Re: Have you hit a rock at 6 knots?
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Hitting a rock at 5 or 6 knots might be expected to cause some strain,
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A CO32 owner might sail around with this outlook but it would be unwise for owners of round bilge bolt-on keel designed yachts to view underwater encounters so lightly. I think 50% of yachts sailing around the English Channel fall into this later design category.
If a Sigma 33 or Westerly GK was to hit a rock at this speed you can almost guarantee the GRP repair man will pay a visit with his angle grinder to fix the damage.
To my eye those new pictures undermine the Bavaria’s association of the lost keel with evidence of general underwater grounding incidents in the same fleet. The internal pics are not informative. The external flaking around the keel joint… well yes it indicates the keels are flexing in a seaway relative to the hull structure and some fairing filler is flaking away.
This month Yachting World has published the best assessment of the lost keel saga that I have read so far. Detailed instructions were issued to Bavaria agents late last year about reinforcements recommended for Match 38's and 42's. The diagrams published in YW show the engineering calibre instructions issued, including heavy additional grp lay-up around the keel plates (my guess is about 3-4 square meters) and replacement internal keel bolt support plates about 4 times larger which incorporate their own rib reinforcement. The extra lay up is bonded high up onto the sides of the internal floor grid moulding, about twice the overlap I see in my Match 35.
My own non expert take on this is that AWB manufacturers have addressed the age old problem of fin keels pushing upwards at the aft end and breaking grp support ribs during an underwater collision but Bavaria underestimated the additional downward tearing motion that results at the forward edge of the keel.
[ QUOTE ]
Hitting a rock at 5 or 6 knots might be expected to cause some strain,
[/ QUOTE ]
A CO32 owner might sail around with this outlook but it would be unwise for owners of round bilge bolt-on keel designed yachts to view underwater encounters so lightly. I think 50% of yachts sailing around the English Channel fall into this later design category.
If a Sigma 33 or Westerly GK was to hit a rock at this speed you can almost guarantee the GRP repair man will pay a visit with his angle grinder to fix the damage.
To my eye those new pictures undermine the Bavaria’s association of the lost keel with evidence of general underwater grounding incidents in the same fleet. The internal pics are not informative. The external flaking around the keel joint… well yes it indicates the keels are flexing in a seaway relative to the hull structure and some fairing filler is flaking away.
This month Yachting World has published the best assessment of the lost keel saga that I have read so far. Detailed instructions were issued to Bavaria agents late last year about reinforcements recommended for Match 38's and 42's. The diagrams published in YW show the engineering calibre instructions issued, including heavy additional grp lay-up around the keel plates (my guess is about 3-4 square meters) and replacement internal keel bolt support plates about 4 times larger which incorporate their own rib reinforcement. The extra lay up is bonded high up onto the sides of the internal floor grid moulding, about twice the overlap I see in my Match 35.
My own non expert take on this is that AWB manufacturers have addressed the age old problem of fin keels pushing upwards at the aft end and breaking grp support ribs during an underwater collision but Bavaria underestimated the additional downward tearing motion that results at the forward edge of the keel.