Cold water construction specs

[ted655]

I "love" to watch "Deadlyest Catch". Crabbing in the Bearing Sea, brrrr!
I know there is different steel grades & welding schedules for artic boats. What I don;t know is the issues an alumomium trawler might face. Is alumonoum suitable for freezing waters? Is there a "class" or spec the boat (125' lol), it would bee built to? I assume insurance carriers have a say in this.
An all alumomium crab trawler, what a great idea, I think.

[kc135delta]

Just the thought of ice would make me choose steel over alum.

yes the colder it gets the stronger aluminium becomes, its a fact, there is no charge for this Gem of info)

[ted655]

Originally Posted by lazeyjack

yes the colder it gets the stronger aluminium becomes, its a fact, there is no charge for this Gem of info)

Stronger to the point of brittal?

no, not at all, there are many successful alloy sailing yachts go s down there from NZ, Peter Blakes Seamaster was one of them

[marshmat]

There are plenty of aluminum vessels that are built for icy conditions. S/V Seal http://expeditionsail.com/ comes to mind as an example, albeit a bit smaller than what you're talking about.
Aluminum does become weaker at elevated temperatures; whether it becomes stronger in the cold is not an aspect of the material of which I am aware.m I'm pretty sure it doesn't become weaker in the cold.
I would suggest digging out the classification society books- Lloyds, DNV, ABS etcetera- for this one. For ice work it seems the usual practice is to take the strictest of the class society rules on each individual topic, and ensure that every requirement is exceeded by a fair margin.