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Thread: Munch

  1. #36
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    Default Re: Munch

    Quote Originally Posted by Chris249 View Post
    Yep, the difference between old racing catboats (which were very quick for their day) and the modern ones is why I noted that "the ones around now" seem to be pretty sedate. I was wondering whether Bolger was referring to a 19th century sandbagger type or something like a Cape Cod Cat, which isn't a very fast boat.

    As I think you know, I HAVE looked into the history!

    https://sailcraftblog.wordpress.com/.../19/sailcraft/

    https://sailcraftblog.wordpress.com/...ailcraft-pt-3/

    https://sailcraftblog.wordpress.com/2016/05/23/519/

    Personally I'd say that while Una etc were enormously influential, if there was any way to trace the bloodline of Lasers etc it would be that of a canoe, Rater and "sail and oar" dinghy as much or more than catboat. Obviously it's all so mixed the lineage can't really be traced, but the history of the major dinghy class in the place the Laser's creators came from, for example, seems to derive more from canoes and "sail and oar" tender-type dinghies than anything else;

    https://sailcraftblog.wordpress.com/...s-small-boats/

    https://sailcraftblog.wordpress.com/2016/05/23/701-2/
    Kirby was an international 14 guy. I don't think it's a coincidence that modern dinghies evolved in Cowes, where Una boat racing had been popular. As you know, many UK una boats were converted to sloops. There are some missing links, but I think it's reasonable to suppose there was an evolution Una to International 14 to Laser. Certainly, abandoning the straight keel had something to do with local building traditions as well.

    In addition, as I'm sure you are aware, only the Cape Cod catboats were notable for their wide beam. Look at the specs Charles Kundhardt gave in Small Yachts, you'll notice that many of them were about as narrow as the sloops of that time.

    Here, for example, is a replica of the Rushton catboat:


  2. #37
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    Default Re: Munch

    Quote Originally Posted by Chris249 View Post

    Personally I'd say that while Una etc were enormously influential, if there was any way to trace the bloodline of Lasers etc it would be that of a canoe, Rater and "sail and oar" dinghy as much or more than catboat. Obviously it's all so mixed the lineage can't really be traced, but the history of the major dinghy class in the place the Laser's creators came from, for example, seems to derive more from canoes and "sail and oar" tender-type dinghies than anything else;

    https://sailcraftblog.wordpress.com/...s-small-boats/

    https://sailcraftblog.wordpress.com/2016/05/23/701-2/
    I would tend to agree, strongly. The Una cat boat was a short lived fad over here, I think that it survived for longer in Germany than the UK as the hull form is not suited to any of our waters. The rig did survive on Windermere according to Dixon Kemp but on a hull suited to Windermere's conditions. So if there was any transatlantic influences on dinghy design, catboats did not figure much, whereas sailing canoes thanks to Uffa Fox were truly international.
    It really is quite difficult to build an ugly wooden boat.

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  3. #38
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    Default Re: Munch

    Quote Originally Posted by johnw View Post
    Kirby was an international 14 guy. I don't think it's a coincidence that modern dinghies evolved in Cowes, where Una boat racing had been popular. As you know, many UK una boats were converted to sloops. There are some missing links, but I think it's reasonable to suppose there was an evolution Una to International 14 to Laser. Certainly, abandoning the straight keel had something to do with local building traditions as well.
    If there was any influence in the "displacement" '14s from the catboat form, that link was broken by Uffa Fox with his planing hull form '14s in the 1930s.
    It really is quite difficult to build an ugly wooden boat.

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  4. #39
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    Default Re: Munch

    Quote Originally Posted by Peerie Maa View Post
    I would tend to agree, strongly. The Una cat boat was a short lived fad over here, I think that it survived for longer in Germany than the UK as the hull form is not suited to any of our waters. The rig did survive on Windermere according to Dixon Kemp but on a hull suited to Windermere's conditions. So if there was any transatlantic influences on dinghy design, catboats did not figure much, whereas sailing canoes thanks to Uffa Fox were truly international.
    Kemp shows the lines for Una, 1852, and the lines for a British 'una boat' from 1870. I'd say the 'fad' lasted at least 20 years, and the boats continued sailing for a good long time. In fact, I read in Classic Boat quite some time ago about one re-rigged as a sloop that was still sailing.

    And according to ACB, Uffa said that on heavy weather days, all the 14s were planing, but Avenger was the only one that planed in the conditions usually encountered. Not only was the link not a clean break, the 14s have returned to the U shaped bow sections used prior to Avenger.

  5. #40
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    Default Re: Munch

    Quote Originally Posted by johnw View Post
    Kemp shows the lines for Una, 1852, and the lines for a British 'una boat' from 1870. I'd say the 'fad' lasted at least 20 years, and the boats continued sailing for a good long time. In fact, I read in Classic Boat quite some time ago about one re-rigged as a sloop that was still sailing.

    And according to ACB, Uffa said that on heavy weather days, all the 14s were planing, but Avenger was the only one that planed in the conditions usually encountered. Not only was the link not a clean break, the 14s have returned to the U shaped bow sections used prior to Avenger.
    A bow alone does not a fast boat make.

    When going flat out the bow of a 14, or any modern dingy is out of the water.
    I will admit that the "U" shaped bit at the keel will make a difference though, better in flatter water and OK if you and the hull can stand slamming in lumpy green wet stuff.

    Uffa was commenting that even inefficient hulls can be over driven in a gale. Apparently the double ended Shetland boats can plane if pushed hard enough.
    It really is quite difficult to build an ugly wooden boat.

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  6. #41
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    Default Re: Munch

    Quote Originally Posted by Peerie Maa View Post
    A bow alone does not a fast boat make.

    When going flat out the bow of a 14, or any modern dingy is out of the water.
    I will admit that the "U" shaped bit at the keel will make a difference though, better in flatter water and OK if you and the hull can stand slamming in lumpy green wet stuff.

    Uffa was commenting that even inefficient hulls can be over driven in a gale. Apparently the double ended Shetland boats can plane if pushed hard enough.
    I doubt the boats were raced in a gale. In any case, if they were still building them 20 years after Una was imported, they must have been suited to some UK waters.

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    Default Re: Munch

    E.L. Knight's Small Boat Sailing on Sea and River, published in London in 1905, says una boats are well suited to use on rivers, small lakes, and broads.

    https://books.google.com/books?id=SM...%20una&f=false

  8. #43
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    Default Re: Munch




    Images from Chris's blog. I'd say the real progress was made at the stern, in the rig, in materials and techniques. Morgan Giles was not so far off on the bow and mid section.

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    Default Re: Munch

    Quote Originally Posted by johnw View Post
    And according to ACB, Uffa said that on heavy weather days, all the 14s were planing, but Avenger was the only one that planed in the conditions usually encountered. Not only was the link not a clean break, the 14s have returned to the U shaped bow sections used prior to Avenger.
    Quote Originally Posted by johnw View Post
    I doubt the boats were raced in a gale. In any case, if they were still building them 20 years after Una was imported, they must have been suited to some UK waters.
    OK, half a gale
    Unless they were raced as one designs, which I doubt, the hull form will have evolved to better suit our waters, whist keeping the rig, just as happened on Windermere.

    that is the same hull form as the other Windemere yachts of the time that were cutter or sloop rigged
    It really is quite difficult to build an ugly wooden boat.

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  10. #45
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    Default Re: Munch

    Quote Originally Posted by johnw View Post



    Images from Chris's blog. I'd say the real progress was made at the stern, in the rig, in materials and techniques. Morgan Giles was not so far off on the bow and mid section.
    Just so. As I said, a bow alone does not a fast boat make. Real progress was made in the stern, in the buttock lines actually. Howlett has improved over Snark by further straightening those buttocks. Just as Uffa improved over the displacement boats by making the same change.
    It really is quite difficult to build an ugly wooden boat.

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  11. #46
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    Default Re: Munch

    Quote Originally Posted by johnw View Post
    E.L. Knight's Small Boat Sailing on Sea and River, published in London in 1905, says una boats are well suited to use on rivers, small lakes, and broads.

    https://books.google.com/books?id=SM...%20una&f=false
    As I pointed out that is the rig, not the hull form. The book states that the hulls are built deeper for sea work as the shallow cat boat form is only suited for sheltered river and small lake work.
    I have just taken a handbook of 1904, first published by Cassell in 1899 on Building Model Boats. It discusses a pond yacht suited to a course that included a beat to windward and a run home having a "semi cat" rig with a small jib. This on a conventional fin keeled skimming dish pond yacht hull. It is always the rig, not the hull that the English refer to when discussing cat or Una boats.
    It really is quite difficult to build an ugly wooden boat.

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  12. #47
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    Default Re: Munch

    Quote Originally Posted by Hooligan navy View Post
    Even today the old wooden boats can hold their own in class racing.
    Depends on the class; Dragons, Thistles or Lightnings perhaps, but mostly the plastic boats are quicker.

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    Default Re: Munch

    Wood is great but modern composites are just too good from an engineering standpoint. A friend who is a pro builder said that carbon is the ultimate boatbuilding material (for yachts) does not fatigue, incredibly strong, light etc... But this is a wooden boat forum
    whatever rocks your boat

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    Default Re: Munch

    Using an Alden design 1928 60' schooner plans, let's say, could an all composite boat be built. At what cost, and what are the trade offs? Can it be steam bent? Does it look good in the interior? Does a composite boat weigh more than wood? Is composite good for masts? Since composite has plastic in it, does it finish well? I guess I like old hull designs. They were pretty fast and sturdy.

  15. #50
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    Default Re: Munch

    Of course such a boat can be built. With correct engineering, she could even have exactly the same outside shape and have a superior distribution of weights. How she'd look is all about how she's finished and there's no reason for that to be inferior.

    Alden had quite an evolution of his schooners and ketches. Subtleties matter and his last was never as wonderful - fast, easy motion, all that - as his next. So Alden would be the last to fantasize that any of his boats was the last word. Some "modern" boats are focused on a rule but are not so satisfying all around. Some are design evolutionary dead ends. Some are constrained by economics. But the field advances and many are simply wonderful. My personal aesthetic likes the '50s-'60s CCA types best but I have no illusions that they are the best boats ever for everything.

  16. #51
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    Default Re: Munch

    Of course a composite Alden schooner could be built, at significant cost and with the "trade off" that it would probably have enormously greater stability and impact resistance (since although carbon isn't great at impact resistance per se, you could make it extremely thick but still be much lighter than wood).

    Does composite look good in the interior? Well, if you use Nomex core, carbon skins and then lay over a veneer of wood it can apparently look great.

    Does a composite boat weigh more than wood? Errrr, no, it can weigh a fraction as much as wood; a modern carbon cruiser/racer can weigh as little as 5.2 tons, with full interior and a 50% ballast ratio. An Alden of comparable length is way above that, even with a lower ballast ratio.

    Is composite good for masts? It's incredibly light for its strength, so in many ways it's outstanding. Of course, it also has issues.

    How does one define "pretty fast"??? The classic 52' S&S ketches Dorade and Stormy Weather, which wiped the field with the Alden schooners in the 1930s, are only about the same speed as a good late '70s/early '80s production cruiser/racer 36-38 footer. A good modern fast racer/cruiser would be about 25% quicker than an Alden schooner of the same LOA.

    NOTHING of the above means that a wooden Alden is inferior, but the advantages of modern boats should also be recognised.

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    Default Re: Munch

    My 14 foot catboat often exceeds her theoretic hull speed of 5knots, on occasion by as much as 2 knots. Most of the hull sections were stolen from Bolgerís Bobcat, which I assumed was the explanation for this anomaly. Bolger understood how to design hard-chined hulls.

  18. #53
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    Default Re: Munch

    The "hull speed constant" (about 1.34 if using feet and knots) is not such a real thing. Even for the 'wave formation speed log' I show in #17, it's only an approxomation and changes with temperature, salinity, depth, and other factors.

    In addition, there are a lot of ways to explain what happens at hull speed so here's my somewhat poetic version. I'll not be hurt if our resident NAs correct me. So, getting to "hull speed" - you have a nice bow way a bit abaft the cutwater and you have the second, now stern, wave somewhere abaft the stern. The stern is sitting in the trough between the two waves. You are essentially sailing up hill. You can do it with enough power but each fraction of a knot requires exponentially more power. You get to the point of diminishing returns and somewhere past that you get to the point where the boat can't float a large enough power plant.

    Here's where NAs can get tricky. My Marco Polo Granuaile had a nominal (1.34 constant) "hull speed" of 9.3 knots. But she was only 10' beam and the 1.34 was really the wrong constant. We were sailing in a westerly Gale (Force 8, winds 34-40 kts) up along the back side of Cape Cod so flat water and a nice lee. A friend happened to be flying and got some great shots. LFH's legerdemain so fooled the water that I could not make out Granna's wake at all. But I was towing Leeward that even light showed a large stern wave that was almost 100' astern! We were doing close to 15 knots. The actual average for that romp from dropping the mooring in Hyannis Port to abeam Highland Light taking it as just straight line was a bit over 11 knots.

    Point is, a boat that's skinny enough for her displacement makes the waves, but the hole is just not that deep, you're not climbing such a steep hill. And there are other tricks besides just beam. The Bolger cat has a deceptively easy entry and lots of buoyancy in her buttocks so she does not squat as much as another boat of her length and beam. All these NA tricks make using the 1.34 constant just a rough starting guide. Hull speed is not like the sound barrier.

    G'luck

  19. #54
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    Default Re: Munch

    Quote Originally Posted by Mike.Higgins.94301 View Post
    My 14 foot catboat often exceeds her theoretic hull speed of 5knots, on occasion by as much as 2 knots. Most of the hull sections were stolen from Bolger’s Bobcat, which I assumed was the explanation for this anomaly. Bolger understood how to design hard-chined hulls.
    There is not a huge difference in bottom shape between this

    and this


    which can do this


    What you have and Bolger designed is a semi displacement hull with straightish buttocks and a wide bottom aft intended to operate at above hull speed.
    It really is quite difficult to build an ugly wooden boat.

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  20. #55
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    Default Re: Munch

    Science shows us that the predominant variable, if you wish to escape 'hull speed' and travel at semi displacement speeds is length to displacement ratio or slenderness ratio. All other hull factors are minor to this. Semi planing and planing is a different game again.
    Last edited by Edward Pearson; 12-03-2018 at 10:33 AM.

  21. #56
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    Default Re: Munch

    Quote Originally Posted by Hooligan navy View Post
    Using an Alden design 1928 60' schooner plans, let's say, could an all composite boat be built. At what cost, and what are the trade offs? Can it be steam bent? Does it look good in the interior? Does a composite boat weigh more than wood? Is composite good for masts? Since composite has plastic in it, does it finish well? I guess I like old hull designs. They were pretty fast and sturdy.
    You need to define what composite means for you. Wood skin on steel frames, FRP single skin or sandwich, or laminated wood.
    The laminated wood option is simplest to do, you respect the original scantlings and replace metal fasteners with epoxy. If Alden specified woods that are difficult to glue with epoxy like teak and white oak you replace them with something of similar weight that goes better with epoxy. Frames and backbone get laminated, skin gets strip plank or cold molded or both. In the end the boat weighs the same, is wood, and the interior can even look the same if you want. The boat will just be stronger than any carvel buildt one. Costs depend on the materials used but epoxy is not going to be more expensive then silicone bronze screws. Labour hours might or might not increase depending on who is building. This is of course not the most elegant option, the thing to do would be to have a NA recalculate the scantlings and structure to suit the new materials and techniques. If you want to go FRP this becomes a necesity, you can not do it by eye. Converting a heavy displacement boat to sandwich construction or carbon fibre is probably futile, but single skin glass with polyester is possible and could even prove cost effective (depending on location).

    Here is an example of modern construction. 2.5mm (something over 3/32) single skin carbon with 200mm (7 7/8) spaced ribs and some bulkheads, plus local reinforcement where needed. That for a 60 feet sloop that was expected to have an average speed of aprox. 20kn in order to be competitive racing around the southern ocean. https://www.gettyimages.de/detail/na...foto/473041050

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    Default Re: Munch

    Quote Originally Posted by johnw View Post
    Kirby was an international 14 guy. I don't think it's a coincidence that modern dinghies evolved in Cowes, where Una boat racing had been popular. As you know, many UK una boats were converted to sloops. There are some missing links, but I think it's reasonable to suppose there was an evolution Una to International 14 to Laser. Certainly, abandoning the straight keel had something to do with local building traditions as well.

    In addition, as I'm sure you are aware, only the Cape Cod catboats were notable for their wide beam. Look at the specs Charles Kundhardt gave in Small Yachts, you'll notice that many of them were about as narrow as the sloops of that time.

    Here, for example, is a replica of the Rushton catboat:

    Well, while I respect Uffa's designs a lot and agree that they were very influential, IMHO modern dinghies evolved in many different places. We know that there were small rowing-type hulls that were sailed even before catboats evolved, and given the importance of early "oar and sail" derived racing dinghies like the Auckland Peach Boats, the Norfolk dinghy, the Thames gigs, the Canadian 14s (which clearly came from rowing tender roots and were adopted by an organisation that had its own roots in canoe-influenced double-ended St Lawrence Skiff types) we can see that there were a lot of development streams that seem to have had no real link with the catboats. Perhaps the Kiwi story is an example - it seems to be fairly clear that until the little catboat Sea King arrived in Auckland, they had no real awareness of catboats. The boat was very influential in Kiwi design, but they had racing dinghies before that first catboat arrived.

    The Int 14 that Bruce and Kirby had sailed in seems to have been very much a development of the Norfolk dinghy and other oar and sail boats. The rig appears to have influences in the Finn which of course was derived from Swedish canoes. That's not to take away anything from the enormous influence that catboats did have, and I think we both agree that Una, Truant, New York and the other early exports were enormously important in the development of dinghies. I'd just hesitate to say that they were the main influence in the Laser, since canoes and oar and sail types seem to have also played a major role in the classes that inspired Kirby, Bruce and Fogh.
    Last edited by Chris249; 12-03-2018 at 11:10 PM.

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    Default Re: Munch

    ^ As I posited above, there were so many differing hull forms that carried the cat or Una rig that I do not agree than cat boats influenced the hull form of modern planing racing dinghies.
    When you talk of Norfolk dinghies are you referring to Norfolk punts that developed out of gun punts, or Norfolk USA? The Norfolk puntss developed (convergent evolution) into big versions of the single handed International canoe. I think that the key thing is that when designers like Uffa Fox were working, and breaking the mould on both canoe and 14 design, it was a transatlantic cross fertilisation of ideas leading to planing dinghy hull forms.
    It really is quite difficult to build an ugly wooden boat.

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    Default Re: Munch

    I was referring to the 14 ft Norfolk Dinghies that, with the WEC Dinghy, became one of the foundation classes of the (Inter)National 14s.

    http://gbr.international14.org/histo...nal-14-part-1/

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    Default Re: Munch

    Quote Originally Posted by Chris249 View Post
    I was referring to the 14 ft Norfolk Dinghies that, with the WEC Dinghy, became one of the foundation classes of the (Inter)National 14s.

    http://gbr.international14.org/histo...nal-14-part-1/
    It is a pity that there are no pictures or drawings of those early boats.
    There is this, of a later one design boat

    The Norfolk Dinghy class was built by Herbert Woods from 1931 to 1968
    A bit narrow in the stern to be considered an originator of modern dinghy forms.
    It really is quite difficult to build an ugly wooden boat.

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    Default Re: Munch

    There is an interesting local connection between the Norfolk Punts and the International 14's of the classic era.Stewart Morris,one of the all time great sailors,learned to sail in a Norfolk Punt.As Nick says the 14 foot Norfolk One Design first saw the water in 1931 and by then planing 14's were far from unknown.The differences between the Uffa Fox era boats and the Howlett design really relate to the different rules in force at each point in time.Geometrically the boats went from fairly narrow to as wide as the rules permitted in order to increase righting moment and this was boosted even further by the adoption of a trapeze.The boats also became much lighter with changes in construction techniques and the abandonment of the heavy old centreboard (110 lbs comes to mind).Couple this with better sail cloth and lighter metal spars and the picture is almost complete.Self bailers did most of the rest and now the class is self draining.Quite a catalogue of incremental improvements.I crewed them a little in the seventies and eighties and soon found I was too short and too light for the class.These days I'm still not tall enough.

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    Default Re: Munch

    However, even if planing 14s were around in 1931, the stern of that Herbert Woods 14 is too narrow to plane effectively. It is still a displacement hull form.
    It really is quite difficult to build an ugly wooden boat.

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    Default Re: Munch

    It's interesting to note that over a lifetime of having the opportunity to become familiar with many old school wooden yachts it became apparent to me that it's a shallow run aft that the fastest of them have in common. L. Francis Herreshoff's boats in nearly every instance exhibit a good turn of speed when comparisons based on waterline length are made. The reason is instantly apparent when one goes below on LFH's yachts and realized that the after bulkhead is much closer to the middle of the boat than one sees in the modern "sleeps six with two fully-enclosed heads" thirty-six footers. There's very depth aft in the LFH designs, generally speaking.

    Another feature which affects stability more than speed, actually, is that fiberglass boats, being built in moulds, cannot have tumblehome unless an expensive two-two part mold is employed. Tumblehome makes a bit difference when a boat is sailing hard on the wind "on her ear."

    I'll leave it to the naval architects to explain how and why, which I think would be of interest to the "younger crowd."

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    Default Re: Munch

    Quote Originally Posted by Bob Cleek View Post
    It's interesting to note that over a lifetime of having the opportunity to become familiar with many old school wooden yachts it became apparent to me that it's a shallow run aft that the fastest of them have in common. L. Francis Herreshoff's boats in nearly every instance exhibit a good turn of speed when comparisons based on waterline length are made. The reason is instantly apparent when one goes below on LFH's yachts and realized that the after bulkhead is much closer to the middle of the boat than one sees in the modern "sleeps six with two fully-enclosed heads" thirty-six footers. There's very depth aft in the LFH designs, generally speaking.

    Another feature which affects stability more than speed, actually, is that fiberglass boats, being built in moulds, cannot have tumblehome unless an expensive two-two part mold is employed. Tumblehome makes a bit difference when a boat is sailing hard on the wind "on her ear."

    I'll leave it to the naval architects to explain how and why, which I think would be of interest to the "younger crowd."
    The only effect that tunblehome has on stability is a reduction of weight at the deck, as there is less deck so lowering the VcG. I can think of no other beneficial effect.
    It really is quite difficult to build an ugly wooden boat.

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    Default Re: Munch

    If the sheet is all the way aft, tumblehome prevents it from getting hung up in a tack.
    -Dave

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