Saturday, September 24, 2016

Can Nylon Rope Melt Due to Load Cycling --- Myth Semi-Busted

The Problem. There have been reports of nylon sea anchor and ground anchor ropes failing due to heat build-up when repeatedly cycled to a high percentage of rated breaking strength. True? Let's try a few reasonableness checks. We'll start with climbing ropes, since these are tested for energy absorption and the results are well known.

In a UIAA (the governing authority for climbing gear) test fall 2.5 meters of rope arrests an 80 kg object falling about 5.6 meters, stretch included. This is an impact so severe that the rope is only expected to survive 5-15 cycles; I doubt any anchor rope would do as well, so this is very conservative. if we convert this to US units:

Energy = 176 pounds * 18.3 feet fall/8.2 feet rope = 393 ft-pounds/foot of rope

Expressed as heat. However, only energy dissipated by hysteresis (it takes more energy to stretch a rope than it returns--it is not a perfect spring) is converted into heat. After all, a metal spring does not heat, true? Hysterisis with nylon rope is about generally about 10-20%. We'll assume the worst.

0.20 x 392 ft-pounds/ft = 0.10 BTU/ft

How much heat needs to be lost? If the rope is cycling at more than 50% of this load it won't last long for many reasons, so I will assume 0.05 BTU-cycle as the limit, which corresponds to 25% of the breaking strength and 200% of the safe working load (SWL), which is normally taken as about 12% BS for nylon. 

How many cycles? Assuming we are taking about storm waves, 20 second period seems reasonable, or 180 cycles per hour.

Heat = 180 cycles/hour * 0.05 BTU/cycle = 9 BTU/hr*ft

How much strength does a hot rope lose (PA66 is nylon 6/6)?

About 18% weakening by 80C (176F). There is a reason clothes don't fall apart in the drier! Long-term, there are oxidation effects, but these take months.


How fast can a dry rope loose heat? Assuming strong winds, about 6-8 BTU/ft2-F, depending on the reference. Assuming there is some spray in the air, we will use the higher number. A wet rope will cool more quickly due to evaporation and better heat conduction within the rope.

Heat loss = 0.11ft2 area/ft * 8 BTU/ft2 * (90-80) = 9 BTU

Clearly the rope won't get that hot. In fact it will top out at about 10F above ambient. Noticeably warm, but not in any danger.

What if the rope were larger (3/4-inch is what the Dashew's reported failing), of a less efficient construction (3-strand), and operated at a higher load factor (30%?)? The surface area to core ratios is greater, the heat generation per cycle is double, and the rope generates about 20% more heat due to the construction difference. What if the boat were tied to a dock and the period was much shorter? The core temperature gain can reach about 140For 60C--still not in the danger zone. Isolated fiber bundles could get hotter, if the load is not evenly carried or if there is significant friction between the fibers in that location.

 Note: I've greatly over-simplified the engineering. Insulation from the rope fibers and the cylindrical coordinates need to be considered. However, the result was similar, about 20% higher. On the other hand, we've assumed that no spray is striking the rope (it remains dry) which seems VERY unlikely in storm conditions.

 Observation 1: Lines smaller than 1-inch do not heat significant under cyclic loading unless they are significantly undersized, in which case they would fail anyway.


Below 3/4-inch rope heating due to cycling is probably not an important factor, even in the worst hurricane docking situation; failure will be due to something else. Beginning at 1-inch moving upwards, it can be important, since the larger rope cannot cool as easily. Large Barge tow lines can heat. Thus, the myth seems plausible, but not in sea anchor applications; the period is too low. The rope would need to be ~ 2 inches in diameter to provide sufficient insulation.

So why did the rope break? First, lets look at the load. Several investigators have found the wind load to be about 1/4 the ABYC estimates (these are based on anchoring with all-chain) and the load on a nylon rode to be about 1/2 the estimate. For a 50-foot boat, that would be about 2400 pounds. The SWL of 3/4-rope is about 2000 pounds. But that is before we include weakening due to wear and water. Dynamic tests by UIAA (climbing standards group) shows as much as 50% strength loss for wet rope in impact conditions. The SWL in practice is probably closer to 1400 pounds. In short, the rope failed predictably at 20%  BS after some time in the storm (probably higher due to a larger wave) with predictably melted ends. It was simply under speced due to a misunderstanding of SWL.


What about heating under chafing gear? 

First we should do some forensic thinking. What does nylon rope look like when it breaks under load? In fact, it always looks melted, the result of the enormous energy release at the moment of rupture. IF the rope was slightly warm from cycling the effect would perhaps be slightly greater, but it would not be the cause. The larger the rope sample broken in the lab, the more noticeable the melting.

 This is very load speed break testing, yet the ends are melted. I think folks just don't understand what they are looking at when they claim mysterious heating. One sailor reported a false observation and it became internet fact.


Observation 2: Nylon ropes always appear melted when broken at high load.

 Yes, there can be some heating, as calculated above. Covering the rope will make it worse.
  • If the gear is waterproof, that prevents both water cooling and reduces the internal lubrication that water provides. Bad.
  • The gear provides insulation, like an over coat on the line. Thus, a 1/2-inch line is going to heat like a 3/4-inch line, and a 3/4-inch line like a 1 1/4-inch line. Bad.
Thus, any chafing gear that keep the line dry will weaken a line subject to hard cycling for a long period, such as a hurricane or nor'easter.. Only permeable gear is acceptable. But that said, the weakening will be only a small percentage. Even without heating, the gear will break under the gear because it is probably over an edge. So just because we see rope broken under chafe gear with melted ends, we should not believe heating was the culprit. The rope was simply too short to absorb the energy and was under engineered. Nylon rope looks melted even when broken at very low speeds and cycles; it is an artifact of the enormous energy release at the moment of failure.

Observation 3: If the rope breaks under the chafing gear, don't leap to line heating as an explanation. The rope was just too small and too short.

Bottom Line: Lines don't heat up, but users often underestimate the load, over estimate the SWL, and sometimes use docklines and snubbers that are too short to absorb energy safely. 

__________________


An exhaustive report by the US Coast Guard goes deeply into synthetic moorings. It's a big deal for deep water ATNs. 

Thursday, September 22, 2016

Jamaican Stew Fish

I picked this one up during a business trip to Kingstown. It seems the only used oil recycling going on in Jamaica at that time (about 1990) was a couple of septic tank service guys that had a pit in the ground they could pour it in. The inter-modal terminal in Kingstown is one of the largest in the world, conveniently located for shifting boxes before or after transiting the Panama Canal. Shipping companies were obviously uncomfortable with pouring their oil in a hole in the ground, inconvenienced by having to haul oily bilge water and used oil to their next port of call, and my company was being encouraged to build a recycling plant. That project never happened, and the boys wondered how used oil is recycled in Jamaica today.

But that stories got nothing to do with good eats!





Jamaican Stew Fish
Makes any fish island style.  Serves two very hungry sailors.
·                     1 pound fish (spot, croaker, flounder, or rockfish. Pork and chicken also work well).  If all you caught were little fish, add more vegetables!
·                     1/2 medium onion , sliced
·                     1–2 cups baby carrots, sliced in half lengthwise
·                     Salt & pepper
·                     0–1/4 teaspoon ground red pepper, according to taste
·                     1–2 tablespoon soy sauce
·                     1/2 teaspoon ginger, thinly sliced
·                     Several sprigs of thyme
·                     1 teaspoon butter
·                     1/4 teaspoon cumin, 1/4 teaspoon curry powder, according to taste
·                     Water
·                     Oil for frying
·                     1 lime
·                     1 cup rice
Preparation:
1.                  Clean the fish (fillet or whole), dry, and rub with lime.  I like it with the skin on.  Allow to soak for 10 minutes.  Butter both sides.
2.                  Brown fish lightly in preheated oil.   Need not be fully cooked at this time.  Set aside to drain.
3.                  Sauté sliced vegetables, ginger, and seasonings on a high flame for five minutes, using the oil from the fish.
4.                  Reduce heat. Add soy sauce and water to not quite cover.  Stew vegetables for 10 minutes until brown. Salt & pepper to taste.
5.                  Add fish, covering with stewed vegetables.  Stew covered for another 10 minutes, until fish flakes apart easily.
6.                  Prepare rice separately.  Serve over rice.
_____________

Jessica's first catfish, caught on croaker guts in the C & D Canal; catfish aren't fussy. [circa 2012]

 

Wednesday, September 21, 2016

Introduction to the New Sail Delmarva

This is not a site for racers. Although I did race performance catamarans in my youth, I've lost the taste of it.


This is not a site for bluewater cruisers. Popular magazines are full of tales of daring-do, circumnavigators, and crossings to the Mediterranean.

 
For many of us, the pull is summed up by the powerful quote from The Wind in the Willows; “Believe me, my young friend, there is nothing - absolutely nothing - half so much worth doing as simply messing about in boats.” But that chapter one quotation is often stretched completely out of context, into a moral imperative to ditch all and go to sea. in fact, in chapter 9, the very same innocent water rat, so taken in chapter one with the river and his simple clinker-built  rowboat, spends a day with a charismatic seafaring rat. Our simple, provincial water rat is so completely mesmerized by the vast and sweeping stories (exaggerated, no doubt) told by the wayfaring rat about his adventures aboard a coastal freighter, and the mysteries of the many ports of call, that immediately upon returning home he begins to plan his own departure to the sea. HE tries to explain his compulsion to his friends but can't find a rational argument. He fights through fits and seizures until, in his own words, he regains his sanity.



What most of us need is a miniature adventure. It suits the time available. More to the point, it fits our priorities. We have families ashore. We have friends. We have shore-bound interests at least as important and valid. In other words, the myth, yea the fantasy, of casting all aside and following the winds across an ocean isn't something we're avoiding out of cowardice, but rather because it makes no damn sense to us. For heaven sake, we're land animals and we like it that way.

I'm writing for coastal cruisers. I haven't circled the globe, but I have sailed 25,000 miles round and round the Chesapeake and along the Atlantic coast over the past 30 years. Yes, much of this will apply to bluewater sailors; coastal sailors get knocked around right good sometimes to and I believe in strength and safety. Many of us go offshore, now and then. Some will apply to racers; I sail the sailor that does not care about sail trim are going as fast as he can within the limitations of his boat, doesn't really enjoy sailing. As the old saw goes, any two boats going the same direction or racing. Some will apply to daysailors; we are all daysailors. And I hope armchair sailors can enjoy reading along.

But mostly I've accumulated the sort of 15- to 50-mile day sort of experience that you need, navigating shoals, anchoring or docking daily, and returning to my real life after a few days to week afloat. We don't sail gold plated boats we bought from a dealer. We sail 5- to 30-year old boats and we spread our upkeep dollars thin, but without sacrificing function or safety.

I certainly enjoy reading about bluewater adventures, though I have no more desire to cross an ocean than to climb Mount Everest, that coming from an addicted rock and ice climber who simply sees no point risking brain cells from lack of oxygen. The plain truth is, that there are bloody good reasons why coastal sailors outnumber bluewater sailors one thousand to one. For most of us, it's just better.

I'm not a famous racer. I haven't sailed around the world. But I have spent 35 years as a refinery engineer, 30 years as an avid sailor, and of published over 100 articles about marine equipment, how it works, and many topics about the engineering related to sailing. I'm not an authority on how to sail across an ocean or even how to sail particularly fast, but I become an authority on each topic, one at a time, as I research it and dig into it. I learned details I never expected. I find vendors selling snake oil and rubbish to the public, and I debunk them. I know my limitations, but within them, I hope I have earned my place as a trusted source of information.

I plan to add a voluntary subscription button when I get this site built out a bit more. While I love the idea that so much is free on the internet, it's taken many thousands of hours to put this together. It's grown far beyond a hobby. Writing and researching is my living. I think I have as much to share as any shiny magazine, driven by advertising dollars rather than truth. In fact, I've written a few things for that sort publication, but mostly they want stories about blue lagoons and infomercials for the stuff their advertisers sell. They can't profit from the simple truth about what works.


Please comment every time you are tempted. Dialogue builds knowledge, and it helps me know what is interesting and what direction to take this website.

Fare Winds!

Drew

Monday, September 19, 2016

Tether Shackles--No quick Release For Me








Before hoisting the spinnaker I inspected this shackle and double checked that it was latched. I remember staring at it, thinking I would never trust my life to a quick release mechanism so easily released as this.



The spinnaker flew perfectly for hours, and then while putting it away I realized the shackle had blown apart, the result of being dragged over the lifeline. No excessive force, just the the weight of the sail and sheet as I pulled it on board. Somehow the circle pin came off, allowing the pin to shoot out the other side. This is a common failure mode, one I have experienced before. No excessive force, just the the weight of the sail and sheet as I pulled it on board.

_______________________

Today's experience simply reinforced my tether decisions:

1. Harness carabiner should be locking but with simple release. I like the Kong Tango because it is large enough to clip railings and is easy to unclip even with wet, cold-numbed hands. I really like the feel in my hands. I also like that I can clip in with one hand, something I cannot do with a snap shackle.

Kong Tango (Black)


2. Jackline carabiner's must be locking type. I like aluminum rockclimbing carabiner's", which seem to remain jamb free so long as I treat them with waterproof grease annually.  I like simple climbing carabiners, since I generally leave the tether on the jackline and unclip at the harness end when entering or leaving the cockpit.

Black Diamond Positron Screwgate Carabiner
This makes sense for us because our boat is center cockpit, but for most boats with aft cockpits, there are better choices. Some makers, including West Marine and Kong, use the Kong Tango on the jackline end of the tether. They like a snap shackle for the harness end, I don't.

3. Tether material is nominal 8 mm UIAA certified 1/2 or twin nylon climbing rope. It has the toughness and shock absorbing capacity to handle any conceivable fall or misstep without generating rib-breaking impact forces or overloading the jack lines or anchor points.

4. Custom tether lengths. I use two leg tethers. The short leg is 2 feet and the long leg is 8 feet. These lengths better suit my specific boat. The answer for yours could be different. However, I'm willing to bet that 3 feet is too long for the short leg on most boats.


Phase I: These were tied from 1-inch tubular nylon climbing webbing. I also inserted a Yates Screamer for testing, though it was later removed. These are the simplest to make and are quite safe, based on generations of rock climber experience.


Phase II: After many experiments, these are the tethers I use. 
  • 8mm climbing rope for shock absorption (easier on the ribs). 
  • Kong Tango at the harness end. 
  • Sewn ends (can be knotted--do not attempt sewing unless you have access to pull-testing equipment). 
  • 2'/8' lengths (fit my boat). The short leg just kept getting shorter.
  • Small "parking clip" so that I do not have 2 biners clipped to my harness (inhibits unclipping in an emergency).

Note that in both cases the middle carabiner is cow hitched and can be moved. This is important to getting the best fit. The cow hitch is secured with a seizing to prevent sliding (hidden).

Saturday, September 17, 2016

Periwinkle Soup

(Inspired by 2 days spent kayaking on the Little Choptank River)





The northwest Indians said the "ocean rolls out the dinner table twice a day," observing that with each low tide an edible bounty was uncovered, free for the picking. For the kayaker, it's even simpler than that, with periwinkles presented at eye level at every turn. They're small size will make you work for your meal, but they're tasty, fresh, free, and just begging investigation.

I'm sure you can Google up 20 better recipes, but this is an easy one I always have the stuff for on board. Given the choice, potatoes and a chowder approach is better, and linguini is very nice.
  1. Collect a lot. Select the largest, about one cup/serving.
  2. Check that they are alive when you get back to the kitchen. Just spread them out thin in some seawater and watch for movement. Takes only a few minutes. Chop vegetables while you wait.
  3. Chop about 1/3 onion per serving. Season with cumin, pepper, curry, and ginger. I add 1/4 of the "chicken" flavor packet. Or what every you like.
  4. Boil the periwinkles in the shell for 5 minutes.
  5. Some say pick out the meat, but I find a nut cracker is faster. A water rinse (stir or shake the bowl) separates the shell bits that you missed.
  6. Simmer meat, vegetables and seasonings for 20 minutes.
  7. Add raman noodles for the last 3 minutes. 
Yummy, rather like mussels but better.  All summer I seem to bring food home from cruises, finding a good portion of what I eat.


Tuesday, September 13, 2016

Ethics

Mold in Antifreeze

Blogging About Products and Posting Amazon Links

As a begin a new phase of my blogging career, I need to feel certain that I am on solid ground. We've all read blogs that link to every gadget the writer is ever come across, trolling for affiliate program dollars, most often without any firsthand knowledge of whether the gadget is worth beans and without a care as to whether represents any value to the reader.

First, I have a strong loyalty to the magazines I've worked with. (Link to Practical Sailor in top bar.) I don't want to poach subscription membership by offering the same content. That means that although many of the products I'll be talking about I have reviewed previously as part of a large product slate, I won't reproduce that data, reuse that article, or all of the discussion that accompanied it. I will guide you to products that did very very well, and the products that represent a good value. I think this is ethically the right thing to do, since it benefits the companies that make good products.

I was drawn to writing initially by the claims of certain fuel additive manufacturers. I was certain they included a whole lot of puffing, a few lies, and some downright fraudulent misrepresentations. Even as I write this post, I am working closely with NMMA and ASTM on standards for gasoline and fuel additives that will one day close the regulatory loophole that allows some players to sell junk to the public so bad it can actually harm your engine. And the same is true about many other products. I feel it's a good thing for testers like me to guide you to good companies that deserve recognition.

Second, I won't be guiding you to any product I have not either tested along side a whole slew of products using scientific method, or at the very least used enough wrong products over the years to recognize when I finally found the right product. In 30 years of sailing I've bought a few of the wrong products, and in 36 years of engineering, I've learned how to run testing programs that can reveal the difference.

Towing scale model drogues on the Chesapeake in a 30-knot breeze. I am towing  a Seabrake with a Delta Drogue following. The advantage of tandem drogues, with a good space between them, is that both cannot be pulled out, and that they stabilize each other. Much different from tandem ground anchors. 

This sort of testing is as much about engineering systems as choosing a specific product. I'll be posting more stuff like this too. I've got an interesting series of articles on drogues and multiple anchor systems coming out in Practical Sailor. You'll have to read about that all oft hat there.

Finally, there is no financial influence on my recommendations. Accept no advertising. I do get a small commission from Amazon, but not any different that if I directed you to a different product. For goodness sake, don't buy anything you are not in the market for! I'm cheap and I hope you are too.

If you think I get off base or lose my moral compass in this effort, just tell me. Allow me the opportunity to explain why I think my advice was honest and forthright. If we can't agree, I'll take the post down.

And then there is the matter of the donation button (not up yet). I'm not looking for people to support my cruising habit. But it does cost money to run tests. It does take time to write about both products and D-I-Y topics. At some point in the distant future, when there's enough content on this site and that content is well enough indexed, I may consider doing something with subscriptions. I'll keep it cheap. For now, if my blog is at least as interesting as a sailing magazine that is 80% advertising and 10% paid infomercials (a lot of the articles are written or at least heavily coached by advertisers-- it's pretty depressing), consider sending a few bucks. It'll help buy something I can test.

Time to get busy writing. Time to get busy testing. Let me know what you think. Write in with ideas of things that need testing or things that you would like to hear analyzed from an engineer's perspective.

Silica Gel Vent Filters--Dry Diesel and Gasoline Makes for a Happy Engine


rev 9-13-2016


The Problem. Ethanol loves to absorb water from the air. For all the talk and trouble water in the gasoline causes--far worse with e10--to me it's rather conspicuous by its absence that neither owners nor builders ever took a serious look at vent filters. Cars have had sealed tanks fitted with both pressure controls and filters since 1971. I considered this a few times--I've installed very large descant traps on very large chemical tanks--but figured if it was so against the conventional wisdom in the boating community, it couldn't be right. Funny.... That's not like me.

For the past 5 years I've had vent filters in the field on my boat and a number of friends. I monitored the humidity inside and outside and found the relative humidity to be 20-40% lower on the tank side of the filter, sufficiently dry to prevent water absorption. I've backed this up with lab testing and found a lot to like.

The value proposition:
  • Drier gas/fuel.
  • Less evaporation, to the tune of $8-$12/year. The unit should last ~ 10 years with very little service *, so that will nearly pay for it. Reduced engine troubles are the cake.
  • Reduced volatiles loss means better starting, particularly in cold weather.
  • Reduced alcohol loss means better resistance to phase separation/emulsion.
  • Reduced volatiles loss mean less gum formation (better solvency).
  • Reduced volatiles loss is good for the environment. Yes, that counts.
  • Less oxygen (less convection) means less gum formation.
  • Less water mean less risk of diesel bug. Just eliminating free water is not always enough. The little buggers can survive on emulsified and dissolved water. In testing, vent filters actually dried the diesel very slightly!

And the big one:
  • Less water means less corrosion. Even dissolved water is an electrolyte, allowing free movement of ions and accelerated corrosion.

Why am I sure? Because I believe in systematic testing.


Evaporation Testing

One liter bottles with 500 ml e-10, starting levels marked with tape. From left to right:
-  Plain 1/8-inch ID vent.
-  10 ml silica gel descant
-  10 ml activated carbon  adsorbent

The non-filter bottle lost 3 times as much fuel as the carbon and silica gel jars. Lost volitiles means hard starting, gum, and money lost.

Both carbon and silica gel are both adsorbents that pull water and organic vapors from the air. Silica gel (the packs you find in with your new DVD player) has a higher affinity for water, while carbon has a high affinity for organic vapors. However, both adsorb reversibly; that is, if exposed to high temperatures, and either clean air or an excess of something else, they release what they have previously adsorbed. Carbon can be flushed by steam and air, while silica gel can be flushed by alcohol, gasoline and air. Both have the effect of keeping the tank drier and reducing evaporation, adsorbing and desorbing with each day/night breathing cycle.

But silica gel is better from the boaters viewpoint:
  • Better water adsorption.
  • Water is self-scrubbing for years with e-10. the alcohol is enough to push the water back off, refreshing the filter for several years.
  • Carbon gets water saturated from dew in a marine environment. After just a few weeks of testing, my carbon filter was soaked and ineffective. Silica gel does not do this.

Corrosion Testing
Then there is the matter of corrosion. In my experience, the leading cause of carburetor trouble in this age of e-10 is not gum, but is plugging cause by aluminum hydroxide gel resulting from carb bowl corrosion. Dry fuel and less oxygen means less corrosion and better fuel stability.

Corrosion samples. No vent filter on the left, silica gel in the center, carbon on the right. This change took only 3 months.

Bottom Line: A gasoline of Diesel vent filter is a cheap investment in reduced engine trouble. The is simply nothing more aggravating, right down to your bones, than an engine that won't start when you are ready to head out.

Although the test filters photographed above were fabricated from PVC, this is NOT safe practice for permanent installation. PVC is not highly resistant to gasoline vapors and the adhesive is quite vulnerable over time.  While it won't fail in this laboratory setting, based on refinery experience with PVC, the joints will fail if I add heat, vibration, and wait several years.



The Solution. Only one company makes these, but they are rugged and none of our test units have failed. A few weeks ago I opened my carbs for the first time after 5 years, just in the interest of product research, since they are still running fine. As expected, they were shiny as a mirror, not pitted as I have observed in the past, in the same time period, with the same model motors. I used to clean carbs all the time, but not since I installed a vent filter, which is nice.




Installation note. They need to be at a high spot where sea water cannot enter and tank overfills cannot contaminate the gel. I put a Parker Lifeguard between the tank and vent for mine, which has worked very well.

My filter first vent filter was custom fabricated so that I could test many options and take measurements more easily, but it works the same. Note the high location and the fuel/air separator to the left.


 *  Regeneration: Experience shows they do required regeneration every few years, but it's free and quite easy. Simply remove the silica gel fill. put it in a pan, and slowly heat it on the grill until it turns blue again. This takes about 15 minutes, there is virtually no smell, and can be repeated numerous times. Allow to cool before reinstalling the gel. Piece of cake.








Monday, August 29, 2016

Driving to Windward...

... With a Cat with Low Aspect Keels


Those of you that learned the sport racing Hobies and Prindles probably know this stuff, but for the rest of you cruising cat sailors....

No Back Stay. This means that the forestay cannot be kept tight unless you want to turn your boat into a banana and over stress the shrouds. Although swept back, they are only designed for the side force and a trace of forward pull. Real tension on the forestay comes from mainsheet tension.

Why must the forestay stay tight? Sag allows the genoa to become more full, since a sagging forestay has the effect of injecting more sailcloth into the sail. The draft moves aft, the slot is pinched, drag increases, and lift does not. This is OK off the wind, but not to windward, since heeling and leeway (sideslip) increase, which also increases drag. Going to windward is about lift:drag, not just power.

How do you keep from easing the mainsheet in strong winds? Ease the traveler a little, being certain to keep the main outhaul tight (a full main pinches the slot). Reef; it's better to keep a smaller sail tight than a larger sail loose. You will see monos with the main twisted off in a blow. Ignor them, they are not cats. Use the traveler instead. It is also physically much easier to play the traveler than the main sheet.

SheetingAngles. Depending on whether you have stock keels, you may or may not have enough area to support large headsails or have them positioned correctly for balance (the keel mod was written up in Practical Sailor). Either way, the genoa lead angles must be in the appropriate range. Too tight, you sail sideways. Too loose and you can't point. I covered it pretty well in the link below. The goal is be able to crank the jib in tight and flat without pinching the slot.

Sheeting Angles and Keels

Again, you are not a mono, you have less keel, and slightly wider tacking angles will be faster for you. You also do not have a hull speed limit; let that work for you. Just don't get tempted off onto a reach.

Watch the fore/aft lead as well. You want the jib to twist off to match the main. Typically it should be right on the spreaders, but that depends on the spreaders. If you have aft swept shrouds, you may need to roll up a little genoa, 105% max.

Luff Tell Tales. On the jib there are ribbons all over, but on the main the only ones that count are on the luff. Keep them streaming, all but the top one. Any telltales on the body of the main are confused by either mast turbulence or jib flow and won't tell you much.

Clean Bottom. It's not just speed, it's also pointing angle. Anything that robs speed makes you go sideways, since there is less flow over the foils. I like a good 2-year paint, but I'm too lazy to scrub. West Marine's PCA Gold has been working well. Micron 66 is excellent in saltwater.

Push Hard, but reef when you need to. You will have the most lift vs. windage when you are driving hard. That said, I reef at about 20 knots apparent. It's not about speed, it's about pointing. If you don't want to push hard, then reef earlier, but keep the sails in tight (traveler down a little). The boat will also be more controllable than with twisted full sails.

Pointing Angles. Pinching doesn't work for cats. Get them moving, let the them get a little lighter, the result of good flow, and then head up until the feel begins to falter. How do you know when it's right? Experiment with tacking angles (GPS not compass) and speed until the pair feel optimized. With a genoa and full main trimmed in well, inside tracks and modified keels, and relatively smooth water, I can tack through 100 degrees GPS with the boat on autopilot. Hand steering I can do better. If I reef or use the self-tacking jib, that might open up to 110-115 degrees, depending on conditions. Reefing the main works better than rolling up jib.

Sunday, August 28, 2016

Reasons To Go On Deck...

... Or 10 reasons why leading all of the lines to the cockpit is not my cup of tea.

  1. Friction. I can hoist my main all but the last two feet without a winch, and I can do this in less than a minute. A high mast exit point exposes the halyard high enough for me to put my full weight on it without any strain, and there is only one pulley in the system. The jammer is nice and high, and the winch is right at my chest when it is time to grind the last few feet. I keep a winch handle at the mast.
          Also less stretch because the lines are shorter. This allows
          the use of polyester line.
  1. Simpler. Cheaper. Also saves twists, tangles and stuff that can break.
  2. Clean Deck. Fewer turning blocks and line organizers. Less to trip on and more space for the feet.
  3. Less spaghetti in the Cockpit. Gotta do something with all of those line tails.
  4. Eyes out of the cockpit. There is a new disease afoot, where the helmsman stares at the instruments more than where he is going, loosing both spacial, situation, and weather awareness. Folks actually think they need instruments, in spite of the fact that none of this existed when sail was king. Folks should sail  part of the time with the instruments off or at least covered. New sailors should be allowed only a compass until they have mastered every maneuver and basic piloting without them.
  5. Practice. If you never leave the cockpit when the weather is less than perfect, will you be ready when the furler jams in a blow, the anchor works loose, the main won't come down, or that wonderful single-line reefing knots up? I've told many climbers that unless you plan on climbing at least once a week you have no business leading challenging traditional climbs. A climber needs to know exactly exactly what they can and cannot do do without falling. Same with a sailor on deck; you only become and stay skilled and comfortable on a heaving deck if you do it frequently.
  6. Tethers and practice. Same thing. Sailors who don't use them regularly get caught up in their knitting and then blame the system. The problem is they are not used to the system. Just like people who claim they can't work in gloves, invariably they have not really tried to learn. They have deigned to try. Jacklines should be permanent, and used frequently, like seat belts.
  7. Inspections. There is no better time to look at the equipment than when it is under load. You will see things that aren't visible at the dock.
  8. Trim. Get another perspective on the sails. It's surprising how often I see some thing that wasn't obvious from the cockpit. Anyone who does not want to understand trim is not a sailor.
  9. Because you can. Isn't sailing about freedom to go where you want, and why shouldn't you be free to travel the whole boat?
and finally..

    11.  Exercise. A passage spent in the cockpit is cramping. I like moving on deck.
  

Wednesday, August 17, 2016

Crowds or Isollation, What is Your Pleasure?

It's natural to crave solitude after a week of hand-to-hand combat in the rat race. Can't they all just get out of my way and leave me alone? Even if you you like your trade, perhaps it needs a rest.



But after a few weeks away and a string of blue lagoons (or even solo time up a muddy Chesapeake creek), people start to get interesting again. You wonder what they have been up to and you have your own stories to share. Sometimes I'll just dinghy over to the beach or waterfront and sit on a bench, half listen to the local talk just to learn what is different about this place or different about folks. I'm not snooping, I'm just interested.

In a few weeks most of the Chesapeake sailboats will take their last trip of the season, most likely a Labor Day trip to a locally popular spot. And then, in spite of the fact the September is the best sailing month of the year around here, the boat will be parked until it is time to winterize, and then hauled out until May at least. It won't be too cool for comfortable wading until late October, and sleeping in 50-60s is infinitely better than 80-90s.

The only down side to off-season sailing--all but the core of the winter, when cold becomes an obstacle--is that shops close up, people go away, and the waterfront gets quiet. Do they stay home because everyone else stays home, feeding a self-fulfilling prophesy? Are people so attached to crowds that they can't sail without them, no matter how vehemently they claim to seek solitude under sail?



People are weird. And I'm one of them. For me, cruising is more interesting when there are sailors around. Not so many I'm fighting for space, but folks to interact with. I'm human.



So get off the couch this Fall, Winter, and Spring. It'll be fun.