In the middle of the movie when the Americans just got on the Nazi sub Mr. Tyler asked the torpedo guy how many torpedos they had. He said 4, but if you remember in the beginning the Nazis shot two torpedos at a ship. And I thought our men new how to subtract.
Well, unbeknownst to some people, U-boats could carry more than just the torpedoes in the tubes. Each torpedo tube at at least one backup. But I can see how you'd think that.
I guess you've never heard of reloads, right? The sub had 4 torpedo TUBES, but they carried more than 4 torpedoes. I'm not sure exactly what class U-Boat the U-571 was supposed to be, but they typically carried anywhere from 14 to 20 torpedoes when fully armed.
It doesn't say how many torpedos the Nazi sub can hold, maybe it holds 8 like the American S class sub, and they've already fired 4.
I'm not sure, but didn't they say they only had 1 left, and it was in the stern torpedo room but there was no way of transferring it forward?
I under stand that they can relode but what time did they have. There engine was shot and they could not maneuver. They new they would be dead meat even if they had torpedos or not. If they tried to move out of they way of a torpedo shot by another ship they would waste the last bit of energy in there battery. They were all sitting around waiting for the resupply ship to come.