Posted January 19th, 2012, 02:31 PM
Other things to consider are how much headway did the ship have after the initial grounding? Were the azipods or thrusters used in turning around, and why was there a need to turn in the first place? She could have been placed alongside the shore port side to. The VDR will provide those answers. Not having a good plan of the ship makes speculation difficult. For example the hole in the port side may have been in a ballast tank, the engine or generator room, and that would have allowed cross flooding to starboard.
There's already too much speculation by people who know nothing about ships and damage control.
Close-up photos of the rock appear to show machinery visible forward of it, so probably not a balast tank, rather it was probably either an engine room or auxilliary space (I sure would like to see hull plans). The Concordia has conventional shafts/screws rather than azipods, with bow thrusters.
With no power, I don't personally believe the good captain Cazzo was maneuvering the ship after the impact. If he was, my opinion is that he did absolutely the wrong thing by turning in an attempt to ground the ship. Generally, modern ships have sufficient reserve bouyancy to survive even this much damage--though it's admittedly impossible to know without the hull plans.
As far as steel vs. aluminum for the superstructure, it's really pretty irrelevant. The issue for a naval architect involves the relationship between the roll center, center of bouyancy, and center of gravity. Their relationship to each other determine the "righting moment" and "stability curves." Without these data, it's impossible to determine whether the ship would have capsized or recovered herself absent grounding.