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Tom Lathrop

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Tom Lathrop last won the day on September 29

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About Tom Lathrop

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  • Birthday 09/17/1931

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    Oriental, NC

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  1. Tom Lathrop

    Chick's Micro Power Cruiser Project.

    When I was running the early tests of the BJ24, I bolted on a Duel Fin and ran through the usual tests. The difference was a reduction in speed at all RPM levels. This indicated an increase in drag with no benefit observed. I could not detect any significant change in the trim of the boat with the fin. The natural trim of the Bluejacket appeared to generate a lot of longitudinal stability in trim and overpower any effect added by the fin. Perhaps if there was a greater angle of the transom a fin would have more effect in lifting the stern and/or depressing the bow but on LIZ, this was not the case. There is a lot to say about hull trim and the effect of balance and hull bottom design on it. I second Graham's thought to add a more forward steering station on Old Codger for both better control of hull trim as well as making long passages less tiring. Maybe Chick's tolerance for holding that tiller forever is greater than mine. I get cramps thinking about it.
  2. Tom Lathrop

    Chick's Micro Power Cruiser Project.

    Down by the stern Chick? The aft chine is barely touching the water in the photo at rest. You must be hiding some bags of helium in there some where for the boat to look so light. Ordinarily, I hate the idea of adding weight to a powerboat but, in your case, maybe Mike's thought of trying a bit of weight in the bow is appropriate. What does your designer say?
  3. Tom Lathrop

    B&B Preps for Florence

    You are correct, of course Dave. The real villains do their work behind closed doors in the Raleigh legislature. Not that some of the mess isn't natural but we should not be making it worse unnecessarily. We usually blame the "heads in the sand" tendencies for ignoring impending disasters but, in this case, the complete lack of a spine allows our leaders to poke their heads up their own asses.
  4. Tom Lathrop

    B&B Preps for Florence

    We are still slowly working our way through the mess left by Florence and our not-perfect preparations. There is one important issue I want to bring to anyone who faces floodwater. A friend here in Oriental was infected by a virus found in the mix of river flooding and brackish water that is deadly. My friend contacted it in shallow water in his garage before it was completely drained out. It started to bother him soon after the exposure and he went to the doctor. The doctor said he had to get to hospital quickly and he wanted to go to Duke Medical but the doctor said he would not live to make the trip to Durham. Wow. They had to amputate his leg and some other bits immediately or he would not survive. Liz and I visited him yesterday and it looks like he will make it out of the IC with one leg. The virus can apparently penetrate skin without the need for a cut or other raw entry. Another man in Wilmington was less fortunate and died as a result of the same or similar virus/bacteria from Florence waters. https://www.coastalreview.org/2018/09/public-health-safety-key-issues-post-florence/ Not to broadcast scare tactics but this is serious stuff that most of us have never heard of. I've worn boots when in hurricane water and and only once in deep water without protections to encourage hurricane Irene to leave my shop by prying a door open. Never again though. Two people out of about a total of 13 or 14 deaths in NC due to Florence is way too high statistically to ignore.
  5. Tom Lathrop

    Heresy and abomination: Bluejacket with a bracket?

    This is a sketch of what the hull extension/bracket would look like. Details would vary depending on the application.
  6. Tom Lathrop

    Heresy and abomination: Bluejacket with a bracket?

    Bluejacket plans already include a plan for an integrated bracket/swim platform. None has been built yet, so far as I know. My preferred version is not a bracket, as such, but a hull extension almost identical to Sam's Red Salmon although 600 Verado horses charging along behind is kind of scary. I think this may what you are looking for anyway.
  7. Tom Lathrop

    upwind sailing

    A good starting point, Dave. Of course, the mizzen will be sheeted in closer than the main. A cat ketch is not going to point as high effectively as a well sailed sloop or cat. All the great handling manners of a cat ketch has a price and this is it. It should be looked at as a challenge to learn how to get the best out of your boat.
  8. William, The highest stress point of a free standing mast is at the point where it exits the deck. Some flex immediately above this point helps to relieve part of this stress. The tabernacle/mast assembly in the illustration looks to be much stiffer than an equivalent length of mast and that it will increase the stress beyond that of a normal free standing mast at this weakest point. A logical solution to that problem is to make the lower mast section much stronger that the rest of the mast.
  9. Something went haywire but it apparently uploaded anyway. The forum attach process seems to have changed today.
  10. This is the second version of a mast gate for a rotating tabernacle.
  11. I did design a second version based on Dale's problem with space at the base of the tabernacle. I sent it to Dale by email for his comments but have not heard in return. I think it is a better solution in that it takes up no additional room in front of the mast base and is remotely locked and released by control lines so you don't need to gain access to the base of the tabernacle to operate it. This lock could be retrofitted to an existing non-rotating tabernacle to eliminate the need for operating the bolt/wingnut which some find a bother.
  12. All the early B&B cat ketches did. We just did not reef them, although a few people made some apparently complicated arrangements for reefing them. Some traditional sharpie workboats reefed by brailing up the sails to the masts.
  13. Dale, I don't have a drawing of the CS17 so don't know how much space is available in front of the mast. Some builders have installed a tabernacle on a CS17 so there may be adequate room for the flop board mast lock, which I think is a plus to have that way up in the bow so you don't have to go there underway if you need to. I have seen a similar mast lock on another type boat but nothing quite like this or part of a tabernacle. You would be the beta model although I'm pretty certain it would work. There are other methods for rigging a gate at the bottom of the tabernacle that don't require any additional room forward of the mast. The purpose of any of these base locks is to avoid the need to manually set up the bolt.
  14. Tom Lathrop

    Racing advice in light air

    There is a line between rolling while tacking and tacking in order to do a roll for the purpose of propelling your boat. The judges will decide if you are guilty. Of course, you will already know if you are guilty. Very few know how to execute a roll tack well anyway, especially in a two or more crewed boat. Getting everyone well synchronized is not easy without lots of practice. Locally, we often have 18 or more college teams from all over the east racing in scheduled events. Some of these kids can roll tack well in a wide range of wind speed. Many do not get good coordination or execution and do not get good results from their efforts. Those who do are generally the winning teams. http://www.sailpack.org/2018orientalsailpack
  15. Dale, I see that there has been no rush to offer a new wizbang tabernacle for you so I have gone to the drafting board to draw one that was in my head a while back. I also liked the rotating mast I had on my Bay River Skiff LOON for its simplicity, ease of rigging at the launch and permanent storage of the sails. Going to sail tracks and battens with leech roach changed all that. Some performance was surely gained but at the loss of a lot of time and convenience and I really missed the former ease of handling in launching and docking, especially into a downwind dock or beach. With the years catching up to me, I also was starting to need a tabernacle on the main and about two years ago I designed a tabernacle that would accomplish both objectives. Details were not completely worked out and some things needed refinement when it was actually laid out on paper following your request. This sketch shows the resulting unit. I actually gave LAPWING to my son Mark and it now sails on coastal Maine where he and Jan live on Georgetown Island. It should be pretty clear in that there is little difference in the actual construction other than the ears on the side that allow for the pivot bolt to attach to the mast tube. I would make that collar of fiberglass bonded to the tube. Based on past experience the sides of the tabernacle should be made very strong to take the stress of a bending mast in a breeze. I’d wrap it in 1808 biaxial non-woven glass and add a through bolt near the top. The added ears should be made strong to take the expected stress as well. Another change from the normal CS tabernacle is the lock at the base. The bolt works fine but often calls for some fiddling hands on work to get it fitted and secured. The flip board shown should hold the mast in place securely at the base with no hand-on needed. If the spring loaded hinge is not considered secure enough in the event of a capsize, a magnet under the board near the mast should add more security. A trip line could be rigged so the release could be done remotely for easier single handing. If it were mine, I would have no battens in the sails and wrap them on the mast permanently. There is a sailmaker in Florida who makes sails with vertical battens that may look a bit off to traditionalists, but seem to work well. These can be wrapped around the mast.`As on LOON, the masts/sails would be stored in a canvas sleeve and placed in cradles above the mast tubes. This is great for traveling as well as a tarp support for storage. Tom Lathrop

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