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Tom Lathrop

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Everything posted by Tom Lathrop

  1. Graham and I had the same experience in Southern Skimmer in high winds. Grounded in shallow water before attempting a test run trough the Harlow Canal for the NC Watertribe Race. Wind drove the boat backwards and busted the CB through the pin and locked it in place. Good anchor though. I had a knife and was able to finally make a purchase hole in the CB which we used to force the board up. Luckily there was a private marina close enough to get to and find transport to go for trailer. Not our finest hour. I always provide support for a centerboard on the trailer. For many years, I have covered all small boat trailer beds with a sheet of 1/2" treated fir plywood. The floor supports the CB, allows hull supports to be anywhere you like, provides space for storing the rudder, tiller and sprit booms as well as protecting the hull from road debris. Also makes it easy to climb onto and launch or retrieve when you don't want to get wet.
  2. Don, That is a perfectly workable system. The drawback of a cascaded system is the room taken up, which is restricted by the forward bulkhead in a BRS. I use that same method on other boats. I actually like the horn for its simplicity and as an indicator of board angle. Must make special allowances for the crew though. I would not be concerned about the shape of the board bottom as you would not notice any difference in performance between the one on the plans and the more optimum elliptical shape. The rectangular shape does offer more area. I much prefer the epoxy/rope edge to a lead one as I am convinced that it is stronger and makes for a more durable CB. There is no real need to add screws, nails or anything else to hold the lead in the board. A simple chamfer around the edge of the cavity will do that and even that is overkill with a glass overlay.
  3. A 10# lead weight close to the bottom of your CB will be the right amount to get the CB down and not so hard to pull up. I used a 1 gallon rectangular solvent can to melt 10# lead into because that gave the proper thickness. Just thick enough to allow fairing over with fiberglass. Pouring and fairing the lead can work but is more work and less accurate than this method. You still need to hold the CB up so I still have the horn on the CB. How do you plan on getting along without the horn?
  4. Don, Graham entered the BRS in the first design contest that Woodenboat ran in 1992 or '93. The experts at WB deemed the "Perfect skiff" as the winner and the BRS only got its lines shown. Saw the Perfect Skiff in a Newport, RI boatshow and the judges must have been drunk as that boat has lots of problems that are don't exist in a BRS. Never seen another perfect skiff so other boating people must be smarter. To be fair, there were other entrants much better than the judges choice also.
  5. I'm glad to see interest in building the Bay River Skiff continues. I built the second sailing version over 20 years ago, the first with the current interior layout. The Core Sound boats are better sailboats in some respects but the BRS is the best all round sail/row/power and work skiff I know of. Liz and I were sailing LOON on Penobscot Bay, ME and came upon a typical Maine wooden ketch out for a day sail. The people aboard that really beautiful boat exclaimed that LOON was a "just right" beautiful boat. Don't soon forget praise like that.
  6. I haven't heard of anyone having problems with just friends doing the turnover. Most find that your friends really want to be involved in this simple way and are happy to be called on. The boat is well protected by the turnover frames and the amount to be lifted is not so great because of the tilting and sliding arrangement.
  7. Hollow back stainless is plenty strong enough for any of the boats we discuss here and its far cheaper and much lighter weight than the solid stuff. After 14 years on the keel and rubrails of a 2000 lb boat, it still hold up fine except for some scratches and solid stock scratches just the same.
  8. Low friction is good on the keel to help in loading on a trailer. I like hollow-back stainless for the keel because its stronger than brass.
  9. Dave, Many, maybe most, of the edges I've either done or advised about have been on foils that have already been in use. Routing a groove would make for an added complication. Sometimes a rat tailed file has been used on the bottom rounded edge to help hold the line in place. Otherwise the flat edge has not caused any problem at all. I'm glad that my desire to build a lapstrake boat has resulted in a nice addition to Graham's design list as well as some beautiful boats by other builders. I made a stainless edge for the stem of Bluejacket LIZ. After 15 years and a couple dings from various sources, I'm certain that a large epoxy line would have been much stronger and required less maintenance although the shiny stainless is pretty.
  10. Dale, The size of the line depends on the job. Make the size to fit the shape you want on the foil or stem. I always just plane off a flat and size the line so that it continues the surface shape you want. I soak the line, fix one end with a nail and stretch it in place. Then slather on some thickened epoxy to fill gaps and place some plastic sheet over it. Pull and tape or staple the plastic so that the edge comes close to the proper shape. You can shape the surface with a flat board to close to what you want. I used to clamp a couple pieces of thin ply over each side to help shape it. Don't do that any more unless a fairly sharp leading edge is needed. It may need a little more filling after the plastic is removed along with a bit of shaping although you can forget about shaping the line itself as it is too tough for that. The fiberglass sheathing goes on last. Its easier to do than to explain. I think some 3/8" or 5/16" line would be right for a CS CB. I don't remember what Graham used on the 44' catamaran stems but it would be larger than that. I used some 1/2" on teh leading edge of my Grand Slam 7.9M daggerboard. That boat hit an old engine block in the creek at about 5kts which stopped us dead. No damage from stopping 6,000 lbs. The aft end of the trunk did suffer some damage though. I also used 5/16" line on the bow of Windmills. On paddle tips for a whitewater canoe, I used 3/16" as protection from rocks.
  11. A simple experiment should convince anyone of the superiority of an epoxy soaked synthetic line to any other kind of protective leading edge for a foil or even a stem of a boat. Try a short piece your self and then try damaging it with a hammer on a workbench. Since the epoxy soaked line was my original idea, I have to speak up now and again. It has protected the stem of racing boats that were damaged in collisions as well as both bows of Graham's 44' power cat. The fact that the combination of the soft line and harder epoxy makes for a very tough combination is the real secret behind its success. It does deform a bit on impact but absorbs the force and the shape is not permanently changed. Since quite a few people have used this technique on their boats, I would like to have a report if anyone has ever had a damaged leading edge from any reasonable source.
  12. LOON had ports in all four side tanks and the bow plus the first watertight lockers seen on any of the boats. We were able to store everything needed for beach camping in there and the rest of the boat was completely clear. Worked great as the photos on B&B website show.
  13. If you know that you have completely sealed the seat/tank and the boat will not be exposed to very hot temperatures, no openings are necessary. Sealed hull areas have been known to distort and/or split seams in hot weather. I always drill a very small hole (approx 1/16") in a protected area if a compartment is completely sealed to prevent this. If a plastic or other port is installed, there is no need as some leakage can be expected. When ports are used, its a good idea to open them for storage to allow drying out. In either case, tank interiors should should be well coated with epoxy. Your idea to fit a PVC pipe to the locker for long stuff sounds like a good one.
  14. All true for the general case of glued plywood lapstrake boats but in a Lapwing there is another feature that is even more important in establishing the structural integrity of the boat. For proof, look at the design source of Lapwing which is the CS15 and most of the smaller B&B sailboats. These non-lapstrake boats have plywood panels of relatively large area but do not have and therefore cannot benefit from glued laps as they have none, but are still a strong and rigid structure. The main reason for their structural integrity is the interior seat and air tank design which was arrived at over several years development. The seats and air tanks with internal transverse bulkheads form rigid box structures that resist torsional forces. The monocoque principle is the same as that used in aircraft and modern automobiles which eliminates any need for frames. Sometimes a stringer may be useful for large open spans but even these are not usual in the smaller boats. The result is that the CS boats are plenty strong and the round hulled glued lapstrake Lapwing is even stronger. That these boats are lighter weight than more traditional plank-on-frame or ply-on-frame boats of equivalent strength is a major bonus and often the main reason for using this kind of structure. Edited: Just reread PAR's post and see that he also wrote about the same feaures.
  15. My only excuse, and not a very good one, is that it was late and my eyes got tired and added a non existent extension to Austria. Bluejackets are probably not very good at mountain climbing but would undoubtedly slush downhill well in the snow. That is, if global warming hasn't hit too hard in Austria. Bluejackets would be perfect on rivers like the Blue Danube though. https://www.facebook.com/vesseldede
  16. Toni, All the info is there but I have just rearranged it so it is more readily accessible. Liz agreed that all was not in the most clear locations in the menu. There is one Bluejacket 24 afloat in Brisbane and some plans in Perth and the west coast.
  17. Wojtek, Late getting to your post. Not sure I can give you any precise answers to your questions, if that is what you want. Lapwing rates favorable to other similar boats I have sailed over the years. Like all of B&B cat ketches she is a pleasure to sail and easy handling is superior to sloops or catboats. That video was made a few years ago and my memory is that the wind was variable as it usually is in that restricted area at that time of year. It was high enough to promote an occasional plane but not sustained. Actual speed of any sailboat is not a good reason for having one as it is all relative to how it feels to the people aboard. In that respect I rate Lapwing equal to the CS15. She is not really bigger and the extra inches in LOA was put in to make her look better with lapstrakes which can look awkward on a bluff bow. Wetted surface is somewhat less than CS 15 because of the round hull shape. Initial stability is slightly less for the same reason but still plenty adequate. The main reason for choosing Lapwing over a CS is because you want lapstrake or somewhat prettier boat, as I did. As a comparison to a Windmill, which I have lots of experience with, Lapwing is heavier, beamier, more stable and has about 15% less sail area. Windmill is much faster and the penalty is that if you attempt to sail a Windmill in similar conditions with a laid back attitude, you will soon be swimming. Sails are the same as the CS15. CS17 is much larger in all respects. All CS versions except EC22 might be considered undercanvassed compared to similar size racing boats. For our daysailing use, this is a good thing and average speed suffers little from the rig or sail area. When pressed to their limits all CS boats offer similar impression to the people aboard that faster racing boats do. 10 to 12 miles per hour feels very fast on any small sailboat and 6 MPH is plenty active for most of us. Sailboats spend most of their time at less than that. Lapwing is fast enough to give you the pleasure that you seek from a small sailboat. When added to the other attributes, the entire CS and Lapwing series come out high on bang for buck (or sweat).
  18. On a boat with Marissa's design, speed will be determined by power and weight so I would expect 32kts with 60hp. Lightly built and loaded to minimum displacement she will go faster. You may need to make some tests to find the best prop diameter and pitch since the best calculated one may not be available from stock. My guess is 13.5 to 14" dia. at 17" pitch for general use. MPG depends entirely on displacement and your throttle but Graham's data gives a clue.
  19. I have had LIZ out on the water for a couple days taking photos of sailors for other countries sailing for the World Championship in the Sunfish Class. ON Tuesday there was a good press of wind and waves on the wide expanse of the Neuse River and some rally good action was seen. The attached photos were taken in the 72 boat senior, or masters, division. All boats are new for this regatta and provided by a local dealer. You need to look carefully to see just what is going on with the individual boats in the two photos. I know we are powerboaters here but our roots are in sail.
  20. Jim, There is a lot more to this and the plans include detail of structural modifications. The smaller bracket in the center would be much easier to retrofit while the full width extension would not be a big deal to fit to a new build. One other extra is that a kicker can be added to either type easily if that is wanted.
  21. Having my usual problems with my computer and can't seem to get a scan to work well. This is a photo of the two versions of outboard extensions.
  22. Having my usual problems with my computer and can't seem to get a scan to work well. This is a photo of the two versions of outboard extensions.
  23. We are having the annual single handed race off Oriental on the Neuse today. The race now allows double hand crews with a total age over 150 so I'm going sailing today but will post some drawings of the extended motor mounts this afternoon.
  24. I thought this topic deserved its own thread so brought the reply over here as well. Duane, I have developed some plans for a couple types of extensions or brackets that make boarding much easier and also add buoyancy. These are included with the plans if wanted. We had 4 Bluejackets of all lengths at Georgetown and Charleston last October and did not have any water entry problems through the scuppers even with the cockpit loaded with people. I have seen this issue though and have suggested that the cockpit sole be raised. There is only one negative to doing this. That is that the step down to the pilothouse will be greater and the headroom for entry will be reduced unless the pilothouse top is raised. I consider this a good thing. Henry plans to raise the cockpit sole when they get back home. One mistake that is often made about outboard brackets is that they offer more cockpit space. This is wrong because the boat is as long or as big as it is from stem to the end of the outboard. They do offer more space if the bracket is added to an existing hull but in a new build, making the boat as long as the end of the bracket will always give more cockpit space. Still, the boarding/swim platform advantage can be attractive with an easy entry door in the center of the transom. The plans show this version also. A further advantage to raising the sole is increased fuel capacity, which has also been an issue for Henry for one of the long legs of the trip that he has taken care of with an added temporary fuel tank. I recommend in the plans than a custom aluminum fuel tank be part of the building process. This offers a lot of additional fuel volume because the off-the-shelf tanks from Moeller don't make good use of the available space. When properly installed and protected, I consider aluminum tanks to be a good deal even at the added expense and they will have baffles that prevent fuel sloshing about.
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