Hull Cracked / Deck Damaged - Beneteau 311

[wetass]

Why doesn't the original poster, Raul, post an update of what he found and what he's doing about it since there's so much interest in the subject? ...unless he's under his lawyer's advice to keep quiet.
S/V Adagio

Yes, it would be really interesting to know. As I said earlier, for how these boats are meant to be used, it appears this design is just fine. I think the reason there is so much attention on this thread is BECAUSE its such a unique failure - I have never seen a sheer ripped apart like that. And while very sad for the OP, it is interesting.

The 90 degree angle the sheer makes is a bit of a stress riser and it failed where you would expect it to - if it were to fail (Which I have already admitted is a rarity). The designers used the toe-rail to spread that stress out over as much of the sheer as possible, but in this case, for some reason, it failed. Loose shrouds, tight shrouds, loose toe-rail, collision, built on a Friday ...... Who knows, but I sure would like to.

 

[Jackdaw]

Yes, it would be really interesting to know. As I said earlier, for how these boats are meant to be used, it appears this design is just fine. I think the reason there is so much attention on this thread is BECAUSE its such a unique failure - I have never seen a sheer ripped apart like that. And while very sad for the OP, it is interesting.

The 90 degree angle the sheer makes is a bit of a stress riser and it failed where you would expect it to - if it were to fail (Which I have already admitted is a rarity). The designers used the toe-rail to spread that stress out over as much of the sheer as possible, but in this case, for some reason, it failed. Loose shrouds, tight shrouds, loose toe-rail, collision, built on a Friday ...... Who knows, but I sure would like to.

Wet,

I totally agree. It would be very interesting to see how that area was supposed to be constructed... Even a small amount of extra matting and resin, and a good fillet would have really helped.

I just still cannot get over the fact that happened on a shakedown. Assuming no malfeasance, I feel bad for both the current and past owner.

 

[Caboteur]

Hull cracked / Deck damaged Beneteau 311

Hello all of you super engineering pros...
I was a little nervous about my own boat a 2009 Beneteau 31. I went to the boat to-day, checked the battery levels and tried to look at the construction method since this is a direct descendant of the 311 and 323.
There seems to be a heavy reinforcement tube glassed to the inward flange of the hull a few inches abaft of the chainplates. This arrangement seems very solid: I don't know how far lower it extends as it disappears behind the cabinetwork. I wonder if there was any reinforcement resembling this on the 311?
What looks like water damage below the stanchion bolt is simply an overlap in the fiberglass.
It has put my mind to rest for the 31... though I have a little more than 8,000NM on her and have been out, with very little sail up, in 35 gusting to 40... and all has held up very well.
Pierre

 

[Clayton]

Oh my. I never thought I'd see this again.

I was seriously interested in a late 80's Catalina 34 about 20 years ago. The boat had the exact same damage, but lower down on the hull. The owner said he didn't know the exact cause but was offering the boat at a good price so I called Catalina.

The gentleman I spoke to told me to ask if the boat was moored near a piling. It was. His logic was that to tear the hull in this way would take more stress than the boat would ever see in any amount of wind before knock-down. He said the fail point would be through the plates first unless the hull itself had been weakened and then stressed from the mast. It is no surprise that this area is nearly dead center, where extreme force would take its toll if repeatedly banging a piling or the corner of a dock if the skipper is not very good.

The irony is that he specifically warned me away from a single point of contact chain plate design like the blue boat on the first page of this discussion. He said that placing the load in one place more than doubles the shearing factor and that this is the weakest design for this type of shear.

I didn't buy the boat, but I sort of wish I had. The price was right and the fix not too bad. I ended up with a C36, which was a bit too big!

 

[Old Skool Neil]

They keep designing them lighter and lighter, roomier and roomier. Give me a good old boat with real bulkheads, chainplates bolted to those bulkheads, substantial (not necessarily heavy but not marginal either) fiberglass and a conventional rig any day.

Forget the armchair engineering, which side of the lawsuit would you like to represent?

A boat designed so marginally that it can't moor to a piling? Phooey. Bill Lapworth, William Crealock, William Atkin, Colin Archer, Herreshoff, these were the guys without computers whose designs are still often revered today. I'll even throw in Alan Gurney to prove I'm not overly biased against proven racing designs in the modern era. He designed the legendary ocean racer Windward Passage and another successful production boat with a racing pedigree, the Islander 36.

Here are two pictures of a boat I built 26 years ago, still going strong with blue water passages under her keel. Doesn't fall apart after bumping a piling, can take a lickin' and keep on tickin'.

 

[anchorclanker]

I don't disagree with anything you say here. But I don't see your point.

My point is, if shroud tension alone can open up the deck like a tuna can, well, I see that as a pretty weak design. Thats providing the boat wasnt damaged, overstressed, or altered somewhere along the way. I've seen tons of pictures of chain plates torn right out of decks, but none where the whole deck tore away from the hull. I do agree that we need to hear more of the story however.

But in any case. knees wouldn't add a ton of weight, likely no more than 50 pounds or so, certainly not 100's. Even so, I would accept the extra weight in that area as well as their impact on the aesthetics, for the added strength you would gain. Sure be a bummer to have one open up like that far from land.

 

[Clayton]

Give me a good old boat with real bulkheads, chainplates bolted to those bulkheads, ...

This was sort of my point in writing about this. The Catalina 34 IS a good old boat and I thought it was pretty well designed. And yet the hull opened like that tuna can.

If the glass is damaged to the point of weakening due to some major unexpected or repeated stress (like crashing way too hard into a piling), I don't think it makes much difference how its built; the weak point in the mix will always fail given time.

 

[Old Skool Neil]

My position is these lightly constructed boats, computer engineered to the edge without a significant margin of safety in terms of strength, will not survive the test of time. That may not be the case here but it sure looks like it to me. I don't know if the failure was caused by previous damage or whether it was an engineering or construction issue, maybe a little of both.

Either way, Mr. surveyor had better be sure his Errors and Omissions insurance premiums are current.

I wonder if the 311 in question was built in France or the US or if that even makes a difference. This whole episode reminds me of Indy car racing. Those cars are so lightly constructed that they disintegrate if they hit a grape on the track.

I dunno, sailing puts your life and that of your crew at risk. I think I'd want something substantial under my feet. Light construction for a speed advantage will never trump safety for me regardless of the boat brand.

 

[Ron20324]

Not sure of the dates made, but there was the 331, 321, 311, 323, 31, and the 30. There has been a trend to keep the boats affordable so they sell. No doubt this "shroud-to-the-toaerail" design was meant to make the boat cheaper take make/sell, and is engineered to the latest design concepts- and increase the interior volunme as demanded by the buying public, like the wider beam of the boat. In the 323 line, I have wood paneling on the cabin walls. B went to the vinyl, like many overheads have to save money. Then I noticed the duplex AC outlet went from two plugs (like at home) to just one plug. Don't know what the saving was in that change. Then B went to the 30/31 sizes to keep the boat in the 100K price range.

 

[Jackdaw]

The irony is that he specifically warned me away from a single point of contact chain plate design like the blue boat on the first page of this discussion. He said that placing the load in one place more than doubles the shearing factor and that this is the weakest design for this type of shear.

I don't understand this. This type of rigging has been used on modern sailboats for the the last 20 years, and the loads are well understood by the marine engineers that design them. Maybe the guys at Catalina didn't understand it in the 70s. Hopefully they do now.

 

[Jackdaw]

My point is, if shroud tension alone can open up the deck like a tuna can, well, I see that as a pretty weak design. Thats providing the boat wasnt damaged, overstressed, or altered somewhere along the way. I've seen tons of pictures of chain plates torn right out of decks, but none where the whole deck tore away from the hull. I do agree that we need to hear more of the story however.

But in any case. knees wouldn't add a ton of weight, likely no more than 50 pounds or so, certainly not 100's. Even so, I would accept the extra weight in that area as well as their impact on the aesthetics, for the added strength you would gain. Sure be a bummer to have one open up like that far from land.

OK, I get that, and that's cool.

Sadly we don't know WHY this one boat suffered this damage. That would be the missing piece for sure.

 

[Old Skool Neil]

This type of rigging has been used on modern sailboats for the the last 20 years, and the loads are well understood by the marine engineers that design them.

It may (I said may) turn out they don't understand the loads as well as they thought.

Maybe the guys at Catalina didn't understand it in the 70s.

Maybe they did and decided against it.

 

[Clayton]

It may (I said may) turn out they don't understand the loads as well as they thought.
Maybe they did and decided against it.

Yes, I too think Catalina is a pretty solid company with well engineered boats. I know my C36 was a brick * house. But the unexpected or freak accident can always ruin the best of plans, as was the case with that C34.

 

[anchorclanker]

I dunno, sailing puts your life and that of your crew at risk. I think I'd want something substantial under my feet. Light construction for a speed advantage will never trump safety for me regardless of the boat brand.

I assume that is what has all of our attention here. I know it has mine.

 

[Jackdaw]

It may (I said may) turn out they don't understand the loads as well as they thought.

Possible of course. But I can tell you this as fact. I have personally seen more chainplate-related total rig failures on these four (70s/80s boats) Catalina 27 & 30, Oday 26 & 28 (8 total) than I have ever seen on the entire Beneteau line (this 1).

Maybe they did and decided against it.

That's really not possible. This type of rig (chainplates on the gunwales) normally requires the boat to fly only non-overlapping headsails (jibs). That this not become common until the mid-90s.

In any case Catalina never would have done that in the 70s. Frank Butler (bless his heart, I've owned and loved two Catalina) was not a Naval Architect. All of his work at this time was basic, overbuilt, and often based on the previous smaller model. It was not until Gerry showed up that the engineering side of the house was up to snuff.

 

[Jackdaw]

I assume that is what has all of our attention here. I know it has mine.

Klanker,

I totally agree with you here. The only place we differ in in the notion that lighter, more modern designs are inherently LESS SAFE.

 

[redhead78]

I agree wf Maine, chainplates look a little light, but what looks to me like a poor design, is the distance between the 2 chainplates. It seems to me if they were spread apart say another 10 -12" it would be stronger, spread out the load. My 2 cents... and as far as engineering...remember the old quote"never be afraid to try something new, remember amateurs built the ARC, and professionals built the Titanic"...Red

 

[Stu Jackson]

Yes, I too think Catalina is a pretty solid company with well engineered boats. I know my C36 was a brick * house. But the unexpected or freak accident can always ruin the best of plans, as was the case with that C34.

C34 and C36 chainplate design is quite rugged. The C34 chainplates come through the deck and are fastened to large bolts that fasten to a portion of the fiberglass down below. The C36 forward chainplates are tied to the forward bulkhead, different than the C34.

I'm sure not too many boats will stand up to continued rubbing against any piling, although some boats undoubtedly have heavier construction than some of the coastal cruisers from the 80's. The C34 was produced from 1986 until a few years ago.

 

[DJBrookster]

It may (I said may) turn out they don't understand the loads as well as they thought.
Maybe they did and decided against it.

Lest we forget the titanic sank! Please add to the thread.

 

[Old Skool Neil]

But I can tell you this as fact. I have personally seen more chainplate-related total rig failures on these four (70s/80s boats) Catalina 27 & 30, Oday 26 & 28 (8 total) than I have ever seen on the entire Beneteau line (this 1).

If we're going to compare your anecdotal observations:

• Of the failures you quote, how many of them were supporting hull structure failures as opposed to chainplate or rig failures? In this instance the chainplates and rig are still intact, it's the supporting structure that failed.
• Of the failures you quote that were actually supporting structure failures, what were the ages of the boats? If we're comparing apples to apples, age is a factor.
• Of the failures you quote, how many of each model were produced? This figure gives us a failure rate for the design, design being in question right now. For example, there were roughly 7,000 Catalina 30's produced compared to roughly 120 Beneteau 311's. An equivalent failure rate would be 58 Catalina 30's to this one B311 and again, that's supporting structure failures.

This type of rig (chainplates on the gunwales) normally requires the boat to fly only non-overlapping headsails (jibs). That this not become common until the mid-90s.

Please refer to the pictures I provided of my previous boat. Although difficult to see in the perspective, both the jib and staysail overlapped the mast and the chainplates were bolted to the hull sides. That's a 1970's design.

Frank Butler (bless his heart, I've owned and loved two Catalina) was not a Naval Architect.

Yet he designed the most successful 30 footer in history, naval architect or not. I'd suggest using a different example.

It was not until Gerry showed up that the engineering side of the house was up to snuff.

What do you mean up to snuff? What about the Catalina history was not snuff-worthy? I'm not suggesting Gerry Douglas' work is not outstanding, it certainly is but what was in defect before he arrived?