What was built after the R and S class boats?

We had built about 40 “fleet boats” in the 1930s. This includes the Porpoise, Perch, Salmon, Sargo and Tambor classes. These are the boats that were built as we incorporated new technologies and what we learned through operational experience. These boats were larger than the S-boats, had greater range and carried more torpedoes. They were almost the size of the Gato/Balao/Tench boats we built during the war and had similar capabilities. A table, below, compares the sizes of our submarine classes in WW2.

The fleet boats were operational at the start of WW2 along with some of the S-boats. About 16 of the fleet boats were lost during the war. Many of the others were still in active service at the end of the war.

NOTE: The name “fleet boats” generally refers to the various classes of U. S. submarines built between WW1 and WW2. The reference is to the fact that these boats were intended to sail with the fleet, or ahead of it, and engage the enemy first. The main problem was that these boats were not fast enough to sail with the fleet. Even if they could, they would be giving away their greatest advantage – stealth. Although it wasn’t practical for these boats to sail with the fleet, and rarely if ever happened, the name stuck. The name was sometimes also applied to the Gato, Balao and Tench classes that we built during the war.

There were also a few larger boats built after WW1. These larger boats had two six-inch guns and they were slower and less maneuverable. Therefore, they were more likely to be used for minelaying and for special operations.