Favorite rough weather technique

Discussion in 'Sailboats' started by gonzo, Nov 10, 2009.

  1. Fanie
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    Fanie Fanie

    Richard, I have a question. In an earlier post you said you steam right head on to the eye of the storm. Ok so when you are in the eye, what then :D

    Makes sense Gonzo, the boat will be more sensitive to react. Never thought of it that way. So, if the boat is too 'reponsive' you need a longer or heavier mast... :D
     
  2. Brent Swain
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    Brent Swain Member

    You are dead wrong on this one. By the time a boat is knocked far enough to be in danger of capsize , with a heavy rig, the wave has passed, and the weight of the rig then become irrelevant. With a heavy rig it's far less likely to go anywhere near that far, than with a light rig. I'd rather have heavy water over the bow than a drastically increased risk of capsize, which you get with a lighter rig. From inside my wheelhouse, water over the bow is a non issue. As I prefer to stream the drogue from the stern , water over the stern is also a non issue in a steel boat with lots of reserve buoyancy there, far more than I have at the bow..
     
  3. apex1

    apex1 Guest

    No Fanie I did never say that. Sorry..........
     
  4. apex1

    apex1 Guest

    It will capsize in the right (wrong) conditions, no doubt.
     
  5. BeauVrolyk
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    BeauVrolyk Sailor

    Thanks for taking the time.... comments below

    Mike, thanks for taking the time to have a look at what I wrote, I've responded mixed in below....

    Let's start to "standardize" a few things. In this thread we've all be talking in generalities. So, let's assume exactly the same sized wave etc... applied to all these various boats. My point was about the "rig", not about the weight of the boat. If you have the exact "same" boat hull etc... with a heavy rig vs a light rig then the following will happen in exactly the same wave size/energy.

    First, the wave will strike the boat from abeam, if the rig is lighter then you are right the boat will roll more quickly. In addition, the wave won't have nearly as much tendency to climb up over the boat as the boat will present the beam of its hull to the wave whilst rolled over.

    Second, once the initial impact of the wave has been felt and absorbed, then the boat's ability to get back on her feet will be a combination of the hull form (form stability) combined with the ballasts stability (weight in the keel). However, the ability to come back up again will be reduced by the weight in the mast - this is an important point oft overlooked. Moreover, the ability of the boat to start to recover is not just the effect of the various stability forced balanced against the weight of the rig, the polar moment must be considered. This is where the weight of the rig becomes a large problem. It is also why I pointed out that the resistance to acceleration, which is what we're talking about here, goes us as the square of the distance from the roll center.

    In conclusion, the same identical boat with a light rig vs a heavy one will start to roll more slowly, will roll further (because of the momentum of the rig once it's moving), will start to right itself more slowly (for the same exact reason it started to roll more slowly - momentum), and finally the heavy rig will overshoot and actually roll further to windward as the momentum of the rig continue to push the boat back past vertical.

    This is all really well described in Marchi (sp?)

    Exactly, but the "cost" or "problem" with the "reduced roll angle" is that the water goes up and over the boat. As I've said before, when you increase stability and resistance to roll, the water will simply go over the boat rather than moving it. This happens in exactly the same way for rolling and pitching.

    While I agree, that pitching doesn't feel as bad as rolling in a heavy rigged or heavy ended boat, I would point out that the inertia involved is identical. The mast still weighs the same amount. Most of the time yacht designers (non-racing designers) will pretty much ignore the polar moment of the boat in the pitching axis. This is exactly what I was objecting to. Sure, you can make the ends of the boat fuller so that there is more force created to stop the pitching. Note, that you are increasing the forces on the hull and rig, and if you have a boat with a great deal of reserve buoyancy in the ends you'd better design the rigging accordingly. When a long narrow boat hits a wave with her bow the deceleration is gradual as the bow pierces the water, the water flows around and over the bow and then the boat starts to slowly lift. I own an IOD (a lot like a meter boat) that does this on every wave. Where as when a boat with full bow sections hits a wave the deceleration is much more abrupt as the full bow resists being submerged. The full ended boat will put much more load on the backstay as the bow hits the wave. I also own a Moore-24 with a very full bow. The difference is dramatic. All that energy (the kinetic energy stored in the rig) has to go somewhere, and when the bow stops, it puts it into the backstay. The more quickly the bow stops, the stronger the force on the backstay.

    Having sailed a long way on both narrow and beamy boats in large seas, I would continue to argue that a full bow is better, but this is because it reduces what I see as the most common risk in sailing in really heavy weather - being washed off the deck. The occurrence of crews being injured by being pushed around by the water on deck or by being washed overboard is vastly higher than that of boats rolling over. There's simply no comparison. Take really good boats, like the Volvo boats. None of them has rolled over in recent years and they sail in truly terrible conditions. Yet, numerous (well over 20) crew have been injured by water coming aboard and one person the race before last was washed overboard and killed. The primary goal of a boat's design should be to deliver the crew safely and keeping the water off the deck is one of the best ways to increase safety. Making the rig as light as is safe (note, I'm not recommending an ultra light racing rig.) is an easy and simple way to make the boat a lot safer.

    Mike, as I think I said in my original post - it's my rule of thumb. I do not accept that making the lightest safe rig runs "counter to modern naval architecture", quite the opposite. I think Marchi (sp?) and Skene would both agree that increasing the Polar Moment of Inertia is a bad thing is all cases.

    By Polar Moment I meant the moment of inertia around an axis. I used it in talking about the rig because the rig does, indeed, bend when loaded by inertial and its the way we've always talked about rigs and keels when the boat either rolls or pitches. You are correct, if one is simply talking about the forces then "Mass Moment of Inertia" is actually more accurate. But, the change in the terms doesn't alter the physics at all.

    The reason I was picking on rigs is because the distance from the roll center, around the horizontal axis running fore and aft, is relatively large and so many sailors simply don't attempt to reduce the weight aloft. I can't tell you how many times I've seen folks "beef up" their rigging and put things aloft like heavy radar antenna etc... and then wonder why their boat doesn't sail well.

    Well, you and I will just have to disagree on heavy rigs. I strongly hold that no rig should be any heavier than it has to be to hold the sails up safely. I certainly don't think one should build something that is too light to be safe, but to have a "heavy" rig and believe that that's the best way to make the boat ride well is simply wrong, IMHO. Take, as an example, a second to consider other ways to change the roll characteristics of the boat, such as chines in the hull or a deeper keel, and then consider if weight aloft really is the best way to do this.

    AK's point is based on the following: There will be waves that are still small enough to allow the damping effect of the rig to help keep the boat upright. But, we weren't really talking about those. We were talking about near terminal conditions. I would point out that simply increasing resistance to roll is a two way street. Sure, the boat will initially resist rolling over and if it still has its rig it will resist righting itself with exactly the same force. Thus, a sailboat without a rig that is rolling more quickly in a seaway is rolling both ways - over - AND - back. By reducing the moment of inertia around the fore and aft vertical axis you will certainly have a boat that rolls more. But, can you really tell me you believe that a boat with its keel in tact and no rig is somehow "less stable" than one with a rig? Think about the massive increase in righting moment without the rig. I will accept that the ride will be less comfortable, but there is a reason that the old timers used to cut the rigs down in terrible storms, it was to keep from being rolled over.

    I have been aboard numerous boats without rigs in all sorts of conditions and while the ride was ugly and uncomfortable, the boat was actually much less prone to rolling over with only one exception, that exception is when the boat is struck by a breaking wave from the beam end. Thus, after all this discussion, we have one situation in which a rig (heavy or light) would help. Whilst we have numerous situations in which the heavy rig makes things worse. I'll repeat, naval architecture is a series of compromises and defending an unnecessarily heavy rig just to allow some small benefit in this near terminal and extremely rare condition seems a very odd choice when it works against good sailing and seamanship in every other condition.

    I fear we have been focusing on the "dramatic" and extremely rare in this thread and have chosen to ignore what really injures most sailors in seriously terrible weather - which is water on deck not rolling over.

    Again, Mike, thanks for engaging in the discussion.

    Beau
     
  6. BeauVrolyk
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    BeauVrolyk Sailor

    Brent,

    You're talking about much smaller waves than I. Off Oregon we were attempting to survive a storm with 90 to 100 foot waves. The breaking tops were fifty feet tall. There is no rig - no matter how heavy - that had enough momentum to keep the boat from rolling over if we'd gone beam on. The only way to stay right side up was to run and keep steering. Fortunately, the boat was a good enough design to run along quite nicely without much water on the deck at all. Wind speed was 50 to 70 knots and it lasted for three days.

    Beau
     
  7. Fanie
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    Fanie Fanie

    Post #70

    I saw this movie where this guy landed in the eye of some storm after ducking for some cows, houses and other flying stuff. As bad as it was outside so peacefull it was inside.

    I was thinking, if one has a boat as big as your's, it's not going to fit in that quiet inside... :D
     
  8. apex1

    apex1 Guest

    Fanie may I ask what is your intention?

    I made very clear, that running away is my preferred method!
    Quoting parts of a statement is not gentlemanlike practice.

    Regards
    Richard
     
  9. Fanie
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    Fanie Fanie

    The intention is to pull your leg.

    I agree. I have to do abuse small parts of your posts or it will not work :rolleyes:

    As for your method of handling bad weather I would do exactly the same.





    BV, you should standardise on the same type of boat in the same weather. Different types of boats behave differently.

    If you're in a sub, stick to 60m below.
     
  10. marshmat
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    marshmat Senior Member

    LOL. Best places to be in a storm: (1) Nuclear fallout bunker; (2) Submarine at a few wavelengths below the surface. A modern attack sub, if it drops a couple hundred feet, can easily outrun both the wind and the waves of a Force 8 gale. Of course, few of us have eight hundred million bucks to spend on a boat and crew....


    Re. rigs and rolling
    A couple of months ago, there was a great example of the effect of a rig's roll moment of inertia down at the yacht club. (I didn't have my video camera, but wished I did.) Two nearly identical boats were moored in adjacent slips, with a hell of a wind blowing and the seas bouncing off the shore and reflecting back inside the breakwater, resulting in 2-foot swells at the docks. One of the boats was just riding it out, rolling four or five degrees but not moving much. The one beside her (about the same size and of a very similar design) had just had its mast unstepped for the winter- and this one was bucking and kicking about like a rodeo bull, rolling about 15 degrees and pitching like crazy. But, like the first boat, she wasn't heaving up and down much; the CG motion was about the same on both boats, but the roll and pitch motions were greatly exaggerated on the one without a mast.
     
  11. Fanie
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    Fanie Fanie

    Something I have experienced is that the length of a boat vs the length of the waves plays a big role in the discomfort on a boat. If a boat is longer than a few waves it is comfortable.

    Then when the waves stretch it suddenly becomes difficult. The nose dives down each wave and up the next. Imo this is where it is most uncomfortable, the boat takes a bashing and is can be dangerous.

    If the waves stretch even more it becomes a matter of going up the wave and down again, like driving over a hill, and is more comfortable again.

    There are of course conditions that no one on a boat should be in.



    Matt, it may well be that the wave length was just in tune with that specific boat's roll moment, hence the excessive reaction. I'm almost sure it the wave's frequency changes, some of the other boats may also start acting up.

    I have actually seen this at a marina. As the wind picked up and the waves get bigger, different boats started bobbing, then subsided after a while, while others started jiving.

    Only the cats in the marina kept still :D

    At the time I didn't pay any attention to it specifically. The fact that your observation didn't have a mast would defenately contribute to some degree, there is no doubt.
     
  12. Fanie
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    Fanie Fanie

  13. mark775

    mark775 Guest

    "Off Oregon we were attempting to survive a storm with 90 to 100 foot waves. The breaking tops were fifty feet tall."
    Wow, that is incredible! How far off Oregon were you? Got any pics or video?
     
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  14. BeauVrolyk
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    BeauVrolyk Sailor

    Mark,

    It was back in the early '60s. Although serious storms of hurricane strength happen up there a lot. In the '60s people didn't have cameras they toted around, let alone video. I think I got my first waterproof Nikonos camera in about '75. I was pretty young and my skipper estimated the wave tops by watching a tattered flag at the masthead, 70' up. It went limp in the troughs and we measured the wind at about 55 to 60 knots at the wave tops, so he figured the troughs were deep enough to get the masthead into the lee of the waves. Not exactly NOAA, but all we had. We were about 40 or 50 miles off of Coos Bay headed south as fast as we could go.

    I couldn't be certain, but if it was the storm of 1962, then the measured wind speed (NOAA) ashore at Newport Oregon was 138 MPH before the wind instrument blew off. You can read about it here on the NOAA site (it's item #3):

    http://www.wrh.noaa.gov/pqr/paststorms/index.php

    There was a similar storm with sustained 60 MPH winds and frequent gusts to 90 MPH in '07 you can read about here:

    http://seattletimes.nwsource.com/html/localnews/2004049894_webcoast03m.html

    There is a wave measuring buoy off the straits of Juan de Fuca and I've been told it sees 80 to 90 foot waves nearly ever winter. I coudn't lay my hands on any documentation of that, however.

    BTW, I would not ever recommend anyone sail around in such stuff. We would have headed into port but didn't make it before the various harbors were closed by surf.

    B
     

  15. mark775

    mark775 Guest

    Having spent nearly half of my fifty years asea, and only seeing 45' a few times and 70', maybe, once (a combined sea of a 30' north and 25' so'east that sometimes seemed to cancel each other and sometimes shortened, combined and peaked into...I don't know... I'm reluctant to say 70', I guess I have to say that I have been a better mariner than your captain in '62.
    You offer a lot to this thread, a depth of knowledge obviously borne of experience. I havn't always agreed with you but your points are well considered and I do appreciate. BUT, when you talked of a hundred foot wave, I was resisting the urge (in my previous post, I measuredly used the word "incredible") to say "BS". I'm glad I did. As you tell it, I'm just glad that I have, for the most part, not confronted such weather. I've seen plenty of wind. If I ever see a seventy foot wave, I will put an oar on my shoulder and start walkin'...
     
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