Here is my post about subs (Since I spent a large portion of my 5th quarter in college playing Silent Hunter to kill a 4 hour class gap on Tuesdays)
Ironically, the first US submarine of the war (S-Class) was also the fastest U.S. submarine for submerged operations, with a top submerged speed of 11 knots. Originally designed as an interdictor submarine during World War I, the theory was to use this superior submerged speed to overrun German U-boats. This was hardly the case however, but the S-class was kept in the interim period between wars due to a lack of anything better. However, the S-class' only advantage was its submerged speed, its drawbacks included the fact that it only carried 12 torpedoes, it could only fire the older Mk10 steam torpedo, its slow surface speed of 14.5 knots, its puny 4 inch deck gun, and the cramped accomodations for the crew.
After Pearl, the U.S. began employing submarines developed during the period when people began believing that war was imminent. The submarine classes namely were the Salmon, T, P, and Barracuda classes. The latter ships were used only as training vessels. The P class however was the earliest pre-cursors to the famous Gato class, and boasted some inprovements over the S-Class, namely welded construction (as opposed to riveting), air conditioning, and additional aft torpedo tube, and an increase of surface speed to 19 knots. However, the deck gun caliber remained at 4" and maximum submerged speed was only 8 knots.
The Salmon class was a go-between in terms of the T and P classes, with 4 torpedo tubes fore and aft and a total of 20 torpedoes. The Salmon's speed was identical to that of the T class except that the Salmon could go .25 knots faster submerged. However, the Salmon had a submerged cruising range of 80 miles, far superior to the T (60 miles) and P classes. One fatal flaw of the Salmon class the cost the live of one submarine, the Squalus, was a faulty hatch covering the main diesel induction. The hatch also failed on at least two other submarines of this class.
The T class (which, incidentally, was the class which the Tautog belonged to. The Tautog had 26 sinkings, the most of an U.S. submarine during the war) was nearly identical to the P class, except that surface speed and submerged speed were increased to 20 knots and 8.75 knots, respectively, two more torpedo tubes were added both fore and aft, number of torpedoes increased by eight to a total of 24, and the deck gun caliber was increased to 5 inches.
My personal favorite of the war was the Narwhal class. The massive "submarine cruisers" were based on the U-boat "milch cows," and the U.S. had only two - the Narwhal and the Nautilus. Modified from the Argonaut mine-laying submarine design, these subs had 4 tubes forward and only two aft, but carried a massive 26 torpedoes, mostly to resupply other subs at sea (in theory). On the surface they were armed with twin 6" deck guns, and could make an impressive 17 knots despite the fact the ship only had one diesel engine (all other subs had at least two, later in the war four became standard). However, the subs were mainly used to transport guerillas, commandoes, and coast watchers, and between the two ships of the class managed to sink 11 Japanese ships.
The Gato, Balao, and Tench classes are so identical that I will only go into detail about the Gato class. The first truly "fleet" submarine, the Gato had a total of four diesel engines and four electric motors, for a maximum speed of 20.75 knots surfaced and 8.75 knots submerged. The submarine was the first class with ten torpedo tubes, six forward and four aft, and carried 24 torpedoes. The Gato class had a maximum surface range of nearly 12,000 miles, and a submerged range of nearly 100 miles. It was of all welded construction with a crush depth of 750 feet, making dives to 300 - 400 common practice (since the Japanese were under the mistaken impression that no sub could survive a dive under 250 feet). The only drawback to the Gato was the fact that it only had a 4" deck gun. 185 submarines total of these three classes (Gato, Balao, Tench) saw service in World War II. The top three submarines in terms of tonnage were all Gato class, totalling nearly 300,000 tons sunk in between them.
This is just a basic idea of U.S. subs in World War II, and is by no means meant to be a total analysis. If there are any questions about anything I asked or didn't ask, feel free to ask me.
