Yacht Construction

[Sailfree]

I am advised that the Jeanneau 439 is constructed not with ribs and stringers bonded to the strengthen the hull but by a 3rd generation inner moulding.

Now personally I would not buy a boat with the Benneteau method of construction (to be fair I think many are now using this method to keep costs competitive) as after any grounding you cannot inspect for separation or delamination without drilling holes etc and repairs are difficult and sailing/racing around Poole I have experience of many boats suffering damage from groundings (most are cracks that are easily cut out and strengthened but occassional the keel also moves!).

Does anyone know what 3rd generation inner moulding is?

 

[G12]

The hull is laid up by itself in its mould and in a seperate mould another structure that looks similar to ribs + stringers is manufactured. This is then glassed into the hull to provide it's rigitity.

 

[Sailfree]

The hull is laid up by itself in its mould and in a seperate mould another structure that looks similar to ribs + stringers is manufactured. This is then glassed into the hull to provide it's rigitity.

Thanks but thats the same as Benneteau have always done - its like gluing a GRP egg crate on the inside to give it greater strength and rigidity (providing the adhesion is strong enough for the stresses imposed) so what is the "3rd generation inner moulding" or simply an case of "new brand X washes cleaner than ever before"!!

 

[30boat]

I saw a documentary on the building of a Catalina 32 and it completely put me off this type of construction.The structural moulding was very extensive and I can only imagine how hard it would be to track a leak or make a repair in the event of a collision or something.Another thing that troubled me was the bulkhead attachment to the hull .They were simply slid into grooves on the moulding .I don't know how Jeannau does it these days but IMO the whole concept is faulty.
I'm sure everything works as intended but if something goes wrong and a repair is needed it'll be a nightmare.

 

[Seajet]

30boat,

spot on ! I had a Carter 30 with an extensive inner moulding - strangely enough the floor / bilges were accessible, but the rest of the boat was a nightmare - no way of checking the size - or even presence - of backing pads, or putting on new deck / cockpit / rudder fittings without grp surgery !

I'd love to see what this '3rd generation' is about, but I have a strong suspicion it will be an inner moulding with a stripe, and a graphic saying "3rd Generation Turbo i "...

 

[G12]

Fancy betting a Guinness on it?

 

[Seajet]

So what are you saying, that an applied bunch of stringers & webs is new and the 3rd Gen ? This has got to have been done before, it's just that usually people take the opportunity to fit other stuff as well ( often in the way, as mentioned ).

 

[G12]

Yep - maybe they've advanced the technology of the layup a little and then given it a fancy name to market it.

 

[Seajet]

So, I should've bet that pint ?!

 

[Deleted member 36384]

Yep - maybe they've advanced the technology of the layup a little and then given it a fancy name to market it.

That is quite common in industry. Its called "change control" and the fact that they are on their 3rd generation of this method shows that they have an active improvement process.

Some other examples: Fifth Generation Semi Submersible Mobile Drilling Units, 3rd Generation Dynamic Positioning Systems.

The "generation" nomenclature is not a standard but tends to be applied to a system as technology improves functionality. Its likely that each generation change is more than just a "little" as the cost of retooling or modifying a process can be quite high. Hence, its only done when the value of the change is positive.

Personally, I would not be dissuaded if the only criteria was ease of repair due to misuse of the product (grounding). If the system gives a strong, stiff, lightweight hull which is good for racing, that may be more important. Races are not won stuck on the rocks.

Why dont you ask Jeanneau? They may be very willing to tell you how their 3rd generation mouldings are superior.

 

[LeonF]

<Personally, I would not be dissuaded if the only criteria was ease of repair due to misuse of the product (grounding). If the system gives a strong, stiff, lightweight hull which is good for racing, that may be more important. Races are not won stuck on the rocks.>


I remember chatting to a chap who raced Sigma 33s but sold Jeanneaus when I owned a Sigma 33. He said two Sigmas collide when racing, usully not much harm done, a gentle knock with a Jeanneau and the internal mouldings break.

 

[Coaster]

...a gentle knock with a Jeanneau and the internal mouldings break.

I know litttle about Jeanneaus but that claim seems ridiculous.

Or did you mean that if a Jeanneau gently knocks a Sigma then the internal fitting in the Sigma get broken? That seems equally unlikely.

 

[Deleted member 36384]

.... collide when racing ....

Leon that's limiting thinking. You dont win races by colliding. I tend to plan for success by avoiding situations which will cause me to retire.

More is to be gained on the course by consistent sailing than by risk taking, that's for sure.

On the three boats that I have been intimate with, all had normal construction and all had to have their interiors dismantled to repair cracked stringers.

 

[LeonF]

I'm only recounting what was said to me, and I can't see why someone selling a product would want to invent a tale.... maybe it takes more than a gentle knock. The surveyor who looked over my Sigma 33 said they were strong boats...simple construction, but strong. I think the use of simple was intended as a recommendation.

Well I don't race seriously, and yes I agree the whole point is not to collide, but on board a 26ft Verl and doing some serious racing.. the Nore race on the Thames..I can see how all that close quarters sailing around the cans with spinnakers can lead to collisions.

Victoria/Frances, supposedly quality build, are not without their problems, especially the later ones when it was costing more to build them than they could sell them for, as I found when looking to buy one. However I had a heavy grounding on the Barrow sands some years ago and the yard were amazed at the lack of damage. Ditto an association boat that was dropped from slings and bounced off the pontoon..totally unscathed.

 

[Resolution]

I remember chatting to a chap who raced Sigma 33s but sold Jeanneaus when I owned a Sigma 33. He said two Sigmas collide when racing, usully not much harm done, a gentle knock with a Jeanneau and the internal mouldings break.

Leon
I used to race a Sigma 33 and also sold Jeanneaus (some years ago), so it may have been me that you were chatting with. Don't remember the conversation, but I am sure that I would not have said a gentle knock would break internal mouldings, mostly because there were no "internal mouldings" as such, just glassed in stringers. Unlike the Beneteaus which did use bonded internal mouldings.
Of course the 1980 Sigma 33 was built with thicker and heavier fibreglass than the 2000 Jeanneau. The science of fibreglass production had moved on a fair bit. So if you were to have a collision between the two, the Sigma would probably win! But the lighter Jeanneaus sailed so much faster and were better in so many other ways that I soon sold the Sigma and moved on.

 

[Sailfree]

Why dont you ask Jeanneau? They may be very willing to tell you how their 3rd generation mouldings are superior.

I have e mailed them but no answer yet.

I have a charter boat and the reality is that at various times it will go aground so robustness of construction, ease of inspection for possible damage and ease of repair are essential features for any replacement boat.


Its a major promotion point on the Finngulf as the boat is designed for the baltic with the attitude that at some time the keel WILL hit a rock.

Like most people I am searching for the best at the cheapest price and the "economy" production boats now all seem to follow Benneteau to produce a cost effective production boat.

 

[Phideaux]

I've just read a survey report on a Dufour 39 where the inner hull moulding requires repair and reinforcement as it has been damaged - probably by the hull striking a floating or submerged object.

My understanding from some of the design books, is that the outer hull flexes but the inner moulding doesn't and this can led to fractures and stress cracks where the inner moulding is bonded to the hull.

 

[Quandary]

I have e mailed them but no answer yet.

I have a charter boat and the reality is that at various times it will go aground so robustness of construction, ease of inspection for possible damage and ease of repair are essential features for any replacement boat.


Its a major promotion point on the Finngulf as the boat is designed for the baltic with the attitude that at some time the keel WILL hit a rock.

Like most people I am searching for the best at the cheapest price and the "economy" production boats now all seem to follow Benneteau to produce a cost effective production boat.

I have owned 2 Sigmas 33 & 38 and now have a Finngulf. I know that Finngulf make a big brochure claim about their impact resistance and also about how every boat they ever made is still afloat but this is just about competing in their perceived market, they are a small company who for years did not even bother with the UK, the boats may be strong but only by todays standards and I have been careful so far never to hit the bottom as hard and fast in the Finngulf as we tended to do to cheat the tide when racing the Sigma 33. Finngulf compete in world markets with X yachts and they like to imply that you can hear the Xs steel internal frame jangling inside them after an impact, it is a bit of marketing banter designed to wind up their rival. I believe from examination of the hull and keel attachment arrangements that a Sigma 33 would survive impacts better, not only because the Finngulf is likely to be going much faster but mainly because the spread of keel bolts on the cruder flanged iron keel casting of the Sigma is better than the modern deeper finer bulbed aerodynamic form of the lead on the Finngulf. However I intend to try to avoid carrying out any serious competitive testing. It is not too difficult to make impressive dents in lead and perhaps that has a minor impact absorbing effect.
The two Sigmas I had were very different structurally the 33 had a simple hull form and moulded stringers and floors with a thick bottom while the 38, a design from ten years later had a massive cellular floor moulding which included the mast step and keel bracing, about a foot deep, probably because of the need to resist the massive hull bending forces of a big fractional rig but also because on a bigger boat there was room for it.

 

[Sailfree]

Thanks Quandary but I am at the point of deciding that there is nothing better in the production line than my existing Jeanneau 43 with things called ribs etc other than far more expensive boats that are probably no stronger.

Can't consider a Sigma as no one goes to Hetz to rent a car and asks for a 20yr old Cortina!

 

[LeonF]

Innesker, the conversation with whoever it was was around 10 years ago so I may not have remembered it exactly, but I do remember the person saying that the inside bits broke easily after a collision. When sailing my Vic back from Chichester, I entered Sovereign Harbour in Eastbourne alongside a Beneteau...I think an Occeanis. He later told me he'd been offered a great deal on a brand new boat, so had bought it but was disappointed to find things breaking already . Now if I was trading up and couldn't run to a Vic 34 I'd definitely look at a Sigma 362.