Stitching and Chafe--Not All that Vulnerable

I've been busy testing coverings and coatings, certain that stitiched eye needed consierdaerable protection. But then I started test the eyes themselves. First I sewed a pair of eye in 3/8" Samson XLS, both with the stitch count limited to break at about 2500 pounds. I could sew a stronger eye, but stitich strength is easier to measure accurately when you are not too close to the line breaking strength (stitch/rope interaction become important beyond ~ 60% BS).

 The upper is Robline #10 whipping twine, the lower Robline #10 Dyneema whipping twine. The Dyneema is smaller, but the strength is similar.

Then I abraded each on fresh-sawn yellow pine for 20 minutes on my abrasion machine.  This is just long enough to wear through the line cover, as can be seen.

The polyester stitching is worn (74% of original strength when pulled to failure), but so much as the cover, which is just into the core.

The Dyneema twine suffered no measurable wear (failed at calculated value). However, the cover is gone below the splice, and considerably scuffed where the Dyneema twine did not protect it.

It seems the polyester whipping twine is a more abrasion resistant weave than the cover of the line. Perhaps the wax helps. So while I will still cover my sewn eyes to protect them from UV and wear, I far less concerned than I was. I also need to rethink Dyneema twine; For reasons of stretch,  polyester will remain the choice for nylon webbing and line, but for polyester and Deneema line... I need to do a little more testing. Polyester makes slightly stronger constructions, but perhaps not in the long run. The jury is out. 

Conclusion: polyester twine was basically as durable as the line, and the Dyneema considerably more so. Interesting.

As for UV, the damage is more uniform that we think. This splice is cover only, but the line broke elsewhere.

Wire Cable vs. Stanchions

I've been investigating chafe protection and Amsteel as it relates to lifeline replacement. Certainly, wire cable is the gold standard. But now I'm not so sure....

After an hour of sawing back-and-forth through a 10mm hole in SS tubing, it had eaten a nice grove and built a corresponding burr on the inside:

After 1 hour.

And though the wire did not look very worn, when we flexed just a bit there was a different story....

Also 1 hour. The damage was not apparent until flexed. Most of the broken wires were inside.

How did Amsteel fare, in the same hole? Before the wire created the burr? Much better with very little wear in an hour. Afterwards, no as well, but still the damage was little more serious than that to the stainless cable. Given that I plan to use 1/4 Amsteel, which is nearly twice as strong as the cable to start with, I'm feeling OK. 1/4-inch it is sufficiently strong that even after 10 years in the Chesapeake sun (not so strong as the desert southwest or tropics) it should have equivalent strength, and with proper chafe guards, the strength loss in the holes should be less than wire. Protected from the son, the pass-troughs may be the strongest part by then.

How does Amsteel like the new hole? Not so bad as you might think and about the same as it like the raw hole, just after I drilled it without deburring. By way of comparison, after the hole was deburred it showed ~ 1/3 this much wear, and if coated with Spinlock RP25, no wear after 2 hours (840 cycles).

After 1 hour on the wire cable gouged hole. About the same as a raw drilled hole, yet much worse than a polished hole.

Alternatively, I tried a dyneema anti-chafe sleeve floating for 3 hours. It could have run for 100 hours without showing wear.

A floating dyneema cover reduces wear to zero.

By way of comparison, this hole wore a polyester line through the cover in 20 seconds and in half in 5 minutes. Amsteel is tough stuff.

No chafe protection? This is the stanchion...

... that caused this.

It's All About the Feet

Ask a climber what gear is most important--the rope, the pitons, the pack--and they will always answer the shoes. You weight is on your feet and your control of that contact point, not strong arms, gets you up the crag.

With ice it's little different, but shoes are now covered with spikes in the form of crampons, and the fingers replaced by ice axes. While the axes are in your hand, in your face , and most immediate, it is still the feet that provide the base. If the feet sketch about, neither security nor style are possible. And so shoe failures are a major problem. I could just buy new ones, but plopping down $500 for something I will use a few times in a good year and for only so many years into the future is bitter, and I like many things about the ones I have.

 Heel Lift. Traditional rubber strap lacing does a fair job of holding the crampon to the but, but with less than rigid boots and vertical ice,he heels can lift an inch or more.

Enter some non standard lacing, or rather something similar to the new heel cup bindings. By threading the ankle wrap through the heel strap, the hold down force is increased about 30%. A new twist on old tech.

I like the Balatoros for their light weight, easy hiking, and agility on ice, but the same flexible ankles that make them fun, make them tough to front point for long periods. Previously, my Trezeta Sherpas did the job, but they suffered from total separation during a Great Falls ice climbing trip a few weeks ago.

But with bulk removal of rotted foam rubber and massive applications of polyurethane, perhaps they will have new life. But I'm not holding my breath. Perhaps they can finish the season, perhaps a few more. Ugly too, though that probably helps.

More Ice

White Oak Canyon, this time. Chris and Drew.

The original destination for the day's expedition was Overall Run, but we elected to approach from
Skyline drive and the Park Service elected to close a drive due to icy conditions (1-inch of snowfall). Faced with a barricade, we retreated and drove to White Oak, where predictably good conditions resulted in 3 leads, numerous top ropes, and tired bodies.

Chris honed gear management leading WI 2 on the lower falls. We both bouldered on the cauliflowered base, marveling at the flow, the lace-like structure others travel to view and photograph, but for some reason we are drawn to scale.

Further up the canyon we found the south side to be unstable and thinner than expected. We talked about possibility, then something substantial fell and better judgment prevailed.

The grotto was nice and cold, though and the steep walls nearer the falls provides some short but stiff leads and top roping. And quiet. No company other than the thunk of ax and the crunch of front points.

Nice.

Ice

--Visit our guide to climbing ice at Great Falls--

Although this latest arctic blast has my boat securely frozen in her slip...

Virginia takes on a different aspect, mid-winter.

(50 yards north of the Microdome, Great Falls, Virginia)

Drippy places, unappealing to summer rock climbers, become a playground...

... and thin ice holds a special challenge. (Left of Gorky Park, Great Falls, Virgina)

 

Classic 60s crampons, making the grade; My fancy high tech boots exploded the week before, but old school hangs in there.

Twine Numbering--They are not Uniform!

As I begin collecting more rigorous data for an up-coming article, I begin testing samples from different manufacturers. I begin searching the net for published data, and I learn a few things that you might already know, and that I knew but just can't get used to:

• Different company's use different numbering conventions. Robline uses the diameter in millimeters times 10. The others pull numbers out of the air.
• Strength data is seldom published. The few data points I've found seem accurate, but mostly thread manufactures expect you to guess. Just pitiful.

For polyester twine, some average values:

Robline #4     0.4mm        10 pounds

Robline #6     0.6mm         21 pounds

Robline #8      0.8mm         50 mounds

Robline #10    1.0 mm         90 pounds

Robline #15   1.5 mm        180 pounds

If it is important to you...

• Make a loop with a fishermans bend or other strong knot.
• Wrap the line around a broom stick such that the knot is 1 1/4 wraps around from the start. Add another 1 1/4 wraps. In this way, the knot will not break.
• Hang 2-4 passes over a pull up bar and stand on a bathroom scale. Read how light you are when it snaps, subtract, and divide by the passes.

Then you'll know.

Taping

Mention tape to a sailor and they think of rigging tape, sail repair tape, and tell tail tape. If they're working on a project, perhaps luff tape or fiberglass tape. Maybe even duct tape.  But those aren't what we use the most of.

Athletic tape. Not very durable, in fact, down right temporary. It's purpose is one-day application for the treatment of prevention of sprains and strains.

I suppose I got the habit back in my climbing days, when taping for abrasion protection was standard for the rough crack climbing we were exploring at the time. Taped up like a boxer (not as thick), we would plunge our hands into 1- to 2-inch cracks lined with razor sharp crystals, twist and cam, and pull ourselves up to crazy heights. I could go through 2 roles in a day if the climbing was tough. Today we went ice climbing; the sole of my boot decided to peal wide as a whale, leaving me flapping and clownish. Tape to the rescue.

Uses on a boat?

• Tiller grip. Doesn't last too long, but renews in seconds.
• Securing rope ends while coach whipping.
• Protecting stitched eyes from UV. Conforms nicely and holds-up if painted.
• Rigging tape. Doesn't last, but is also porous and does not deprive stainless of oxygen.
• Pre-wrap in stainless tubing, so that clamps hold better.
• Protecting stainless from scratching under clamps
• Non-scratch bottom on anything you don't want scratching the varnish or gelcoat.
• Tape your knuckles before sanding; can save a lot of lost skin (as strip over the areas to be protected, then a thing ring between the fingers to keep it in place).

Like duct tape, but cloth, there are many uses. Keep a could of rolls handy.

And the "athletic" uses are endless, treating the bumps and bruises that come with cruising. Almost as vital as ibuprofen.

• Split finger tips
• Rope-pulling syndrome
• Sore arches

... and many more.

Got Rope?

I've had this 30-year old anchor rode hanging in a tree for 15 years, serving a second life as a Tarzan swing. I've got a Kevlar genoa sheet with a shattered core, no longer trust worthy for anything critical.

The rope ladder was a simple project. I've wanted something that was compact, couldn't harm gelcoat, and could be used climbing in or out of the tender. This took about 20 minutes and about 30 feet of line (2x the length + 3' for each rung). A fun night-before Christmas project, complete across my lap, with a glass of hot tea at my elbow, while watching The Polar Express with the family.

The door mat required 100 feet of 1/2 inch line and about 2 1/2 hours to complete. The knot in the middle is rather a lump underfoot, but it looks very traditional. The wrap and sewing took the real time. I soaked it with the borax/washing soda/baking soda anti-mildew blend when finished. My mom thought it a charming gift; since we had enjoyed it on the boat and in the backyard for many years in previous incarnations, it has history with her children and grandchildren.

And 2 lumps of old rope were thus consumed. Good.

Via Ferrata Tethers--Some Good Ideas, But Not for Sailing

Via ferrata trails, literally iron ways in Italian, are climbing trails equipped with rungs and safety wires that allow fit but unskilled personnel to move quickly and safely over difficult terrain. Though they date back into the 19th century, they are best know from their use during World War I, moving troops through the mountains.  Since then they have expanded to thousands of tourist routes in Europe and the United States. Since tether technology is the focus of this post, I'll leave history research to the reader; the internet is great for that.

The climber is protected falling all the way by a pair of tethers that follow a safety wire to the side of the rungs. Periodically, the wire is fixed to the face, and this is the challenge; these points are generally  10-20 feet apart, allowing for  serious falls before the tether takes, and requiring the tether to absorb a great amount of energy, more than a dynamic rope alone can handle. Dynamic ropes are rated for a fall factor of 1.8, whereas a via ferrata fall can be fall factor 5 or more.

The solution is a more extensive energy absorption system, including either friction through an aluminum plate or a tear-type energy absorber, like a Screamer.

Why wouldn't these make useful sailing tethers?

• The allowable impact force is much greater, since the load is taken on a seat harness rather than a chest harness; the human tail can take a lot more force than the ribs. Sailors need a softer catch.
• The falls are really much greater. A sailor will never see an impact beyond fall factor 1; the ISO drop testing required by the ISAF rules is based on a FF1 with a 100Kg mass.
• The end clips on via ferrata tethers are applicable and gaining popularity. The West Marine tethers are now Kong Tango via ferrata biners (pictured on tethers to right), and I like them very much. Fast on and off, one-handed even when cold and wet, locking, light, and fit over most handrails too. Because they are aluminum, they do require periodic lube and rinse. Mine have held up very well, like new after 2 seasons.
• Harness attachment. Sailors like a quick release on the tether, something that can be removed under load. Climbers opt for a locking biner, since no possibility of accidental release is acceptable. Most often the tether is cow-hitched to the harness.
• Length. Sailors like dual lengths (2-3 feet and 4-8 feet) while climbers are restricted to 2 matching arm's length tethers; they never want the clip to move out of reach (if it snags below you this is a real drag).

Certainly there are some ideas here, some worth adapting, but the application is different.

-------

Note on recalls. Because of the extreme nature of the falls and untrained nature of many users, there is some history of failures, most often fatal. In general, the causes have been:

• Fall too great. Anything of 10 feet is trouble and over 15 feet is beyond the equipment rating. The via  ferrata trails generally recognize this, placing tie points ever 10-15 feet, but risk is often part of  climbing; if it looks too scary, go down.
• Worn friction rope. Some designs rely on a rope slipping through a plate with many holes. If the rope wears through use--tour groups use them daily--the rope slides more easily and insufficient energy is absorbed. This type has gone out of production because they are too difficult to inspect.
• Poor or worn stitching, or any other construction fault, though this type of failure can result from too long a fall.

ALL via ferrata falls are bad, far more dangerous than falls on a climbing rope. They feel safer but are not. The impact forces are high and there is much to hit on the way down.

Fids

When we need something, we run to the corner store store, or worse, the mall. When we some thing for the boat, we run to the chandlery, West Marine most probably. What we need is on the shelf. Seldom do we give a thought to making simple tools, though isn't that capability what made us human? Back in the day, for a workman to make his own personal tools was central to the craft. What sailmaker bought his fids from a store? Seam rubbers and wooden fids were crafted as needed, to the individual taste and hand of the worker. Some made fids with a handle or a turk's head worked in a turned grove; this probably worked best for large course hemp lines, but on a small boat with synthetic line, needs have changed. Even my wooden fids are smooth, so that they can pass through one line, towing another. The point is they were made by me to work best for me.

My finishing bench is of my own creation, fits nicely next to my favorite chair, always holding what I need near at hand (I have another sewing kit on the boat). It is a bit smaller than old-time benches, better suiting the size of my projects.

My wooden fids were turned from scrap hardwood dowel in a drill press (I have a lathe, but the drill press is handier for this) and have been worn smooth. There is a hole in the butt to accept a towed line, when that is required.They took perhaps 15 minutes to make, and I enjoyed the process.

My hollow fids are discarded knitting needles. Ask your wife or daughter--I'm they have a few mismatched needles about--or go to a thrift store. Cut to length, smooth the outside edge with a file or sandpaper, and clean the inside edge with a hand held drill bit. I seriously doubt the commercial hollow fids were purpose built, as the volumes are far too low--they are re-puposed knitting needle blanks, I'm sure of it.