As is so often the case with Navy ratings, the establishment of what eventually became the Torpedoman’s Mate rating (TM) came several years after the introduction of the equipment the Sailors in the rating would be working with. Although the U.S. Navy first launched serious efforts on developing torpedoes in 1869 with the establishment of the U.S. Naval Torpedo Station in Newport, Rhode Island, progress on developing a reliable, working torpedo proceeded in fits and starts. Part of the reason was the surprising effectiveness of the German U-boats in World War I, which were sinking so many Allied vessels that almost all attention was focused on developing anti-submarine warfare rather than on advancing existing torpedo designs. In all, the U.S. Navy fired just 11 torpedoes during the hostilities, none of which struck a target. In 1921, the Torpedoman rating was established, and a year later the Navy scrapped a slew of torpedo models and settled on just four for the time being: Mk 7, 8, 9, and 10, with the 7 and 8 models available for use on either destroyers or submarines.

Although the torpedoes originally deployed by U.S. Navy submarines during the first couple of years in World War II were renowned for various defects, the Navy paid attention to the complaints of sub skippers and Sailors in the Torpedoman rating (which was renamed Torpedoman’s Mate in 1942) and worked hard to correct the problems. By 1944, the U.S. Submarine force was wreaking utter havoc on Japanese shipping, thanks largely to the vastly improved ordnance with which they were equipped.
From the start of their development, Torpedoes had been used on aerial, surface-ship, and underwater platforms. As technology introduced new weapons for all these platforms, Sailors in the Torpedoman’s Mate rating were tasked with the handling and maintenance of ordnance and launch/firing systems associated with them. In addition to traditional torpedoes, they were tasked with the maintenance and handling of Anti-Submarine Rockets (ASROC) and guided missiles such as the Tomahawk and Harpoon, as well as various countermeasure systems.
In 2005, the Navy announced that, because of the tremendous overlap in the learning that was being provided at the Apprentice level, the ratings of Torpedoman’s Mate and Gunner’s Mate (GM) would be automatically merged into just the GM rating.