Yet another tragic loss?

[robert sailor]

Ideally I'd like to see the bottom of the boat ripped out with the keel still attached to it, then I know it was really built tough. When the keel comes off with the bolts sheared and the bottom of the boat is complete intact I'm left with a feeling that it was marginally engineered. When this happens at sea the owners all cry that the boat must have suffered a grounding prior that was not properly inspected. The manufacturers all suggest that no matter how light a grounding is it must be inspected before going back in service etc. etc. Can't have it both ways. When you build a boat with a thin hull, which you can do if it's made with a full liner and you use both the hull and liner as the support system for the keel you know that if you ground the boat it's easy for the glue joints to separate as happened in Cheeky Refiki. My feelings are that these liner built boats do a good durable job in everyday sailing but don't have the structure to allow for groundings without a very good inspection process. Manufacturers want the boats hauled and inspected after a grounding of any sort and Polux has suggested that ultrasound is able to find damaged glue joints not seen by the eye although our yard guys tell us that the cost do doing an ultrasound may out way the value on the boat. Stick built boats are easy to inspect by comparison as everything is open to the eye.

[marcofailla]

the mooring operators saw the approaching boat by seeing the upper mast beyond the jetty, then they saw the mast changing direction pointing on the jetty
simple as that....

[double u]

Originally Posted by robert sailor

Ideally I'd like to see the bottom of the boat ripped out with the keel still attached to it, then I know it was really built tough. When the keel comes off with the bolts sheared and the bottom of the boat is complete intact I'm left with a feeling that it was marginally engineered...

absolutely! the keel shouldn't be "the-first-2-go" in a grounding, never mind how severe a hit!

[hpeer]

RE THE STEEL HUL LOSS

IIRC ..... And I'm pretty sure I do....

That was a variant of the typical design. The keel had been designed to be REMOVABLE for transport and had recently experienced a very hard grounding.

So that was a far from typical steel hull/keel attachment.

The commonality wth other similar failures, if any exists, would seem to be bolts. Bolts fail.

[Polux]

Originally Posted by Jim Cate

Pollux, in the case of the steel Vde S, was the keel bolted on or integral to the hull?
Where did the failure occur, at the join or in the hull structure or??

RAther unusual for such a failure in a steel vessel, so if you have any details, please pass them on.

The idea that any FRP boat is likely to survive being thrown on her side onto a jetty is pretty far fetched. If one looks back at the Cabo San Lucas "disaster", quite a few FRP boats were destroyed when pushed up onto a soft sand beach. Several were not, one of which was an Olsen 40, a Santa Cruz built ULDB racer type. Not massive, but quite light... she was refloated and sailed away, while several "crab crusher full keel" types were totaled. Interesting...
Bernard's Joshua, a very heavy steel design, was also eventually refloated and with some effort, set sailing again.
Jim

The boat was a Van De Stadt 48. it happened last year:

[Polux]

Originally Posted by hpeer

RE THE STEEL HUL LOSS

IIRC ..... And I'm pretty sure I do....

That was a variant of the typical design. The keel had been designed to be REMOVABLE for transport and had recently experienced a very hard grounding.

So that was a far from typical steel hull/keel attachment.

The commonality wth other similar failures, if any exists, would seem to be bolts. Bolts fail.

I don't know if the boat had a bolted keel. Most boats have and that includes many steel and aluminium boats. It is by far the most common method to hold a keel.

Your claim that the bolted keel was due to transport needs or was not according to the design seems unfounded to me. For what I know of the design comes with an option for welded or bolted on keel. Both methods have advantages and disadvantages and i am not talking about transport.


The boat was built in Holland by a reputable shipyard and the owner was a retired merchantman, it had 50 years on the sea and was safety concerned. Your assumption the boat was not built according with the plans seems very unlikely. If you have any information regarding that, out of speculation, please post it.

[hpeer]

IIRC .... And I'm pretty sure I do.... You made a lot of similar claims last and were put right the .

To be polite it is far fetched to say a lot of steel and aluminum bulls are bolted on. I believe when you said that before you eventually qualified that you were talking about ocean racers. I've looked at a fair number of steel and aluminum boats and more plans and have never come across a bolted keel.

I suggest you go back and reread that thread before making more statements.

[double u]

second that! imho the vast majority is welded! to tear the keel out of our Pouvreau 1130 would have meant to disembowel the whole boat, the keel was let into the hull for >10" (I seem to recall) with numerous floors welded to it's sides, & all the metal-boats I looked at were built similarly except one dutch 34' steel VdS that had a bolted keel to facilitate home-fitout of the hull (I would have dug a hole for the keel...)

[valhalla360]

Originally Posted by CarlF

Since people often die when keels fall off, keels/hull joints should be engineered to take a lot of abuse.

C.

So give us a statistical analysis to support your assertion:

How many people per year die due to keels falling off?

This is like saying we should design the bimini to protect sailors from meteor strikes because people often die when struck by meteors.

While I'm sure both have happened, unless you are doing something unusual where you expect to run the keel up onto the rocks regularly, the chance of it happening is so low that you don't design for it. Also, there is no guarantee that if the keel stayed attached, that the people wouldn't still have died when the hull collapsed or they were washed overboard without life jackets.

If you want an indestructible keel, that's fine (though impossible to design) but you have provided no safety analysis to support it. You appear to have presented an emotional response to support your already existing opinion.

[nortonscove]

Originally Posted by Eder

I'm pretty sure my keel would take that beating...IP 460

My wife's family have been tugboat owners for a century and having worked in the field of salvage and removal of vessels from rocks I say this would be a silly claim. Watched big heavy fishing boats disintegrate in a matter of hours in big seas and your IP would not meet the expectations of those fishermen.

This isn't a boat problem as much as human error. As are most failures of vessels.

[nortonscove]

Originally Posted by RidgeRunner

Yup.

...

Falling tide and big seas are not the same. Show us how these boats got to these positions are there may be relevance.

[nortonscove]

Didn't PS do some research of keel failure and find the most common type to be failure of welded keels on steel or aluminum?

[hpeer]

Norton,
There is one point of confusion that creeps into these discussions that requires clarification. This was the core of the above mentioned "research". It was a poorly worded article where it mentioned a steel keel breaking off a fiberglass boat. However if you read through it was clear they were only talking about fiberglass boats and the keel composition was not at issue. It was the attachment method (bolts are steel.)

There are steel/aluminum (metal) keels that bolted into boat hulls. Now that hull may be fiber glass, composite or whatever. In very rare circumstances (for cruising boats) it may be metal hull. In those situations the bolts are at risk and the risk would seem to be similar to bolted on fiberglass, or carbon fiber or whatever keeps.

This is not the case in the vast majority of metal cruising boats. There the keels are welded to the hull, integral to the boats structure.

[hpeer]

Let's do this, let's keep a tally of what metal boat owners here have.

I'll start with my experience, just copy the previous post and add your situation.

A. My steel/aluminum cruising yacht has its keel WELDED into the boat hull.

B. My steel/aluminum cruising yacht has its keel BOLTED into the boat hull.

A. WELDED keel attachment
2 (Chouette and Safara)

B. BOLTED keel attachment
0

[marcofailla]

self explaining pictures




***this is not the cause of the disaster but a consequence of it***