Hull difference....german, american

[ETR3(SS)]

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.

A lot would depend on the strength and placement of the charge. Also, it has been debated on what protective effects a greater depth offered against a well placed charge. Would the greater sea pressure already have the hull nearer to failure or would the greater sea pressure contain the explosive force in a way forcing most of the energy up where the water is less compressed?

The greater depth gave a sub more time to manuever out from under an attack and in general it was better to have the charges going off above you rather than underneath.

Just some thoughts - who knows:hmm:

Well drawing from my firsthand knowledge on how submarines work, the ballast tanks wouldn't provide any sort of protection from sea pressure. Reason being is the pressure of the water in the ballast tanks is equal to that of sea pressure, no matter what depth. Now the reason for that is the bottom of the ballast tanks have grates to allow sea water to come in easily when the vents are opened on the top of the ballast tank. I know thats how it worked on my boat and id assume that that part of submarine design hasnt changed.