Boat Capsize Evidence

Discussion in 'Stability' started by Sachi, Oct 10, 2009.

  1. peter radclyffe
    Joined: Mar 2009
    Posts: 1,405
    Likes: 58, Points: 58, Legacy Rep: 680
    Location: europe

    peter radclyffe Senior Member

    what do you think of these

  2. Loveofsea
    Joined: Jan 2007
    Posts: 147
    Likes: 6, Points: 0, Legacy Rep: -68
    Location: Southern California

    Loveofsea New Member

    I'm beginning to think that you don't like me very much :(
    But since my neighbors on both sides and down the block give me their keys when the go on vacation i'll just have to get over that, but it won't be easy :rolleyes: Since when do 95% of boat hulls dive below the surface for no apparent reason :confused:

    Peter, i prefer #9, because i have a flatbottom with special modifications. These modifications make it superior to v hulls in several aspests, running downswell, perhaps the most significan. I use my tiller (and articulate throttle) to work the port chine against the swells just like the FWD edge of a surfboard. One thing i find disheartening about most flatbottoms is that they taper to a V in the bow. That mistake eliminates the single most valuable aspect of a flatbottom--exagerated transom lift without the "bow steering" effect where the V in the bow dominates the effect of the rudder (lower unit on an outbd); broaching IS dangerous. My hull is widest 1/3 bottom length from the bow and it has a SST lifting strake on the transom. Since it lifts at both ebnds, it has a tendency to stay stuck to the surface--the less the bow lifts from the surface, the less it slams back down. Although there is a slight penalty for this conflict, it is negligable. I think # 2 and 6 would stand the least chance of stuffing the bow as indicated in the videos previously posted.

    Tim, the skiff is 19ft. All boats are going to stuff the bow on accasion while in seas. I have a problem with a boat doing that on calm waters, such as a river. Very informative post, thank you.

    Did i mention that i installed a 6" diameter glass window right smack dab in the middle of the cockpit floor :D
    1 person likes this.
  3. PAR
    Joined: Nov 2003
    Posts: 19,133
    Likes: 473, Points: 93, Legacy Rep: 3967
    Location: Eustis, FL

    PAR Yacht Designer/Builder

    Again, you have accused me and most of the designers of the world of possible reckless abandon and you're flippant with your lack of response that might suggest you have a clue. No data, no documentation, no tests, just another ramble of what you don't know.

    I think anyone that makes these accusations should be held accountable. They are libelous, defamatory, unsubstantiated and dangerous to the industry as well as an insulting injustice to the professionals in it.

    If I knew who you were, you be up on charges and forced to make an explanation or serve the mandated public apology that would naturally result from your inability to reply intelligently on the subject.

    Now that this has gone on long enough for others to see what you're about, your value here is what it should be and your posts will be taken accordingly.
  4. ancient kayaker
    Joined: Aug 2006
    Posts: 3,497
    Likes: 146, Points: 0, Legacy Rep: 2291
    Location: Alliston, Ontario, Canada

    ancient kayaker aka Terry Haines

    Gentlemen, you may have to agree to disagree! Terrific vid in post #120 by the way, thank you Love! As for the rest of you, perhaps if you leave him alone for a while he'll calm down and this thread can return to its proper topic. I'll ignore my own advice and have my say, once and once only ...

    Having watched countless power boat races on the TV program "Destroyed in Seconds" (my wife's favorite) in which one or more boats take to the air or vanish below the surface or fragment, I myself have no problem believing a fast-moving boat can do something spectacular if the operator makes a mistake or hits a wave.

    The folk in the boat clearly prepared for something neat, the boat did something neat, and they both waved afterwards. The boat seemed to be rising back up at a phenomenal rate, either they had the bilge pump from hell or it wasn't as bad a swamping as it looked.

    In the video the bow dips about halfway to the surface and pauses there as the boat decelerates. No problemo on flat water. But then they hit the wave they were aiming at which pulls the bow under. Lots of negative gees but no blood on the dash or windshield. Planned and executed with perfect timing. Badda Bing, Bidda Boom.

    Tankers have been lost doing precisely this sort of thing, the bow gets pushed down by a biggy and the ship drives itself under with its own mementum. This boat didn't do that despite provocation.

    There is no way to design a boat that cannot be put into harm's way when there is an ******* at the controls. the seat is for the ******* of course, but not everyone understands that.

    I've noticed that most power boats settle at the transom when the power is cut, they usually have a big outboard trimmed to lift the transom and lower the bow so the operator can see ahead. When the lift stops the boat rolls back on its own wave and the engine weight does its job. However, the boat in the video is of an entirely different breed to the types most folks use to tow their kids around on a tire or do their shopping across the lake. Personally, I hate the beastly things and the smell and the noise and the wash and the bank erosion ... oops, you got me doing a rant now!
  5. Loveofsea
    Joined: Jan 2007
    Posts: 147
    Likes: 6, Points: 0, Legacy Rep: -68
    Location: Southern California

    Loveofsea New Member

    If you condone this one more time:

    You shall be placed under citizens arrest, transported straight to the Hague and be tried for minor crimes against humanity! :p

    Did i mention the SST lifting strake on the transome (the width of the transom w/cutout for the engine--11" in length) really suppresses the movement of the hull at reat. It creates just enough resistance to keep the hull out of synch with the swells. The hull actually comes to rest, then starts to move again. It makes sleeping possible. Imagine how stable at rest the hull would be if the 3/4" plywood bottom stuck out 6-8" all the way around the boat :eek:

    Have a nice day tiger :)
  6. PAR
    Joined: Nov 2003
    Posts: 19,133
    Likes: 473, Points: 93, Legacy Rep: 3967
    Location: Eustis, FL

    PAR Yacht Designer/Builder

    This isn't about condoning any type of behavior. It never has been and it just like a coward, to now attempt to change the subject of their position, one which they can't intelligently defend.

    This is about you accusing all modern designers, myself included of recklessly endangering peoples lives. This was your rant Loveofsea, not mine. I pointed out what was really happening in the video, but you in you ultimate sense of awareness, suggested it was a design flaw. You've even gone so far as to suggest it's just something that happens, unexpectedly in calm water, which you've since, wisely backed away from (probably because you actual believe in the laws of physics that you learn in the 5 grade). You are the one that still makes unsubstantiated accusations of ill fated bow shapes. Of course your true colors have continuously shown through, when after repeated questioning, you've never answered a single one.

    You have accused me of repeatedly designing things that I can be charged a felony for. You've been an inconsiderate, intentionally insulting fool, having declared that this is a design issue not an operator issue. You have called me a liar and suggested I've put people's lives in danger. If you don't think I haven't taken this as a personal assault on my abilities and profession, you are mistaken and you can surely bet, I will haunt your every move on this forum, until you admit to you deeds or offer reasonable explanations for your insults and contemptuous behavior.
  7. Sheepy
    Joined: Apr 2009
    Posts: 27
    Likes: 4, Points: 0, Legacy Rep: 61
    Location: Aus

    Sheepy Junior Member

    I have one question for loveofsea....if your design is so good why haven't you made yourself rich since it is such a good one?
  8. CowMan
    Joined: Mar 2009
    Posts: 8
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Vancouver, BC

    CowMan Naval Architect

    Good sir, I think you'll find that truely applying the principles of aircraft design would design you a boat with a shorter lifespan, not a longer. Aircraft are cut to the bone for weight savings. While we see this in commercial cargo ships to some degree (increased steel weight = less cargo capacity for the same displacement), but it is no where near to the same extent and not generally appropriate to personal pleasure craft. Critical aircraft components, such as wing spars, run with safety factors half of what we'd start with for a ship.

    There is some truth to loveofseas claims, certainly a powercraft designed for sheltered waters will not fair so well as the likes of an ocean going dory on the open seas, but designers are generally respectful of the operational area, and the videos don't prove your point either loveofseas. They just show people being idiots and having fun. The alternative of course is to have a broad bow, but they can submerge too. Here is a tug running 12 knots the wrong way:
    Presented to the water flow, the stern is quite broad and tugs possess enviable stability, with large GM values and lots of sheer. You'd be a raving lunatic to claim that this is a dangerously designed vessel, but it can certainly sink itself.

    Having read this thread, I'd be interested in seeing the lines of your skiff. I've developed a theory - and it is only that. Given your argument that contemporary boats dive by the bow and sink by the stern; yet, your own design does neither - perhaps you've reversed the design - a transom bow and a V-stern!
  9. PAR
    Joined: Nov 2003
    Posts: 19,133
    Likes: 473, Points: 93, Legacy Rep: 3967
    Location: Eustis, FL

    PAR Yacht Designer/Builder

    Cow Man, Loveofsea has done anything but blabber, insinuate, accuse and grossly insult. He can't substantiate any of his assertions and I'm confident his personal design is a joke, in most regards as a modern vessel. The only thing he appears to be good at, is avoiding answers to fair and reasonable questions about his assertions. I'll also bet that I could dive the bow of his skiff or whatever he has said he designed and built. I could do it in a flat calm with not a ripple on the water surrounding the boat.
  10. Loveofsea
    Joined: Jan 2007
    Posts: 147
    Likes: 6, Points: 0, Legacy Rep: -68
    Location: Southern California

    Loveofsea New Member

    You are taking this WAY too seriously and WAY too personal. All i have done here is maintain my position that a safe boat should never even be capable of diving below the surface no matter WHAT the driver did-PERIOD.

    The fact that some drivers have discovered that inherent design flaw and use it to have fun with, doesn't make it legitimate.

    We all have our own perspectives, and my perspective is somewhat unique in that i spend days at a time way offshore alone in a small boat. In the purview of the boating world, i think i have earned the right to my opinion by now. There is no way on earth you, me or anyone could make my boat do that. That is the perspective fiom which i base my opinion about safe boat handling characteristics.

    I am bold on this planet, but i am also a man of true compassion and i realize that somewhere in this thread i must have hurt you deeply for you to respond to me in the way that you have. I am loath to think that i am responsible for such apparent anguish, so with deference to your feelings i apologize to you for our protracted disagreement. Like the anctient kayaker said, you and i should just agree to disagree like gentlemen. You can haunt me if you want, but it will only be a pitiful spectical for the others to see. I am sorry that i hurt your feelings and would much prefer that we be friends, our mutual disagreement notwithstanding.

    Sheepy, i take a lot of pride in being able to say that i have never derived a cent of income from all of my time on the water. I have never charged anyone to use or publish any of my photographs. My hull was designed for one purpose; to be able to spend days and nights at a time, secure in the offshore waters. Realistically, what kind of a market do you think exists for that?

    Did i mention that i have a splash rail (1.5 X 3") that goes all around the skiff except the transom? I can literally walk 360 around the outside of the skiff ;) Not that i have have to do that very often--even the time when an angry sea lion jumped in the boat! That splash rail is a good example of adding substantial strength to the hull without taking up any space on the inside...

    A few years ago my skiff was featured on a web page, if you would like to see some pictures of it, just let me know and i will post a link.
  11. tunnels

    tunnels Previous Member

    Dont sue Stanley , sue you mother for giving birth to a idiot and then you father for planting the seed of stupidity . :mad:
  12. JosephT
    Joined: Jun 2009
    Posts: 850
    Likes: 105, Points: 43, Legacy Rep: 218
    Location: Roaring Forties

    JosephT Senior Member

  13. gunship
    Joined: Jun 2009
    Posts: 144
    Likes: 11, Points: 0, Legacy Rep: 137
    Location: Sweden

    gunship Senior Member

    looks like it... Very very sad...
  14. Perm Stress
    Joined: Sep 2009
    Posts: 554
    Likes: 23, Points: 0, Legacy Rep: 323
    Location: Lithuania

    Perm Stress Senior Member

    Looking at the waterline marks and comparing under water volume (potentially available for weights that increase stability) with all the weight up high, this vessels stability should be even less than that of famous VASA, which capsized and sunk in Stockholm harbor in 17th century.

    "Design process" is similar too...

  15. larry larisky

    larry larisky Previous Member

    at least it float, some don't.
    beside that i will be careful of what i say when professional are in the forum. i find more interresting to read their posts than reading the crap some wrote without any clue.
    i have no clue, i shut my trap, i learn and i ask question.
    i read par post, the man is highly trained, we are lucky he is willing to share his knoweldge.
    i saw one who left because of stupid and offending posts.
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.