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boardhead

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Posts posted by boardhead

  1. On 5/2/2022 at 10:55 PM, Trevor B said:

     

    Bottle Rocket, based in Richmond and doing everything we can race wise. Currently finishing races at 70-80% of the elapsed time of the fast forty footers.

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    Are you talking fast multihulls or monohulls?

  2. Typically production boats are laminated in female molds to achieve a high quality external finish quickly and thus inexpensively. 

    Gelcoats are heavy.

    Applying core material, particularly cross cut to conform with compound curves, is heavier than closely fitted pieces on a male mold - the gaps are resin rich.

    Infusion, largely adopted for VOC reduction, can give wide ranging results.

    Joining large molded components together often involves heavy flanges, mechanical fasteners covering moldings.

    Out of liability considerations the structure may be overbuilt.

    Generalizations not specifically of the subject trimarans but common reasons.

  3. For those not familiar with mrybas he took a well designed, fairly well built but tired offshore cat and completely rebuilt and optimized her into, in my opinion, a better than the current state of the art example. Read Modest Mike!

  4. OhYes I did Kenny - but on improving sailing performance -  just buying decent sails and being able to sheet them to a spot where they will actually flow and drive the boat. 

    On a reciprocal course, both at 90 degrees, true we were drawing out our final leg today so only set the blade jib and here comes a "modern" design similar sized cat under full plain sail. Amazingly we are faster, consistently, under jib alone. I splashed his AIS data!

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    • Like 1
  5. Sweet - goose it up (production) on Bob's, need to get that boy set up for the NEMA season - you know he will sail and sell the hell out of it.

    Too late for me to race my tri there for competition  and (sadly) there won't be a new Dragonfly 40 but we can bring what we got.

    Huge amount of bad mouthing and fawning on this topic so I will be very interested to see your new 40 in person - as you say she looks to be moving well in that brown soup, get Billy Black and Bob on the job for some decent sailing shots!

  6. Modern development!

    That square top is SO easy to stow they didn't do it!

    Might be a tad too much parasitic drag for good upwind speed.

    Sarcastic but that is why I see the potential and have enjoyed the rewards of optimizing older designs before the charter market dictated development - because that's where the money is.

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  7. 3 hours ago, Wess said:

    That worked well for both of us on our F27s, especially well crewed.  But with the 36/37 and I gotta tell you it is infinitely harder.  The AP has trouble controlling the boat DDW with the main centerlined which puts at risk of a round up round up which means one of our doublehanded crew needs to drive while the other tries to handle the reef alone. Its not nearly as easy and we tend to different approaches now.

    So don't DDW and don't centerline the main!

    In any kind of weather, offshore, in the conditions we are endeavoring to reef this big mainsail as described I would be dumping the main completely on the F27 and wishing I had a whole lot more buoyancy foreword in the amas on the F36.

    Our directional control, under autopilot and diagonal stability allows us (my 69 year old wife and I) to reef as described. 

    • Like 1
  8. 4 hours ago, Mizzmo said:

    I have reefed my fat head main downwind by sailing deep downwind and sheeting in hard. This pulls most of the power out of the sail and gets it off the shrouds. My bolt rope main tends to lock up when the sail is not roughly on centerline, but I would think with cars the system would be even easier. 

    No chance of doing that with the loads I see and in a lighter, faster boat, sheeting the main amidships down wind in the conditions we are talking is dangerous if you stuff it and start to round up - get the swim wear out!

    • Like 1
  9. On 2/21/2022 at 3:14 AM, 2flit said:

    RE: the above quote; What does "Squirrelling" mean?

     

    ...and what angle does your shroud base (that is augmented by the runners and checks) subtend?

    ...and at the 110 AWA suggested, what percentage of true windspeed are you running at?

     

    So I was trying to be realistic with the weather conditions that would demand or at least be less exciting with a reef - that biggest, broad headed mainsail that we can cram on the rig is becoming an embarrassment! The faster the boat the less apparent wind pressure experienced as you run deep but conversely the increase as you round up is more - capsize potential - which makes clawing the sail down without rounding up more attractive.

    In order to free the mainsail from the lee shroud the apparent wind has to get behind it so the further outboard the boom can be eased the less you will need to round up. On our cat the chainplates are 5' 3" aft of the mast on 23' beam and the spreaders on the double diamonds run at the same angle, so the subtended angle is around  134 degrees which demands running backstays for support off the wind and headstay sag control upwind - but it does allow the boom and mainsail to be vanged well off centerline. 

    With the boom set up for deep running and the reef and tack downhaul lines on winches the halyard gets eased as we swoop up and across the wave fronts - my "squirrelling" rounding up sufficiently to luff and free the mainsail from the rigging as it comes down.

    I would estimate, on our cat, that the first reef would have us running at 60% of windspeed or 10 to 12 knots boatspeed in 18 to 20 knots true - surfing and gusting higher - but with my wife and family aboard I would already have put set that first reef in anticipation!

    On Skateaway with a similar dimension mainsail and a third the boat weight and wetted surface area we would be sailing at 100% of windspeed making for a more exciting maneuver - I have aged out of that situation, shorthanded.

    • Like 3
  10. 17 hours ago, harryproa said:

    You were both discussing inflatables.  A well designed catamaran tender handles wave slap with ease.  And has all the advantages I referred to above.

    "As to getting cruising catamarans upwind MORE QUICKLY" , hanging an inflatable on it's side at the back of the cockpit would be a negative, in terms of both windage and weight in the wrong place.  

     

     

    Of course we were discussing inflatables, why on earth would we use a hard dinghy! I can deflate, roll it up and put the weight - all sixty five pounds of it sans the seat - anywhere I please on the boat but in the meantime the negligible additional upwind (where it matters) windage pales into insignificance when weighed against the convenience, efficiency and safety it offers. It planes with my 1997, three horsepower outboard - your computer generated fantasy depicts what, a fifteen?

  11. 16 hours ago, harryproa said:

    Not at all.     Usable Area, high aspect ratio, low windage and lower centre of gravity are all key to upwind performance and are more advantageous on the unstayed rig than the stayed rig.     

    Add in ease of use, reduced trimming,  automatic first reef (flexible mast) and reduced opportunities for failure, nothing to replace or maintain and unstayed masts are a no brainer for fast cruising rigs.   

    If we include cruisers who sail overnight, the unstayed rig really comes into it's own as it is so easy to depower or reef that full sail can be carried on a dark and squally night.  As opposed to the typical cruiser who sensibly reduces sail at night rather than having to reef if a squall hits. Or if the squall is strong enough, have to run downwind, then reef with all the fuss you discussed earlier.  

    On a race boat, there are usually 2-3 people constantly trimming the sails.  On a cruiser, it is more usual to set and forget.  An unstayed, self vanging rig is more forgiving of this arrangement than a stayed rig with headsail.  

    As Richard Woods said about unstayed ballestron rigs:  "To my mind the advantages are: Easy sailing. The sails are always working correctly, whatever point of sail. Maybe it would be better to say the rig works to 95% efficiency all the time. A conventional rig may work to 100% if you're an expert, but only 70% if you're not." 

    You would be pretty unique if you trim your sails as often when cruising as you do when racing.  So if Richard's 30% difference is correct, this would be a much bigger advantage than anything else yet suggested.  

    If the unstayed mast is a small-medium section wing, the upwind advantages are even greater.  These sections can be dangerous on stayed masts as they cannot be feathered in a gale.  Thhis is not an issue on an unstayed mast which can always face the wind.   Shuttleworth reckons 35% of the total windage of a 50'ter is from the stayed rig.  An unstayed wing mast has near zero drag.    

    Which leads us to the question most often asked of people who suggest something different:  Why doesn't everyone use them?   

    Perceived cost would be high on the list.  Carbon masts are mostly still being built by race mast manufacturers, with their reduced safety factors, increased risks, warranties and cashed up clients.    We have shown it need not be so, and the message is slowly getting through.  

    Development would also feature.  Stayed rigs have had millions of hours and dollars spent perfecting them; unstayed rigs for cruising cats, almost nothing.  Finn dinghy unstayed masts have been highly developed, and the result is spectacular.   Cruisers like Farfarer have shown how good looking and effective they can be, super yachts (Maltese Falcon etc) have shown high righting moment is not a problem. There are several unstayed monos, the Wylie cat showing what can be achieved, particularly upwind.    Eventually cruising multihullers will catch up and realise that sailing can be much easier and less stressful than it currently is, at which time unstayed rigs will become common.

     

    Snore - nothing to be learned here! Bunch of random generalizations, false claims and the assumption that if you repeat the myth enough times it becomes reality - it doesn’t.

    I am very familiar with the unstayed, ballestron rig, actually persuaded a very good friend to retain and refine it on a very light and well built Crowther 30 catamaran that he picked up super cheap BECAUSE of that awful performing rig - mostly because of the ease of handling.

    I designed and had built a beautiful new square top main and roached, vertical batten jib which increased the sail area over fifty percent. Because of the massive weight and associated pitching along with the awful windage and turbulence behind the round mast section the investment was not justified. We are still great friends - he was aboard my Saint Francis in December when we clocked 17.2 knots on a frigid night in 30 knots, true, as we out paced Skateaway with her, sensibly, cautions new owner aboard on our way south to the Bahamas where I sit aboard typing.

    So, harryproa, if you have something worthwhile to contribute to this subject let’s hear it but please refrain from using it as a platform to promote you goofy, airy fairy theories. 

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