Keel Failure in the Canaries

[FranklinGray]

I know Hunters have a bad rep but I gotta say, I love the keel on this boat (H376). It has a 2' deep keel stub which absorbs impacts (I have ran aground several times which a couple being pretty hard). The lead is bolted on with 7 1" thick bolts in a wide pattern with good size backing plates. The stub is made of 1.5" thick glass. I am very confident in my keel but yes, I would like to drop it next year if possible and check the bolts. I know Hunter mounted it with an epoxy filler mix which should keep the water off them even if the water breaches the keel to stub seal.

[daletournier]

Originally Posted by FranklinGray

I know Hunters have a bad rep but I gotta say, I love the keel on this boat (H376). It has a 2' deep keel stub which absorbs impacts (I have ran aground several times which a couple being pretty hard). The lead is bolted on with 7 1" thick bolts in a wide pattern with good size backing plates. The stub is made of 1.5" thick glass. I am very confident in my keel but yes, I would like to drop it next year if possible and check the bolts. I know Hunter mounted it with an epoxy filler mix which should keep the water off them even if the water breaches the keel to stub seal.

Hunter have made many models, some weren't that great but unfortunately the rap that a few got as been applied to all Hunters, which is unfair.

The 49 for instance is a great boat. Lead keel, bolted hull deck joint, kelvlar layer in hull back to the keel (if I remember correctly) etc

I remember reading about testing, deliberately running in a ground, lifting it with a crane via its rig and shaking it in their tank etc.

The below isn't the 49 and isn't a hard grounding but without spending more time searching it gives am idea.

https://youtu.be/im52WJQ8E_U

[Polux]

There are news about this. A proper investigation has been launched by the MAIB, the same British body that investigated Cheeki RafiKi.

I have tried to know what happen but it seems that the brand Comar, that is no more doing boats (already before the accident) had not made any serious investigation about the accident besides talking with the boat designer that said that it could only happen after a grounding that had caused delamination.

The hull was recovered and I had seen some bad photos. It does not seem to be breached as on the case of Oyster or the Bavaria Match 42.

Only by chance we will know what happen (I hope) since the boat is only being investigated because it was British and because it was used as a charter boat and that means as a transport vessel (that is why the MAIB is investigating).

We need all these accidents properly investigated and that means we need somebody with a jurisdiction over the matter worldwide, charter boat or not, that makes those investigations mandatory otherwise there is no way of getting from those accidents the information needed to better the boats and adjust RCD demands to the problem.

Some weeks ago I made a post about that on my blog.

[arsenelupiga]

Originally Posted by Polux

There are news about this. A proper investigation has been launched by the MAIB, the same British body that investigated Cheeki RafiKi.

I have tried to know what happen but it seems that the brand Comar, that is no more doing boats (already before the accident) had not made any serious investigation about the accident besides talking with the boat designer that said that it could only happen after a grounding that had caused delamination.

The hull was recovered and I had seen some bad photos. It does not seem to be breached as on the case of Oyster or the Bavaria Match 42.

Only by chance we will know what happen (I hope) since the boat is only being investigated because it was British and because it was used as a charter boat and that means as a transport vessel (that is why the MAIB is investigating).

We need all these accidents properly investigated and that means we need somebody with a jurisdiction over the matter worldwide, charter boat or not, that makes those investigations mandatory otherwise there is no way of getting from those accidents the information needed to better the boats and adjust RCD demands to the problem.

Some weeks ago I made a post about that on my blog.

why dont people that have monohulls recognize that keel is a weak point in monohull and add extra (expensive) maintenance item to yearly check keel link to the boat or something similar.

Keel and mast are joined together, directly ore indirectly in monohull and when one beating to windward there are vibrations happening that send out momentarily high loads that cause irreversible damage to keel/mast joints. Monohull architects do not know (or pretend not to) at this point how to build monohull to get rid of that problem. Again, grounding is another issue.

Is not that quite clear, just looking at physics of how monohull works? Looks like people trying to blame this or that but not look truth in the face. It is possible that this issue was simply 'forgotten' in design so one can build faster boats.

[robert sailor]

Originally Posted by arsenelupiga

why dont people that have monohulls recognize that keel is a weak point in monohull and add extra (expensive) maintenance item to yearly check keel link to the boat or something similar.

Keel and mast are joined together, directly ore indirectly in monohull and when one beating to windward there are vibrations happening that send out momentarily high loads that cause irreversible damage to keel/mast joints. Monohull architects do not know (or pretend not to) at this point how to build monohull to get rid of that problem. Again, grounding is another issue.

Is not that quite clear, just looking at physics of how monohull works? Looks like people trying to blame this or that but not look truth in the face. It is possible that this issue was simply 'forgotten' in design so one can build faster boats.

What a load of garbage..everything is joined together on a sailboat, that's the way all boats are built. Your dangerous vibrations that designers have not been able to solve...more silly garbage. How to build a good boat is very well known and has been for years.
Modern high production boats, including yours are not built up to the highest quality standards they are built down to the lowest price and you can not expect high quality and low price to go hand in hand. Modern high production boats are built to a price point, that leads and everything else follows. Designers today are challenged for sure but it's how to get the job done as cheap as possible not as good as possible.

[Polux]

Originally Posted by arsenelupiga

why dont people that have monohulls recognize that keel is a weak point in monohull and add extra (expensive) maintenance item to yearly check keel link to the boat or something similar.

Keel and mast are joined together, directly ore indirectly in monohull and when one beating to windward there are vibrations happening that send out momentarily high loads that cause irreversible damage to keel/mast joints. Monohull architects do not know (or pretend not to) at this point how to build monohull to get rid of that problem. Again, grounding is another issue.

Is not that quite clear, just looking at physics of how monohull works? Looks like people trying to blame this or that but not look truth in the face. It is possible that this issue was simply 'forgotten' in design so one can build faster boats.

I agree on keel inspections even if the one you mention, every year is not expensive at all since it can be made by the owner and it is a visual one.

Each 5 years or so the keel bolts should be verified in what regards being tight, also a not expensive operation.

A bigger inspection should be made each 10 years unless the boat is used intensively on offshore racing and then it is justifiable a shorter deep inspection period.

Yes, there are cycle loads on the keel but has nothing to do with the mast that generally is not over the keel and not connected to it. It has to do with the boat passing waves.

Talking about irreversible damage in the way you are implyng does not make sense.

Yes the cycles stress the material and the fatigue of those materials in what regards number of cycling loads (millions) is not well studied. But the few number of keels lost (perceptually) even on race boats, indicates that the problem as nothing to do with the dimension you are implying.

Yes, we need more studies, more information and better designed sailboats.

I agree on that point and mostly that most sailors don't have a clue about the need of proper keel inspections, the boat brands don't mention anything about that on their boat manuals and that is simply wrong.

There is a lack of information regarding the subject (keel inspections) and industry proper procedures in what regards inspections, time schedules and protocols.

The number of keels lost after groundings and after the boats being "repaired" is a signal of that lack of information and proper procedures in what regards repairs.

[GTom]

Originally Posted by arsenelupiga

why dont people that have monohulls recognize that keel is a weak point in monohull and add extra (expensive) maintenance item to yearly check keel link to the boat or something similar.

Keel and mast are joined together, directly ore indirectly in monohull and when one beating to windward there are vibrations happening that send out momentarily high loads that cause irreversible damage to keel/mast joints. Monohull architects do not know (or pretend not to) at this point how to build monohull to get rid of that problem. Again, grounding is another issue.

Is not that quite clear, just looking at physics of how monohull works? Looks like people trying to blame this or that but not look truth in the face. It is possible that this issue was simply 'forgotten' in design so one can build faster boats.

LoL, quote how many keels were lost in the past 2 decades and try to count how many are sailing the oceans?

Grounding? What grounding?


That "hilariously complex yearly check" is basically looking at a few screws if they're rusty/any rust patch coming out on the side of the keel.

Btw forgot about encapsulated lead keels

Anyway, enjoy your maintenance-free, low running cost cat.

[Polux]

Originally Posted by robert sailor

...
Modern high production boats, including yours are not built up to the highest quality standards they are built down to the lowest price and you can not expect high quality and low price to go hand in hand. Modern high production boats are built to a price point, that leads and everything else follows. Designers today are challenged for sure but it's how to get the job done as cheap as possible not as good as possible.

As cheap as possible but to a minimum given and mandatory quality standard (RCD) that includes keel structure and design. Those standards have been raised not much time ago in what regards keel requirements and for instance the keel of Cheeki RafiKi (First 40.7) would have to be slightly modified to pass what is mandatory today.

By no means I want to say that the Fist 40.7 that sail out there (700?) are dangerous boats, if well maintained. Only two lost the keels and after groundings and improper repairs. Many race high profile races without problems.

More information regarding accidents and the causes is needed to adapt the RCD demands to even better safety standards but in my opinion that is only the tip of the iceberg.

The real problem is that very few make an adequate keel maintenance and I mean a preventive one. Most only do maintenance when the keel is starting to show problems.

There are even funny words for that, the Hunter and Catalina keel smiles (google for it). That is not acceptable except if the boat is only sailed coastally and inspected frequently. On the middle of the ocean on a storm, it can pass from a smile to a loss in a matter of days.

[Pete7]

Originally Posted by GTom

LoL, quote how many keels were lost in the past 2 decades and try to count how many are sailing the oceans?.

Quite, we dry out several times a year on our keels. Carrying a spare keel in case one falls off is a sensible solution for us.

Pete

[cyan]

Originally Posted by GTom

LoL, quote how many keels were lost in the past 2 decades and try to count how many are sailing the oceans?

There were 72 keels lost on sailboats since 1984 (and 24 fatalities) according to the ISAF Keel Structure Working Party, with many more "near misses" documented.

If statistically TWO of us monohull folks will lose our keels this year with an even chance of death, then I think it makes sense to learn more about maintenance and inspection. To be honest, I never really thought much about those bolts before, until reading the lively discussion in this forum... so thanks. I'm not alarmed. Just more aware now.

Keel failure: the shocking facts - Yachting World

[robert sailor]

Originally Posted by Polux

As cheap as possible but to a minimum given and mandatory quality standard (RCD) that includes keel structure and design. Those standards have been raised not much time ago in what regards keel requirements and for instance the keel of Cheeki RafiKi (First 40.7) would have to be slightly modified to pass what is mandatory today.

By no means I want to say that the Fist 40.7 that sail out there (700?) are dangerous boats, if well maintained. Only two lost the keels and after groundings and improper repairs. Many race high profile races without problems.

More information regarding accidents and the causes is needed to adapt the RCD demands to even better safety standards but in my opinion that is only the tip of the iceberg.

The real problem is that very few make an adequate keel maintenance and I mean a preventive one. Most only do maintenance when the keel is starting to show problems.

There are even funny words for that, the Hunter and Catalina keel smiles (google for it). That is not acceptable except if the boat is only sailed coastally and inspected frequently. On the middle of the ocean on a storm, it can pass from a smile to a loss in a matter of days.

I hear what your saying but many of these "standards" are heavily influenced by the boat manufacturers along with their designers. They try to appear like a 3rd party but they are really not.
If the manufacturers wanted to build keels that would survive normal grounding and not fall off later they could very easily do it. They don't need any studies or New information to achieve this. There are no mysterious vibrations that they are not aware of, that's is ballyhoo. What isn't ballyhoo is that to build boats this way costs more money, there is no way around it and they do not want to spend the money as it will hurt their sales.
Certain better built boats have never had keel failures and this is no accident.
Even something as simple as using lead for the keel will reduce the chances of structural failures but because of the cost factor it is never used in the European high production boat builders.
I do agree that as boats get older they do need proper inspections on the keel bolts and the sealant around the keel, no different than inspecting and replacing chain plates in older boats.

PS what you didn't mention on the Beneteau 40.7 was that when the British examined that design they also inspected a half dozen or so other Beneteau 40.7's and found that in most cases the boats showed evidence of separation between the liners and grids where the keel was attached. They also said that they did not need an accidental grounding to suffer structural failure that simply sailing to weather in larger waves could cause a slow degrading of the structural members holding the keel. I'm sure it was this fact and not the loss of the keel that prompted the manufacturers to change the specifications for keel structures. What it really showed was just how tight the "engineering " was/is on some boats. They also built boats with substandard supports for bulkheads in some of their models that resulted in steering failure and ruptured hulls that caused the boats to sink...more signs of modern engineering.

[GTom]

@Cyan: Absolutely right, you have to know what's happening under your boats belly. OTOH, an outright statement that monos are dangerous, and require expensive surveys, buy cats is just as foolish, as saying don't buy cats because they capsize and they attract lightnings with 2x as often as monos.

[Polux]

Originally Posted by cyan

There were 72 keels lost on sailboats since 1984 (and 24 fatalities) according to the ISAF Keel Structure Working Party, with many more "near misses" documented.

If statistically TWO of us monohull folks will lose our keels this year with an even chance of death, then I think it makes sense to learn more about maintenance and inspection. To be honest, I never really thought much about those bolts before, until reading the lively discussion in this forum... so thanks. I'm not alarmed. Just more aware now.

Keel failure: the shocking facts - Yachting World

I saw that list and it gives a misleading idea: almost all are from racing boats.

Even so I am not saying that there is not a problem, quite the contrary and I am quite sure that we had not heard of some cases. For instance listen why X yachts use a steel or carbon structure:

https://www.youtube.com/watch?v=Qw9Vr5Ny4X8

[Polux]

Originally Posted by robert sailor

I hear what your saying but many of these "standards" are heavily influenced by the boat manufacturers along with their designers. They try to appear like a 3rd party but they are really not.
If the manufacturers wanted to build keels that would survive normal grounding and not fall off later they could very easily do it. They don't need any studies or New information to achieve this. There are no mysterious vibrations that they are not aware of, that's is ballyhoo. What isn't ballyhoo is that to build boats this way costs more money, there is no way around it and they do not want to spend the money as it will hurt their sales.
Certain better built boats have never had keel failures and this is no accident.
Even something as simple as using lead for the keel will reduce the chances of structural failures but because of the cost factor it is never used in the European high production boat builders.
I do agree that as boats get older they do need proper inspections on the keel bolts and the sealant around the keel, no different than inspecting and replacing chain plates in older boats.

PS what you didn't mention on the Beneteau 40.7 was that when the British examined that design they also inspected a half dozen or so other Beneteau 40.7's and found that in most cases the boats showed evidence of separation between the liners and grids where the keel was attached. They also said that they did not need an accidental grounding to suffer structural failure that simply sailing to weather in larger waves could cause a slow degrading of the structural members holding the keel. I'm sure it was this fact and not the loss of the keel that prompted the manufacturers to change the specifications for keel structures. What it really showed was just how tight the "engineering " was/is on some boats. They also built boats with substandard supports for bulkheads in some of their models that resulted in steering failure and ruptured hulls that caused the boats to sink...more signs of modern engineering.

You have to be correct in what you say. That is not true that in "most cases the boats showed evidence of separation between the liners and grids where the keel was attached" they found some boats where that was the case, not "most boats" and it was only on a specific point and kind of a starting of losing the bond there and not has you give the impression, close to a catastrophic problem.

This is what says the report as factual "MAIB inspectors visited four Beneteau First 40.7 yachts that had suffered matrix detachment due to grounding, two of which had also suffered matrix detachment in the forward section, and one further Beneteau First 40.7 yacht with matrix detachment in the forward and aft sections. They also received much anecdotal evidence and a further specific example of matrix detachment."

They were asking and looking for boats grounded or with a specific problem, they did not went looking at several First 40.7, chosen randomly and found that most had that problem.

I can tell you that nobody in the industry want boats to lose the keels and yes boat manufacturers have a say on the RCD alterations (they are heard) as well as Naval Architects and Naval Engineers. Their opinion is not in any way the strongest in what regards safety measures to be implemented.

Regarding expensive brands with well built boats never to having lost a keel you are wrong, Oyster, Sweden Yacht, Maxi yachts, Van de Stadt, Comet (all except Oyster after badly repaired grounding damage. We don't know about Comet yet).

Sure there are many expensive brands that never have lost a keel but also many inexpensive brands that had never lost one too.

That does not mean that they will not happen in the future, regarding inexpensive or expensive brands. Some are better built than others regarding that but it does not have to do with money only.

The More are between the more inexpensive sailboats and are among the ones that have a beefier keel structure.

[robert sailor]

I agree with you that no manufacturer wants their boats coming apart but some go to greater lengths than others to insure it doesn't happen in normal use.
High production boat builders go to great lengths to save a buck and it shows in a variety of ways. Fortunately probably 98% of the boats built sit in a marina most of their lives and never travel very far from home base even when they are used and only in favorable weather conditions. This fact alone pretty much ensures that they can carry on telling their stories about how well they are built and how capable they are. These boat manufacturers are in a unique position as they can concentrate on what looks good at the expence of what is good. Almost everything else we buy has to be built well because they get used and abused on a daily basis, everything from our family cars, phones even our bikes are built to better standards every year. I guess this is why charter boats, even though only used for 6 months a year look so clapped out after 5 years.