cheeky rafiki

Ok, thanks.

Steve.

 

And according to the chatter on SA, a very tired one at that.

Earl

 

Should really Beneteau recall yachts built 17 ago, and replaced by newer model 7 years ago ?

 

I have personally heard of two other Beneteaus being lost, all hands were safe, thank goodness, because of keel failure. One was a 40.7 the other a 59' er. Both in the Atlantic. Not at liberty to expand for legal reasons, though not personally involved. Both in the last six months.

 

My guess as to the failure mode is that the keel became slightly loose, perhaps due to compaction of the joining compound or possibly it was removed and incorrectly replaced. When loose, the keel was free to sag slightly when the boat was heeled, this placed a bending moment on the centreline bolts which were close to the edge of the keel due to the narrow width. The centreline bolts failed due to fatigue and the loading was transferred to the six double bolts. The small area of the internal backing plate resulted in high stresses on the backing plate edges which fractured the laminate from the inside until the keel tore away from the hull pulling a large flap of external laminate with it.

If this is correct, then failure is almost inevitable with this design if there is movement at the keel root and the boat is not dry-docked immediately for bolt replacement and rebedding of the keel.
17 years may seem antiquated to a race snob, but it is young compared to the majority of boats out there. Given that keel loss will result in the probable drowning of the crew, yes I do think there is a duty of care from the manufacturer to publicise the problem and come up with a solution.
I also think this has to be seen as a failure of regulation.

 

Nick, I concur with your analysis. When studying keels blue water cruisers this keel design leaves A LOT to be desired.

I think it would be a good idea to contrast & compare this keel with a much more robust design. The designers at Beneteau may appreciate it and consider the input.

Lesson learned for other Beneteau owners: Inspect keels very well before ocean crossings. I would lift the boat and do both visual & NDI inspections if possible. Structural problems on this critical component can obviously be fatal.

 

Another possibility is that the keel was always free to sag a small amount and that this resulted in fatigue of the centreline bolts leading to their failure. In this case, there would have been little warning. Possibly the centreline bolts had already failed even before the boat was caught in heavy weather and it then started to take on water as the hull fractured around the backing plates.

How do you inspect a keel for these issues? Articles on surveying focus on corrosion, fatigue is much harder to identify.

One issue is shortage of information, I was shocked at SukiSolos post that other Beteteaus have recently lost keels as well...but these did not hit the headlines. How can you assess the risk without knowing how other boats are doing?

 

Hopefully the owners of other Beneteau's will speak up & share technical info about their keel failures. One thing for sure is good bluewater hulls have longer keels that distribute loads over a much broader area of the hull. As a result, they rarely fail.

Ref: http://bluewaterboats.org/about/index/

This keel mount is much smaller in comparison to most, and the mounting approach looks to be more for a lighter racing rig than a blue water cruiser.

 

Other manufacturers also have keel issues, a Google search on Bavaria keel loss for example brings up a fair few results.
How long should the design life of an FRP boat at the lower end of the market be? Should manufacturers be forced to state their design life, should there be an explicit note that after twenty years the keel may drop off? Are these boats going to be like the discovery of fatigue in aircraft? There are lots of FRP boats around from the early sixties so there is good reason to think that these Beneteaus (etc) may be only a third or less of the way through their possible service life.
Many years ago I spent two years on a Beneteau First 456 as a paid crew for part of a circumnavagation. I thought it was a solid well built boat and their high market value even now seems to go along with that; but I have been on newer Beteteaus which are much lighter.

 

Culprit is likely a combination of bolt fatigue, corrosion & a vulnerable design. All combined you have a downward spiral that results in failure. A thicker mounting plate with larger stainless studs would have held up in a nasty storm. That keel mount is too delicate. It reminds me of some of a cheap picnic table. Pass it off a structural analyst who can apply some heavy loads and they'll surely tell you fatigue will be an issue sooner rather than later. Beneteau should really not cut corners in this area, especially on boats they market as blue water cruisers that will will no question do battle in storms. For a sailboat, the keel is absolutely critical to safety.

My 2 cents.

 

Comment taken from a yacht surveyor on another forum:
'I surveyed a sister boat a month ago for insurance purposes and while adequate for racing around the buoys on a summers afternoon, there is no way an amateur crew should have been so foolish as to try to cross the North Atlantic in such an extremely light construction toy boat.'

Lets face it, mass produced yachts these days are built down to a price.

 

In my twenties I crewed on a delivery of a Greek built yacht (Atlantic 49) from Ramsgate (UK) to Greece. The boat had been brought to Britain for the winter to see if it would sell there for better value; the unsuspecting public not being aware of the terrible build quality. The public however proved wise and the boat had to be taken back for the charter season. We left Ramsgate in late February. I wanted adventure and experience and like the huge majority of delivery crews I agreed to go without having inspected the boat...and even if I had, what would I have concluded? I didn't know enough. We were caught in a 50+ knot gale in Biscay which in hindsight we were lucky to survive. Gaps big enough to put your fingers in were opening and closing around joinery as the hull flexed in the waves and the rig wobbled all over the place. Was I foolish to go? The boat was commercially owned and operated and I found the place through a reputable crew agency. The CheekyRafiki was (I understand) also commercially operated. I imagine it had an ocean rating? If it had an ocean rating then why should the crew know better? If not, then it would seem unscrupulous to get together an amateur crew (including two in their twenties) for a risky voyage for commercial gain. According to the BBC the owner was Stormforce Coaching (http://www.stormforce.biz/) a sail training and charter business who could be expected to run a seaworthy boat.
Whichever way you look at it I don't think it is a fair criticism that the crew were foolish.

 

Were they there for the ocean miles or were they seasoned sailors who knew how to distinguish between an ocean quality yacht and a round the buoys day sailor? The surveyor seems to be implying the boat design and construction wasn't up to it and therefore by definition, the crew were foolish to undertake such a voyage. Not my words, his.

 

Why "these days" ?

Can you name a mass produced yacht (ie over 500 units built and sold) around 40 ft that is NOT built on price ?

 

Down to a price..
Might find some in http://www.cruisingworld.com/gallery/sailboats/40-best-sailboats
Anyway some of them are built up to a price..