Over at Lagniappe's Lair is a wonderful photo tour of the USS Requin, a Tench-class fleet sub. One of the neatest photos shows the lever switches for three alarms on boxes on the wall. Not only is each of the three boxes a different color so you can distinguish them quickly, but each of the handles has a different-shaped knob on the end so you can distinguish it in the dark. Launched in 1944, and state of the art for its time, it's nonetheless a pretty cramped and incommodious little boat.
But what struck me was the difference between it and the last sub I toured, the U-505, a captured WWII German Type IXC U-boat. The Type IX's dated from the mid-'30s, and are a good sixty feet shorter than the Tench-class boats. The Requin is cramped, but it's cramped like a cabin cruiser or sailboat, whereas the U-505 is cramped like a space capsule. One is crowded while the other is a claustrophobe's nightmare, even brightly lit and safely parked inside a Chicago museum, let alone a hundred feet down in the freezing North Atlantic.
That has got to have an impact on the effectiveness of the crew on a long cruise; the less time you spend having to peel guys off bulkheads, the more time they can spend running the boat. I wonder how much time and skull sweat have gone into trying to figure out the optimum cubic-feet-per-man on a Virginia-class attack sub?