part 2: Northern Marine 90' Yacht Capsizes Upon Launch...!

By a group of invisible people?

What a paid shill YachtVid is.

And the talk about the impact of this on the economy of the PNW. There is not even much impact on the island. They were small compared to others there. Two boats a year. No boat to follow this one. 50 people listed on payroll but far fewer working. 20-30 maximum at most times. Other boats being built in the past only had 5 persons max working on them and often 2-3.

The PR effort continues but the facts remain.

Meanwhile the lawyers are hard at work. 14 court entries in the month of June. Latest with New World getting another extension of time. Delay is the tactic.

And the boats sit, unfinished.

Wow, what a waste of time. He said nothing worth listening to, wish I could get my 2:38 back.

Baden needs a band aid but the host of the video needs duct tape! He's obviously trying to make a name for himself. I can think of a few! Don't waste your time listening to this drivel.

At least he wasn't petting a pet this time.

The comments were pale,, again.
I did see some new video of the event. The tub toy sank further that I had thought. Leeds me to encourage some of my original thoughts; That was a very deep basin.

Unfortunately destroyed by fire.

If it is being restored, it involves some psychic process since there are no human beings on the ship.

Maybe it will go the route of Polar Bear.

Funny, I had the same thought. Wouldn't that be convenient.

Be careful, that has been suggested here before with different wording and it caused a bit of a kerfuffle.

Alaskan was very rude to OlderBoater, but a quick look back at his post history reveals that he is probably either employed by NM or works closely with them. A quick glance through his post history gave me a link to his photo sharing site, where he posted photos of the launch. Some of those photos are taken with a view of the ransome, and constitute photographic evidence that someone was clever enough to shut the transom door as the yacht it backing up and as it begins to list. Unless someone was foolish enough to open the transom door when it was submerged that was not a factor in the sinking.

His gallery is here Northern 90....

My new observations from those pictures;
Aft door was closed.
Design of after cradle trailer looked to be of one piece.
In pic 23 & 47 you can see the machinery exhaust outlet. In pic 59 & 60, something big was running.
Did people go into the hull after it rolled over? 2 to 3 guys on the stern as she was ramped down. One of them checking the exhaust in pic 60.
Pictures also reinforce; She rolled over, THEN sank.

Rudder looks intact. Not a lot of detail but stabilizer fins look good also.

There were six people on the boat. Four got out easily. The other two were deeper and one finally had to be pulled through a port.

Sorry for all the typos, posted last post from my phone.

In the local paper, the yard manager for the builder stated that the trailer's wheel fell off the ramp into a hole, then the port side fin went into the same hole, and this somehow caused the vessel to roll over. I inspected the port side fin from around 50' away today with binocs and there is no visible sign of any damage to the port side fin, which look to be ABT Trac. The story that the vessel rolled over on the fin rather than float appears to be just that, a story, since at a minimum, I should have seen some damage to the fin after that much weight was brought to bear on it.

This still looks to me what it always did - the boat was completely unstable and launch and simply rolled on its side. If the water had been deeper, it would have floated upside down.

For awhile.

It started to go over when it was still supported at the bow. The fact that it was half afloat and half on wheels is a perfectly reasonable explanation for that behavior. But if you watch that video of the launch that Yachtvid posted (and aside for his sycophantic words, he has some very nice videos) you can see that it does enter the water completely at some point. To what degree do we estimate that it was listing when it was fully supported by buoyancy? I would dearly love to see more information about the stability testing that the CG did, and the amount and configuration of the ballast, though I realize that information is unlikely to materialize.

How does support on the bow encourage rolling over and present a "reasonable explanation" for capsizing? Wouldn't such support prevent capsizing? Put another way, if I secure my bow so that it cannot move, will this cause my boat to roll over? Confused, to say the least.

Regarding the angle, it looks to be less than 15%. From the point this still is taken, the vessel is apparently floating free and continues to roll over. If she didn't hit the shore, she'd be upside down.

It is a reasonable explanation of what happened, it is not reasonable to design a boat of this size without doing the calculations to show that that will not happen. The hard support at the front is spread over too narrow an area to hold the boat up. The back being afloat allows the center of buoyancy to move outboard faster than then center of gravity as a well designed boat lists and that provides a righting moment that brings it back to upright. When a boat is on the hard on one point the metacenter is shifted down very low, because the boat pivots around the contact point. If you've got it on the hard on a cradle you've got a tripod and the initial stability is basically infinite, but as you transition between the two there is a point when you don't have enough support from a shifting center of buoyancy to provide the righting moment, and you don't have any support from the back cradle to provide that essentially infinite initial stability.

One of the benefits to running the boat down the launchway quickly is that you avoid spending a lot of time in this quasi floating quasi hard state, and you don't have enough time to tumble into trouble in the interim.

Someone, or several someones, at NM didn't do the basic, mandatory homework required. I'm just interested in figuring out which unacceptable failure mode occurred.

The Roddan Engineering report indicated that the vessel needed to have its 20,000# of ballast augmented with another 38,000#. I gather the plan was to add this after launch, since adding it before hand would have made their Rinky Dinky method of trailer transport launch even less feasible and safe than it already was. What it looks like to this amateur is that the existing CG was not on the centerline, but off to port sufficiently that she simply rolled over as soon as she floated free. I didn't spend any time looking at the study to see if you could explain the list to port based on the paper weight forecasts, but perhaps that information is buried therein.

All I can say is that the explanations offered by management do not conform to what I can observe from the vessel on the hard, so I don't see any reason to take their word for much of anything. Presumably the official report will solve any remaining mysteries.

Spoke with a buddy of mine yesterday...he told me the boat has been moved from it's previous location...wasn't sure where it went...but was going to do some nosing around and provide an update.