the line will be compressed if the edges are sewn first and the needle very difficult to pass through.  A positive is that the stitches pull down into the weave and are thus partially protected from abrasion. If the tail is to be tapered to keep it smooth, a few round stitches will be need to hold the cover down.

Myths:

• The failure of one stitch due to wear can cause zippering. Not true. In fact, in some cases, aft the eye would not break at the full capacity of the test rig (5ooo pounds) I would cut stitiches with a razor until it did fail.While this reduce the average load per stitch to some extent (20-30%), they were still immensely strong. the first example (18 stitches at 4500 pounds) was obtained after cutting excess stitches away under load!
• Pre-compression with clamps or basting down the center helps. Nope, not what we found. As stitching progresses the rope gets quite compressed (round stitches do that). Pre-compression makes it very difficult to get the needle through and results in more fiber damage.
• Even stitch tension is vital. Nope, I'm not a machine and I don't do particularly neat work. While we didn't go around leaving slack in the stitches,  an obvious corollary of the stitch cutting experiment is that moderate tension variation doesn't matter. The waxed twine merely slides a little, like a lashing, and the stress is still carried evenly.The zig-zag shape of a round stitch probably promotes this, one of the reasons a zig-zag is always used in sails, even back in the hand stitching era.

Seizing.
Plain Seizing. Surprisingly, seizing was very hard to quantify. It seems to depend very strongly on the surface of the rope and it seems clear to me that it made more sense on the 3-strand rope of old, where the strands could lock together.

Since the seizing were drawn up about 1 pound with 40 passes per inch, about 80 pounds per inch of

Pre-load. On the other hand, the line shrinks under tension, so there is probably no actual preload.

Instead of counting strands I measured the length of the line-touching-line seizing. The failure was not The force to start sliding varied from 800 pounds per inch of seizing, so a 2 inch seizing should hold about 1600 pounds as a loop. Apparently not much additional clamping force is generated by the strain as the load comes on. Not much value here, compared to stitching. Perhaps the value of seizing was different back in the day of laid natural fiber ropes, but now it is more a matter of protecting the stitching and perhaps reducing fatigue; it would keep stress off the stitching at stress below the point of sliding.
by breaking but by sliding, so there is no point in using heavier thread for strength (UV and abrasion are another matter).

Would a second layer of seizing help? Mostly a second lay prevents abrasion and UV damage. That is the way the old-time sailors saw it.

What about shrinkage with wet dry cycles? That is the greater concern, as a loose seizing is undependable.

And yet, I have used seized-only eyes a few places for many years. Why no failures? I seriously doubt they ever saw stresses above the sliding point. In fact, one of the lines I tested with was an old seized bridle line and it held without apparent strain to 4500 pounds. There were 3 inches of seizing,which brought the capacity to 2400 pounds, plus there some stitching under the seizing, used to hold things tight while working. The 2 acting together shared the load, most likely never passing 50% capacity, and the construction probably matched the breaking strength of the line. Knowing what I do now, I would have added more stitches!

An historical note: 1/2-inch hemp rope had a breaking strength of 2350 pounds. 3-4 seizing totaling 3 inches would have constituted a 90% efficient termination and could have been used make exactly shaped eyes, and tarred and made with linen thread, would have lasted as long as the line. They knew what they were doing. It just does not apply to double braid.

Wracked Seizing. 
I went back a few weeks later and tried a wracked seizing. In this case, instead of simply wrapping the line , the wraps for a figure-8 around the twin strands. I tried #4 whipping twine, #8 whipping twine, and mason's twine (equivalent to #16 unwaxed whipping twine; 1/12 of line diameter is generally recommended (1/2-inch Staset), in this case, #8 whipping twine. No change, it slid at 800 pounds/inch. Perhaps wracking turns made a difference with laid rope, they don't with double braid.

Note on photos, to right: The line broke right at it's rated strength, not at the knot (modified fugure-8), not at the splice, but in between. Both the splice and knot are very near line strength. Just 10 stitches and a small throat whipping held 2100 pounds. The knot is a modified figure-8.

 

Nylon rope is even more difficult to seize than polyester. The problem is that nylon shrinks when it stretches and the seizing comes loose. In fact, even seizing a nylon rope o protect stitching is difficult in high-load applications, because it comes loose when the rope is highly loaded. You could seize when the rope is under high tension, but it's easier to cover it with webbing  or even heavy duty heat shrink.

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The moral of the story? Stitched eyes can be quite strong and reliable. They are even quite forgiving of poor technique. They are far more common in industry than spliced eyes. However, they do not have the same abrasion and UV resistance and should be protected with chafe gear. Seizings look strong but are best thought of as protection for the stitching underneath.

Because of variability in stitching method and rope, and the greater exposure of stitched eyes to UV and wear, it is certainly good practice to apply at least 3x the calculated number of stitches. It's easy to and gives a margin for wear.

My stitched and whipped eye (100-pound Kevlar thread in this case) should have a strength near that of 1/2-inch Warp Speed (stitching and whipping = 25*4*(100/50)*62.5 + 3,000 = 15,500 pounds), although the winch would fail, clew pull out and forestay collapse long before that!

Can't Splice Old Line? Try a Sewn Eye.

rev. 10-27-2013, rev. 8-1-2024

Splicing is the gold standard for forming permanent eyes and joining lines; unfortunately used double braid generally lacks the flexibility required for splicing; the cover won't open and the core won't slide. Knots are a standard solution and work in most cases; yes, there is some loss in strength, but lines generally die from chafe and I can't remember having one fail at the knot, other than in testing. But sometimes there simply isn't enough space or a knot will snag.

Seizing is traditional and just as reliable as ever. I've seized a dozens of eyes over the years and never had a failure. I helps if you cover them for UV and chafe protection, but if the seizing is double layer like the old days, the outside layer is the UV protection and the inside layer holds the load. But seizings are long and stiff and can hang up, since the tail is neither covered nor tapered. So occasionally I use a hybrid sewn/seized eye. This isn't an idea I dreamed up, it is an old one that I read of many years ago in the New Glenans Sailing Manual. They also speak of stropes, the precursor to soft shackles.
  ____________________________________

First I remove about 1 1/2 rope diameters of core. This will allowed the end to be stitched down to create smooth taper. The New Glenans Sailing Manual calls for 3 1/2 to 4 rope diameters of core and I've got 4 1/2 diameters without counting the taper.

How much stitching is enough? Select a whipping twine that is 10-15% of the line diameter; for example, 7/16-inch line is about 11mm, so #10 whipping twine is a good match.  In this case I used 90-pound Kevlar this time, just because I had it and because it is about the same strength as #10 twine. Doubled that suggests about 12 round stitches on each side to reach 5000 pounds. Sure, it is not loaded in-line, but most of the load (about 35-55% in testing, depending on the roughness of the line) is actually carried by line-to-line friction, just as in a seizing. Also remember that due to friction of the eye around the shackle or fitting, the free end is only carrying about 25-35% of the load, depending on line stiffness. The results is that the stitching is only carrying a working load of about 1000*0.30*(1-0.45)=165 pounds and a line failure load of about 825 pounds (assuming 5000 pounds for aged 1/2" Staset); not nearly as demanding as you would guess and as usual, the splice is stronger than the line. The stitching is scattered so that some are in every part of the core.

Whipping Twine Summary

Twine Number        Diameter       Strength

#4                            0.4 mm         35 pounds

#8                            0.8 mm         70 pounds

#10                          1.0 mm         90 pounds

#15                          1.5 mm         130 pounds

(In retrospect Kevlar may be a  poor choice, given its poor performance in flexing applications. Although the stitching does not flex, more polyester twine might be more reliable.)

After stitching I add 2 seizings for good measure. The throat seizing is the important one, as it keeps the first row of stitches from getting over loaded.
(Skip the seizings; they add nothing and become loose as the line shrinks under load.)

(Crowd as much stitching into the first inch of the tail as possible if working with nylon; the nylon stretches so much under load that only the first inch carries any real load. Think about playing tug of war with a bungee cord. A double pass, center and edge, can be a good way to do this.)

Then cover it with something for UV and chafe protection. Heat shrink is fast and poor choice (doesn't last). Webbing is better in severe applications... like winching a sheet along a shroud.

The New Glenans Sailing Manual only calls for 3 1/2 to 4 rope diameters and I've got 4 1/2 diameters without counting the taper.

8-1-2024. The video demonstrates a slightly different method, called a sailmaker's eye. It is not quite as strong in lines larger than 1/2-inch, but it can be >90% strength in smaller lines and is more abrasion resistant for applications where it can't be covered. The clips were made for a Good Old Boat video.

  (Even though the load is carried in the first 3-4 diameters, pull testing shows that stitching in diameters 5-6 does contribute to splice stability. Just don't count those threads in the calculation; only those in the first 4 diameters.)

(Note: when I discovered the line was Warpspeed, 22,000-pound test, I added another solid layer of whipping. Also good for abrasion.)

Notice the strope in place of a shackle. Less steel to flog, removable, and as strong as the larger line because it is doubled.If the eye is small it can't fall out easily. The failure point is always the same; the loop cuts off the stopper knot.  

After just 2 days I learned that heatshrink is not enough, not when winched across a cable shroud. I also switched to Amsteel soft shackles (home-tied) for a bit more long-term security. That and the they fit the clew better; the yacht braid stropes worked fine and would no doubt last for years, but I really didn't have room for 2; the big knots would jam on each other. The yacht brain

strope would be fine for a single set of sheets.  
  

------------------------------

 rev. 1-1-6-2014

I'm currently engaged in a much deeper exploration of the subject for an up-coming Practical Sailor article. I've learned more than a few things, a few highlights of which I have added above in RED.

Freshwater Tank -- Are Bugs Swimming the Back Stroke in There?

6-13-2014, rev. 8-1-2024

According to the plumbing code and AYBC, there should be a screen on the freshwater tank vent to exclude mosquitoes, other bugs and reduce dust. But many builders, including PDQ, leave these off.  On the PDQ 32 the vent line simply goes up and then down through a mushroom fitting under the bridge deck. Yup, I've seen bugs in there, so while I was up-grading my water system, I decide to fix this too.

Clean, huh? Though a strainer won't stop bacteria, it will reduce convective airflow.

The solution was to splice in a simple strainer. The code calls for 16 mesh, but no-see-ums are known to crawl through that, and 50 mesh is common anyway. This strainer is large enough to manage any air venting flow and serve as an over-flow too, though when filling fast, water will back out the fill even without the strainer in place.

Shurflo 255-323. Be warned, PDQ used 1/2" hose on 5/8" barbs. I stayed with the 1/2" hose (cleaned out the gook with a 1/4" rope, soaped up and fished back-and-forth a few dozen times--tie knots in the ends while you're scrubbing) and used a little K-Y to get it back on the 5/8" barb after cutting a fresh end. Great stuff for working with hose.

The PDQ is a catamaran and the pressure water system is located on the bridge deck, between the hulls. Thus, the tank vent actually discharges down, through the floor, about 20 inches above the water line.

A 15 minute fix. No more bugs. Fewer bacteria and mold spores. Mostly self cleaning, every time I over fill the tank, but also easy to clean and easily accessed. I suppose I should clean the tank one last time, but the new filter is doing great.

 

 Look what we found in the spring! Bugs that crawled in the vent.

 

And look what a dockmate found! A tree frog climbed in, and they had eggs coming out the galley tap! Extra protein?

 

Woodwork: the Finishing Bench and the Sea Chest

10-17-2012, rev. 8-1-2024

 

 Certain objects cry "nautical" from the first glance: A wooden ship's wheel, a brass lantern, wooden shell blocks. Not practical, though, and cliche on a modern boat. There are items we accept as functional and usual: a stitching palm, a life ring with the yacht's name, coach whipping on the wheel or tiller. And then there are half forgotten objects with real utility, in my opinion at least, underutilized.

 The Finishing Bench. Still used by traditional sailmakers, a simple bench holds the implements used for roping, adding a grommet, or mending. I made this one about 5 years ago from nothing but scraps and a little varnish, a very pleasant way to spend a few winter evenings. Mostly it sits by my favorite chair, holding magazines and what ever books I'm reading, but my stitching tools and materials are ever present on the far end. Yes, I catch a pant leg on the bench hooks now and then. But whenever sail work is required I carry it out in the front yard where it serves its traditional purpose very well. Smaller projects get sewn up right in my chair, reaching back for traditional tools and materials that are kept conveniently at hand.

No directions. I just followed an old illustration and fit it to the scraps I had. I suppose they were generally built that way, from bits and pieces.

• Cleats on the underside reinforce the legs.
• Numerous holes and vertical dowels on the cutting block secure spools of thread or hold knives and fids. Some holes only go part way through, holding needles and small things.
• Dowels angled just above horizontal on the cutting block end hold scissors, palms, webbing, thread, and a small ditty bag.
• Bench hooks need to be sharp, and it is handy to have 2 different lengths. These were bent from steel tent skewers.

 

 

That first step is about 30 inches.

Sea Chest. Although my boat has some cavernous lockers under the bunks and salon seating, there are never enough small lockers handy in the staterooms. Additionally, getting into the bunk is rather athletic, as the bunks are high and without steps. Additionally, a seating platform with storage blocks the way to the bunk, and it is at an unfortunately awkward height, far too high for putting on shoes. At first I built stools, but they were really too small and too single purpose. A small sea chest, fit to the space, is the perfect answer.

Though I didn't take any pictures of the construction process, anyone with the carpentry skills to make a box should be able to do just as well.

• Traditionally these were painted a muted color and only the inside of the lid would be decorated and bright. Paint best withstood hard knocks, and the interior decoration reminded the sailor that his chest was the one thing on board that was his. However, my wife liked it varnished--all of the reproduction examples I showed her on-line were varnished--and it works, I think. Perhaps I'll paint it later; if so, going from varnish to paint is more reasonable than the reverse process. Because I originally planned for paint, I made no special effort to hide fasteners; I focused on building it strong enough for regular use as a step. I think I like the utilitarian look.
• Strap hinges are traditional, but a piano hinge fits better, and I had a cut-off. I cut a recess for the hinge so that it closes perfectly, with no need for a chain and with all of the weight transfer directly to the sides.
• Be mindful of protruding hardware. While a few scratches didn't matter on a whaling ship, they do to us. For example, the handles were traditionally attached with exposed rivets, but I substituted counter sunk brass bolts. Same on the inside; nothing to snag on clothes. I smoothed all interior hardware with a Dremel tool.
• Side Relief. A characteristic of sea chests is that the sides lean inwards. The practical reasons for this only became obvious as I measured the intended space: if slammed against a bulkhead (ships move) the lid will still open and the handles are still accessible; they better resist tipping; there is less binding when push into or pulled from a tight space. The trim strip on the bottom also helps; it takes a beating and thus should secured with screws, not brads.
• Rope handles. Mine are boring. Starting with a bit of old 3/4-inch 3-strand line, I placed 2 whippings about 9 inches apart, unlaid both ends for about 3 inches, and pinched the strands between handle blocks and the chest sides (I had drilled 1/2-inch holes with the handle blocks clamped together, making half-round groves for each of the three strands), trimming the excess. Tape held the strands in in the groves while the bolts were tightened. Strong and compact enough to fit the narrow space I had to work with, but not fancy; I lack the marlinspike skills to do a proper job. However, even simple rope handles are strong, comfortable, and non-scratching.
• Square the sides up on a flat floor before screwing them together; you don't want a rocker. Likewise, true the lid to the top; otherwise the hinges will work loose in time. When working with scraps, never presume anything to be square or true.
• No latch. I didn't see the need for my purposes
• Hold down. In the stern of a catamaran the motion is never lively enough for the chest to move, but I can certainly imagine boats and places where this is not true.
• Lid cleats. These not only hold the 2 boards that make the lid together as one, they are also carefully tapered to lock the lid in place when close, transfer lateral forces when used as a step to the sides and away from the hinge. Remove the hinge and the closed lid does not shift, not a fraction of an inch.

 

Something more traditional

Tool Box. There is a window shelf outside the head that is of no particular use. Sometimes we keep shoes there. Because of the hatch, spray is always a possibility, limiting possible uses. Nothing tall that might block the hatch. I reason a light box I can pick up and move will find some purpose and stow some clutter. I like the semi-traditional look, it kind of works on a sailboat that is only semi-traditional; though sailing is by nature nostalgic, multi-hulls have to keep there distance.

A simple scrap lumber project, it is made of 3/4-inch pine and 1/4-inch ply. What will we keep in it? I won't know until we've been cruised with it for a while.

__________________

All from scraps. In the first example, I used a few boards that were left in the basement by the previous homeowner and a bit of left over shelf. The dowel was from a discarded seasonal decoration. In the second example, I salvaged a neighbor's old garage shelves and some line left over from a Practical Sailor testing article--the stuff we found under a dock and cleaned. The brass bolts--16 x #8 x 1 1/2"--were also left overs from a writing project--laboratory corrosion testing of gasoline anti-corrosion additives. I think that is the way these sailor's tools would have been made, from the bits and pieces. The finishing bench was free, the sea chest a $2.45 project (a bit of 1/4-inch plywood for the floor--I wanted something lighter than the scrap I had on hand). The tool box was even cheaper and quicker, though I took my time and finished it neatly and well. Very affordable.

When is Smaller Better?

9-16-2017, rev. 8-1-2024

Human nature--or at least American nature--is to covet and to believe that bigger is always better. But if that were true, I wouldn't get so much enjoyment from my thrice weekly bike rides. My theory with rode vehicles is that fun is inversely proportional to size:

• Skate board or in-line skates. I haven't been on skates in a several years, not since I injured my knee. Maybe it's time. I have several pairs.
• Bicycle. 
• Sporty car
• SUV
• Van
• Winnebago
• Semi-trailer

 Actually, the last two are fun for the first little bit, just for the adventure. Each has certain utility. But if I just want to head out for a few hours of smiles, the bicycle wins, hands down. I even switched from SUV (Subaru Forester) to sporty car (Mazda 3 hatchback) a few years ago, and I'm loving it (and the 43 MPG doesn't hurt either!).


 For the last six years, this aluminum and carbon toy has helped keep me in shape. And it is fun.

Does the same hold true for boats? I think it does, perhaps even more so if we include the difference in maintenance requirements. Big boats are work. And even more than the bicycle-to-RV continuum, small boats teach sailing, while large boats teach systems. Everyone should learn to sail a small boat first.

Not counting a few rentals, my first sailing experience was eight years with a Prindle 16 beach catamaran. When the wind gets up, small, over-canvassed boats are strict teachers regarding sail balance, trim, sea state, and situational awareness. Of course, I couldn't leave well enough alone, and I eventually added hiking racks and a bow sprit for a chute, making her quite the rocket.

I got married, decided to get something just a little more group-friendly, but still lively. The Stiletto 27 is really just a beach cat on steroids, just as fast and only a little more stable. This is not a boat to learn sailing on; capsize is possible, and unlike a beach cat, you can't just flip her back on her feet and laugh it off. She taught me more conservative sailing and introduced me to cruising. Although her accommodation were primate, she took us on some long trips (weeks), germinating the cruising bug. Although she was not as nimble as the beach cat, she was still quick to tack, would motor at 12 knots, and we once hit 23 knots with the chute up. Scary. And fun.

Soon I had real cruising ambitions. A larger boat--my current PDQ--would accommodate the family and some of my daughter's friends on long trips in a reasonable level of comfort, and with a fair turn of speed. Motoring is only 7.5 knots and sustained sailing is generally 7-10 knots (not surfing), but we can maintain those speeds for 10 hours, because she is much less tiring to drive. In fact, her stability is so great she is on autopilot 95% of the time. I measure wind speed by a gauge on the dash and direction by wind vane, not by the wind in my hair. She's comfortable in a near gale in the winter, but now I'm insulated from the actual sailing. And yet in a good blow she does come alive, and 9 knots to windward is not unusual. She can really drive.

But it's not like riding a bike. The intimacy is lost when a boat becomes large enough for cruising. In bad weather we want to be insulated from the elements. We call that comfort and seaworthiness. 

The next boat, just month after writing this, turned out to be a Corsair F-24, which I had coveted since the first came out. It looked like fun. It is. I consider it my daysailer for grownups. Lots of strings to pull, easy enough for one person but easy room for 2-3, fast enough, weatherly and fast to tack, yet stable and seaworthy enough.  I'm going to keep her for a while. I might change the waters rather than my boat if my abilities change.