Bavaria Keel problem - Who'd test their boat like this?

[BrianH]

Re: Bavaria Keel problem - Who\'d test their boat like this?

With reference to the keel loss, the claim by Bavaria about grounding was later shown to be a contemptible fabrication in a damage-limitation exercise by the marketing department.

Most of the bad publicity has strangely disappeared from the web but one of the Hungarian participants tells his story here.

Some of this forum's messages are archived here, while a pdf copy of the Bavaria press release is published here.

 

[Refueler]

Re: Bavaria Keel problem - Who\'d test their boat like this?

Keel damage from hitting an object.

Personally involved in a case where a boat - Ridas 35 - was in collision with submerged concrete block in Tallinn Bay. This block was left over from days when Soviet subs would lay alongside it submerged and refuel.
The Ridas 35 during a race hit the block with the leading edge of its lead keel about 30% up from bottom. Speed at time was 7kts.
Boat was lifted immediately after the race finished and placed in stands, keel proud of ground, for Ridas factory to check the boat. I was involved as I was at that time agent for Ridas negotiating import to UK and I lived / raced in Tallinn.

Measurements were taken and keel was found to be less than 1/2 degree out of line with vertical. Hull was unmarked without crazing or damage at keel joint.

Repair consisted of :

a) Undoing the keel nuts that held keel in place. The studs pass up through GRP then the steel frame in hull. The studs being surrounded by sikaflex to provide a shock absorbing medium and then large plates and nuts applied.
b) Ream out the sikaflex.
c) Cast lead filler piece scarfed into keel where chunk was "bitten out by concrete". It was also drilled and pinned. Faired and painted.
d) Keel lifted into place, sikaflex applied around studs as per original specs, plates and nuts tightened.

That boat is still racing 6 yrs later with no problems or signs of damage etc.

Note : I gave up my rights to the Ridas line as the production was sold before build and waiting lists meant difficulty for me as small operator to service.
Regardless of my connection - the Ridas 26, 31 and 35 all outpaced X yachts consistently and would outrun a Match easily .. sorry !

 

[jonjo]

Re: Bavaria Keel problem - Who\'d test their boat like this?

[ QUOTE ]
With reference to the keel loss, the claim by Bavaria about grounding was later shown to be a contemptible fabrication in a damage-limitation exercise by the marketing department.

[/ QUOTE ]
Are you referring to the later claim about the discovery of strange ripples in the keel stepped mast just above coachroof?

I thought Doug Patterson and J&J, joint Match series designers, put their names behind this discovery and the conclusion the ripples indicated rapid deaccelleration of the yacht when hitting a submerged object during a downward plunging movement?

I don't recall a photo of this being published on the net but neither do I recall anyone doubting the finding. Do you have a reference to the counter claim.

Whatever the truth the whole saga illustrated a sad failure of cross boarder Euro investigation into the matter. Had a UK sailor lost his life when the keel fell off a boat chartered in UK waters, then I think the MAIB would have delivered better facts into the public domain.

 

[terrywilson1234]

Re: Bavaria Keel problem - Who\'d test their boat like this?

[ QUOTE ]
With reference to the keel loss, the claim by Bavaria about grounding was later shown to be a contemptible fabrication in a damage-limitation exercise by the marketing department.

[/ QUOTE ]

You got a source for that statement?

 

[BrianH]

Re: Bavaria Keel problem - Who\'d test their boat like this?

[ QUOTE ]
Are you referring to the later claim about the discovery of strange ripples in the keel stepped mast just above coachroof?

[/ QUOTE ]

No, I was referring to the hasty press release that Bavaria made without being able to examine the keel, still deep in the Adriatic.

This was later continued with some face-saving backpedaling in other correspondence such as:
"The actual cause of the accident has not been finally determined. What is known is that other boats in this fleet have serious damage to their keel bottoms, confirming groundings and causing structural damage as a result."
(http://www.sailmag.com/Letters/BavariaResponse/)

The Bavaria press release statement was rebutted by the regatta organisers, also in a press release here

I followed the incident because I was in the same waters at the same time as the regatta and my opinion was formed from reading all the reports of of the incident, most of it in German yachting magazines and on-line forums.

 

[BrianH]

Re: Bavaria Keel problem - Who\'d test their boat like this?

[ QUOTE ]
You got a source for that statement?

[/ QUOTE ]
Most of the sources for my opinion are now pulling up 404 errors, but one summary of the incident remains here.

 

[terrywilson1234]

Re: Bavaria Keel problem - Who\'d test their boat like this?

[ QUOTE ]
[ QUOTE ]
You got a source for that statement?

[/ QUOTE ]
Most of the sources for my opinion are now pulling up 404 errors, but one summary of the incident remains here.

[/ QUOTE ]

Thanks!

 

[Brent Swain]

Re: Bavaria Keel problem - Who\'d test their boat like this?

That's no test at all. Most keels will flex like this if you shake them. So do the wings of a plane - the tips of a 747s wings go up and down a LOT..... The test is if they break when under stress - in a yacht it's when pushed really hard under sail, and in a plane it's during severe turbulence.

Wings on planes have to be kept light . Keels prefer heavy. Air is compressible . Water is not! No excuse for something so flimsy on a boat.
Reading Nevin's rules for yacht scantlings, they advocate one inch of cross section for keel bolts per 1500lbs of ballast. No mention of how wide athwartships the bolts are, or how deep the keel ; major factors, and thus a major oversight.
Narrower keel attachments and deeper keels put far more load on keel bolts.
Common sense ( the least common of all the senses) must be applied to any math calculations.

 

[A1Sailor]

Re: Bavaria Keel problem - Who\'d test their boat like this?

Wings on planes have to be kept light . Keels prefer heavy. Air is compressible . Water is not! No excuse for something so flimsy on a boat.
Reading Nevin's rules for yacht scantlings, they advocate one inch of cross section for keel bolts per 1500lbs of ballast. No mention of how wide athwartships the bolts are, or how deep the keel ; major factors, and thus a major oversight.
Narrower keel attachments and deeper keels put far more load on keel bolts.
Common sense ( the least common of all the senses) must be applied to any math calculations.

Wow. I mean Wow. Are you going for the world record on bumping old threads?
9 years might win it!:encouragement:

 

[Brent Swain]

Re: Bavaria Keel problem - Who\'d test their boat like this?

Right .Shame on me for trying to pass on info which has not been posted so far, on this issue!
Trying to help others ?"
How downright "Unstylish!"
Definitely "Not trendy!"
Maybe in your culture!
Not in mine.

 

[pvb]

Re: Bavaria Keel problem - Who\'d test their boat like this?

Wow. I mean Wow. Are you going for the world record on bumping old threads?
9 years might win it!:encouragement:

I suspect he's doing it deliberately to wind people up.

 

[Tranona]

Re: Bavaria Keel problem - Who\'d test their boat like this?

I suspect he's doing it deliberately to wind people up.

If you look across the forums it looks like he is bored and using the search function to pick up particular topics, mainly related to steel boats. Maybe he will eventually fall asleep again.

 

[Tradewinds]

Re: Bavaria Keel problem - Who\'d test their boat like this?

I think he was kicked off the Sailing Anarchy forum so is looking for somewhere else to post.

He's on my ignore list (both forums).

If you look across the forums it looks like he is bored and using the search function to pick up particular topics, mainly related to steel boats. Maybe he will eventually fall asleep again.

 

[mainsail1]

Re: Bavaria Keel problem - Who\'d test their boat like this?

I did not see this thread when it was first posted. I wish I had.
The film shows exactly what happened to my 3 year old Bavaria 44 keel and it cost over 6 grand to put it right with no help from Bavaria.

 

[Kelpie]

Re: Bavaria Keel problem - Who\'d test their boat like this?

Surely a better way of discussing old topics is to start a new thread with links to all relevant threads and other sources.
That way the whole discussion starts out with up to date information, active posters, and nobody wasting their time trying to answer questions from a decade ago.

 

[pvb]

Re: Bavaria Keel problem - Who\'d test their boat like this?

Surely a better way of discussing old topics is to start a new thread with links to all relevant threads and other sources.
That way the whole discussion starts out with up to date information, active posters, and nobody wasting their time trying to answer questions from a decade ago.

Absolutely right!

 

[RichardS]

Re: Bavaria Keel problem - Who\'d test their boat like this?

I think he was kicked off the Sailing Anarchy forum so is looking for somewhere else to post.

I've no idea what the Sailing Anarchy forum is but the concept of being able to be thrown off an anarchy forum seems something of a contradiction.

Richard

 

[grumpy_o_g]

Re: Bavaria Keel problem - Who\'d test their boat like this?

Wings on planes have to be kept light . Keels prefer heavy. Air is compressible . Water is not! No excuse for something so flimsy on a boat.
Reading Nevin's rules for yacht scantlings, they advocate one inch of cross section for keel bolts per 1500lbs of ballast. No mention of how wide athwartships the bolts are, or how deep the keel ; major factors, and thus a major oversight.
Narrower keel attachments and deeper keels put far more load on keel bolts.
Common sense ( the least common of all the senses) must be applied to any math calculations.

Wrong on almost every count.

Water is compressible, just nowhere near as compressible as air.

The denser materials are also structurally weak and anyway you want the mass at the end of the keel, hence the bulb design which reduces both weight and drag for a given righting moment. The keel itself (which maybe nothing to do with the ballast or may just be a method of incorporating the ballast structurally) actually needs to be as light as possible for much of it's structure. If you want to see how strong and flexible a composite structure can be have a look at this video:

Designers try to put as much of the a/c's weight as possible directly into the lifting surfaces for obvious reasons. The wings on a large aircraft provide way over 100 tons of lift - if the wings only weigh 5 tons each then the main spar attachment is now coping with 90 tons (at that's just at 1g). That's why aircraft have wing tanks. There's other reasons to keep the weight in the wings but that'll do for now.

Nevin is not exactly state of the art - Swordfish's were still being built when he wrote those rules I would think. These days stress analysis is orders of magnitude more accurate and his "rules" are meaningless.

The only bit of your post there's any hint of truth in is that a narrower keel attachment or deeper keel will mean more load on the keel bolts, all other things being equal. There's a lot more to keel attachment than keel bolts though and the statement is simplistic in the extreme. It's perfectly possibly to design a deeper keel version of a boat that actually has less load on the keel bolts.

Math's calculations are Math's calculations - even in quantum mechanics they are simply right or wrong. Common sense is totally irrelevant to Mathematics at all levels.

In summary the original 13 and-a-bit year old video you're posting about is utterly meaningless with regard to any real or perceived keel problems as you can't see what's happening at the actual keel attachment to the hull.

 

[savageseadog]

Re: Bavaria Keel problem - Who\'d test their boat like this?

"Rule of thumb" is probably a reasonable way to proceed, rule of thumb is based on experience of boats already made and tested at sea. I suggest that it's probably impossible to accurately model how composite structure and keel will perform, tried and tested seems sensible.

 

[Tranona]

Re: Bavaria Keel problem - Who\'d test their boat like this?

"Rule of thumb" is probably a reasonable way to proceed, rule of thumb is based on experience of boats already made and tested at sea. I suggest that it's probably impossible to accurately model how composite structure and keel will perform, tried and tested seems sensible.

What a depressing outlook. Do you really think there have been no technical advances in the last 100 years since that "rule of thumb" was used? Have there not been enough boats built to different design standards then used and tested at sea to demonstrate that the standards work?