I agree with Philip. Often the lift operator will put some of the weight on the keel blocks (there are hydraulic gauges in front of the operator so he knows how much load he is lifting), place the jack stands, then ease the rest of the weight onto the stands. I think they often get too much weight on the stands.
Personally, after they go away so they don't see me doing it, I get a hunk of 1 1/2" pipe and loosen, then re-tighten, each jack stand to even up the pressure. Of course it may be too late by then. Personal supervision of the jackstand placement is the best bet if you can find cooperative yard personnel. Many think they know much better than their clients. It is a Good Thing to use jack stand chains that go from each jackstand, under the keel, to it's partner on the opposite side of the hull to keep them from popping loose, especially nice when a squall comes through. Most stands have a little slot in the steelwork up by the screw to slip the chain in sideways. Some yards use the chains, some don't, but all should. I think the best situation would be to put almost all the weight on the keel, check for no list with a level, snug up the stands with little or no slack in the chains, slack the lift straps slightly, then even up all the stands. Stand legs should have wooden pads (usually 5" square 3/4" CDX plywood) under each leg to prevent them from sinking into the ground, even on pavement, unless it is concrete. Before the lift give the lift operator a large photo of your boat in slings, with the slings properly placed, to show him the best location for them. Norm S/V Bandersnatch Lying Julington Creek FL 30 07.72N 081 38.4W ----- Original Message ----- From: Philip To: [email protected] Sent: 4/2/2008 9:16:49 AM Subject: Re: [Liveaboard] on the hard & 'dented' - question re properblocking practice Look for a new surveyor. You are right - The stands are not meant to carry the weight of the hull. The keel is. Some inexperienced, or uncaring yard monkey failed to put the stand on the bulkhead, then screwed them too tight. Take photos, have the yard reposition the jack stand and get a surveyor to determine how much structural damage has been done. Make a fuss. What I have done on my boat is to mark the strong points on the hull with tape before the haul. Then supervise where the yard workers place the stands. I have encountered some incredibly stupid yard workers, but tactful teaching always gets the job done right. Usually the yard workers, who oft times are simply inexperienced and un tutored in their trade, become a friendly re-source during the haul out. Philip At 04:20 PM 4/1/2008, you wrote: Lagniappe is on the hard for new motor mounts etceteras and I just noticed something pretty disturbing. The port, stern-most, stand has pushed the hull in (concave at the pad) and I can see stress cracking on both sides of the 'dent'. Philip & Marilyn Lange AE4OV & KD4JRC, ORYOKI Witness 35 Catamaran
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