Advice: Hull deflection after put in cradle incorrectly

JoshE

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Hi,

I hope that there might be some surveyors or knowledgeable people to advise on the following...

My yacht was lifted out this week and placed too far back in the cradle. There was a large portion of the boat hanging out the back of the cradle and the pads did not pick up the bulkheads.
The result is that the boat has a pull in / deflection / con-caved area on the port side where the structural support picks up the shrouds plate ring that links to where the upper and lower shrouds connect.

The boat is 31 foot long and 10’6” in beam and has a tall fractional rig.

The yard promptly re-positioned the boat in the cradle the next day but the deflection remains. It pulls in just under a 1cm about 30cm below the toe rail. It does not appear to have cracked the gel coat, but the deflection is noticeable. I have been able to look inside yet.
We had hoped it would come out once the boat was re-positioned.

My question is how bad is this and what should I do?

Thanks in advance.
 

William_H

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Sounds horrible. Mostly a boat is put ina cradle with the weight on the keel. If not on the keel it should be taken in slings. It sounds to me like the side supports were too close so that the hull was jambed or pressed into theside supports.
Anyway it is surprising the deflection did not come out. It will be vital to check inside the dented area to check for signs of damage. Ultimately it will be the aesthetics that matter. If it is a new or valuable boat then it will take a lot of repair work to cut out the damaged GRP replace and fair off. Or just fair off with filler. In any case it amy then need a new hull paint job to cover repairs.
I will be interested to hear the outcome. Was it the yard's fault? good luck olewill
 

JumbleDuck

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The yard promptly re-positioned the boat in the cradle the next day but the deflection remains. It pulls in just under a 1cm about 30cm below the toe rail. It does not appear to have cracked the gel coat, but the deflection is noticeable. I have been able to look inside yet.
We had hoped it would come out once the boat was re-positioned.

My question is how bad is this and what should I do?

Potentially very, very bad indeed. Larger areas of GRP should flex and spring back easily; a permanent deflection suggests significant structural damage. I suggest that you notify your insurance company at once. At some point a surveyor's report will be needed. Make sure you don't use any old shaved chimp with a moisture meter - you need a qualified expert in composite structures.

My commiserations. I had a small deflection (1/2cm) in my hull when the boat went onto her cradle a bit too far forward a couple of years back, but it was on an area unsupported behind and as soon as she was lifted again the hull sprang back without a trace.
 

RichardS

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It's surprising that the deflection has not sprung back out again. Are you sure that it wasn't like that already.

When my cat was out last year is was supported on tne buklheads but these supports had to be moved away from the bulkheads and supported on the hull for a 24 hours whilst the Coppercoat layers were applied to the areas where the chocks were. During this period the sole boards were rocking when I walked on them due to the GRP distortion but once the boat was back in the water everything went back to normal.

Richard
 

30boat

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Fiberglass should be able to pop back out. You must look at the interior side of the caved in area and see what happened. Was there crushed or dislocated furniture? Is the hull single skin or sandwich? It could be crushed core. I'm assuming the boat is plastic. If the deformed area is near the shrouds attacment point special care will be needed.
 

JoshE

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Hi,
Thanks for the comments so far.
We have looked inside now and there is cracking around the rib that picks up the shrouds (port side) which is bonded to the hull, also the bottom of the lockers as been moved upwards that has cracked the fibreglass that held them in place around that rib/structure piece.
Also the forward bulkhead seems to have moved as the shelving in the forward cabin has come detached and dropped a few inches at the stern end on both the port and starboard side.
There is also cracking on the internal moulding above the forward cabin door.
Now the boat is sitting better in the cradle the dent is slowly becoming less but it looks like the damage may have already been done inside.
Welcome any thoughts/comments/advice.
Thanks in advance
 

Avocet

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Sounds dreadful. Please don't take this the wrong way, but of there's no visible damage (inside or outside) and it hasn't spring back or cracked, is it posible that it was always like that? The only reason I ask is that I have seen a boat which had a very slight "dent" (well, more of a "flat" than a "dent") near a cradle pad and the owner told me it had always been like that.
 

30boat

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Sounds dreadful. Please don't take this the wrong way, but of there's no visible damage (inside or outside) and it hasn't spring back or cracked, is it posible that it was always like that? The only reason I ask is that I have seen a boat which had a very slight "dent" (well, more of a "flat" than a "dent") near a cradle pad and the owner told me it had always been like that.

In fact I've seen many boats with pronounced hollows at the shroud attachment points.Fiberglass will always return to it's normal shape unless being held in by something.
 

Daydream believer

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My 31 ft boat was poorly propped for 4-5 weeks at Inverness marina & the floorboards sprung half an inch. Yard said they had propped it correctly but I never had this at my own marina.
I found that the gel coat developed minute crazing just about the aft end of the keel.
When in the water, or propped at my home marina, the crazing was less noticeable. The insurance Co were notified & sent their surveyor to look just to record the situation in event of later problems. His opinion was that the gel was a little thick at this point & had cracked under tension. He felt that there was no structural damage.

So it may be worth lifting the floorboards & checking the same point on your boat. I know of a Dehler 29 that was stood in a cradle with little support to the stern & one could flex the boat about 4 inches just by pulling down on the stern. One could see the reverse curve just aft of the keel ,so poor propping does affect this area as well as at pressure points by the props
 
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richardwvm

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Another consideration might be whether or not you intend to sell the boat in the near future. I was very interested in a Westerly 33, until on the third visit I noticed the hull had dished where the cradle pad had missed the bulkhead on the port forward quarter.

I pointed this out to the broker, partly to establish whether it would likely pop back out, but also for the sake of the owner who no doubt wouldn't be too pleased. He walked away and mumbled some dismissive comment about the cradle "needs adjusting".

To me, despite being a very nice yacht, it was a deal breaker.
 

wooslehunter

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I just helped to lift 30+ yachts into the club compound. I do this every year so have some reasonable experience of lifting into & out of cradles.

The yacht should be perfectly balanced in the cradle with almost all of the weight taken by the keel. The props are there just to stop it falling over. Putting it in involves stropping for perfect balance & then lowering into the cradle. The props are then wound in & up to support the boat before the strops are removed. We'll position the boat to within less than an inch of where it's going to lie. It sounds like yours was either put into the cradle while the props were already wound in so it sat on the props, or the balance was completely wrong causing lots of weight to be up on the props once the strops were removed.

If the yard put it there & then moved it, it goes without saying that they got it wrong. Why would they move it otherwise. It shouldn't be difficult to prove they got it wrong first time. The difficulty will be in proving that this is what caused the damage. You should get a survey immediately that should state that the damage is new. If you have any pictures of the boat in the first position, that would help too.

Good luck.
 

Daydream believer

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The yacht should be perfectly balanced in the cradle with almost all of the weight taken by the keel. The props are there just to stop it falling over.
I dispute that to an extent
A lot of AWBs flex at the stern & the weight of the stern ( & to a small extent the bow) needs firm support to remove the sag.
At our yard they put supports ( with a lot of pressure) under the stern on lots of boats - mine included- to remove this sag. If boats are left for long or have a long bow overhang they do the bow as well. Leaving the stern supported by keel only will be detrimental to the hull
 
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