Rotating a 2 ton hull?

[6mIR]

In sunny Saint-Tropez, I'm preparing for the restoration of my 6mIR (36'). In the "Misc. Boat-Related" Forum, I've asked for ideas on the work shed which will be a few pillars, a roof and ideally two horizontal girders to enable me to lift the boat (2 tons of hull, plus 2 tons of lead ballast keel currently detached from the boat.

Is it loony to consider rotating the boat to facilitate working on it (before adding the lead keel): clamping two big belt wheels on the boat, attaching two more on the horizontal girders and letting the boat hang on two belts?

[Thad]

Been done many times. Herreshoff did it with hulls at least 80' long. Bruce Dyson, here, is finishing an 8 meter built in his garage extension over the last couple of years; he rolled the hull in a space with only a couple of inches to spare on it's beam ends. Work out your engineering and go for it, but don't get hurt.

[Ian McColgin]

For something that big, I'd make a modified cradle that goes out to a wheel rim. This can nest in rollers at floor level. You'll have to dig to let a spance for the rim to go underneeth or have to have the boat a bit higher in the air and put the rollers up on something that's strong and won't spread apart under the load. If you get a look at the old Herraschof plant you'll see such a rig - looks a bit like a pair of giant bicycle wheels around each boat. You want to have a well fitted cradeling against the hull so that the point stresses of the 'spokes' are well spread and of course you'll need supports across the top, gunnel to gunnel.

I made a hanging sling arrangement for Il Pipe but that's just a Thistle hull that weighs under 300#. For something as big as a couple of tons, I think it easier to engineer a structure that is on the ground.

Generally you want a system where you can shore the boat either upright or upside down as in most real life projects you only turn it once.

If you're good, there is much to be said for finishing off the interior with the boat upside down as then you're guarenteed nice clean bilges.

No matter what the structure, there is a flop zone almost like the point of inverse stability when the boat is floating.

It will get harder and harder to turn the boat over and then when you get the gunnels somewhere past verticle it will want to crash over. Whatever tackle you use to roll with should have a tackle opposing as well.

G'luck

[6mIR]

Thanks for your replies. I've got a year to prepare for it. It I do it, I'll post a report.

[TimH]

what? no pictures?!?!?! smile.gif :confused:

[guillemot]

Couldn't be a bigger deal than this one!:

http://www.imagestation.com/picture/sraid16/p7f635e97b6abfab54d81f98a6b2f27b6/fdf0190e.jpg

http://www.imagestation.com/picture/sraid16/p67be7f19c6c3ccc63e21bd94b11e21fe/fdf0190c.jpg

:D

good luck!
jeff

[ 01-16-2004, 07:47 PM: Message edited by: guillemot ]

[werner]

Hi,
take a look at http://www.fintra.de/Galerie/Restauration/Stand_08_08_2002/stand_08_08_2002.html
looks like a safe system ?
perhaps not a bad idea to reinforce the hull/deck
greetings ,
Werner

[ken mcclure]

http://www.gartsideboats.com/pgimages/surpriseroll.JPG

This from the Gartside Boats website : http://www.gartsideboats.com/

Look in the "building projects" under Surprise