85-Foot Motor Yacht Sinks at Launch

[SaltyMonkey]

ballast might make it float for about another 10 seconds, but its turtle enabled to the core.

[Jim Cate]

Maybe we are just too used to looking at proper sailing vessels... lots of motor yachts look top heavy to me.

But a sad event for all involved.

Jim

[BandB]

Originally Posted by SaltyMonkey

ballast might make it float for about another 10 seconds, but its turtle enabled to the core.

Well, the Coast Guard and the Insurer are running stability tests. It will be interesting to see the results. But it was tilted before it ever hit the water. They stopped. Then continued.

“The boat tilted to one side, and though not unusual, the amount of tilt was a little abnormal, so we paused to collect ourselves and assure that everything was going be right, and as we continued to lower it down, it pitched and that’s when it went over,” said Fridell.

And the photo before hitting.

http://yachtcaptainblog.com/wp-conte...-image/204.png

Among all the questions, why would you possibly continue to launch at that point? Was it for some reason a "must happen today regardless of anything"? Was their money (an immediate progress payment) riding on it being launched? I don't know. But I know if a boat is tilted as it was, I'm halting the proceedings until I get control of things. It that means another day, so be it. If it means a crane. But now they get the crane with a sling.

[BandB]

Originally Posted by Jim Cate

Maybe we are just too used to looking at proper sailing vessels... lots of motor yachts look top heavy to me.

But a sad event for all involved.

Jim

Well, even to those of us who regularly look at lots of motor yachts, this one looked exceptionally top heavy and that was before knowing how light it was.

One motor yacht type even posted on another site something regarding stability and wondering about it tilting over within less than two hours of the launch time. The news was only a couple of posts down from that.

From the time of the original simulated photos it continued to grow. You can't tell much from photos and artwork, but it appeared as if the deck heights increased. Maybe just an illusion.

When it looks wrong, it just may be wrong.

[SaltyMonkey]

insane. I cannot see how it would ever recover from a knockdown, and I'm doing my imaginative best. wow. can't wait for the post mort report

[jostalli]

Nordhavn's all look extremely top heavy as well but they are supposedly self-righting.

[DeepFrz]

The Nordhavn 86 has a 24 ft beam and an 8'2" draft. And it weighs in at 400,000 lbs (181.44 MT), of which a large percentage would be fuel, water, machinery and ballast, pretty much all below the waterline.

Ballast: Approx. 30,000 lbs (13,608 kg) lead fixed per machinery layout drawing. 4,000 lbs (1814 kg) of lead ingots supplied loose by builder. Vessel trimmed to suit during commissioning.

When a vessel is "partially" ballasted it means that there is some moveable ballast left to trim the vessel after she is in the water.

[MarkJ]

The previous owners Rep blogs.... Includes stability report


Yacht Captain's Blog (Aaron Pufal)

[David M]

Just a minor point, the profession is called naval architects and not marine architects.

You can't tell if a vessel is top heavy just by their looks. If you have ever seen a lightly loaded container ship from the bow or stern, you would wonder how it ever stays upright.

Stability is related to the vessels center of gravity, yes, but it's mostly determined by where the center of buoyancy shifts with respect to the center of gravity....you cannot see this visually. This movement of the center of buoyancy determines the vessels righting moment. The angle at which the righting moment goes negative is the point at which the vessel capsizes.

In this case the naval architect screwed up OR the naval architect was not given the correct data with which to make his calculations. Stability and Trim really is an exact science and not guesswork.

Sailboats typically have a lot more righting moment than a powered boat of the same dimensions because righting moment puts a horizontal load on the sail which creates a greater pressure differential on the weather and leeward sides of the sail.

An inclining test is used to prove (or possibly disprove) the naval architects stability curves.

The Coast Guard does not do inclining tests, they witness them. Inclining tests are typically only required for vessels that carry passengers for hire which includes Subchapter T and larger commercial vessels. I have never heard of them witnessing an inclining test for a pleasure boat....but then perhaps this vessel was intended to carry passengers for hire?

[hpeer]

This one got scrubbed before launch....

[Pelagic]

I am quite sure the blame will fall with the launch master or builder (if he is an employee)

Almost empty Slack tanks/ unknown "light" design CG for a "taking the keel" moment was really the risk they took when launching at a ramp that was not designed for that size of newbuild.

To save money they took a big chance at the ramp..

rather than first craning into deep water with slings.. Balasting to light ship marks then releasing slings and starting inclining tests at various
Fuel/water/ loads to confirm stability curves

Taking or Releasing the Keel is the most dangerous time in a ship's stability and you don't risk that at a ramp without controls.

Have seen it happen a few times and read the reports with the same conclusion

Going cheap and sloppy cost them big time....

I feel for the Owner.... there will be lots of finger pointing by the lawyers

[Adventurebound]

I bet the owner wanted the "Empire State Bldg" of all boats. To keep his business, thay gave it to him.

[dpddj]

we used to call vessels designed in such a way as seven decks and no bottom. Visually, it looks unstable, but depending upon hydrostatics, trim and stability calcs (if in fact they were adhered to) it could pass muster. Or not. Look at cruise ships - they look so ready to roll over but there is so much heavy equipment below decks....... The fact they were talking ballast so early on is indicative of a big OOPS.

[goboatingnow]

I don't think some people here understand a lot about stability. A keel is not primarily on a sail boat for stability. It's merely one of several places where ballast can be usefully stored.

An Ovni has no ballast keel. It has a centreboard., it's ballast is in the hull. Yet it is clearly stable


Dave


Sent from my iPad using Tapatalk

[markpierce]

"Heart pounding" describes an owner's emotional state when one's boat is hanging by a "thread." Thankfully, have a low center of gravity and weighing only 14 tons:



My theory is that the subject boat's trailer failed, dumping the boat before it was floating on its lines.