Nasty Wooden Boat Accident - Gold Coast

Members might be interested.
News reports yesterday of a classic wooden boat flipping on the Nerang River on the Gold Coast in Queensland Attachment 260556yesterday tipping all of the occupants including a baby and a 60 year old man into the river. Quick assistance from a jet skier and fellow boaties retrieved all of the passengers and passers by on the river dragged the boat ashore downstream some distance from the accident. The baby and the 60 year old were taken to hospital for treatment to lacerations.
Witnesses reported that the gentleman's runabout failed to negotiate some wake and the sharp bow turned in to the water at speed and flipped.
A nasty way to finish what must have promised to have been a glorious day on the Gold Coast. Thankfully no fatalities.

Yeah, this happens and it's called "tripping", a common issue if you attempt to turn at too high a speed or don't know how to handle chop at high speed. Modern hulls don't have this tendency, nearly as much as designs before the "63 series" tank test conducted by the USN. After these tests, most every designer that had any interest in powerboats, quickly realized they where doing things wrong and made adjustments. The results are powerboats that now, don't have a "hump" in acceleration, don't lift their bows in the air nearly as badly, ride much better, turn much better, don't trip over chines or deep forefoots, etc. A powerboat design I did recently, climbs up on plane at the same angle as it's launch (about 3 degrees of bow up) and holds this angle to about 90 MPH (145 KPH). None of the bad habits that are common in antique designs. Sometimes you have to be careful what you wish for. So, if you want an old, mahogany runabout, be careful, because these things generally are ill mannered beasts, of questionable design and certainly antiquated design philosophy.

Thank you very much for posting this. A mate just rang me and told me of another flipping in Launceston a while ago.

I really appreciated the photo (leaves no doubt about the boat type) and the explanation. Having watched the son of a friend flip one of my ski boats (17yo's should not be encouraged to go wave jumping in Haines 1700's - even if it is great fun:) ) I can attest to how fast it happens, and from quite benign conditions. It could only end in a great deal of tears for a very heavy, massively engined wooden masterpiece to demonstrate aerobatics at your expense. Objects of beauty they are, creatures of the air they are not.

Again, thanks for the post. Yes it can happen, yes it does and will continue to and no it needn't. Be gentle...

Nuttin wrong with the boat - loose nut behind the wheel!.

You see it a lot.

Agreed, the skipper may have made a mistake, but in their defense, these older hull shapes, where often challenged in stability and maneuverability. At speed it's a lot easier to "stuff a bow" or trip one of these, much more so than they may be accustomed, in a more modern design.

I wonder if the skipper of the Costa Con Cordia will use this excuse? :D :wink:

Drive a car according to the road conditions at the time and a vessel within it's design limitations and the sea state at the time.

I guess it didn't come with a stability book and GZ curve. :U

Not a wooden boat, but is this "tripping"?

https://www.youtube.com/watch?v=FtUU...yer_detailpage

Operator error - he appeared to come off a wake and stuff the bow, then get thrown out of the cockpit helm seat.

If you watch just before hitting each wake he backed the throttle off hard each time.. and i think the 3rd time he dropped the bow into the back side of a wake at a tangent to direction of travel.... tripping - well if you want to be generous you could call it that? Really hard to tell from the angle inside the boat - we can't see what the helmsman could see at the time in order to make the judgement calls he did.

Seemed like some radical throttle maneuvering there - IMHO that might well have been what brought him undone by stuffing the bow.

Also hard to see how the boats powered, I suspect it's a jet.... and when you off gas like that - you lose all forward thrust steering control.

I saw him operating something on the dash with his right (throttle) hand early on which i suspect strongly was a set of Bennet hydraulic trim tabs - used to trim the nose up or down and set the amount of heel side to side... and they are real tricky things if you don't know how to operate them....in that they are counter intuitive, the switch is usually wired so that pushing the top of the two rockers lowers the trim plane to push the bow down... and vice versa - BUT I've seen the switch unit mounted upside down in the dash before today and pushing the top of the rocker lifts the bow etc so unless your intimately familiar with your own boat and how the trim planes are operated... :?

So if it is a jet powered vessel the thrust from the jet lifts the bow while the trim planes at the rear lower the bow - if you back off the thrust rapidly the way he does...over each wake wave - the bow drops - and the trim plane then operates to bury the bow further... ending up with a stuffed bow and that rapid slewing to the right due to lack of steerage from the jet - with the helmsman then ejected from his seat rapidly the way he was due to the steep un powered rapid turn.

Normally a vessel heels into a turn (unless its a cat) under power - but a jet boat will certainly pull that stunt unpowered, i.e. throttles off, and with the trim plane setting now acting not against the thrust of the jet but wholly on it's own...to bury the bow.

If you trim the nose down with the trim planes and the jet is trying to raise the bow they are fighting each other - when you yank back on the jet throttles suddenly like that (the ay he did 3 times) - you lose the bow lift from the jet nozzle - and the trim plane takes over and it's effect can double or triple suddenly - burying the bow the way it did.

In short the bloke driving it was a peon. :wink:

Quote:

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Originally Posted by Soredust

Not a wooden boat, but is this "tripping"?

https://www.youtube.com/watch?v=FtUU...yer_detailpage

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I'm glad no one was seriously hurt....because I cant stop laughing...one minute there sitting there with their cool sunglasses and the next there head-butting the floor. Peon is an understatement.

Quote:

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Originally Posted by PAR

Yeah, this happens and it's called "tripping", a common issue if you attempt to turn at too high a speed or don't know how to handle chop at high speed. Modern hulls don't have this tendency, nearly as much as designs before the "63 series" tank test conducted by the USN. After these tests, most every designer that had any interest in powerboats, quickly realized they where doing things wrong and made adjustments. The results are powerboats that now, don't have a "hump" in acceleration, don't lift their bows in the air nearly as badly, ride much better, turn much better, don't trip over chines or deep forefoots, etc. A powerboat design I did recently, climbs up on plane at the same angle as it's launch (about 3 degrees of bow up) and holds this angle to about 90 MPH (145 KPH). None of the bad habits that are common in antique designs. Sometimes you have to be careful what you wish for. So, if you want an old, mahogany runabout, be careful, because these things generally are ill mannered beasts, of questionable design and certainly antiquated design philosophy.

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Just came across this thread and have to add some comments regarding old hull designs.
I own and use a late 50's built bondwood ski boat (late 40's/early 50's design) as a family ski boat which we run at least 50 hours/year since 2008. Several issues Par mentions I have; excessive bow lift, poor ride and a deep forefoot. Excessive bow lift has been solved with a different prop, poor ride is overcome when the water gets choppy, by adjustable trim plates, but it took 3 years to find out that in one particular circumstance it would burry that deep forefoot and scare the crap out of me, have had this happen only once again in exactly the same circumstances (stupid).

Par is correct, these things can bite and without warning. Took 3years to find out what mine was capable of and then another 3 for it to happen again. My incidents were just not as terminal as old mates in QLD.

I lost a friend to a tripping incident, he experienced in a race among other old and antique designs. They all knew the potential dangers of these puppies, but class racing is an illness that is hard to shake, once you have it. The hull tripped in a turn, he was tossed and then hit by a prop. I'm not sure if it was his boat or another, but the result wasn't good in either case. It's a hell of a price to pay, just to have an old design, when you can just as easily have an old looking design, with modern design features that remove much of this potential ill mannered stuff.