[QUOTE=tugsailor;136191]The US built most ships with double curvature plating up until the 1960s. Look at tugs, fishing boats and ships from the WW II era. We have this time tested technology.
They bayou boat builders pioneered that massive building of barge shaped boats with hard chines for simple reasons: they needed the shallowest possible draft, they had primitive yards (essentially building outside on the bank of the bayou), and it is cheaper to build a single chine hull.
Given that most of the cost of a vessel is the machinery and gear that goes inside, the extra cost of rolling plate for a moulded hull over a hard chine hull should not be that great of a factor. Especially in an icebreaker.[/QUOTE]
I would think that the fuel savings alone by a hydrodynamic efficient hull shape would save in the cost in machinery. Especially for large companies that can utilize mass production in the shipyards they own.