Gunboat G4 with UptiP Foils

Discussion in 'Multihulls' started by Doug Lord, May 12, 2014.

  1. CT 249
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    CT 249 Senior Member

    To all those who are criticising the handling - the crew apparently included Mischa Heemskerk, one of the world's best cat sailors and a foiling expert. PJ himself has been sailing high performance boats since the '80s. How many of those blaming the crew have sailed against or watched Mischa or one of his A Class rival sailing a fast cat in big breeze?

    Criticising sailors of that standard for making a mistake is a bit like criticising Laird Hamilton for hitting the wall at Monaco; their "mistake" is that they dropped down to just being a few levels better than normal people for a moment or two. Most sailors would probably have made 30 "mistakes" like that in the first race. There doesn't seem to be much to be gained in blaming the crew for the flip when at least some of that crew can sail a cat far beyond the level of just about anyone commenting on them.

    Sure, in a perfect world, maybe the crew could have stopped the flip and kept the boat performing at its best. But this world isn't perfect so why pretend that it is? People will always make mistakes and design has to allow for some of them.

    That apart, the minimalist aspects of the G4 are appealing, and PJ seems like a fine guy.
     
  2. Gary Baigent
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    Gary Baigent Senior Member

    It was obvious (just look at that rig, not to mention the foils) that the G4 was not a cruiser and maybe Gunboat made a mistake advertising it as such. Really G4 is the top end of modern race boat development (with some nice luxuries) ... and most people seeing the boat/beast would figure that out.
    But in the video the foils are doing a great job so my premature comments about platform sailing height were very wrong.
    Maybe they should go back to block and tackle sheeting though.
     
  3. brian eiland
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    brian eiland Senior Member

    I'll agree to that
     
  4. brian eiland
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    brian eiland Senior Member

    And I will agree to that....been there, done that mistake a couple of times....ha...ha
     
  5. P Flados
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    P Flados Senior Member

    Actually, with these foilers, any time you heel too much you are probably loosing speed.

    Remember how flat they ran the 72' AC boats.

    The challenge to keeping this size boat flat may just be a learning curve at the helm. At speed with everything loaded up, it is probably too much work to adjust the main constantly. Direction shifts are much easier.

    If helm alone just wont do the job, I wonder if a hydraulic accumulator with an energy recovery system would help. I can see a system using discharge fluid as you sheet out to charge a pressurized accumulator that gives you a boost as you pump to sheet in.

    And please note that I am not "blaming the crew" in any way. Learning curves are what the are with new technology and when pushing the limits.
     
  6. cavalier mk2
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    cavalier mk2 Senior Member

    It would be entertaining to have heard audio from that "well crewed" ride. Who called the shots and who did what. I think it fair to say they didn't know how the boat would respond and didn't appreciate how close to the edge they were. Like golf sometimes the pros get their clocks cleaned at the masters thinking they are beyond the Joes who showed up. So to be fair I'm available for trails if they want to fly me in and put me up....and if this works I'll try upsetting somebody in the Cup to get a test ride there:)
     
  7. coralislander
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    coralislander coralislander

    Racing gunboat 4 Learning the ropes I guess or extra beam needed.



    Not so much fun was Gunboat G4 Timbalero III's dramatic capsize today. No one was injured, and the brand-new foiling catamaran was righted within two hours.
     
  8. Doug Lord
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    Doug Lord Flight Ready

    G4 cruiser/racer on foils!

    From Scuttlebutt and Swizle tonight: http://www.sailingscuttlebutt.com/2...&utm_term=Undaunted and More Badass Than Ever

    Undaunted and More Badass Than Ever

    by Bill Springer

    My heart sank a little when I saw Sharon Green’s photos of the G4 that capsized in the last race of Les Volies in St Barths yesterday. That’s because after the magical three days I spent flying on the G4 recently, I’ve become attached to this adrenaline-pumping/category busting/never-seen-before-speed-machine that’s also equipped with a fridge and a kitchen sink. I felt for the crew. And I felt for all the folks at Gunboat and Holland Composites. And I felt for whoever was at the helm when they sailed up to–and then over–the edge.

    But then I realized, there’s nothing to be bummed about. In fact, in purely scientific terms, something like this provides as much, if not more useful data than simply drag racing under the sunny skies off the ultra-swanky beaches of St Barths could ever reveal. I wasn’t aboard, (sounds crazy but I really wish I was), so I’m just going by what the folks who were there have said but, for me, learning that a boat like this is so well-built and well engineered that it can recover from a full capsize with minimal damage (except for some cell phones, some battens, and maybe a bit of pride to the crew) is simply amazing. They know where the edge is. They’ve expierenced it. And gone 180 degrees over it, and bingo, they’re back up and will be foiling in no time.

    I mean check Sharon’s amazing photos out. Look at the foils. And the rudders. And the mast. And the rigging. And the main. All intact after what must have been a pretty abrupt stop. Totally amazing.

    Johnstone himself was aboard and called it a “dumb” capsize. And some of the guys from Holland Composites have it absolutely right where they say:

    “The G4 capsized sideways yesterday – obviously. Crew are fortunately okay, one team member suffered minor injury. Mobile phones have been lost, as such we back at home in The Netherlands do not have all info available. Once more is known we will update you.

    “During production the boat was referred to as the Batboat by many. Being quite fond of the last trilogy I recall a phrase in such Batman movie where the butler asks a young Bruce Wayne ‘why do we fall?’, and follows with the answer ‘to learn how to get up again’.

    “The upside (no pun intended) to what you see here is that the limit has apparently been found, that the boat was pulled back up very quickly again and the only damage appears to be two broken battens in the mainsail. Electronics are drying up and we hope we can get them working again shortly.

    “In spirit of the butlers words, we got up again and now work hard to see you all in Antigua in a few days again. Lessons learned.”

    You can’t wan’t to do this without being aware of some of the risks.

    Other early reports cite the need for a quicker main-dump system. Which makes perfect sense and is a relatively easy fix.

    As for being one of the lucky ones who know what it feels like (and sounds like) to foil at over 30 knots on the G4, I want one more than ever.

    And you gotta tip your cap to a truly unflappable guy like Peter and the folks at Holland Composites who not only design and build one of the coolest and most radical new designs any of us jaded sailing writers have seen in a lifetime, but they’ve done it in the uber-bright light of one of the highest profile regattas there is with only a couple of weeks testing prior! Chapeau to their audacity and their tenacity! The future is here. There’s going to be lessons learned along the way but man, this is what creating a whole new thing looks like.

    Because as it is in life, you never can see what someone (or something) is truly made of when things are good. Adversity brings out greatness. Just wait till Antigua Sailing Week. I predict the G4 is going to light that regatta on fire.
     
  9. hump101
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    hump101 Senior Member

    One of the issues with foils in general is the raised CoG when flying, and with the J foils this is exacerbated by the offset of the lift centre inboard. Looking at the G4 going over, the point of vanishing stability for this design is relatively low when flying, only about 32 degrees, so they have very little margin.

    When they approach this angle the boat falls off the foils and the stability limit correspondingly increases, but then the boat slows, causing the AWA to increase, highlighting the slow sail release.

    As such, this type of system relies on the boat being kept relatively level within a narrow margin. Sailing it like a beach cat is not appropriate, since the crew weight can't be used to offset the CoG, thereby increasing the stability margin, in the same way. Looking at an A cat, for example, the point of vanishing stability when flying is nearer to 70 degrees, and so a different set of parameters need to be applied by the helm in judging the safe limits of the boat.
     
  10. brian eiland
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    brian eiland Senior Member

    Not sure, but I think there is an attempt at that direction shift here....

     
    Last edited: Apr 20, 2015
  11. daiquiri
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    daiquiri Engineering and Design

    Yes there is, but towards the portside and into the wind, not to he starboard. Check the rudder angle:

    G4 capsize.jpg
     
  12. daiquiri
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    daiquiri Engineering and Design

    Anyways, that video was posted by the Gunboat, so I can't help but praise their sense of humor and self-irony. :)
    Evidently, they are not worried about the consequences of this accident and see this capsize as a natural part of the learning process. Those who want to own and play with a foiling bare-to-the-bones-cruiser will still want to have one, and those who don't want to rely on a professional crew will carry on with non-foiling cats and monos. Things will remain as they are.

    I still remain on the opinion (which I have expressed several times in this forum in the past years) that the terms "family cruiser" and "foiling" will remain two separate worlds until a reliable and stable automatic flight control system (controlling both underwater appendages and sails) is introduced on the market. And I think that's what the future will be, sooner or later. Manually-handled sailboats will become a thing of the past.
     
  13. mundt
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    mundt Junior Member

    laird hamilton hit a wall at monaco?
     
  14. brian eiland
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    brian eiland Senior Member

    But that particular frame is when the boat is already going over, so no telling what helm forces might then be exerted by 'falling' helmsman, or no helmsman at all at that point.

    Can you get a little earlier frame,...like that one at around 0:42, 0:43, 0:44 ??
    Doesn't it appear as though helmsman is leaning back, pulling tiller, which would be turning to starboard?

    Sorry had my frames times screwed up, !:59 was time of whole clip
     

  15. daiquiri
    Joined: May 2004
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    daiquiri Engineering and Design

    This one was taken at 0:48

    G4 capsize.jpg
     
    Last edited: Apr 20, 2015
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