Bavaria Match 42 lost its keel...

[Tvermoes]

Scared I follow the discussion

Well, to bolt a keel in the hull laminate with small or no sheets of metal to distribute the load seems a design error of the type "don't understand what I'm doing".

The comment on Bavarias site: "...the actual thickness of the laminate (13,25mm) is larger than required thickness (7,93mm)" makes me pale, 8 mm laminate cannot suport a keel with sheets, transom's needed.

The upgrade, 9 layers of GRP to a 30mm thickness won't help the design error and if not properly made it will de laminate.

The pictures to be found indicates that the Match has a "moving keel", it is common with bottom paint missing in the curve where the keel goes over to the bottom -a typical indication.
Pictures from the inside shows cracks where the innerlining/hollow transoms-frames begins, indication movements in the unstiffended laminate.

The discussion that the boat has hit a rock in high speed is based on the mast damage and to some extent the hull damage. No (I may have overlooked this) picture of the actual keel or any mentioning of keel damages -that would very easy verify a collison or not.
I can hardly understand how the mast could move a meter forward due to a collsion as stated on the Bavaria homepage, with the rigging intact.

Of course, a collision gives tremendous loads (push downwards from the mast), that is one reason for transoms.

Based on the damage on the lost boat, it hardly looks like the keel has been ripped off backwards.

A collision in 6 knots should not be enough to rip of a keel.

All in all, I feel bad about the speculations of the cause of the disaster, the neglect to report in english and that many other Bavaria's have the same indication of unhealthy movements in the hull. But with a whole wharf at stake, blackening is a way to keep the sale and 2nd hand value up.

Who believes a GRP laminate of 13 mm can hold the load from some 10 bolts with small surface for distributing the load and the keel is some 2 metre down, weighing some 2 tonnes?

 

[JamesUk]

>> Well, to bolt a keel in the hull laminate with small or no sheets of metal to distribute the load seems a
>> design error of the type "don't understand what I'm doing".

I think it is more a case of Bavaria thinking, "it works for the 1000's of cruisers we build each year so why do anything different".

>> The comment on Bavarias site: "...the actual thickness of the laminate (13,25mm) is larger
>> than required thickness (7,93mm)" makes me pale

Hopefully this case will go to Court and the prosecution will respond and ask J & J, "please name one series production yacht of similar dimensions where a deep performance keel is hung off an 8mm or 13mm thickness hull skin on 3 small backing plates or disc washers.

>> The upgrade, 9 layers of GRP to a 30mm thickness won't help the
>> design error and if not properly made it will de laminate.

I don't understand this comment. If the hull is reinforced to twice the thickness this will reduce the local bending of the hull at the keel attachment points. If the extra 1cm of laminate is bonded right up the sides of the frames then the bonding of the hull skin to frames will be massively strengthened compared to the token GRP tabbing evident in the photos. If the width of the backing plates is trebled as per the J & J specified mod then sideways leverage force is reduced.

Those new larger backing plates have become a 3D structure in their own right with the extra ribs welded on. These plates should have rounded corners to eliminate the cutting edge problem identified in the Zucker survey.

Finally if the job is done with epoxy laminate rather than polyester I think the result should be a good long-term structural fix.

I don’t understand why you think the modification will delaminate, but I would be interested to hear your view on this, because I am thinking of personally funding a similar mod on my own Match 35 even though Bavaria are claiming some design differences mean the Match 35 is exempt form the whole problem.

 

[Tvermoes]

Hull upgrade

Well ,
Yes, thickening the hull will increase the stength. I missed that they do not stipulate epoxi to be used, since polyester will not bond as good -hence the delaminating comment. No boat repairer recommends other than epoxi.
Since I live in Sweden where we have hard winters I've seen much of frost lift damage due to humidity/water. Even if the polyester repair will work, it is a matter of time (5 or 15 years) before the humidity might creep in (polyester is not watertight).

I can tell a lot about damages in sandwich decks due to water leakng in.


It is correct that laminating the reinforcement to the existing frames will increase the strength, although this relies on the frames to have been correctly made (laminated to the hull) and of enough strength to distribute the load.

The larger backing plates, I don't knw the area, will of course distribute the load better (note that I recall info on the net about some M42's has been delivered without any plates, i.e. a nut against 8 (13)mm GRP for some 2 tonnes (?) keel. Scandalous.)
Still I'd like to see the keel bolted through the frame since then the frame would distribute the load to the hull in a better way. But this may not be possible due to the design of the boat, but this is the "old fashioned" way.
One shall not forget that making a partial strengthening in a hull might/will give another distribution of the load, maybe causing a fault to occur at another too weak place. Thus your planned mod might just shist the problem to another part.

Coming back to the damage, try this link, it is from a very experinced company.
The 2nd picture shows how the bottom paint loosens if the keel moves relative to the hull, resulting in bending marks where the paint curves outwars. The pictures in the Zucker report shows this very clear -on almost every boat. The movie is nice to look on!

It would be interesting to walk with heavy steps close to the rail on a M42, where the mats is not on. This means the rigging does not "tension up" the hull. I had a 39 foter, 7feet 10" (6 feet draft) wide with a rather deep hull. This boat was designe in the happy 70's where the belief in GRP strength was high. As I walked fron the stern and stopper at the cockpit, some 30 feet, I noticed the boat swayed some time giving small wawes on the sides -and this was in totally calm harbour. I found that the keel moved.. Higher tramsoms solved the problem.
I would not be surprised if this occur on a M42 -gather some guys and march on the rail.

So what to do? Well,

 

[tamkvaitis]

hi, i have repaired several bavarias. believe me there are a lot of problems on these boats. I think it was jus the matter of time then accident likes this should of hapen. There are a lot of parts witch is designed to be simple to manufacture.all in all its sad that a sailor was involved in this accident.

 

[jginnes]

hi, i have repaired several bavarias. believe me there are a lot of problems on these boats. I think it was jus the matter of time then accident likes this should of hapen. There are a lot of parts witch is designed to be simple to manufacture.all in all its sad that a sailor was involved in this accident.

Dear tamkvaitis,

My plans ar to purchase a 50 footer... either Bavaria, Jeanneau or the like... Can you please identify what repairs you have personally made to all models of Bavaria yachts. I am particularly interested to know if you have made a repairs to any of their current models.

Thanks in advance.


Jim

 

[Lee Condell]

Bavaria repairs

Hi JIm,

Firstly, I'm biased because I sell Jeanneau here in Sydney, but it so happens that numerous Bavaria's are being rebuilt and having keel-plates fitted just adjacent to us including the cruiser range. The Match 42's are a real problem and the 38's aren't much better, though so far the 35's seem OK. If you look at the details of the Jeanneau SO49 versus the Bavaria 49 you'll find the Bavaria is 600Kgs lighter, but with the same rig dimensions, keel weight and similar deck hardware, so the saving is in the structure. To make matters worse the resins and core materials they are using are not the best. This was brought home to us last year when a 42 went aground on the way up the coast and the keel bolts simply pulled through the bottom of the boat and the keel fell off. The bolts had no backing plates and were small for a yacht of this size, and there were just small undersize washers. This combined with a clearly under spec'd laminate schedule in the keel area simply meant the bolts pulled straight through the bottom. I saw this with my own eyes, and I'm an ex boat-builder and engineer, so I've got some idea what I'm talking about.

 

[Tvermoes]

Aha!

Well, this is what I anticipated by judging from the pitcures of the Zucker survey and other. It verifies that the boats in question do not meet any design criteria higher than "for mooring only".

I suppose the roation accidne wil evetuelly hurt Bavaria very badly and 2nd hand value will rocket down - or is there any value with such a bad design?

Would be nice if you had any picture of the damaged boat.

 

[Herman]

For what I have seen, there are 3 problems on these boats:

1. Only washers or small backing plates under (small) keel bolts.
2. Laminate too thin.
3. Stringers do not adhere to skin.

What would I do to get these boats going again:

1. Rip out complete bottom structure
2. grind laminate aggressively
3. Beef up laminate with epoxy and glass, nicely tapered into existing laminate, untill at least 30mm thickness has been reached.
4. Create new stringers from high density foam, round of all corners
5. laminate over stringers, again tapering into existing laminates.
6. Drill new holes for keel bolts.
7. Coat everything with an epoxy coating, including interior of holes.
8. replace keel bolts with thicker ones, if possible.
9. Reattach keel with liberal amounts of putty.
10. Make yourself a nice epoxy putty (aerosil+epoxy) and bead sufficiently thick stainless steel counterplates in the hull.
11. Don't forget washers and nuts...

By the way, I supply materials to a lot of repair yards. Some of them say to me, when asked how business is:
"As long as Bavaria is producing boats, we are fixing them..."

and another one:

"I love the way they fix keels and produce rudders. It pays my mortgage...."

And a phrase to remember:
"If you pay peanuts, you get monkeys". This is true for labour, but also for boats...

 

[JamesUk]

Herman,

You obviously do not have a clue about the specifics of this case so you just decided to pitch in with generic Bavaria slander.

The floor grid on the Bavaria Match series is a massive structure, it almost a spaceframe around which the rest of the boat is attached. The misnamed "stringers" you refer to are plenty large enough, the problem is how to securely bond the skin to the frame.

 

[Herman]

Stringers, a space frame of whatever that is not bonded to the skin, (on which a keel is hanging), cannot be called "reinforcement". The only decent way toreinfoce such matter is to pull it out. I have seen people fiddle epoxy resin in between the tabbing, to solve these problems. However, unsanded (DCPD) resin is not a suitable base to glue anything on. You really need to sand it, and the skin needs beefing up to a greater thickness. Also the created stiff structure needs to be faired into the rest of the surface to minimise hard spots. (which could result in more problems)

The quotes are real quotes from repair yards in the Netherlands. They see a lot more Bavaria Yachts coming in, if they are used for sailing. (many of them are moored only, only a small part of the boatsmen do really sail).
However, it clearly indicated the way they think about a Bavaria product.

Bavaria shaves off every bit of cost, to produce boats which look nice and are financially attractive. They succeed in that, but I think they have reached the maximum which can be pulled out of a boat, without letting go on safety. And there is another point: PEople who buy Bavaria boats are probably looking for a cheap boat, and are not looking for state of the art technology, which an experienced sailor is looking for. Thus these boats WILL run aground, and will be mishandled from time to time.

There is so much to say, but only Bavaria can DO

 

[sharpii2]

Floored by failure

Just checked this out.

Didn't these people ever hear of floors?

According to my ABS booklet, they are supposed to span half the Beam. If I were designing it, I would have four floors crossing the length of the fin plus four more, with the same spacing, past each end.

Then I would have a Steel I-beam keelson span all twelve of these floors with a total of twenty four bolts with eight of them going throught the fin flange and sixteen of them going through just the keelson, the floors and thickened hull lanimates.

I think then I would have a structure that I just might trust to the usual hazards of the sea. Hidden bars and reefs, towering waves, and loose shipping containers.

I don't particularily like the modern bulb keels because the fins tend to be short and deep leaving them poorly supported both transversely and fore and aft. If the asociated hull dosen't fail, the fin itself could be next. What you have here are a collection of concentrated "point loads". You have all the ballast concentrated at the very bottom of the fin which, itself, acts as a huge crowbar trying to either smap the bolts or pull them through the hull. With the deeper fins, the leverage is even more horrific.

It seems to me that we are using engineering techniques that date back to the model-T (the H28 for example) where the loads were more spread out lengh wise with much longer ballast castings that were proportionately wider as well. And they were no where near as deep.

I think that a good alternative would be to take the bending loads of the fin well within the hull. This would mean that the fin would actually be rooted in a dagger board case like structure with all the floors extending to the top of the case. And a keelson would extend well past the length of the keel on either end spanning an equal number of floors on each end.

This, of course, would take up a lot of cabin space. The cabin sole would have to be much higher to cover all this, so you might lose standing head room. To that, I say tough tanoogies. In a 'performance boat' speed and safety are going to have to trump comfort. Safety may not come first in this equation, but it damn well better not come last.

Perhaps, with this type of keel, a center cockpit is called for. The zillion headsail changes and extra long footed genoas that made aft cockpits a necessity in the past (with relatively short mast head rigs) are no longer with us. They have been replaced with huge, high shouldered mainsails.

Just my $0.02

Bob

 

[jginnes]

Thank you Lee et all.

I will be attending the Boot 2006 in Dusseldorf. It will be interesting to talk to Bavaria first hand.

 

[Herman]

Pull the floors as well. See how the keel is attached. Do the same with other boats (probably less industrially made). Could be a nice comparison.

 

[JamesUk]

Stringers, a space frame of whatever that is not bonded to the skin, (on which a keel is hanging), cannot be called "reinforcement".

The floor grid of a Bavaria Match is bonded to the internal surface of the hull. The problem is the thickness amd area of the bonding, the pictures show cracks developing at the 90 degree turn from hull to the vertical face of the frames.

The J&J spec modification increases the area of the bonding by about 70% and the thickness of the bonding by 300%.

http://www.bavariayachtbau.de/typo3/typo3temp/pics/f2f45e4496.jpg

However, unsanded (DCPD) resin is not a suitable base to glue anything on. You really need to sand it, and the skin needs beefing up to a greater thickness.".

Two months ago the magazine Yachting World published a sequence of photos showing the steps of the reinforcement to a Bavaria Match. The pictures and text confirm the whole area of the bilge is cut back with an angle grinder including the inner hull surface and the side of the support frames.

Bavarias are not really sailed….

In the 2004 ARC (transatlantic) there were about 18 Beneteaus, 13 Bavarias and 10 Hallberg Rasseys. Doesn’t sailing across the Atlantic count as real sailing in your book?

http://www.worldcruising.com/arc/entry04.htm

 

[JamesUk]

Just checked this out.

Didn't these people ever hear of floors?

According to my ABS booklet, they are supposed to span half the Beam. If I were designing it, I would have four floors crossing the length of the fin plus four more, with the same spacing, past each end..

In which case I think you will be impressed by the following photo of the floor grid in my Bavaria Match 35. Four beams take the main weight of the keel and there are additional beams fore and aft of these.

http://i14.photobucket.com/albums/a340/BavariaMatch35/KeelGridWhole.jpg

I think that a good alternative would be to take the bending loads of the fin well within the hull. This would mean that the fin would actually be rooted in a dagger board case like structure with all the floors extending to the top of the case. And a keelson would extend well past the length of the keel on either end spanning an equal number of floors on each end.

This, of course, would take up a lot of cabin space. The cabin sole would have to be much higher to cover all this, so you might lose standing head room.

In my Bavaria Match 35 I have standing headroom in the aft cabin and the fore cabin but there is a small step up to the sole in the main cabin. The reason for this upwards step is the height of the beams supporting the keel.