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Thread: Max Wind Speed for windward sailing.

  1. #1
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    Default Max Wind Speed for windward sailing.

    In NZ over the weekend a well found yacht was wrecked on the West coast after being caught in a 70 knt blow and despite starting out with more than 60nm sea room, she was driven onto the lee shore.

    This thread is not to pass any judgement on the above event. It is never pleasant when a vessel is lost.

    After reading some other comments one in particular stood out - That it's hard to imagine any 32 footer clawing to windward in 70 knt.

    After thinking about that I wondered what people would consider realistic for the maximum wind speed (and correlated sea state) at which different hull types could sail to windward.

    ie, fin keeler vs deep longkeel cutter of same waterline length.

    I imagine that it is some ratio between the sail area that can be carried in a given windspeed, and the effective total windage, against some multiplying cofactor of the the lateral plane.

    At some point I imagine that the sail area that can be carried to produce effective thrust is overwhelmed by the windage, therefore giving a theoretical advantage to the low wooded heavier displacement.

    Thoughts?
    R
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    Default Re: Max Wind Speed for windward sailing.

    I saw the news clip of the skipper being rescued, I hadnt heard that the boat had washed ashore. A sad thing, but good that he was picked up.


    If you had two boats with the same topsides but different keels the windage would be the same, but I think the one with better pointing ability would have an advantage even with a stormsail.
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    Default Re: Max Wind Speed for windward sailing.

    More to be taken into account. Wetted surface area and stiffness. Pete Goss turned back to rescue a fellow competitor in the Vendee, if i remember right,he pulled to weather blowing 60+ knots,and made good progress. This was a very light racing "surf board" with canting keel that gave much more abilty to carry sail. For us mortals, storm sails, a drougue, good handling and a healthy dose of luck will have to suffice. Long keels and large wetted area may help reduce drift,but not guarenteed progress to windward in comparison to a light fin keel. Having said that, give me a fat Colin Archer, they were designed to tow boats of lee shores in just that sort of weather.....not fast, but sure. I think a lot depends on the skipper, but a boat that has no ability to carry sail in a blow will be a liability. Even a wee Hurley 18 can make progress in a Force 9, but she has high displacement ratio and longish,deep keel.

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    Default Re: Max Wind Speed for windward sailing.

    Does a long keel actually reduce drift? I am thinking leeway and drift within this discussion are the same thing are they not? Fin keeled boats in my (albeit limited) experience usually make less leeway than long keeled boats.
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    Default Re: Max Wind Speed for windward sailing.

    Dunno all the vectors, but the sea state in a 70 knot wind would produce the effect of a strong surface current that would overwhelm virtually any sailboat's pointing ability, or ability to make way up wind. Added to that is the problem of reduced efficiency of reefed sails, combined with the proportionate increase in windage from the standing rigging. If you can't carry sail, you are basically going to go downwind, at which point the issue is not how to go up wind, but how to slow the speed downwind. We can carry enough sail to make reasonable progress upwind at about 35 knots or so, but then it's pretty much all done if you are looking at a real beat to windward. Maybe 45 plus or so if you are trying to make a course perpendicular--such as keeping off a lee shore.

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    Default Re: Max Wind Speed for windward sailing.

    The current would be a big issue, and despite pointing ability, may overwhelm hull speed - in that case the longer the wl the better - really big wind does seem to cut down your pointing angle for many reasons, one being that the gust factor prohibits optimal sail out - ie. your always reefed in a bit further just in case a gust blows a sail out, and even without the current there's wave tops banging against the boat

    sayla

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    Default Re: Max Wind Speed for windward sailing.

    Depends on the boat.

    Granuaile was able to get 30 miles to weather one ghastly long day into the teeth of a Storm (Force 10, winds 50+ knots) with many sustained gusts of 10 minutes or more in the Violent Storm bracket (Force 11, wind about 60 knots) This was down from Boston to the Cape so the seas were not open ocean seas. Rather, at the outset we faced very steep and closely spaced 15 footers that kept the same period but diminished in height once we were within a few miles of the Cape's lee.

    We were under forestaysail and double reefed foresail only, no jib or main or mizzen. I kept her about 6 points off the wind - were that an exact measure it would be 67-1/2 degrees - tacking through 12 points or 135 degrees. We were able to maintain a fairly fast 6 knots through the water so our rate of advance was about 2-1/2 knots. That gave us a fairly easy angle of attack on the waves so things were about as comfortable as such conditions might be. And at that speed the keel gave us some lift so leeway was less significant than flatter water sailing at a slower speed.

    Granuaile was by no means a weatherly boat in normal conditions, barely able to tack through eight points if pinched - really happier tacking through 10. However, Granuaile was unusually suited for rough weather, being so very narrow and easily propelled even with low horsepower. So when people say windward ability matters, they are telling the truth but may not know just how different windward ability in Storm conditions is from windward ability in more normal conditions.

    One of the worst common mistakes sailors make on a lee shore is trying to go too steeply to weather. Agnes Walters reports one long reach along the North Carolina outer banks not far outside the breakers where he was but marginally tighter than a beam reach and certainly not daring to tack, praying all the while that the shoals wouldn't trend east at all. He ascribed living through that to Bluenose's incredible ability and he was surely right, but Bluenose owed her life to Capt Walters knowing not to pinch her up.

    Most boats, of course, are not remotely capeable of such a feat and the captain must determine early and correctly if there is a direction that might miss whatever is downwind.

    G'luck

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    Default Re: Max Wind Speed for windward sailing.

    My money's on light, stiff, and deep finned. A 505 can "jibe" its board so that it has more lift and it goes to windward like magic. I suspect the idea scales with big boats if you have the $$$.

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    Default Re: Max Wind Speed for windward sailing.

    I have not read the story,but i have one question. Why didnt he start the engine? Engine assisted sailing to weather would have bought her up closer to wind than under sail alone. Did this boat have an engine?

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    Default Re: Max Wind Speed for windward sailing.

    Engines fail in violent seas for many reasons.

    One of the more common - common enough it's happened to me on three different boats - is that all the thrashing around osterizes the gunk in the fuel tank that then, mixed so in the fuel line, overwhelms the filtres and the engine gags to death. Changing a filtre is an easy fix if that's all you have to do and the weather is nice. Doing it in a hot engine room that's undergoing massive verticle displacements while rolling from about horizontal to 60+ degrees and all the while corckscrewing about is just not on.

    My own personal favorite for causing an engine failure in violent seas was an air conditioning compressor freeing itself from its mounts and taking the injectors with it to desruction. Glad I wasn't in the engine room when that thing was airborn.

    Two engines I know could not be run in violent weather because the angle of heel on one tack prevented the lube oil pump from getting any and the pressure dropped, so the engine was shut down to prevent damage.

    It is true that with a motor assist one can head more steeply into the wind than otherwise in routine "heavy" weather sailing. It's just that the wind's force at 60 knots is geometrically greater than the force at 40 knots. And pushing that steeply has it's own risks that the slower speed will so increase leeway that you will net worse than cracking off a couple of points. (Remember a point is 11.25 degrees so cracking off two points is significant.) I've never even owned a boat that could punch into anything stronger than a Gale under power alone though with sail that sort of thing can be done for a short while.

    A proper boat can sail herself out of more trouble than she can motor from. And to repeat, heavy weather weatherliness is not well predicted by normal sailing weatherliness.

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    Default Re: Max Wind Speed for windward sailing.

    Coming back from Stamford to Larchmont after the Vinyard Race one year we had 55 from the South. With a reefed main I was able to edge to weather in an IOR 3/4 tonner, a J-34, of course there was little fetch and it had just piped up, so the waves were moderate.

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    Default Re: Max Wind Speed for windward sailing.

    Skaraborgcraft, he did run the motor. It is stated he was under series drogue but still making about 3knots though the water. He ran the engine astern for some time to see if that would reduce the rate. it did but not appreciably. He was not trying to sail to windward, it was not possible in this situation for him, I believe. The wind was too strong for any sail is what I understand.

    However, This is not a what he coulda/shoulda done thread, more of what you can sail into if your life depends upon it. Motoring may give some advantages to some boats, but if your 70knt blow lasts three days I think most yachts would be out of fuel.

    I've not been on a boat that could motor into seas that it couldn't sail into.
    R
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    Default Re: Max Wind Speed for windward sailing.

    Sounds from what you say he did all he could,but just ran out of sea room. Not many production boats are designed to sail in those conditions,let alone lay-a-hull in those type of seas. British steel challange boats racing around the world against the prevailing winds returned to the UK with the steel hull plates in the bow, buckled inwards against the stringers,that shows the power of a heavy boat ploughing forwards,but these were designed for it, and fully crewed.

    You say he was laying under a series drougue and ran his egine ASTERN for some time. From this i can only assume he was heading towards land at 3 knots, bow first, with the drougue towed from the stern?

    Theres too many factors involved to give a definative answer the the OP question, but sail carrying abilty in the form of hull stiffness or achieved by high ballast and strong rigging would be a start. Sea state will change things, sometimes a light displacement boat will virtually fly over waves and make headway, but if the tops of the waves are breaking,then the light displacement will lose the punch of the heavier boat to push through.

    No one has suggested a multi hull. Even an old Piver was supposed to sail to windward in extreme conditions under bare poles alone......was that a myth? Cheers

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    Default Re: Max Wind Speed for windward sailing.

    Interesting input. Thanks for your reports Ian. I've never had to deal with 70 knots (well, except in a CG Cutter) and hope never to do so. I found last fall in a strong north wind that my boat would barely power through the steep seas in the inlet. She is overpropped, perhaps to give more power at the expense of top speed. If at sea I would attempt Ian's tactics, or heave to.

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    Default Re: Max Wind Speed for windward sailing.

    A little more on this from a hydrodynamic point of view, a keels ability to lift, to resist leeway, is dependent upon forward motion. Pinching the boat reduces speed, dramatically reduces lift, and increases leeway. In extreme cases, the keel can be stalled and the boat going nowhere but sideways. This is often the case where the keel is a high aspect ratio foil with a narrow optimum angle of attack and a need for high waterflow to be efficient. A long keeled boat will have a larger relative keel area and may ( may! there are always exceptions to any rule) be a lot less sensitive in this respect.
    In heavy conditions it pays to bear away and trim for speed, the speed giving control, a better angle of attack on the keel which produces lift and reduces leeway. The improvement in control will also give an improved ability to change course a little to dodge the crests.
    Ians tactics are absolutely right. A few degrees made good are better than pointing high and going sideways.
    All that said, every boat has its limits, those limits are not only found by wind strength but the sea state can have an effect as well and those limits are often lower than commonly believed.

    John Welsford

    Quote Originally Posted by Ian McColgin View Post
    Depends on the boat.

    Granuaile was able to get 30 miles to weather one ghastly long day into the teeth of a Storm (Force 10, winds 50+ knots) with many sustained gusts of 10 minutes or more in the Violent Storm bracket (Force 11, wind about 60 knots) This was down from Boston to the Cape so the seas were not open ocean seas. Rather, at the outset we faced very steep and closely spaced 15 footers that kept the same period but diminished in height once we were within a few miles of the Cape's lee.

    We were under forestaysail and double reefed foresail only, no jib or main or mizzen. I kept her about 6 points off the wind - were that an exact measure it would be 67-1/2 degrees - tacking through 12 points or 135 degrees. We were able to maintain a fairly fast 6 knots through the water so our rate of advance was about 2-1/2 knots. That gave us a fairly easy angle of attack on the waves so things were about as comfortable as such conditions might be. And at that speed the keel gave us some lift so leeway was less significant than flatter water sailing at a slower speed.

    Granuaile was by no means a weatherly boat in normal conditions, barely able to tack through eight points if pinched - really happier tacking through 10. However, Granuaile was unusually suited for rough weather, being so very narrow and easily propelled even with low horsepower. So when people say windward ability matters, they are telling the truth but may not know just how different windward ability in Storm conditions is from windward ability in more normal conditions.

    One of the worst common mistakes sailors make on a lee shore is trying to go too steeply to weather. Agnes Walters reports one long reach along the North Carolina outer banks not far outside the breakers where he was but marginally tighter than a beam reach and certainly not daring to tack, praying all the while that the shoals wouldn't trend east at all. He ascribed living through that to Bluenose's incredible ability and he was surely right, but Bluenose owed her life to Capt Walters knowing not to pinch her up.

    Most boats, of course, are not remotely capeable of such a feat and the captain must determine early and correctly if there is a direction that might miss whatever is downwind.

    G'luck
    An expert is but a beginner with experience.

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    Default Re: Max Wind Speed for windward sailing.

    Posts like those above are what keep me here. Thanks guys.

    Kevin
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    Default Re: Max Wind Speed for windward sailing.

    Quote Originally Posted by Breakaway View Post
    Posts like those above are what keep me here. Thanks guys.

    Kevin

    +1. Rookies like me really soak this stuff up. Thanks for sharing.
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    Default Re: Max Wind Speed for windward sailing.

    Quote Originally Posted by john welsford View Post
    All that said, every boat has its limits, those limits are not only found by wind strength but the sea state can have an effect as well and those limits are often lower than commonly believed.
    John Welsford
    More than 25 years ago I discovered this when trying to return a charter boat (a Mirage 33) on the last day of the charter back to Comox from the north end of the Straight of Georgia when a sudden front came through and we found ourselves facing 35 kts gusting to 40. We were down to triple reefed main and reefed small jib. The seas quickly built to 6-8 ft and they were short and steep. The boat would sail to windward like a witch in flat water but against those steep sided seas, it seemed that the angle of the bow exactly paralleled the waves so that we would build up speed going down the wave then get slammed by the face of the next wave, almost coming to a stop. We were, in theory, making 5-6 kts through the water but in fact were making almost no headway. It was a long day. I was surprised the boat wouldn't do better.
    Alex

    "A man who is not afraid of the sea will soon be drowned, for he will be going out on a day he shouldn't. We do be afraid of the sea, and we only be drowned now and again" Arran Islands Fisherman

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    Default Re: Max Wind Speed for windward sailing.

    It's complicated..... You must have enough drive to push through the sea and be able to carry sail. Ian an John Welsford are right. The big long traditional keel will resist sideways drift and produce some lift at low speeds. A high aspect fin or centre-board will stall at low speeds and will need to be sailed more aggressively to keep adequate speed. The boat must be stiff enough to carry enough sail to get enough power. Pretty much all sail boats would be best advised to bear off to 5 or 6 points off the wind to reduce the effect of the waves and to get as good a sailing speed as possible.
    I remember sailing Windrush (20 ft moderately heavy displacement sloop) to windward in 40 odd knots of wind, under storm main and working jib. 6 points off the wind ~5 knots.
    I have sailed Whimbrel ( LFH Meadowlark with high aspect ratio leeboards) to windward in 35 gusting 45. Light displacement, and easily driven, with lots of driving power with little sail, and easily balanced. She is the easiest small boat in these winds I have ever sailed. Easily making as much speed ( 5+ knots) as I might want and as close to the wind as I need say 50-55 deg, in 2-3 metre seas in near coastal waters. She seldom pounds and almost never too hard. I have not had her in open sea conditions, but I do not doubt her ability.
    Balance is another thing. Some boats do not balance well under reduced sail and become really bitchy. Slow speeds make it worse.
    I am not sure any sailing vessel would go to windward in 70 odd knots of wind. Possibly something like Mr. Goss's 60 odd feet of light racing dinghy, with canting keel and dagger-boards.
    Near Coastal seas may be worse than open water deep sea conditions, being often shorter and steeper. We used to joke about taking two or three runs at a wave before we got over it.
    Last edited by gilberj; 03-09-2012 at 12:32 AM.

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    Default Re: Max Wind Speed for windward sailing.

    Sorry the last post is a bit disjointed. It was from my phone and not easy to see what was happening .

    Now I have tried to edit the worst of the last post, but I am over-tired and it still may not be completely fixed.......
    Last edited by gilberj; 03-09-2012 at 12:34 AM.

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    Default Re: Max Wind Speed for windward sailing.

    It is complicated.
    As John has said, "A little more on this from a hydrodynamic point of view, a keels ability to lift, to resist leeway, is dependent upon forward motion."
    A bit of leeway is also needed to achieve a workable angle of attack.
    This can be problematic if you are working in a strong current, the tendancy to try and point up too high (and stall) when you are faced with a lee shore requires repeated accurate bearings and nerves of steel to know you are making good. Sometimes it can't be done.

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    Default Re: Max Wind Speed for windward sailing.

    Quote Originally Posted by gilberj View Post
    Sorry the last post is a bit disjointed. It was from my phone and not easy to see what was happening .

    Now I have tried to edit the worst of the last post, but I am over-tired and it still may not be completely fixed.......
    It makes great sense to me.

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    Default Re: Max Wind Speed for windward sailing.

    In this day and age the lee shore is a little less of an issue. A century or so ago sailing ships were not extremely weatherly. they were designed to carry cargo so the hull had little refinement and the rig was not very much affected by the developments which had been taking place in the yachting world.
    Navigation in those days was pretty rudimentary using sights, and land bearings, and compass time runs. A lot of ships were lost because the timed runs did not reflect the reality of weather generated currents.
    Most working sailors would have a lee shore yarn or two because between sometimes dubious navigation and relatively poor weatherliness.
    In this day and age we have remarkably accurate weather forecasts, ( don't groan)........ and extremely accurate position receivers with GPS. The risk of the dreaded "Lee Shore" has been very much reduced, though not eliminated. We can with a little care make a landfall when the conditions are favourable, and or know in thick weather our position and set a safe course, before its too late.
    The ability of a seagoing boat to go to windward in a gale is still valuable .

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