Monday, June 27, 2016

How Long Should a Tether Be?

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'.



I like custom sizes. These are fabricated from 8mm climbing rope with sewn splices.

Saturday, June 18, 2016

Renovating a LifeSling


A reader wrote into Practical Sailor that his LifeSling had basically fallen apart, the result of UV exposure. The blue webbing straps tore under hand pressure (a write up in PS will certainly be forthcoming). The age was uncertain (probably more than 20 years) and I believe it may have been stored upside down, since the straps should be on the bottom, completely protected from UV.

But the other issue is that the LifeSling cases are notoriously UV sensitive, or rather parts of them are. I bet the failed LifeSling was in a failed cover. The coated polyester itself is pretty durable, but the stitching goes and all of the Velcro fastenings go at about year 5-10, depending on the latitude and whether it sits on the rail year-round, like mine does.

Packing. Packed according to the instructions, all of the critical parts are well protected. The line (VERY vulnerable is in a tube in the center, with the sling over it; triple protection. After 19 years, mine is still pritine. The tail of the rope that attached to the stanchion base is covered with webbing. Although the webbing is sunburned, the rope is fine.

I cut a section open to look. Note that there are a few failed strands on the lower left, where sun must have peaked in. Polypropylene is touchy stuff.

Velcro Top Closure. I dislike the UV vulnerability of Velcro, so I replaced it with a tubular webbing and pin system, something like a door hinge. Just pull the red flag. This endured for 10 years without damage, so I left it alone this time. Durable, secure, and fast.



Velcro Ties. Really, a stupid application, when a knot will do better and last forever. Again, the Velcro fails in 5-10 years, I cut the remaining stitches, attached a 2" x 4" webbing strip on the inside with Sikaflex, a 4" circle of Sunbrella on the outside with Sikaflex, and punched a pair of holes. I was going to install grometts, but the laminate was too thick, about 1/8", so I simply threaded webbing.



Stitiching. Some of the seams had gone at 10 years, where they rubbed on the rail. I hemstitched them 10 years ago using whipping twine, and they are still fine.

Paint. I had some white vinyl inflatable paint left over, so after a good TSP scrubbing I painted the whole thing to provide some sunscreen (I masted off the instructions--that section seemed OK and has no seams or stress points). I have used Kilz primer plus house paint on projects like this before, through, so don't run out and by special paint.

I will 20 minutes work I should get another 10 years from the cover. Since the initial cover needed repairs at 10 years, I'm OK with that.

Sunday, June 5, 2016

Mooring Between Pilings

With the approach of hurricane season, I look forward to another season of watching people add lines without a plan. They double lines to cleats that are too small,  underestimate slack requirements, and put lines the wrong places. I've got a long article on dock lines and forces coming out next month in Practical Sailor. I

got a lot of funny looks, sitting on the dock edge during gales and squalls, taking reading on on line tension on both my boat and others using a block and tackle and load cell. Just two thoughts here:



Instead of adding a spider's web of lines that take loads in unpredictable ways, try a simple pattern of full spring lines. If you squint, notice how they form 4 over lapping Vs, with redundancy in every direction. Additionally, no cleat has 2 lines on it. (the double green/orange lines refer to data in the article--they are single lines.) This is how I tie my boat every day, and it really minimizes motion. Because the springs are actually continuous from piling to piling, they only take seconds.


Which brings us to the mind-ships cleat hitch. Because it is only one line but must be secure in both dirrection it is just a little different. Basically a standard cleat hitch, with a crossing turn after the locking hitch to reverse the rotation, and one more round turn. Very easy and clean.



The end result is that I can break any combination of 2 lines and still stay in my slip. The other result is that I don't wear lines, because they are always sharing.Easy and robust.

I have another article on  bulkheads in progress. More load cell testing. The interesting take-away from that one is that I use polyester spring lines (on bulkheads only--nylon between pilings) to reduce fender movement.

For storms I would add a few more, but that is another story.

Saturday, May 28, 2016

Cambridge, Oxford, Fishing, and the Joys of Working Part-Time

I visited Oxford once years ago for a log canoe race. It hasn't changed much, which is good. The guide book says the holding in Town Creek is poor, which I do not understand (I anchored in the wide spot across from Squeazers. I also suppose it could get crowded in season, but the cove to the east is huge for the shoal draft (lots of 4.5-6 feet).

Just a short walk over to the Strand.



I toddled over to Cambridge the next day. Some load testing, but nothing photogenic.


One the way back home the next day, a little fishing.

35 inches, 20 pounds, on a hand line with a plug. Like pulling in a tire.


A good break from, well, my break. Actually, a lot of time was spent trolling for ideas, measuring stuff, and taking detailed photos that are needed for articles but, frankly, are dull.

Saturday, May 21, 2016

The Last House on Holand Island

If you've ever sailed down to Tangier or Smith Island, you've probably seen THIS HOUSE on the horizon.


It wasn't always that way:
http://sometimes-interesting.com/2013/04/08/the-last-house-on-holland-island/

However, it is gone now, below the waves.

Friday, May 20, 2016

Three Days of Pure Relaxation

For those or you that either didn't notice or have forgotten, I also have a page about kayaking on the Chesapeake; The Other Chesapeake, with a link on the right. Lots of special out of the way places, mostly not in the usual guides.


Day One. Deale to Warehouse Creek. Light winds, one 28-inch rockfish, good kayaking.

 Making 5 knots in 4.5 apparent.



Day Two. Paddling in the morning, a brisk sail to the Wye River, followed by hiking and paddleing in the afternoon.

Over 275 years old and going strong.


Day Three. Sailing home in light winds.


Hauling this in while still making 5-6 knots was a bear. But it's hard to kill speed with the chute up.



Saturday, May 14, 2016

So What Do You Do When Your Boat Drags It's Butt?

Glue on and extension, of course. You can claim shes now a 37-foot boat with a swim platform!


The amazing thing is that this is the Gemini Freestyle. They took the Legacy, removed the cabin, and it is STILL overweight. But they have lots of interest, suggesting there is a market full of sailors that that don't know boats and who will believe what they are told, if it looks good and it's cheap enough.

I used to actually like Geminis. Now I'm sad.

Tuesday, May 10, 2016

A Better Secondary Anchor Rode?

Rev. 6-10-2016

For the primary rode the conventional answer is chain. Strong, cut-proof, fits a windlass, well proven. It requires a snubber to keep the load reasonable if you are in shallow water (not enough centenary), but other wise, pretty fool proof, and we can all use that.

But the requirements of a secondary rode are different:
  • Chafe protection counts, but since the boat will not swing if set in a V, the problems are far less. It is also not our sole source of security, should it fail.
  • I primarily use a secondary in very soft mud; low cutting hazard, but it must set deeply.
  • Light. Must often be set from dingy or kayak and I have carry it around the boat.
After 20 years of sailing cruising boats I had an "ah-ha" moment, something that should have been obvious a decade ago. But I guess it takes time for the bits and pieces to come together. I was brainstorming through and anchoring puzzle with another sailor when the right way to use Dyneema in an anchor rode came to me.

Anchor + 20' Dyneema + 10' chain + nylon to boat

The trick is to use a 20-foot Dyneema leader right on the anchor, followed by chain, followed by nylon to the boat. The advantages are:
  • Anchor sets deeper. The Dyneema is much thinner than chain, presents less setting resistance, and results in a stronger set with the same force. Limited Practical Sailor testing (February 2014) suggests going to wire or Dyneema increases holding about 25%.  Thus...
  • A smaller anchor may be feasible. I'm not suggesting tiny, just eliminating ridiculous up-sizing of storm anchors.
  • Better strength in wind shifts. A deeper anchor is more reliable.
  • Less weight on shank. Fortress states that excessive chain weight on the shank can press the shank down into the mud, impairing setting (I've experienced this and discussed it with the factory). A pivoting fluke-specific problem, but Fortress is probably the most common secondary on the Chesapeake, since it is great in soft mud.
  • Better catenary efficiency. The chain can't serve as catenary once it is underground, can it? Thus, from a catenary viewpoint, the first 10-20 feet are completely wasted in soft mud. Instead, the chain weight is place 20-30 feet from the anchor, where it can do some good. I save the weight of 20 feet of chain, which is a bunch when you are carrying the anchor in one hand and sloppy loops of chain in the other. Which brings us to...
  • No need to carry the chain at the same time as the anchor. This will save a lot of scratched decks and some backs. Carry the anchor, and then make a second trip for the chain.
  • Less weight to lift out of the locker. And instead of lifting with 2 hands and nothing for balance, you can lift with one and hold on with the other.
  • Better safety on-deck. Instead of having both hands full, one hand is free for balance.
  • Less weight when lowering. Just the anchor.
  • Less weight when raising. Just the anchor.
  • Less mud to clean up. Dyneema does not bring up mud.
  • No additional fittings. Splice eyes in both ends (Brummel for chafe), luggage tag it to the last link of chain and use the existing shackle on the anchor (seems like a chafe point other wise). The rode can be spliced to the rode as well, if desired.
The Caveates? I don’t think this is for everyone or for every situation. It makes sense if:

  • Secondary anchors deployed as a V, because there is no yawing. 
  • Anchor deployed by hand, because the chain is easier to handle. 
  • Soft bottoms with no large rocks (shells and small mobile rocks are OK).
  • The force to recover the anchor goes up faster than the additional holding power, and Fortress anchors were never easy to recover. This is the down side of a deep-setting anchor.

It does not make sense if:

  • Single anchor 
  •  Deployed by windlass. Chain is better and the gypsy will not handle Dyneema. 
  • Anchor is too heavy to deploy by hand. 
  • Rocks or coral. All chain is best.
  • Strong tide. A Fortress needs the weight of chain to get it down if there is a strong tide. May be applicable by lengthening chain section.

What about cutting? When moored in a V the rode does not move side-to-side much, even less so when underground. It will drag forward, into oyster and rocks, as the anchor sets, but it will be  low-speed action and there will be no sawing action; I will keep an eye on this.Dyneema is also some tough stuff to cut; I've had to sharpen a lot of knives when splicing. Finally, a secondary rode is not all-or-nothing like the primary; if it cuts I am still anchored. If I were paranoid, I could go up a few sizes to something 2x as strong as the chain and still have a very light, flexible, thin rode. Overkill.

Threading webbing over the splice (the Dynema is inside) or even whole leader) would make it as cut resistant as steel cable. Because the webbing is thick, floats, and is not under load, even a sharp knife can't hurt it. If it rubs on a rock, it moves with the rock. I have tested this combination side-by-side with steel cable and found the cut resistance to be better in most scenarios. Even more important, when the webbing gets scruffy, it is $25/foot to replace, keeping underlying the Dyneema good as new.


How long does the leader need to be?
  • Setting improvement. Probably 5' would be enough. That would take the weight off the shank and give the anchor a good start. after that I can either go to chain or at least cover the Dyneema against cutting and to improve grip. For now I will leave it bare so that I can see where chafe and cutting occurs.
  • Long enough to reach from locker to dinghy.  For me that is about 15'.
  • Long enough to reach from the set anchor to a cleat to break it out. I really don't like chain grinding against the hull during recovery. That means 3(underground) + 4(freeboard) + 7 (water depth) + 2(cleating) + 4(allowance) =  20 feet. In fact, this is the thing that always limited my leader chain to 6-8 feet before; the chain need to end before the cleat, or start after the cleat, and 8-20 feet is the scrape-the-ull range.
Thus, I'm thinking it may be very practical to run a cover over the Dyneema, either full length starting from the anchor, or just the last 15 feet. The challenging part is covering the splice, since bury splices are traditionally left naked. A conventional double braid splice is all wrong for Dyneema (much weaker), and the Brummel only makes it more bulky. I could cover it with 9/16" tubular nylon webbing, which will make it is cut resistant as steel cable. Cast plastic covers are also use over industrial eyes.

Why not just a kellet in the same position as the chain? It might be easier to handle. I'm not sure of these reasons, but they are mine.
  •  I want catenary effect.  If the weight buries I loose that.
  • Chafe resistance at the mud/water interface where the motion is possible. the chain provides this.
  • I had the chain.
  • A weight would resist burying unless streamlined; I would need a big, strong, torpedo with eyes at both ends. I don't where you get that.
  • Dropping a kellet on deck is much worse than dropping chain.
Do we need the chain at all? I'm not convinced that catenary does anything for a Fortress anchor. All of its hold generates from deep burying, and once it engages, the nagles are driven more by the drag of the shank and chain than the pull angle, so long as the scope is reasonable. Additionally, chain makes recovery that much more complicated. I would like to try using the mast winches, though simply wrapping a turn on a bow cleat and using the motor is good. I also beleive that at least in the Chesapeake, a chain is not needed for chafe protection, not when used as V (less motion, main as back-up). I will be removing all of the chain for the rest of the summer.


I can carry the anchor to the locker and stow it without dragging the chain!

 In fact, setting a secondary anchor becomes an easy job for a kayak. Try that with a pile of chain.

I put this together from materials I had on the boat. Perhaps the Dyneema could be a little shorter and the chain a little longer. I may fit the Dyneema with chafe gear or god to a tougher products (New England Ropes WR2 has been very impressive in some tough chafe tests, nearly equivalent to wire rope). But for the moment I will test this flawed system and watch where chafe occurs. Before I declare victory I need a full season under my belt, but the initial trials were pure pleasure. This is now my standard set-up.

Much easier to work with and a faster and better set. Nice.

Sunday, May 8, 2016

Irony Splice

Joining chain to rope in a manner that allows it to feed smoothly has always been something of a challenge. Back in the day of weak chain and hemp rope, a 2-strand splice was developed to allow bulky rope to fit through a link. One strand was unlaid way back and the remaining strands go through the link in opposite directions, laying flat and sharing the load evenly. Even with the los in strength around the link, 4 strands were as strong as the 3 strands of the rope. One of the strands would be laid back in the empty groove and terminated in the manner of a long splice, and the other back tucked like a 3-strand eye splice.

Feeds through a windlass like silk

Then ropes got smaller and stronger, and a simple 3-strand back splice or crown splice became the standard. The smaller line was as strong as BBB chain. Then we introduced G43 and G70 high tensile chain. By the time we use a rope as strong as the chain, the splice was too big for the windlass gypsy, and so the irony is we wind ourselves returning to 19th century splicing technology.

It is a little more difficult to get the strains even, and the spice takes a few minutes longer, but you gonna love the way you windlass feeds. No more jams!

-------

The name "irony splice was coined by Brian Toss, and this method is well described in his book, The Rigger's Apprentice.

Friday, April 22, 2016

Remember this Vega?




Sailed around the America's, via the Northwest Passage and Cape Horn, this Vega 27 lived an adventurous life. Now she can be found in the "broken dreams" are of the Herrington Harbor North boat yard, worn out and done.



Kinna sad. Simple boats, but a number of Vegas had traveled far.

Solo the Americas