Bruce Farr Design ruins Beneteau First reputation

[rotrax]

Well, a most worthwhile debate.

It now seems clear that the complex matrix systems can be repaired by skilled operators in well equiped facilities with complex and detailed instructions from the builder/designer and using modern materials and special adhesives If the glider/ aircraft comparisons are correct.

Going to cause problems for long distance voyagers when far from these expert facilities and the insurance of these types of craft has not yet been mentioned.

Repairs and surveys of this type of construction are likely to be costly-will premiums rise?

 

[JumbleDuck]

Here's an example for JD - I had a glider (Astir) on which the original hollow mainspar end pins that plugged into the opposite wing root ribs had to be replaced with solid ones (as a result of stupid overspecified fatigue testing by the RAF on behalf of the ATC). This meant cutting off the end of the mainspar of each wing - horror! probably the most critical highly stressed bit of the whole aircraft - and rebuilding it round a wooden block holding the steel pin. The rebuild scheme was very precisely specified by the manufacturer and involved a long scarf and a build up of multiple layers of glass cloth in very specific positions and orientations, only permitted to be done by repairers who underwent specific training on it.

A perfect example. I used to fly the club Astir at Sutton Bank from time to time, by the way.

 

[Daydream believer]

Well, a most worthwhile debate.

It now seems clear that the complex matrix systems can be repaired by skilled operators in well equiped facilities with complex and detailed instructions from the builder/designer and using modern materials and special adhesives If the glider/ aircraft comparisons are correct.

Going to cause problems for long distance voyagers when far from these expert facilities and the insurance of these types of craft has not yet been mentioned.

Repairs and surveys of this type of construction are likely to be costly-will premiums rise?

But does that that mean it is OK to "botch" the repair (albeit to various levels of botch) because access to a "reputable or acceptable" repairer is not available

 

[Talulah]

Repairs and surveys of this type of construction are likely to be costly-will premiums rise?

In order for an insurer to remain competitive you could get insurers declining to insure this type of construction over a certain age.
If that was the case second hand values would fall off a cliff.

 

[awol]

So if I understand it correctly, the consensus forum opinion for repair the hull of this type of boat is :-

a) remove the keel
b) remove the deck
c) remove all internal bulkheads and furniture
d) split the matrix from the hull despite the bond being stronger than the materials
e) then put it all back together.

and it will then be as good (or as fragile) as it was before.

As for the "fall offs" - you forgot the bow - S&S 40 in Pacific.

 

[lw395]

So if I understand it correctly, the consensus forum opinion for repair the hull of this type of boat is :-

a) remove the keel
b) remove the deck
c) remove all internal bulkheads and furniture
d) split the matrix from the hull despite the bond being stronger than the materials
e) then put it all back together.

and it will then be as good (or as fragile) as it was before.

As for the "fall offs" - you forgot the bow - S&S 40 in Pacific.

I don't think you'd need to remove the deck or bulkheads.
I would think it is possible to analyse what parts are going to be damaged by grounding.
If it was a bike or a landrover, you'd just put a new chassis in....

Perhaps what is needed is a 'crumple zone', i.e. accept racing boats will ground, and design them to fail in a controlled and repairable way?

It's not for nothing that my racing dinghy has a lifting centreboard and rudder....

But at the end of the day, we need to accept that the ocean is a wild place and there will always be an element of risk going there in a small vessel.
You can give people safer and safer kit, they may just push their luck to compensate?

 

[pmagowan]

There was a link on here once (?Viv cox) to a keelbolt that had a marker that showed if it had lost its torsion. It may be possible to add various things into the design of a boat, when it has modern agressive keel designs, to show up if any significant force has occured during a grounding. After all, the force is likely to be compression towards the stern of the keel and tension towards the bow.

 

[JumbleDuck]

So if I understand it correctly, the consensus forum opinion for repair the hull of this type of boat is :-

a) remove the keel
b) remove the deck
c) remove all internal bulkheads and furniture
d) split the matrix from the hull despite the bond being stronger than the materials
e) then put it all back together.

Yes, perhaps, but only if the matrix-hull bond has been damaged, in which case it will no longer be stronger than the originals. Highly stressed composite structures are lifed everywhere else they are used - why should yachts be different? That rustling noise is many heads (not yours) being buried in sand.

 

[rotrax]

But does that that mean it is OK to "botch" the repair (albeit to various levels of botch) because access to a "reputable or acceptable" repairer is not available

Of course not.

 

[Daydream believer]

So how does the metal frame that is used by some boats to spread the loads from rig to keel etc work
I cannot see the metal being " bonded " to the hull if only due to differential movement of material
If a boat with such a structure has damage presumably one just welds a new bit in- or is that not on

Then what about boats that have a female " socket" cast in the hull so that a keel with a male stub fits inside it
Must be stiffer for keel retention& bolts mounted sideways as well as vertically must make the incidence of keels dropping off much less likely. Although total socket failure would resuly in rapid sinking.
( lets ignore the keel that fell off because the male bit was welded to the rest of the keel & the weld failed)

Failure can also occur elsewhere . When in Ijmuiden I spotted a Salona 45 that was shrouded in sheets to hide the fact that the lead bulb had been hit so hard that it was hanging off the cast keel with a 50mm gap between the 2

 

[30boat]

So how does the metal frame that is used by some boats to spread the loads from rig to keel etc work
I cannot see the metal being " bonded " to the hull if only due to differential movement of material
If a boat with such a structure has damage presumably one just welds a new bit in- or is that not on

Then what about boats that have a female " socket" cast in the hull so that a keel with a male stub fits inside it
Must be stiffer for keel retention& bolts mounted sideways as well as vertically must make the incidence of keels dropping off much less likely. Although total socket failure would resuly in rapid sinking.
( lets ignore the keel that fell off because the male bit was welded to the rest of the keel & the weld failed)

Failure can also occur elsewhere . When in Ijmuiden I spotted a Salona 45 that was shrouded in sheets to hide the fact that the lead bulb had been hit so hard that it was hanging off the cast keel with a 50mm gap between the 2

If you hit things hard enough they will break.So to an extent no boat is completely safe but what I find objectionalble is that the safety (or endurance) margin is so low on these lined hull boats.More traditonal,read less economic to build,boats have visible and accessible structures than can be inspected and repaired without great difficulty as opposed to the highly technically demanding nature of the repairs on this more trendy,read cost effective, type of construction. So ,to me, they are not acceptable unless in highly tuned racing machines where high maintenance costs are to be expected.

 

[rotrax]

I have been criticised on here for my very conservative choice of boat.

The designer, Bob Johnson, was for many years a designer of guided missiles and other high tech areospace stuff.

The boats he designs and builds are extremly strong, durable and can be repaired anywhere with low tech methods.

They do cost a bit though.........................

 

[lw395]

I have been criticised on here for my very conservative choice of boat.

The designer, Bob Johnson, was for many years a designer of guided missiles and other high tech areospace stuff.

The boats he designs and builds are extremly strong, durable and can be repaired anywhere with low tech methods.

They do cost a bit though.........................

I don't criticise you for your choice of boat.
Perhaps one can go too far in suggesting others are wrong in their choice?

A look at the other thread about a boat lost shows lower tech, lower performance boats are not immune from the ocean either.
At least nobody died in that case, but was that simply because they knew to get off in time?

 

[rotrax]

I don't criticise you for your choice of boat.
Perhaps one can go too far in suggesting others are wrong in their choice?

A look at the other thread about a boat lost shows lower tech, lower performance boats are not immune from the ocean either.
At least nobody died in that case, but was that simply because they knew to get off in time?

Again you choose to misinterpret the point, which was that the designer has aerospace experience for leading edge companies using leading edge materials and design but chooses to be very conservative in the boats he designs and builds.

IP have recently gone into agreement to build Blue Jacket yachts of more contempary design and have recently announced another agreement to build Seaward yachts at their Largo factory.

They dont just build slugs!

Any critisism I made was intended towards the potential for serious structural failure with some designs. In those designs it appears crucial not to apply loads to the hull/keel joint that the designer took no account of on the drawing board.

Unfortunatly we dont live in a perfect world and $H1t happens.

 

[lw395]

Again you choose to misinterpret the point, which was that the designer has aerospace experience for leading edge companies using leading edge materials and design but chooses to be very conservative in the boats he designs and builds.

IP have recently gone into agreement to build Blue Jacket yachts of more contempary design and have recently announced another agreement to build Seaward yachts at their Largo factory.

They dont just build slugs!

....

A quick look at the Blue Jacket 40 shows it is a deep bulb keel.
With a pretty short chord.
Exactly the kind of thing that will put a lot of stress on the hull-keel join.
However well it's designed, give it 5, 10, 15 years of charter life and boatyard repair, will it be any better than the bendy toy?

 

[grumpy_o_g]

And that is where I think you may be overoptimistic (stress on the word "may"). There may (stress repeated) be some composite structures for which a good repair simply is not possible, or economically possible. As a parallel, if rot gets into the join between the main chassis rails and the cross members at the back of a Citroën DS, you are Stuffed with a capital S. Although it's just a matter of welding, the sections are so complicated and so much metal has to be cut away to get to the problem area that scrapping is the only sensible option.

Perhaps the only satisfactory cure for a delaminated grid on 40.7 is to strip out the entire interior, cut out the grid and rebond from scratch. Certainly possible ... but would anyone pay for that? For all the assurances we have about the specification and implementation of the previous repair to Cheeki Rafiki, four men died when - apparently - it failed again.

I hope this doesn't sound argumentative - it's not meant that way, and I completely agree that in many cases composites can be repaired very well indeed.

I agree completely - I think the key focus needed is not on the repair but on the NDT and the reporting. Even gliders have basic accelerometers and heavy landings, etc. are almost always reported. Testing includes penetrative dye, ultrasound, x-ray, etc. and the maintenance regime is not just thorough but carefully designed, structured and logged. Daily Inspections, 25 hours, etc. and only carried by trained folk (albeit the training may be light).

That isn't the case in a marine leisure environment at all.

 

[lpdsn]

So how does the metal frame that is used by some boats to spread the loads from rig to keel etc work
I cannot see the metal being " bonded " to the hull if only due to differential movement of material

I've a van de Stadt designed Dehler (apparently it was Cees van Tongeren who did the design).

It has a steel frame. There's a glassed in steel plate as part of it that the keel bolts pass through. There are then two steel frames which extend up to two chain plates at deck level on either side. These are covered by substantial fibre glass frames. There are also other fibre glass frames of the same size, spaced about something like two foot apart fore and aft of these. There is an inner moulding but it is raised well clear of the hull in the region of the keel bolts.

The steel is only exposed behind the seat backs and wood panelling - and some dismantling is required to get to it.

Dehler had become quite practised with steel frames by then. I think some of their earlier work on racers was less successful.

 

[rotrax]

A quick look at the Blue Jacket 40 shows it is a deep bulb keel.
With a pretty short chord.
Exactly the kind of thing that will put a lot of stress on the hull-keel join.
However well it's designed, give it 5, 10, 15 years of charter life and boatyard repair, will it be any better than the bendy toy?

I expect it will be substantialy better.

Both designers-its a joint project led by Tim Jackett-have taken on board the things that affect quality. Tim Jackett states his design takes into account IP's prefered way of building boats. I suspect they will be pretty strong. Take a longer look. The Yanks often do things differently with sail boats. So far the BJ 40 has had goodish reviews.

But, as you quite rightly suggest, time will tell.

 

[Sailfree]

In order for an insurer to remain competitive you could get insurers declining to insure this type of construction over a certain age.
If that was the case second hand values would fall off a cliff.

Amazing we have one example of a heavily used possibly poorly repaired boat being lost and the forum concluded that premiums for fin keel boats will rise and resale values fall.

Insurers know where their claims are and price premiums accordingly - just like cars- and I don't see this one off CR incident affecting the market. It is though pandering to some sailors prejudices regarding types of yacht construction.

Keep things in perspective please!

 

[Malo37]

Lots of sensitive noses out of joint in this thread and similar threads on the quality of modern boat construction. In general you get what you pay for.