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Tom Lathrop

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Tom Lathrop last won the day on July 28

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About Tom Lathrop

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  • Birthday 09/17/1931

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  1. 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.
  2. 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.
  3. Something went haywire but it apparently uploaded anyway. The forum attach process seems to have changed today.
  4. This is the second version of a mast gate for a rotating tabernacle.
  5. 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.
  6. 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.
  7. 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.
  8. 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
  9. 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
  10. Tom Lathrop

    Racing advice in light air

    In light air, heeling the boat is advantageous for several reasons. One is that heeling reduces wetted area, two is that heeling adds weather helm which is an aid in pointing high, three is that adding weather helm helps in tacking, finally heeling gives the sails a better shape because of gravity. Position of the crew is adjusted to maximize the other variable mentioned. Heeling reduces the height of and horizontally projected area of the sails to the wind and those are negatives. All of this changes with the particular boat and the wind speed. Nothing is as important as going in the right direction and that can change if you need to go off the closest course to chase spotty wind around the lake. You absolutely need to learn to read the water as an aid in finding where the wind is. Tieing off the tiller on centerline and sailing around through tacks and jibes by moving your weight around will teach you as much as anything about these conditions but you can do that with moderate wind also. At some point you may wish to learn how to roll tack which can actually propel the boat forward in a dead calm even if its not legal in racing.
  11. Tom Lathrop

    B&B's first annual "Capsize Camp" July, 20-22

    I started out in a competitive Windmill racing fleet before I really knew how to sail. Had read all the library books on sailing boats but in 1966, that was not very many. In our first couple races with Liz as my crew, we dumped in blustery conditions at the leeward mark. The early Windmill was completely open and did not have any flotation other than the wood in the boat so flipping it back up and sailing on was out of the question. I was able to bring it back vertical with tons of water inside and tossed out the anchor which brought the boat head to wind. With Liz hanging on to one rail, I bailed with a bucket until the water was below the daggerboard slot and climbed aboard to get more water out. Finally I was able to pull my long suffering crew aboard and hauled the anchor. We finished the race and and Liz asked me if that was the worse that could happen. After I assured her that a capsize was about it, she said "well I won't worry any more" and we went on to years of more racing capsizes, some easier, some worse and a few much more difficult. The experience gained from easy situations stood in good stead whenever Murphy decided to try new tests of our skills. After this episode, I installed port and starboard air bags that allowed for much easier recovery. One crazy capsize occurred in a regatta in Chick's back yard at a small lake just south of Asheville on the first week of November. While attempting to get relief from very blustery wind, I sailed into a downwind cove. I immediately saw that this was a stupid thing to do as the wind remained high as well as having large shifts side to side in the cove. Managed to tack around but one shift just flipped the boat over. My boat "Don Quixote" rolled mast down and on through a 360 and came back upright. By this time the capsize practice paid off and I just walked the boat all the way over and stepped back inside, where the water finally came over the top of my boots and got my feet wet for the first time. The lake is cooling water for a power plant and is so tepid that tropical fish live there. Of course on the first of November, the air is cold and we sailed back to the club dock for my crew to get out and dry out in the warm clubhouse. I was ashamed to admit to my crew that I was all dry and he may have never forgiven me. Many capsizes in Lasers and many other boats came along at regular intervals while racing. It is a general truth that if you do not capsize from time to time in a high performance boat while racing, you are probably not sailing on the edge that is necessary to win. A boat can go under water with out a normal capsize. Racing against Graham in frostbite races in Spindrift 10s, I sailed the boat under the water down wind in strong wind. With the sail of a Spindrift so far forward, the pressure overcame my ballast sitting on the transom and just went under a wave. Graham just looked over at my swamped boat as he sailed by and won the race. In all 50 plus years since 1966, I have never capsized when not racing. Capsize drills, like all drills are intended to make the real thing less serious and allow you to follow your training and do what is necessary without having to think for the first time about how to go about it.
  12. Tom Lathrop

    Chick's Micro Power Cruiser Project.

    Chick, One of my "yacht" design books offers the dictum that slope of a coachroof should intersect with the top of the bow. As may be, but that probably holds only for boats that aspire to being a "classic" design. Probably few boats seen on the water today satisfy that rule and probably none of the smaller ones that hope to house humans inside. I would not have any opinion on perfection, having never seen any. There was this girl once but then, I never got to meet her so could be wrong about that as well.
  13. Tom Lathrop

    Battens

    I dislike the battens that come with most sails as being far too stiff toward the luff. It may or may not create a big loss in performance but the typical vertical sail crease along the forward end of battens is just ugly. My solution is to make my own battens. I used to make them of ash when racing regularly but now make battens from fiberglass. Wooden battens tend to develop the bends over time unless treated with great care. Regular woven fiberglass is no good for this job as it is much too flexible. I use biaxial 18 oz or heavier with long linear strands taken from biax laminated inside. More strands aft and fewer forward until you get the shape you want. The forward end should be very flexible. The sandwich is laid up between plastic sheets and clamped with straight wooden planks on the outside. It takes some experimentation to get the stiffness and flex where you want it but a great sail shape is the reward. The first try will probably be too limber but you cans simply add more on top of the earlier one. If you have access to small diameter linear fiberglass rods, that is ideal. Admittedly, this is a bit of trouble but it is only time and I always enjoyed fiddling with such stuff if it resulted in better performance. Even if the increase in performance is not measurable, your mental state may be improved and that is just as important.
  14. Tom Lathrop

    Core Sound Challenge Race June 28th

    We found out about how little the charts and markers can be trusted on Core Sound a couple years ago. Depth about one foot over large areas where chart calls for relatively deep water. Deep for Core Sound, that is. Anywhere near Drum Inlet is questionable since Hurricane Irene. Best to stay nearer mainland when near Atlantic, I think. I don't think any waters similar to Core Sound even shows up on the NOAA Gov. to do list for new soundings work. One of you young computer wizards need to develop technology for depth charting from satellites or such. Unmanned surface drones aught to be doable with existing technology and small money.. We plan on doing the Sound from the Neuse through Thorofare to Beaufort soon so will make sure to have push pole and spare prop aboard. If Taylor is still on speaking terms, civil speaking that is, you are set for the long term. Tom
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