Dangerous designs?

Discussion in 'Sailboats' started by usa2, Nov 18, 2005.

  1. D'ARTOIS
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    D'ARTOIS Senior Member

    I agree with you on that - your point is clear and correct. Nontheless, log in at SA and read the comments of the sailboatcrews that are not expressed in this forum....tyhen you will follow me.
     
  2. usa2
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    usa2 Senior Member

    i would think that the next generation do get more freeboard, because the way they are right now nothing is going to stop them from running straight through the back of a steep wave and consequently sinking themselves. Also, with the Farr boats nosing down, you may see the introduction of a T-foil near the bow to combat this tendency.
     
  3. guit
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    guit Junior Member

    First of all, here's some videofootage of the type of blue-water cruising they are doing down there...: http://team.abnamro.com/web/show/id=107902 :D

    Then some more worrying news:
    From: http://www.sailing.org
    Overnight, Paul CAYARD’s (USA) Pirates of the Caribbean was overtaken by movistar when the crew noticed cracks in the area of its keel support structure. Water was coming into the boat from those cracks and still is. The rate of water flow is manageable at this time.
    For the whole article: Cayards keel problems.
    Or (much later) the statement on the VOR-site: VOR Article
     
  4. BOATMIK
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    BOATMIK Deeply flawed human being

    Model T Foils

    I don't know if the angles of wave faces and backs are similar to the angles I have chosen in the example below - but I think they might be - from experience.

    I wonder if anyone has data - I know Crowther do/did serious modelling of sea condition versus boat behaviour.
    ________________________________

    Not sure that a T-foil will work because of the extreme angles involved - boat comes down a 15 degree face and hits the back of the previous wave which is pitched 15 degrees in the opposite direction.

    For the T-foil to be dead neutral it has to be at a positive angle of 30 degrees plus the 7 degrees or similar you need to develop lift. Total is 37 degrees. Which has to be trimmed out progressively as the bow lifts.

    I suspect it is not a simple technical problem.

    If you set up with a wand sensor for the water surface - how does it know whether it is on the mean (average) water surface as opposed to the top or bottom of superimposed chop?

    It may a much simpler problem then I am thinking - but I won't be surprised if there are significant problems to be overcome.

    I have heard anecdotally from crewmembers that one of the big problems with wing keels in sea conditions was that the boat would surf down a wave and then spear into the back of the previous wave because the keel refused to let the boat rise. So a horizontal foil at the wrong angle of incidence is a BIG problem.

    The bigger the boat, the more the bow and stern will go under in the trough and the more sudden its need to move from bow down trim to bow up trim.

    For example if wave crests are 50 ft apart a Moth on foils has almost 5 boatlengths to change its trim.

    If you have a 50 or 90 ft monohull it is a different story.

    Wheeeeeee!

    Best Regards
    Michael Storer
    my boat pages
     
  5. RCSail
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    RCSail Junior Member

    The issue of a wand sensor at least is reasonably simple to solve: a system with properly tuned flexibility will filter out high frequency low motion movement, leaving you with the greater movement from the swells.
     
  6. BOATMIK
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    BOATMIK Deeply flawed human being

    "properly tuned flexibility"

    Do you think it will work easily when there is a 5 metre swell with a confused cross chop superimposing a short frequency at amplitudes of plus/minus half a metre with the boat moving at 20 knots.

    Maybe it will be easier than I think, but it sounds like a complex problem to me. And the wand has to deal with a much greater mix of frequencies and amplitudes at sea.

    And in this case much larger boats and much larger forces.

    You may be right, but I don't think you can be so confident that it is a solution.
     
  7. Milan
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    Milan Senior Member

    Someone mentioned submerged Merlin:
     

    Attached Files:

  8. Vega
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    Vega Senior Member

    Yesterday, from the VOR70 website:

    “Mike Sanderson on ABN AMRO ONE has sent a long email today, much of it defending the Volvo Open 70, the canting keels and the concept of the boat, which makes it required reading for many of the armchair pundits who have been making strident claims about the safety of the boats.”:rolleyes: :rolleyes: :rolleyes: :rolleyes: :rolleyes: :rolleyes: :rolleyes:

    Yesterday Cayard had said:

    .....“It is not hard to spend time wondering how long these boats can take this type of punishment.”:eek: :eek:

    Today Cayard reports :

    “Last evening at 1845GMT the crew of the Black Pearl noticed cracks in the area of its keel support structure. ….“We have run tests with zero, 20 and 40 degrees of cant while inspecting the area. Forty degrees is definitely alarming. The cracks open and close as the loads change and the water flow is more and less accordingly.:(

    …... There is danger in being out here for long time”(the boat is 1,775 miles south west of Freemantle).:( :( :( :mad: :mad:
     
  9. RHough
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    RHough Retro Dude

    Perfect, that is the photo I was trying to find! Thanks!
     
  10. Vega
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    Vega Senior Member

    QFB Mike Sanderson/ABN AMRO ONE – 10/01/2006
    Quote
    “I heard through the grape vine that there is a growing concern that these boats are dangerous and that we are being reckless out here. I just want to take this opportunity to say that I will happily sit down with anyone and explain to them the thousands of hours that have gone in to the making of Team ABN AMRO's keel systems as safe as possible. ….
    So the safety of everyone is at the top of the list no matter how you look at it.

    QFB Mike Sanderson/ABN AMRO ONE – 13/01/2006

    Quote
    “Very disappointing news this morning to hear that Paul Cayard's Pirates have suffered structural damage. Man this leg has been tough on the boats. It will be very interesting to see what the race management and the measurers do in Melbourne with regards to the boats’ current certificates.
    Quite clearly with these boats we are seeing some load cases that the models that are used to design them can't predict. We have broken parts both during the race and more so pre-race which I know that Juan and his team just say isn't possible. Our tiller arm on the first leg was one case, and the canting keel system break that we had on the white boat pre race has had, until quite recently, plenty of people scratching heads……
    “I think in Melbourne, the race management group will have to give us the two weeks to do only the changes the teams and the designers think is necessary to make the boats tough enough, and then we have to re-weigh and take lead off our keels accordingly. It is the only solution I can see that is going to get this fleet around the world. “


    Well, in three days he changed his opinion about the boats, it looks that, after all, they are not strong enough, it looks they are dangerous boats to be out there, on the roaring 40's:confused: :rolleyes:
     
  11. D'ARTOIS
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    D'ARTOIS Senior Member

    Bull***t, Nonsense and Poor Quality

    What became quite clear to me just after the start of the VOR becomes bit by bit more evident.

    The main designer and Naval Architect have brought the whole adventure of his clients in a fairly hopeless situation. Fodder for lawyers so to say.

    It is too late to add reinforcements that will cater for the job. Integral reinforcements are always secondary bondings and the boats are to wet, in and out do be able to do a thorough job. Someone who engineered the CK system of one of the boats, told me that that particular boat vibrates like a Guarneri played by Paganini...... and there you go......

    The frame of the CK system, which is not really a featherbed frame, is just in place of the keel and forming a solid and very hard point. The rest of the boat moves, rumbles, and bends around this hard point.

    The connection come loose, causing the water coming in.

    20 years experience, thousands of miles of safe sailing........according to Doug Lord......

    Who is the fool?

    Any beginning Naval Architect knows that the keelstructure is the basis of the boat. Just like the foundation of a skyscraper.

    A CK system requires a keel that sits in a structure; that is spread over the full length of the boat; that is an integral part of the hull and engineered in such a way that deflects as are occuring now in the VOR fleet, particularly in the Farr designed boats, cannot happen.

    Poor engineering, poor manufacturing, and poor sailors who have to endure this without knowing that all these highly paid architects are still amateurs.
     
  12. guit
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    guit Junior Member

    Well, I don't think he changed is opinion. Safety is still, maybe more, on top of his list for the entire fleet.
    The fact that the yachts (mostly the Farr designs) will need to become stronger, means the hull will become heavier. A heavier hull means the bulb will need to be lighter since there is a max weight on the combination. If everyone would be allowed to beef their yacht up, but keep the same bulb, the teams that have build a tough enough yacht will be punished.
    Assuming ABN ONE is strong enough, a re-weigh means he gets more advantage over the competition. No re-weigh means not everyone has a yacht within the rules.
    My interpetation from his (Mike Sanderson) statement is that he is not happy with the bad publicity the race gets, due to the fact that some syndicats have crossed the fine line. In the greater interest of the race, anymore problems will probably mean a setback in sponsorship. Besides that he seems to want a check on the boats to see if all still comply with the box-rule of the VO70.
     
  13. mholguin
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    mholguin Junior Member

    I just don't see the point in discussion here. This type of high performance boats are not for everyone, just like a Formula 1 car is not meant to be driven by the regular Joe out there.

    These crews are professionals being paid to do a dangerous job. Just like a F-1 driver (remember Ayrton Senna?).

    For me, not a designer but a sailnig lover, it is amazing to see that breed of boats shattering the 24 hour run record set by Mari-Cha IV, a high tech boat twice as long as the VO-70...

    Will the lessons learned from the VOR yachts be trasnferred to the general public? Some will, some will not. Same as with the Americas Cup.

    Remember, we are not talking about production boats made for the regular Joe to buy and sail and that could put his life in danger. Why not just sit back and follow the race?
     
  14. RHough
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    RHough Retro Dude

    Big Difference.

    Driver safety is a very high priority in F-1. If the car fails, it is designed to give the driver a very good chance of walking away.

    When a F-1 Car fails, like Kimi's front suspension failure at 200kph + the car came to rest and Kimi got out and walked away.

    The crew cannot walk away from a catastrophic failure of a VO70 boat. If the hull fails and there is a large hole where the keel system used to be attached, is the boat going be a safe place for the crew to await rescue?

    If the VO70 was sailed in 70 multi's they may pitchpole or capsize, but the crew would be left in inside a 70ft life support system.

    The 70ft mono's rely on the ballast for self righting/rescue. That will only work if the ballast stays with the boat. What we are seeing is that the entire ballast system is trying to abandon ship and sink, leaving the hull with a huge hole and no survivability.

    Even with the ballast intact, ABN 2 was bailing every 30 minutes during her last record run. In my mind, a boat that has to be bailed out every half hour is not exactly seaworthy.
     

  15. Windvang
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    Windvang Yacht Designer

    If the ballast abandon's ship there is nothing left to sink the ship, except maybe the engines. The core allone will make it float.;)
     
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