Hull difference....german, american

[Sailor Steve]

Originally Posted by cmdrk

Drawing from my previous readings, which hasn't been recent, it is my understanding that the Type VII's pressure hull was exposed more to direct contact with the ocean. The ballast tanks were saddled onto the pressure hull's exterior.

While the US boat's pressure hull had ballast tanks wrapped around it with an outer hull encasing the whole. The pressure hull's steel was thinner and maybe less strong than German hulls. But, the outer hull and ballast tanks should have provided some outer protection - kind of like surface ships torpedo blisters.

I'm pretty sure the outer hull is for hydrodynamic purposes only, and has a lot of vent holes in it. The 'pressure' hull is just that; it takes the pressure directly.

As to the debate whether the depth reduces the effective radius of the charge or makes the hull more susceptible to damage, the only answer I can think of is "Yes". Sorry, doesn't help much, but both seem to me to be true.