Sans Bateau
Well-Known Member
I would suspect, based on what you are saying, that there will be a fair bit of damage to the leading edge of the keel, the evidence that the keel was given a heavy whack.
Cornish Cruising has incredibly safe boats.
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bluedragon
Well-Known Member
Official (and public) report?
Does anyone know if there will be any sort of enquiry into the circumstances of this incident? And if the findings will be made public?
There has been a huge amount of interest and speculation amongst the yachting community in the UK, some "informed" some not, and to be fair to all parties involved, including the reputation of Jeanneau yachts, there should be some definitive answers.
This incident has implications for all of us, not just those who charter. Most yachts these days have bolted-on keels, some getting on in years now. Owners may have in the past just assumed that looking for movement or water ingress around the keel bolts is sufficient after a grounding. It seemed that wasn't the case here. I also wonder to what extent repeated minor bumps over the life of a boat weaken keel attachments with no obvious signs? Was that an issue here? There's no point continuing the speculation...IMO we need to know definitively what actually happened, and if there are any lessons to be learned for the yachting community as a whole.
Does anyone know if there will be any sort of enquiry into the circumstances of this incident? And if the findings will be made public?
There has been a huge amount of interest and speculation amongst the yachting community in the UK, some "informed" some not, and to be fair to all parties involved, including the reputation of Jeanneau yachts, there should be some definitive answers.
This incident has implications for all of us, not just those who charter. Most yachts these days have bolted-on keels, some getting on in years now. Owners may have in the past just assumed that looking for movement or water ingress around the keel bolts is sufficient after a grounding. It seemed that wasn't the case here. I also wonder to what extent repeated minor bumps over the life of a boat weaken keel attachments with no obvious signs? Was that an issue here? There's no point continuing the speculation...IMO we need to know definitively what actually happened, and if there are any lessons to be learned for the yachting community as a whole.
imsodepressed
Member
Well this month's Yachting monthly has a 2 page spread, but it seems to lack technical explanations.
Especially as it now appears that, on return from the Scillies, the boat was chartered again, to some people who went to Plymouth and back, complaining of steering problems, where again, nothing was done, then came the novice's trip to the Helford and back.......!
Especially as it now appears that, on return from the Scillies, the boat was chartered again, to some people who went to Plymouth and back, complaining of steering problems, where again, nothing was done, then came the novice's trip to the Helford and back.......!
snooks
Well-Known Member
The next issue has more information, the magazine deadline was too tight to get the whole story. It gets better......
Sans Bateau
Well-Known Member
Snooks takes on marketing roll, building expectations of whats to come, hoping to boost sales and his bonus!
bluedragon
Well-Known Member
Snooks takes on marketing roll, building expectations of whats to come, hoping to boost sales and his bonus!
Well it's worked...I'll be getting the next issue
snooks
Well-Known Member
Snooks takes on marketing roll, building expectations of whats to come, hoping to boost sales and his bonus!
Just letting you know that Dick has been doing some more digging around for more information about the story. We went to press with what we had at the time, 4 weeks later and there is more to the story.
I wish I did get a bonus for coming on here and drumming up sales, but sadly I don't
Just letting you know that Dick has been doing some more digging around for more information about the story. We went to press with what we had at the time, 4 weeks later and there is more to the story.
I wish I did get a bonus for coming on here and drumming up sales, but sadly I don't
I hav'nt read the whole of this thread because it got a bit boring after the first four pages but I am pretty amazed at the way the 'boat tests' don't seem to pay much attention to below the water line.Maybe from now on in they will as it does seem to make some difference as to whether you have a keel or you do not
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Seajet
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I've always been a fan - and after this episode a lot moreso - of the 'pre-flight check', usually of rigging split pins, fuel & supply line, lift keel position, rudder down & unlashed, etc.
I admit I might not have checked if the keel was still on the boat in question ( the keel is visible internally on my boat ), maybe a look at the bolts and bilge water if I was feeling keen...
One thought I did have, did that charter boat have an auto' bilge pump, hiding possible leaks ?
As I mentioned elsewhere, when de-tensioning the rig ready for lowering this end of season I found my boat had been hit hard by some ******* on her mooring, as it was above deck level the damage was not obvious - but a chainplate had been dislodged despite a much better than average backing pad; might have been awkward if I'd set off in a stiff breeze.
I remember once waiting over 40 minutes for a Test Pilot to 'walk around' a Sea Harrier before it's first flight, he was also a sailor so may have been on to something !
There's no such thing as too many checks ( apart from missing the tide )...
Apart from initial embarassment, I can't help thinking we might be well off using 'check-lists', tailored to the boat class ?
We owe it to those mariners who have given their lives before us to learn the lessons; and if Chief Test Pilots always refer to a checklist in even the simplest aircraft ( aeroplanes being very similar to boats but with seconds instead of hours for things to go pear-shaped ) , I can't help thinking there's a lesson there.
I admit I might not have checked if the keel was still on the boat in question ( the keel is visible internally on my boat ), maybe a look at the bolts and bilge water if I was feeling keen...
One thought I did have, did that charter boat have an auto' bilge pump, hiding possible leaks ?
As I mentioned elsewhere, when de-tensioning the rig ready for lowering this end of season I found my boat had been hit hard by some ******* on her mooring, as it was above deck level the damage was not obvious - but a chainplate had been dislodged despite a much better than average backing pad; might have been awkward if I'd set off in a stiff breeze.
I remember once waiting over 40 minutes for a Test Pilot to 'walk around' a Sea Harrier before it's first flight, he was also a sailor so may have been on to something !
There's no such thing as too many checks ( apart from missing the tide )...
Apart from initial embarassment, I can't help thinking we might be well off using 'check-lists', tailored to the boat class ?
We owe it to those mariners who have given their lives before us to learn the lessons; and if Chief Test Pilots always refer to a checklist in even the simplest aircraft ( aeroplanes being very similar to boats but with seconds instead of hours for things to go pear-shaped ) , I can't help thinking there's a lesson there.
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Grumpybear
Well-Known Member
Check lists are a good idea in principle, formalizing the mental routines we all have. But PLEASE keep this quiet, or we'll soon be receiving harangues from the good practice fascists trying to shame us into filing signed check lists as appendices to our passage plans and lifejacket confirmations.......
Seajet
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Grumpybear,
I agree we could well do without fascists with clip-boards !
However a laminated list with a chinograph pen might be useful, especially for people new to the boat type ( sail or power ) ?
Just a thought...
I agree we could well do without fascists with clip-boards !
However a laminated list with a chinograph pen might be useful, especially for people new to the boat type ( sail or power ) ?
Just a thought...
imsodepressed
Member
Bit of the Technical stuff from the latest YM
When the 2-tonne, 6ft 4in keel was subsequently recovered by divers, the impact point could be seen about halfway down the leading edge (there are two photos of the keel) The keel was lost, not because of corroded keel bolts, but because of the impact at the exact vertical position of the yachts centre of gravity, The force of the impact can be likened to a karate chop capable of fracturing a pile of concrete blocks - or in this case, sheering the keelbolts. There was no 'moment' (force x distance) applied to the hull, which would have made the yacht pitch. Any resultant pitching would have decreased the decelration period with a consequent reduction in the force applied and the hull structure would have been damaged as it absorbed the impact. With no pitching, deceleration would be almost zero and therefore the force applied would be enormous - all concentrated on the keel studs.
When the 2-tonne, 6ft 4in keel was subsequently recovered by divers, the impact point could be seen about halfway down the leading edge (there are two photos of the keel) The keel was lost, not because of corroded keel bolts, but because of the impact at the exact vertical position of the yachts centre of gravity, The force of the impact can be likened to a karate chop capable of fracturing a pile of concrete blocks - or in this case, sheering the keelbolts. There was no 'moment' (force x distance) applied to the hull, which would have made the yacht pitch. Any resultant pitching would have decreased the decelration period with a consequent reduction in the force applied and the hull structure would have been damaged as it absorbed the impact. With no pitching, deceleration would be almost zero and therefore the force applied would be enormous - all concentrated on the keel studs.
Ubergeekian
Well-Known Member
Assuming you've transcribed that correctly, there are two glaring errors to it - possibly the result of a journalist who doesn't understand mechanics.
Firstly, applying a force at the centre of gravity does not give zero moment, unless (roughly speaking) the object in question is symmetrical. A yacht is quite definitely not symmetrical: there may be as much mass above the impact point as below, but since the stuff above is distributed a lot further from the C of G, it has a bigger lever arm and will give a moment at impact. To have zero moment the impact must take place at the centre of percussion.
Secondly, "Any resultant pitching would have decreased the decelration period with a consequent reduction in the force applied and the hull structure would have been damaged as it absorbed the impact. With no pitching, deceleration would be almost zero and therefore the force applied would be enormous - all concentrated on the keel studs." just doesn't make any sense at all, unless it was meant to say that pitching would increase the deceleration period (thereby reducing the acceleration), so that with no pitching the deceleration would be very high. Confusion between deceleration and deceleration period.
That's not a criticism of the proposed model, just of ow it seems to have been reported. I haven't been able to buy the December YM yet, but hope to get it today.
Seajet
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If one understands and takes the gist of what's said, rather than worrying about terminology to an in my view unnecessary degree, the point being made is pretty clear.
I raised my eyebrows at the Cof G remark too, but one can see what's being got at.
However, even if the impact resulted in a clean shear, I simply cannot believe the crew didn't notice !
I raised my eyebrows at the Cof G remark too, but one can see what's being got at.
However, even if the impact resulted in a clean shear, I simply cannot believe the crew didn't notice !
Ubergeekian
Well-Known Member
My Jouster (no reasonable offer refused) weighs a ton. Half of that is the keel. The keel is held on by twelve stainless steel bolts, 3/4" in diameter. The shear capacity of a 20mm stainless bolt is between 35.5kN and 90.1kN. Taking the lower figure, and assuming sequential failure of the bolts, the deceleration of the non-keel bit of the boat would be 35.5kN/500kg = 71 m/s^s = 7.24g. If the bolts sheared in pairs, 14.48g. I'm pretty sure the crew would notice that!
A fast fracture would involve far lower forces though ... boy, would I love to see some good photographs of the fracture surfaces. Oi, YM, can you get some for Vyv?
jimi
Well-Known Member
They must have been tanking along..I cannot believe it was'nt blindingly obvious both at the time and subsequently because in the change in boat behaviour. I actually did see the boat in question on the hard and there was obviously massive force and also some hull damage, it obvious that not only did theymanage to whip the keel off but also they scraped some of the hull on rocks
Seajet
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and there was obviously massive force and also some hull damage, it obvious that not only did theymanage to whip the keel off but also they scraped some of the hull on rocks
Which returns me to an earlier post, I hope these charterers are hauled up severely for this, basically they knowingly let the next crew/s go out in a potentially lethal boat, for the sake of getting their deposit back...
Which returns me to an earlier post, I hope these charterers are hauled up severely for this, basically they knowingly let the next crew/s go out in a potentially lethal boat, for the sake of getting their deposit back...
photodog
Lord High Commander of Upper Broughton and Gunthor
I should have paid attention in maths. Somehow I feel so inferior to all you science and engineering types. Real Men talk about that sort of stuff, and build dam's.
dt4134
Well-Known Member
I bought the mag. There is a photo of one of the sheared bolts. The original charterer seems to have been pretty adamant that it wasn't a major blow they felt. Interestingly there's a side note that the surveyor involved is investigating whether or not the keel bolts were as originally fitted by Jeanneau, but that was as far as it went.
I really would like this one to be investigated by the MAIB and I'm surprised they haven't taken it forward (it was a coded boat after all so it must have been reported to them). Hooligan V was simply a designer taking a few risks with safety factors and a dodgy sub-contractor not building what was specified, but the keel loss on Polbream has far more significance as it potentially questions the standards of boats built under the RCD.
jimi
Well-Known Member
Agree completely!! ... and also, I cannot see how they got the boat back from Scilly right way up unless they were fully aware of the keel less state and nursed it back accordingly.
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