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Old 01-12-2015, 07:54   #181
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Re: Oyster Problems?

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Originally Posted by Polux View Post
There is another point here that is to know if that type of keel structure with a stub is the more adequate regarding performance cruisers. I see that structure being used a lot on heavier boats but I don't see it used on performance cruisers.

That structure relies on thick laminate to maintain the integrity of the stub and a performance cruiser does not use normally thick laminate (comparatively) but a better distribution of efforts by the hull.

On that article on the Russian magazine a Spanish surveyor put the major cause of the accident on the lack of thickness of the laminate on that area.

Curiously a less adequate design can have as origin the relatively conservativness of Oyster owners: That keel structure (with a stub) looks stronger than an apparently lighter structure and less voluminous keels that are used on most performance cruisers (even big yachts). Things are not always what they look
Guys! Let's call things with the right name: Oyster 825 is a cruising boat, not a fast cruiser, and in any case if they would put 500 kg more of rexin in the bilge area and 500 kg less of lead in the bow, the boat should be strong her and faster.......is not necessary to be Eric Tabarly to understand that!
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Old 01-12-2015, 07:59   #182
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Re: Oyster Problems?

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Originally Posted by Alessiocannoni View Post
if they would put 500 kg more of rexin in the bilge area and 500 kg less of lead in the bow, the boat should be strong her and faster.......it doesn't need to be Eric Tabarly to understand that!
LOL

Yea, honestly you and the owner should have asked for a refund right then and there when you found Oyster had to trim the boat that way. That's just **** design in this day and age (unless you and/or the owner changed the fitout specs a lot on the yard after design finished). But even so, the keel should still have stayed on !

This case reminds me of the Halberg situation a couple years ago - when an owner took delivery of a new boat and the hull started falling apart and Halbery refused to give him a new boat, and the owner then got on the internet and started posting truely damning pictures of Halbergs construction failures and copies of the really unhelpful correspondences from Halberg. It seriously damaged Halbergs reputation both for construction and customer support. I believe in the end a 3rd party lab determined that Halberg had made a fundamental serious error when laying up the laminate (along with dozens of other errors just showing no care or attention to detail).
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Old 01-12-2015, 08:04   #183
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Re: Oyster Problems?

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Originally Posted by Polux View Post
There is another point here that is to know if that type of keel structure with a stub is the more adequate regarding performance cruisers. I see that structure being used a lot on heavier boats but I don't see it used on performance cruisers.

That structure relies on thick laminate to maintain the integrity of the stub and a performance cruiser does not use normally thick laminate (comparatively) but a better distribution of efforts by the hull.

On that article on the Russian magazine a Spanish surveyor put the major cause of the accident on the lack of thickness of the laminate on that area.

Curiously a less adequate design can have as origin the relatively conservativness of Oyster owners: That keel structure (with a stub) looks stronger than an apparently lighter structure and less voluminous keels that are used on most performance cruisers (even big yachts). Things are not always what they look

Stubs are widely used In the past and this days often, and they are a genuine way to end a keel to hull joint, they offer a proper keel sump, they absorb a lot of energy from a grounding, 2 points.... now 15 mm of laminate around is just silly, and looks like the bottom laminate thicknes is 15 mm to.... you get the picture?? as a example a VOR 65 canting keel dead box is several inches thick in carbon, so yes performance boats as you say they have often in some ways thicker parts of the hull or deck and still preserve light numbers in their hulls... Polina Star is a fiasco in terms of hull construction quality , why? good question but I guess they jump in a new playfield with larger boats and lightness is the main consideration , if you want light, fast and strong, use CF or a mix , but playing with several tons of lead holding from a tissue paper laminate is just sick!

And at some point I believe Alessio when he mention the in behind in the curtains glassing and reinforcing the stubs in others 825... sure a dirty patch to save the ass in the storm, but as I say previously I hope I'm wrong and Alessio to and others 825 are made diferent , this issue remind me the Rafiki accident at some point, but with a reputable boat brand....
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Old 01-12-2015, 08:24   #184
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Re: Oyster Problems?

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Originally Posted by neilpride View Post
Stubs are widely used In the past and this days often, and they are a genuine way to end a keel to hull joint, they offer a proper keel sump, they absorb a lot of energy from a grounding, 2 points.... now 15 mm of laminate around is just silly, and looks like the bottom laminate thicknes is 15 mm to.... you get the picture?? as a example a VOR 65 canting keel dead box is several inches thick in carbon, so yes performance boats as you say they have often in some ways thicker parts of the hull or deck and still preserve light numbers in their hulls... Polina Star is a fiasco in terms of hull construction quality , why? good question but I guess they jump in a new playfield with larger boats and lightness is the main consideration , if you want light, fast and strong, use CF or a mix , but playing with several tons of lead holding from a tissue paper laminate is just sick!

And at some point I believe Alessio when he mention the in behind in the curtains glassing and reinforcing the stubs in others 825... sure a dirty patch to save the ass in the storm, but as I say previously I hope I'm wrong and Alessio to and others 825 are made diferent , this issue remind me the Rafiki accident at some point, but with a reputable boat brand....



Certainly would be easy for the owner of any 825 to ascertain whether their boat is built like this or not. All they have to do is care enough to try. This case is another indicator that a full and very thorough survey should be conducted on all new hulls before accepting delivery. A really good surveyor would have detected this issue.
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Old 01-12-2015, 08:30   #185
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Re: Oyster Problems?

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Originally Posted by minaret View Post
Certainly would be easy for the owner of any 825 to ascertain whether their boat is built like this or not. All they have to do is care enough to try. This case is another indicator that a full and very thorough survey should be conducted on all new hulls before accepting delivery. A really good surveyor would have detected this issue.
So, excuse my ignorance Mina , but who is responsible in QC about the proper scantlings and resin ratio when they finish a hull? those famous 15 mm are standar in others hulls or is just a mistake accident in the mold by the operators, its a surveyor in site during construction or just a factory manager?
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Old 01-12-2015, 08:37   #186
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Re: Oyster Problems?

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I agree with all that but that does not take anything regarding what I have said. Light boats require a more careful building, better control quality, better materials and better built and that results in comparatively more expensive sailboats.

Lots of very strong performance cruisers around for many years doing extensive racing without problems, being sailed harder and doing more miles than most heavier cruisers.

Normally the brands that do that are specialized on that type of built, some coming or doing also race boats and mastering the building techniques and the needed quality control.

Sometimes brands that have been doing other type of boats and change the type of boats that are doing have problems. That happened with Bavaria and now with Oyster.

Regarding Oyster let me point out that has nothing with the boat being too light. A D/L of 121 for a boat of that size is on the high side regarding performance cruisers of that size. Lots of successful boats built with the same materials and techniques with that D/L for the size.

The problem is not being too light but being badly built or badly designed.

Let me remind you that Oyster had in the past built performance cruisers comparatively lighter than this one, the light wave line, and the boats were well built and strong. One of them is a famous one, the Red Oyster, a 48ft 28 year's old design, that has been extensively raced with an incredibly number of miles under his belly.

Right now it is making a fantastic ARC on the racing division sailing as fast as a Outremer 51 or a Pogo 50 and sailing not far from the first Oyster 825 and ahead of the 2nd one.

I guess they forgot how to build that type of boats

There is also another issue that is being making bigger and bigger yachts very fast coming for smaller boats that is what they have built for many years and that with an increasing production of boats.

Adverts like these don't inspire a lot of trust on me, from a brand that made the first boat over 80ft just some years ago:

"...we had just set a new world record. With nearly 6.3 tonnes of resin flowing in around four hours, this was the largest single continuous infusion anywhere in the world – the previous record being a bridge structure at around 6 tonnes."


That'd be "Scarlet Oyster" you're talking about I presume? Ross is an acquaintance/friend of mine. Saw him last at the TR 2015. That boat did have a rudder failure recently, but was an internal weld failure, and the hulls are generally excellent, strong design/build, and Ross sure puts it through hell. Of course the earliest Oysters were indeed race boats. Ross is a superb tactician and dedicated Ocean racer. Great bloke.

I agree about the too big too fast trajectory, and the ad.
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Old 01-12-2015, 09:40   #187
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Re: Oyster Problems?

The Russian journalist has independent advice that that dry looking laminate could also be the result of "excessive tensile loading".
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Old 01-12-2015, 09:49   #188
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Re: Oyster Problems?

Quote:
Originally Posted by minaret View Post
Certainly would be easy for the owner of any 825 to ascertain whether their boat is built like this or not. All they have to do is care enough to try. This case is another indicator that a full and very thorough survey should be conducted on all new hulls before accepting delivery. A really good surveyor would have detected this issue.
Amen to that, but can we imagine that this boat was accepted by the owner without a survey? Seems inconceivable to me. I would bet donuts to dollars that an expensive survey was done on this -- 6 million euro? -- boat. Why the surveyor missed this, I don't know, but maybe he was not tasked to evaluate the scantlings themselves.


I don't really want to perpetuate a pile-on to Oyster, a marque which I greatly respect, for among other things having produced the most beautiful and elegant cruising boats of the '90's, but I will share this incident which happened to me at the Oyster factory in the 00's.

I was trying to buy a used Oyster 485 from the Oyster factory, and after a number of failed negotiations, I finally ended up making an offer on one built in 2000, so not that old at the time, which had been owned by a famous person, the present owner of the UK America's Cup team. We finally agreed on a price, signed a contract, and I paid a rather large deposit (about $50,000 IIRC). Then I requested a date for the survey, and they insisted that I identify who the surveyor would be. I was using a well known and tough surveyor from the South Coast, expensive but with a reputation for great thoroughness. The survey was proposed to take three full days, and I was going to participate in it personally in order to see all of the nooks and crannies of the vessel with my own eyes.

Imagine my surprise when the Oyster guys said -- sorry, we don't accept that surveyor, you have to choose a different one. Here's a list of acceptable local surveyors. WTF? I thought. Local surveyors who are dependent on Oyster? Fat chance of getting a good survey out of one of them. So I insisted -- FFS, I have the right to use whatever surveyor I choose. The survey took place, and the result was pretty horrible. Despite a month of haggling, we couldn't agree on what to do with the list of serious defects, and the sale fell through. I did get my deposit back, but I lost several thousands pounds on de-winterizing, launching for sea trial, re-winterizing, lifting and blocking off, although they sold they boat immediately after me and without re-winterizing and blocking off, as I found out later.

A few weeks later, I bought my present boat, on the rebound as it were, after it passed survey with flying colors, from the same tough surveyor.

Anyway, I guess that's apropos of nothing at all, sorry for the ramble.


As Minaret said, for God's sake, appoint a good surveyor to observe the build at various points, review the designs, and inspect the boat for delivery, any time you buy a new boat. Worth its weight in gold.
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Old 01-12-2015, 10:10   #189
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Re: Oyster Problems?

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Originally Posted by neilpride View Post
So, excuse my ignorance Mina , but who is responsible in QC about the proper scantlings and resin ratio when they finish a hull? those famous 15 mm are standar in others hulls or is just a mistake accident in the mold by the operators, its a surveyor in site during construction or just a factory manager?


These would be excellent questions for any prospective buyer to ask the factory.


Scantlings are always the critical basic concern, right along with materials and design, but resin ratio's are the real dark secret in today's industry, IMHO. Right along with laminate schedules. I've seen a lot of newer boats with many "non critical" parts built with what appears to be only matt and core matt in the layup. I wouldn't buy from anyone who balks at the suggestion of lab burn tests of hull samples during construction. In fact, I'd insist they send me the cutouts from all through hull installations for independent lab testing. I'd probably want to be there when they do them in fact. But then I'm jaded from too many years of fixing poorly built boats...
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Old 01-12-2015, 10:30   #190
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Re: Oyster Problems?

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I don't agree with all this. The thick cross section of the keel stub if properly designed and built will give an enormously strong keel, far stronger than a thin keel using the same amount of material. That is a simple engineering issue. I think it is wrong to imply that a stub keel is not tied as well as a thin fin keel into the rest of the hull structure. It is usually as it should be. It looks stronger, that is true and if it isn't going to be made stronger then there is no point in it at all.
.
You are misunderstanding what I said, I did not said that on an heavy boat a stub keel cannot be stronger. I only raised doubts about the suitability of that type of design for a performance light boat.

How do you want to use the same amount of material? One is directed bolted to the hull and to a structure, that on performance boats sometimes is on carbon or steel, on the other you have a primarily structure that distributes loads by the hull and a secondary one that links that one the the keel and Ballast, The secondary one has to be massively strong as well as the links between the first and second since we are not talking about steel bolts but about composite.

A composite material (not carbon) to have the same resistance of steel has to be heavier.
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Old 01-12-2015, 10:32   #191
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Re: Oyster Problems?

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Originally Posted by neilpride View Post
Stubs are widely used In the past and this days often, and they are a genuine way to end a keel to hull joint, they offer a proper keel sump, they absorb a lot of energy from a grounding, 2 points.... now 15 mm of laminate around is just silly, and looks like the bottom laminate thicknes is 15 mm to.... you get the picture?? as a example a VOR 65 canting keel dead box is several inches thick in carbon, so yes performance boats as you say they have often in some ways thicker parts of the hull or deck and still preserve light numbers in their hulls... Polina Star is a fiasco in terms of hull construction quality , why? good question but I guess they jump in a new playfield with larger boats and lightness is the main consideration , if you want light, fast and strong, use CF or a mix , but playing with several tons of lead holding from a tissue paper laminate is just sick!
..
You are misunderstanding what i said. See above post.

I don't like to make speculations without having all the data but as I said before I believe that Spanish surveyor is right regarding the connection between the stub and the keel to be undersized in thickness.

I only said that if you want to build a light performance boat that is not the best way to have a strong and light keel/keel structure. That is probably why that system is not used on performance sailboats.
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Old 01-12-2015, 10:42   #192
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Re: Oyster Problems?

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You are misunderstanding what i said. See above post.

I don't like to make speculations without having all the data but as I said before I believe that Spanish surveyor is right regarding the connection between the stub and the keel to be undersized in thickness.

I only said that if you want to build a light boat that is not the best way to have a strong and light keel/keel structure.
Heeee?? so whats the light and strong keel structure in your opinion?
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Old 01-12-2015, 10:54   #193
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Re: Oyster Problems?

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That'd be "Scarlet Oyster" you're talking about I presume? Ross is an acquaintance/friend of mine. Saw him last at the TR 2015. That boat did have a rudder failure recently, but was an internal weld failure, and the hulls are generally excellent, strong design/build, and Ross sure puts it through hell. Of course the earliest Oysters were indeed race boats. Ross is a superb tactician and dedicated Ocean racer. Great bloke...
Yes I know, it was on the 2014 middle race and they brought the boat to port without assistance in the middle of a storm. Quite impressive as it is impressive the way they are sailing the boat now on the ARC.

Regarding the rudder on this type of light sailboats a rudder with more than 25 years, specially on a boat pushed as hard as that one, should have been replaced already or at lest remade to see if the interior of the rudder structure and the interior welds were allright, so regarding that I would not put blame on Oyster.

At that time (80's) Oyster had two lines, one of heavier cruisers and other of performance cruisers (Light wave).
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Old 01-12-2015, 11:32   #194
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Re: Oyster Problems?

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Originally Posted by Alessiocannoni View Post
Guys! Let's call things with the right name: Oyster 825 is a cruising boat, not a fast cruiser, and in any case if they would put 500 kg more of rexin in the bilge area and 500 kg less of lead in the bow, the boat should be strong her and faster.......is not necessary to be Eric Tabarly to understand that!
Except that would not have solved the boat balance problem due to the boat being enlarged. Moving the keel forward would but that would be more expensive.

Yes, not a true performance cruiser by modern standards but the truth is that the Oysters have become faster, particularly the 825, with a D/L as low as 120 in what regards Polina Star and that puts them on the border regarding true performance cruisers.

It is also true that regarding the 825, Oyster calls it a sailing "coupé", referring to the auto world, and whatever that exactly means, it refers to a more sportive sailboat. That goes with the owners of those boats. Two are sailing the ARC and one of them on the racing division, being that boat pushed really hard, going has fast as a Marten 68, a racing class 40 and faster than an Outremer 51 or a Pogo 50.
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Old 01-12-2015, 11:38   #195
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Re: Oyster Problems?

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Heeee?? so whats the light and strong keel structure in your opinion?
That is not my opinion, it is what cruiser racers use and I don't mean it is stronger than a much heavier structure. Stronger regarding the relative weight if it is a light one.

I have explained why on a previous post (the one I asked you to look at) as well as the type of structure I was referring to.
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