Steel hull thickness

[Jaguar]

On the subject of second hand boats, I was wondering if anyone has any experience of sailing in arctic latitudes. My choice is definitely a 40 to 44ft steel yacht, but what thickness the hull? Most second hand examples seem to be in the 4 to 5mm range. I have seen a couple built using 6mm plate. I don't want to lie awake at night worrying about re-enacting 'Titanic!'.

 

[mtb]

Re: swings and round abouts

Well on the one hand you have thin steel = more frames
other thick less frames
but things dont quite follow that rule, as an expensive steel hull would proberly be built to suit the area that it would be used in , that in its self is a main factor .
I would always try to go for a hull thats designed for the job .

I read a book some years ago called " Winter on ice " a couple sailed up into the ice and stayed there ,along the way many good tips re hull design and so on .
I tried to get the book from the library but they said none existed by that name !!
Other books on the subject which I have but Sorry Wont Lend are
"small steel craft " by ian nicolson pub alard coles ltd ooh look cover photograph by courtesy of motor boat and yachting !!

Ship construction by d.j. eyres pub heinemann
Both good books , that book shop in Regents street should have them cheers
Mick


http://homepage.ntlworld.com/boats
I want a big steel ex trawler / tug v / cheap or swap for tug

 

[AndrewB]

If you go with 6 or 7mm steel all over, with a yacht this length you will almost certainly have to adopt severe compromises in the design to avoid a major stability problem. This might be acceptable for specialist shorthanded Arctic sailing, but would make yacht unsuitable for much else.

My yacht was designed to sail in the arctic, and though it has not been used for that purpose other yachts in the same class have. It was built out of 3/16" (4.7mm) steel in the hull and 1/4" (6.4mm) steel in the keel. Incidentally Bernard Moitessier used the same hull thickness for "Joshua", but 9/16" (7.4mm) in the keel plus some 13/16" (20mm) reinforcement at the stem and bottom of the keel. "Joshua" was designed primarily for strength, though for dealing with coral atolls rather than ice.

For a real arctic specialist, you might find out how Willy de Roos' yacht "Williwaw" was built. This yacht got through the North-West passage. It incorporated a bow ice-breaker, but I do not have its specifications to hand.

 

[Guest]

Jet Jaguar:
Pretty brave in cyberspace eh flame-boy? It isn't the Arctic Ice I would be worrying about in your case, me-hearty...more like the mud in Newtown Creek, and up by Port Solent that you seem to like parking yourself on.
I'm surprised that You and Zippy didn't perch the floating skip on the Needles at the RTIR either.
...Ouch...

 

[alex_rogers]

Re: swings and round abouts

I think it's called 'Time on Ice' and they sailed down to the ice in Antartica ;-)