
Grayback-class submarine

The "Grayback"-class submarine was a class of two guided missile-carrying submarines of the United States Navy. They carried the Regulus I and Regulus II nuclear cruise missiles, deployed 1957–64, that were phased out by Polaris Submarine Launched Ballistic Missiles (SLBMs). They and were the sole submarines designed specifically to carry Regulus missiles, and the only submarines capable of carrying Regulus II. However, and were modified earlier to carry two Regulus I missiles per boat.
Design.
On the "Grayback"s, two missile hangars allowed for a total of two Regulus II or four Regulus I missiles each. Since Regulus II was cancelled in December 1958 except for test firings, the class deployed with four Regulus I missiles. They were originally ordered as sisters of , similar to the last s, but were converted under project SCB 161 to missile submarines during construction. Torpedo armament was the same as the "Tang"s, with six bow and two stern tubes. The stern tubes were for "swim-out" weapons only, such as the Mark 37 ASW homing torpedo.
In "Grayback"'s later role as an amphibious transport submarine, the former missile hangars were used to store SEAL Swimmer Delivery Vehicles and other equipment used by the SEALs and Marine Force Recon units.