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Thursday, March 17, 2016
Cheston Creek off the West River
I needed and over-night get away, the prevailing winds suggested the western shore north of Deale, and I always search out places I haven't been before.
I anchored in 8 feet of water just a short distance inside the mouth. I'm not too certain how much deeper I could have gone, but there was a fish trap just a few hundred yards farther in, so it seemed pointless. Holding is solid, but it is exposed to the south and east.
There is a nice sand spit sort of beach just inside the mouth, probably off limits but certainly inviting for a few moments walk.
A nice thin about Spring and Fall sailing is the clarity of the water. Not island clear, but enough to see 6 feet easily.
The creek is a wildlife management area, shared between the Smithsonian and local farmers and is well screened with trees. I bobbed mindlessly by one downed tree, watching a ground hog busy himself preparing a burrow for a littler to come. A hundred yards further down the creek s red fox was doing the same sort of sring house keeping.
Definitely worth a follow-up visit this summer.
Monday, March 14, 2016
Playing with Drogues
I've been able to learn about full-size drogues at higher load with 2 tricks. First, pulling them at short scope (actually the best method for emergency steering) gives insight relating to pulling out of a wave face, since a following wave also changes the rode angle. Second, getting a running start at a drogue, hitting it at as much as 7.7 knots (with extended transoms and a clean bottom, that is my best speed) with a non-stretch rode gives some high forces, but I wanted something a little easier to manage and some thing that I could pull continuously at storm-like loading. Like the tandem anchoring trials (coming in 2017 in Practical Sailor), I went to models.
For anchors, I was able to get roughly 8 inches across, I was able to find 2-pound surrogates in the form of a 2-pound Guardian, 2-pound Claw, and a 2-pound Mantus Dingy Anchor (very nice--get one!). But for drogues I was out of luck. So I sat down with a pile of old canvas, a roll of pulling tape, a palm, scissors and tape measure and made my own. Roughly 8 inches in diameter, if towed by a small diameter rode with mating scale chain, they perform just like their big brothers!
- Drag is about 9 times less (expected to vary as the square of diameter)
- speed/drag relationship is consistent (varies with V^2), like the larger versions, but now proven through a larger speed range
- Pulsation behavior is similar (load varies at about the same range and frequency as larger drogues)
- Behavior--yawing and surfacing--is just about identical
And so now I have a set of tiny scale drogues I can test at scale in small craft advisory conditions, as through it were a gale.
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The really weird part is that I have already learned some things I that either the manufacturers don't know or are in denial about. Failure patterns--both mechanical and performance--seem to come from pretty basic errors. Not the better manufacturers, though; they seem to know and communicate better.
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The early take-aways?
- Anyone can need emergency steering when they hit a log. It is not a black art, but you need the right gear. I tried warps and chain, and it aint' going to work for you. No way.
- Towing warps is not much of a storm strategy. The drag is perhaps 10 times lower than recommended drogues.
- You get what you pay for. So far, the more money, the more stable and rugged the drogue.
- There is a speed limit. All drogues have stability problems over ~ 5 knots in big waves, and my gut at this point is there is no engineering solution. You either carry enough drogue to stay below 5 knots or the risk of the drogue pulling out of a wave face goes up when the waves get steep.
I have one article on drogues in Practical Sailor, with more on the way.
Extension Ladders On-Deck
To the spreaders. I don’t like going too much past the spreaders for a number of reasons. On smaller boats—less than 30 feet—the ladder adds weight to an already top-heavy situation. The deck space for the foot is limited resulting in a ladder set at too steep an angle. For larger boats, the required ladder is simply impractical. Extension ladders become progressively more ungainly the longer they become, and a 40-foot extension ladder is a monster for one person to handle, or even for 2 on the deck of a modest boat. A ladder reaching only to the spreaders, on the other hand, can be quite reasonable.
Another reason we like ladders to the spreaders is that it seems most of my work is there, on the forward side of the mast. A ladder gives best access to the steaming light, deck light, lazyjack anchors, flag halyards, spreader boots, and RADAR. On a previous fractionally rigged boat, we could reach halyard exits and shrouds. When climbing with ropes the mast is ascended from behind because the main halyard is used. On the forward side only the spinnaker halyard—if there is one—is available, and often it is suspended from an external block on a crane; the spinnaker halyard is not recommended for this reason. A genoa halyard is available, but you have to lower and clear away the sail. We still use ascenders when we need to go clear to the top, but that is nearly always just an inspection trip, without the repeated up-and-down laps for tools and parts.
- Tie the boat more tightly. While docklines require some slack to deal with tides, the motion at the spreaders will be less if you minimize the slack. Very tight lines can actually increase motion, so leave about 1-foot of slack. Remember to re-set the lines when you are finished, and adjust them as needed if the tide is swinging
- Light weight ladder. While ladders used in industry are heavy duty and are rated at 300-375 pounds, it will be far more pleasant to use either light commercial (225 pounds) or household (200 pounds) ladder on the deck of a boat. They are much easier to work with, and because of the way it is to be secured (to the mast and deck), it will be stable and reliable. Of course, if you’re a big guy you will need a ladder with the proper rating and should be able to handle the weight.
- Secure the top rung. Pad the top rung of the ladder by wrapping with a towel secured by sail ties. Additionally, secure the top rung to the mast with a sling around the mast and back to the ladder. This should be an easy fit, free to slide, but not so loose that the ladder rails can slide completely off the mast to one side. This will guide the ladder as it is extended, siding up, and can be tightened once climbed, if desired. This sling should be strong, at least 3/8-inch or 4000-pound breaking strength, like any climbing anchor. Second, attach a spare halyard or topping lift to the top rung. This can be used to help raise the ladder and provides some additional security.
- If the halyard is used to lift the ladder it can be advantageous to lash the sections together. Otherwise they may pull apart.
- Raise the ladder to within the range of angles marked on the ladder. Too vertical is neither safe nor fun. It will also result in slower work.
- Secure the base. Secure the base of the ladder against fore-aft and side to side motion using the genoa sheets (I used spinnaker sheets in the photos) to prevent side-to-side motion. Do not over-tighten with winches; ladders can be pulled apart. Secure the bottom rung to the mast to prevent kick-back. There should be NO possibility of motion. Pad the deck if you must, but the rubber feet will be more secure and should not unduly load the deck, no more than jumping down on a heel. Place them carefully and they should not mark. If there are spikes on one side, tape them up. Thus secured, the ladder should be as safe against falling as any fixed ladder, and at a better angle than many. However, boats move, and that requires additional precautions.
- Climbing harness. If wakes can cause the boat to roll, a climbing harness can be a good idea, either belayed by a crew member or attached to a tight safety line paralleling the ladder by a rope grab. Unlike climbing by rope, however, there will be no discomfort from harness pressure. Harness is generally not needed on catamarans, though this depends on the person and the work to be done. If two hands are needed, use a harness, if only to tie-off once at your working stance. The tie-off should be nylon—the impact force of even a short drop will shake your teeth loose and can create dangerous loads. In principle, the tie-off is for side-to-side motion only, not falls.
- Climbing and work posture. While climbing keep both hands free. Don’t carry anything, but rather trail a line to a tool bag, as though you were ascending by rope. Tighten the rope securing the top rung to the mast as soon as you get there. Have a way to secure all of your parts and tools while working, whether by lanyard or deep-sided bag. While working, be certain to keep your knees locked into the sides of the ladder. Use a firm and slow hand with all tools and parts; a light touch is prone to dropping things.
Sunday, March 13, 2016
Beard Eradication
My wife determined it had to be removed in stages and that those sages be recorded, for the amusement of all.
And once the mustache came off, I felt clean for the first time in months.
Saturday, March 5, 2016
Emergency Steering
rev. 7-24-2024
So what, it snowed yesterday. Testing does not wait.
This grew into a number of articles for Practical Sailor and Good Old Boat. Later articles focused on emergency steering drogues you assemble in minutes from gear on hand: An anchor, some chain, and a fender. Hang the anchor from the fender, with some chain in front of it, and then use as a steering drogue as below. It works and people have sailed 1500 miles with that rig and no rudder.
That said, I repeated the test with a commercial drogue (Delta Drogue) the same day, and the Delta Drogue was much easier to handle and very compact to store. If I were crossing an ocean I would pack a commercial drogue. More importantly, I would take a test day, as below, and try it out in a breeze. There are lots of ways to rig it wrong and screw up. Best to learn near home.
This past fall I jammed a rudder on a submerged tree. Two loud thumps, the helm did not answer at all, and the boat was turning left. To reach my destination I adjusted sails (genoa in, traveler down) and even lowered one engine (just for drag--not running) and played the traveler as though it was the helm. Maneuvering into the harbor under power was made reasonable by having 2 engines. Once anchored, I disconnected the jammed rudder and enjoyed the rest of the cruise on one rudder with slightly mushy steering. The autopilot even worked , so long as I kept the sail balance fair.
What if I had only one rudder, like most half-boats? A rather expensive tow would have ensued, perhaps anchoring for a time when I reached shallow water. The cruise would have been ruined for certain. I always thought emergency steering and drogues where for ocean crossing and storms, but now I realized that even on the Chesapeake, a bent rudder can lead to trouble in short order. And so my closet interesting in drogues (I actual have 2, leftovers from my Stiletto off-shore days) has exploded into full-on testing for Practical Sailor. So far I have 4 brands lined up and one factory team that wants to help me play. What fun. The intention will be to try them all on all courses and hopefully in several wind speeds, seeing what works and creating drogue speed polars. There will also be some high-load testing related to storm use, but that is separate article.
Though I have had these for years, I never tried them for steering. A few tips:
- For storm use, of course, they go farther back, 150 feet-250 feet.
- But for steering, bring it in close, as little as 20 feet off the stern. Much more responsive.
- Spinnaker sheets work well for a bridle. You can actually steer by sitting next to a winch and playing just one leg.
- Attach the sheets at the widest point, particularly on monos. Near the stern is fine for cats, but a little forward is better (more responsive).
- 100-110 true with the rudders jammed 65% to leeward. I was surprised. The wake was reasonably straight and leeway less than I feared.
- 70 true with rudders straight.
- Very slow in light winds. You are going to loose about 1-3 knots. The Seabrake is too large for this boat. We'll have to see how the Small Shark works. I also need o try the Seabrake in close, partly out of the water, to reduce drag. I forgot.
- Pretty stable. I can imagine using it for days, with crew. Not as good as autopilot, but not bad.
- There is a tendency to round up if sailing to weather in variable winds; when the genoa looses pressure, the drogue is still pulling, and the boat comes up. But if you catch it before it stalls, by releasing the windward bridle line a few feet, it recovers well.
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With the rudders straight we could make some ground to windward... but slow. Only about 70 degrees true course over ground, and slow. Notice that the drogue is nearly centered. The drogue is clipped to the sheets with only 8' of 3/8" BBB chain as an extension.Slower than sailing, but much faster than sailing in circles, faster than waiting for help, and more comfortable than drifting beam-to-waves. Good for parking the boat transom-to-waves while making any sort of repairs (they will be easier if the boat is not rolling).