Friday, March 20, 2015

Tandem Anchoring

(Yup, another Practical Sailor project in its infancy)

While a single large anchor of modern design is generally the best answer for every situation, there are times when something more is needed. For a Chesapeake sailor the problem is a soupy bottom that won't hold anything and a fast approach squall with a 50-knot gust front. You don't want to re-anchor elsewhere:
  • Is anywhere very nearby better?
  • My anchor is already well settled in; moving will very likely mean a weaker set.
  • I've got 10-20 minutes to do what ever I'm going to do.
You also don't carry any special gear for storm anchoring. Like most Chesapeake sailors, you've got a Delta, Rocna, CQR, Mantus, or Manson Supreme on the roller, and a Fortress in a locker somewhere. The Fortress is your "storm anchor," but really, it's for kedging off mud. It has only a little chain, it's light and easy to row out (in a pinch you could swim it out on a PDF), and it has terrific holding power in soft mud.

There are many possible ways to rig tandems.Here are just a few I'm playing with.

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I've been playing with these on the beach an on my boat, so I'm not guessing, not entirely. But I have a lot more measured testing to go.






Secondary rigged to tripping hole. Terrible idea. If the tripping hole does not rip out (it has been reported--it is not made for high load), it will make the primary trip when the wind shifts and prevent re-setting; I've tested this, don't even try it.








Secondary rigged to tandem hole. Better. This is what Rocna suggested, and it is doing better in my testing. But
  • You need a Rocna
  • You would need to lift the primary to add it, which we don't want to do. 
  • It is a bugger to know if BOTH anchors are set, not fouled with chain, and that the primary set first. 
  • It's not much good in wind shifts. Better, but not much.
  • The second anchor must be smaller or it trips the first.
Could you drill your own Tandem hole? Possibly, but it will start corrosion and eventually weaken the anchor... though that depends on where you drill the hole. I wouldn't drill the shank, but it might be safe to drill in the tail of the blade in a non-structural area. Interesting. Could you chain the tandem on? Folks do it, but I bet the chain moves around, and if you chain it to a brace, how strong is that?








Secondary rigged near primary shackle. This is what you might do if there is no tandem hole. Not quite as good, same problems. Additionally, if the primary is not buried, the secondary rode can foul, and since we set them on the same rode, we can't be certain that it is (the secondary might have grabbed first and held the primary on its side).

In these first 3 cases the scope must be ~ 2 X normal scope, because the lifting force on the primary is 100%, but the pull is only 50% (the rest is passed to the secondary). If the secondary is Fortress-type, they are all hopeless; the secondary tension lifts the primary out, since the secondary is holding 70-85% of the load--the Fortress generates its holding without dragging (it is stiffer).










Secondary rigged 1-3 boat lengths up the rode. This can be done without lifting the primary, as I have done many times. Simply row the secondary out ~ 20' past the primary, set from the boat, then come up on short scope and connect the 2 rodes with a soft shackle. The secondary rode must terminate here to avoid tangles (we clip a long polyester line to it during setting and recovery to make things easy). The primary will not be fouled by the secondary rode if is set deeply in soft mud, which should be the case. You know that both anchors are set, because you power set each separately.








And what if the secondary is a Fortress? Since this is what we have, what many of us have, and what I have used for years, we need to understand how to use it. It turns out that this is NOT trivial change. In fact, because of its greater stiffness, it changes the math considerably. Since the Fortress has higher holding power in soft mud than the primary, most of the load is on the Fortress. The primary, on the other hand, serves more to keep the load in-line with the Fortress. On the beach, at least, this is by far the most robust rig.

Unlike the first 3, the scope requirement on the latter 2 rigs is not effected because the rodes are sufficiently separated. 7:1 should do fine.

_______________

So why is this last rig not the obvious answer? Several reasons:
  • Tripping. If the primary is not buried, the rode better not slide over it. Cutting is also a concern with a fiber rode.
  • Deploying. Actually, not really. You only handle one at a time. The primary is already down. Setting and retrieval are a matter of either extending the rodes to the boat (easy) or clipping a temporary extension while setting and retrieving (better).
So there is more testing to do. I'm pretty certain that the 1st and 3rd rigs have nothing going for them, based upon beach testing; the 1st is a disaster (might as well leave the second anchor in the locker), and the second is less stable than the 4th, simpler but more physical to deploy and less reliable (you can't know which anchor set). All of the first 3 can leave the primary hanging in mid air if the secondary holds and the roll out. I need to study the behaviors in mud.

Yes, I have been advised that small anchors do not scale up. I've had the small anchors for 20 years and I really do know how differently they perform compared to big brothers. But I do think the affects of geometry will scale up; bad rigging is bad rigging, and I expect the small anchors will be even more vulnerable to mistakes, which I like.

Fun stuff. I will play on the beach. I will play in the shallows. I will anchor my boat (full scale tandem) over soupy mud and pull these mini-tandems with my primaries, taking force measurements and diving to watch. A lot of playing in the mud this summer!

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Comments PLEASE! Do you have a favorite tandem rigging you would like to see tested? I will add it. I will be using Claw, Guardian, and Mantus anchors, since these come in small sizes and have close analogs at full scale. I will test in both firm sand and soup.


Friday, March 13, 2015

Winter Hangs Tough

The Clocks have been changed. The days are longer. The average temperature is supposed to be in the 50s. So how come the Coast Guard has banned boating on the upper Bay until April 15 due to dangerous ice conditions, and the mouth of Deale harbor still has 4" of slushy ice clogging it?

So we return to our regular programming, which this February has featured ice climbing, several times each week.

Great Falls, VA. Just bouldering, really, but a convenient training ground close to home.


Deck Shoes for Ice

Just starting up. This one is tall enough for a rope. And the frozen river is a death fall.

Topping out while hoping the ice is good.

And some shots from White Oak Canyon


Not really sailing weather. Not for a few weeks at least. On the other hand, the engines start, no maintenance is needed beyond a quick oil change, and the season should start with a roar... as soon as the water gets a little softer. The spring thaw will also bring a torrent of freshwater, with tree trunks and debris sufficient to make the water hazardous for props for at least another week. The plus side of heavy snow melt is a light year for jelly fish and a late season for rockfish, and that is all good.

Saturday, January 10, 2015

Dry Suit. The Ulimate in Foul Weather and Survival Gear?

Better than a Survival suit? That is the question Practical Sailor Blog asked this month. Conventional survival suits are so ungainly that sailing is impossible and they are not donned until the boat is headed down, often too late. A dry suit, on the other hand, offers the same or better agility and livability than conventional foul weather gear, with complete cold water protection (except for the head and hands). Since it can be worn while sailing, it offers protection you are more likely to have on.

But that isn't why I bought mine. Kayaking is one of my favorite activities, and once the water temperature drops below 60F, it become more and more difficult to dress safely. While I have never capsized (other than white water) on open water, there is always a hypothermia risk. Additionally, I think the dry suit will make reboarding from the water easier, because you avoid heavy, soaked clothing. Instead, you gain significant all-over buoyancy.




Not me. I'm much better looking.
Demonstrating the conversion from stand-by mode to fully sealed.


A favorite feature, and one that makes this suit (Ocean Rodeo Ignite) particularly suitable for sailors, is the standby mode. The pants are supported by suspenders and fit well, with attached socks. As shown in the above photo, the pants can be pulled up and the jacket zipped without put the head through the neck seal and zipping in, giving great ventilation. Converting to full seal takes only moments.

There are wrist seal, lotsa pockets, and a fly. The fabric is like a heavy duty 3-ply Gore Tex and seem very durable. The entry zipper is across the shoulders and doable alone (many drysuits require help). They are cut for athletic builds; if you've been hitting the pasta a bit too much, have very large shoulders, or shoulder mobility problems, go up a size; I am near the upper limit of height and weight for the medium (5'8" x 165#) and the fit was spot-on with my typical cool weather dress (long johns, fleece pants, shirt plus fleece sweater). With 2 thin fleece layers, 32F water is pretty tolerable (but the fit through the shoulders is more snug), and I've even done a little bottom cleaning like that. However, I strongly recommend trying the suit with the layers you intend to wear. Fortunately, getting out is easier than getting in, so you won't get stuck!

Note on trimming seals: the wrist and neck seals on dry suits tend to be one-size-fits-all, which is to say they are probably too tight unless you are built like a stick. In fact, over tight neck seals can inhibit blood flow to the head, which is bad.  I found the wrist seals fine, but the neck seal was miserable. Trim one ring at a time with very sharp scissors, leaving no jagged areas that could stat tears, until the seal is snug but acceptable, your adam's apple can move, and blood flow seems normal. Divers keep them tighter than kayakers and sailors should. Seals are replaceable, but with care last a long time.

And when you peal it off... You're dry!


Saturday, November 15, 2014

Helm Visability

I'm told hard dodgers really restrict visibility and make judging sail trim difficult.

Whatever


I was bored and the wind went light. The day before I had done hours blasting into 20 knots with 45F air temperatures; a hard dodger is the difference between a pleasant day in a sun room and frostbite on the nose. Oh, it's still plenty cold on deck!

(Fall is wonderfull on the Bay; wind, empty waters, and quiet coves. But it can put a premium on warm clothes, dodgers, and cabin heaters. But a cozy night with a movie, hot tea, and lots of blankets beats sweating it out.)

Dyneema Lifeline Burn Through

Dyneema has generated a lot of interest as a lifeline material; light, easy to fit, and comfortable to the hand. There are issues with chafe at stanchions (solved by polishing and sometimes chafe guards), but never the less, it was approved by ISAF 2 years ago.

But now ISAF is reversing course. There have been chafe failures due to rail meat and poor installation. They could stand that, I suppose, except it keep happening. Sometimes it is installation stupidity. Sometimes delivery crews switch to wire (more trust) and screw up previously polished holes, leading to failures. Ironic.

More concerning are cases of burn through, where the friction of a line, typically a spinnaker sheet on a large yacht (the only documented cases have been on maxis), generates enough friction to cut through a line in a single bad jibe. This can't happen on a small yacht (forces and lengths too small), but certainly it can be a source of wear, depending on the rigging locations. Many have been happy with Dyneema. Never the less, ISAF is now allowing Dyneema on class 1 and 2, but requiring wire on all higher classes. They are hoping to generate experience before revisiting the issue.

Judging from the burns on my PVC covers, this is a problem in need of a solution, at least on my boat.

Monday, September 29, 2014

Bleach and Aluminum Corrosion

Rev. 10-14-2014

I've got a series of 4 articles on water treatment coming out in the next few months, describing a simple approach, soup to nuts. One of the more interesting thing to com of it is a treatment that seems safer for aluminum tanks. Both of these images show the worse pit after 14 days, at about 200 magnifications.

Puriclean Aqua Mega Tabs, 1 ppm free chlorine. Later I determined that I could lower the dose 4x below this and still maintain the same free chlorine due to the cyanurate buffering. Overall, the surface has been smoothed rather than pitted, with ~ 50% reduction in weight loss.


Bleach 1ppm, free chlorine.

Safer for aluminum tanks? That is my impression, particularly if the dose is lowered below manufacture recommendations to the lowest effective dose, but more confirmation work is needed.

What about hydrogen peroxide? During the writing of my water treatment articles, numerous sailors asked me to consider H2O2 as an alternative to bleach for aluminum tanks. One problem, of course, the lack of established standards for sanitizing with hydrogen peroxide. The Water Quality Association (certifying organization, similar to NSF) recommends 30,000 ppm hydrogen peroxide (3%), which is full-strength drug store peroxide, and 3 hours contact is required. Compare this to 30 ppm for bleach with a required contact time of 1 minute. There is no recommendation for routine use, but health approvals place and absolute limit of 1000 ppm peroxide, which is most likely below the effective dose. Not at all practical, and any stories of effectiveness at lower levels from cruisers are anecdotal and probably not based upon any science.

But just for laughs I did some corrosion test, using 3000 ppm peroxide for 4 days (ASTM D1384 test coupons at 65F).

No pitting... but remember this would have taken 40 pint bottles to sanitize a 25 gallon tank, even then using only 10% of the WCA recommended dose. Not practical.

  • Aluminum. Minor discoloration, no pitting.
  • Brass. Minor discoloration
  • Copper. Minor discoloration
  • Solder. significant corrosion, about like bleach on aluminum. Expect premature failure.

Friday, September 26, 2014

Fresh Water Flush--a Miniature Water Closet?

Seawater contains bacteria and sulfate. Flush with seawater, deprive the bacteria of oxygen for long, and facilitative (those that can go aerobic or anaerobic) start using sulfate (SO4-) as an electron source. The result is H2S (rotten eggs) and the head stinks. The cure? Either use the head every 8 hours (thus, smell is not a problem when living aboard or actively cruising) or flush with fresh water.

But you can just plug the freshwater pipe into a manual head; water will blow through, flooding the compartment, and bugs can swim up-stream. The water closet, introduced a century ago, prevents both by employing a float valve and creating an air gap (bacteria can't fly, as a rule).

What about a miniature water closet? $38 from McMaster Carr


Made for commercial ice machines, this unit holds enough to flush 3' of 1.5 inch line--not enough for most manual heads--and refills at 0.33 gpm, or about 1:20 seconds per full flush (12 strokes or so). Clearly, a larger size, holding about 60 cubic inches, is what is needed. It could also be expanded by mounting a 1-3' length of 3" pipe under it to serve as a reservoir (4' of hose can be flushed for every 1' of 3" pipe). Mount it to a bulkhead somewhere handy and you should be good to go. A pair of valves would allow switching from seawater and isolation.

But I haven't tried it. I'm happy enough with sea flush and a rinse with potable using the shower head before going home.

Friday, September 12, 2014

Knees, Close-up and Dirty


 The protruding wire does make for some odd bumps and can be sore against pants, and kneeling on the cap is out of the question.
 
31 years ago during an informal club bicycle race I dodged a pedestrian, got into the gravel, and shattered my right knee cap into 16 pieces. It healed up well, all things considered, though it is lumpy and 20% larger than its mate. I still have some wire, the back side was rough enough that sustained cycling was out for almost 25 years, and I had some permanent weakness in my right quad; I tended to favor it.

A little rough on the backside, but the Doc says it will go the distance. Not bad for that long after that much repair.


The wire broke during the healing process, but its purpose was served. No need to remove it. Notice the spacing is less on the right side, though I may not have been standing straight.

And as a result of favoring it, I tend to come down more straight-legged on occasion, which ironically, is the opposite of a favor. Additionally, having very flat feet (feet pronate inwards), a disproportionate amount of weight is carried on the medial side, in spite of wearing orthodics for the past 30 years. A year ago I felt and heard a pop in my knee when stepping high on a boulder, heel to butt with all of my weight on that leg; I started a tear. It bothered me some, never felt right, but never caught. Then a few weeks ago, while helping my daughter move back into college, the tear spread. I felt like I was taking light loads, not moving too fast, and I never felt anything... until it tightened up an hour later. ~ 8 trips up 6 flights was too much.

A nice little tear. Though it would bear weight, bending the knee more that 10 degrees cause locking and lots of pain.

 Cleaning Up...

And a few signs of wear, but not too bad for an old guy. Should go the distance, with some increasing pain.

While it is too soon to say much, just one day after surgery it hurts less than it did. They say I can go back to skiing and all that, but I think I'm done with that; I know I can't back down from the double blacks, so I'm better off going sailing and wearing a brace, just to be sure.

But for the next few weeks... time to write, I guess.

Update, 9-13-2014. As surgery meds wore off, the pain showed up. I strong recommend getting a Breg Polar Care 500 ($168), whether insurance will cover it or not. My wife had one left over from knee replacement surgery, and this is the only way to keep ice on the knee at night. This really helps with both swelling and pain. The temperature is adjustable, but if you wear an Ace bandage on the knee, the amount of insulation is perfect for comfort. Lasts about 10-12 hours on a fill of ice. The knee version (not pictured but very similar) comes with Velcro.

During the day, packs of frozen veggies (one over, one under) are best, conforming nicely. We get ones we don't like (lima beans) so that we don't accidentally try to eat something that has been refrozen 20 times.

Update, 9-18-2014. I'm mostly off the cane, but I walk slowly and stairs are still far out of the question.Still icing (Breg) at night.

Update, 10-5-2014.  Started on exercise bike. Mowed part of the grass yesterday, but did no try to finish. A little muscle soreness today, but the joint seems fine.


Wednesday, September 10, 2014

Re-hooking

After about 5 years of faithful service, my collection of saltwater plugs was looking sad. One fish lost to a hook that snapped off, a little too much metal gone. Time for new teeth.



Is it worth the trouble for a few lures? These are good sized lures, $10-$15 each for 8 of them, so yeah, time well spent. About $2 for the hooks and 15 minutes work, they should serve another 5 years. It's also good to inspect the rig, trim the end off, and tie new knots.

Other lures are generally just replaced. Jigs are cast in one piece, and generally the skirt goes first. Blue fish hose eels are generally too chewed up to worry over, and the stainless hooks last forever.

Boot Drier

A few days ago I was following a thread on a sailing forum regarding how to best dry a pair of high-dollar leather and Goretex seaboots. Suggestions from experts ranged all over, but missed that most obvious answer; a boot drier. Perhaps this won't resonate with warm climate folk, but it should; I've seen enough mold and mildew in Florida to make it the state plant... if it were a plant.

I built this one15 years ago in an evening, for the specific purpose of drying wet snow gear, but it has certainly been used far more for rain soaked gear.



Even the most sodden boots, shoes, or gloves are dry, warm, and fresh in a few hours. Odor is eliminated, as there is no chance for anything to grow. Wet gear has a proper place, and space is conserved since less gear is needed. The materials came entirely from the might-need bin, but I suppose it could be built for $30 if everything were purchased. It could be made longer, for a larger family, with very little change in cost.

The fan provides just enough flow. A bit of flashing creates an internal baffle, directing all of the air flow over the bulb before it goes to the pipe outlets. A 60W bulb seems to provide just enough warmth, but a larger bulb or lamp-base heater could adapt the design to larger sizes. Hardware cloth keeps small fingers and trash out. Pipes could be made longer for sea boots. The unused pipes are plugged by dropping a large bolt in the hole, focusing the heat on a reduced number of holes. The weight is sufficient to keep it from tipping over.

  • 110v computer fan
  • ceramic socket with 60W bulb 
  • box and switch
  • a salvaged cord
  • 3/4" lumber and some screws
  • 3/4" PVC pipe stubs
  • a bit of flashing and some hardware cloth
  • paint
What would I change? I should have built it for 8 pipes (4 boots + 4 gloves) to better serve 2 people. I should have made the pipes just a little longer (no so much that it could tip over) and drilled a cross-wise hole near the end (so that they cannot be blocked if the boot is sitting on the end). But Jessica is off to college, so it's really just me playing outside, and it works quite well as it is.

I've been tempted to build something similar into the boat--it's really sweet to have warm, dry shoes in the winter--and perhaps I will if I start cruising more in the off season, now that school schedules don't matter.  Perhaps something that diverts warm, dry air from the mini-dehumidifier.