Shrykull wrote:How would that ship do against the torpedo if it had a double or triple hull, or could dodge it?
Double or triple hulls don't do much to limit torpedo damage, you a dedicated torpedo defence system, incorporating multiple void and liquid loaded compartments laid out along the length of the hull to really have an effect. The system also needs armored bulkheads so stop fragments from piercing the compartments (the hull is being shattered and propelled inwards after all). However few vessels short of battleships or large carriers have wide enough hulls to have space for such systems. Other warships thus must make do with good subdivision of compartments, and a unit machinery layout. That means that the boiler and engine rooms are staggered, say boiler, engine, boiler, engine aft to stern. That way no one hit will knock out all power.
Merchant ships tend to have neither good subdivision since a few big spaces hold more cargo and cost less, nor unit machinery layouts because they generally only have one shaft and engine. Thus they tend to get rather fucked by torpedoes. However they also tend to be big, so they can survive a lot of flooding.
As for dodging, its quite possibul to evade the non homing torpedoes of WW2 (homing torpedoes did exist in the later years but only on a limited scale because of there low warhead weights and speed). However to make an evasive turn, you need to spot the torpedoes first, which can be very hard if they're electric rather then steamed powered and thus leave no bubble trails. The fact that subs generally fired multiple torpedoes in wide spreads made things even more difficult, evade one and you might blunder into another. This is when high speed and good lookouts are handy. Merchants tended to have neither, thus they suffered even more. In addition there weak or nonexistent armaments encouraged subs to get as close as possibul, if the torpedoes are fired from say 500 yards range you likely won't be physically able to escape being hit.
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