America's Gato-Class Submarine Was a World War II Killer

During the fiercest period of submarine warfare in human history, the United States relied heavily upon the Gato class—the first mass-produced submarine of World War II. The Americans built seventy of the Gato class (and derived the Balao and Tench class from the Gato), making her the most numerous of America’s World War II submarines. The diesel-powered Gato proved to be a capable vessel and is credited with destroying significant portions of the Japanese merchant marine, and to a lesser extent, the Imperial Japanese Navy.

Introducing the Gato class

Unlike modern attack submarines, which are designed to operate more independently, the Gato class was built as a supplement to the fleet, known as “fleet submarines.” A fleet submarine is a submarine that has the requisite speed and endurance to operate as part of the main naval fleet, which for the Americans during World War II, was built around the battleship.

The Gato was tasked with shooting out ahead of the main fleet and scouting the enemy position. When appropriate, the Gato would engage the enemy, incrementally degrading the enemy's abilities before the main fleet would arrive to encounter a hindered enemy force.

Because so many Gato submarines were made, the Navy had time to tinker and experiment; four different modifications of the class were offered. Variations included adjustments to the navigation bridge, a bulwark around the cigarette deck, periscope plating shears, and machine gun positioning. Generally, the Gato displaced 2,424 tons when submerged and measured about 311 feet long. The beam measured 27 feet while the draft measured 17 feet. For propulsion, the Gato relied on four diesel engines, two 126-cell Sargo batteries, and four high-speed electric motors churning two propellers. The propulsion system was good for 5,400 shp when surfaced and 2,740 shp when submerged. The Gato could hit top speeds of 24 miles per hour when surface (and just 10 miles per hour when submerged). The vessel could operate for a range of 11,000 nautical miles, could stay submerged for forty-eight hours at a time, and could stay on patrol for seventy-five days. The test depth was 300 feet. For armament, the Gato featured ten 21-inch torpedo tubes (six forward and four aft) and a stock of twenty-four torpedoes. When needed, the Gato could swap its torpedoes for mines (Mk 10 and Mk 12). Additionally, the Gato had one 76-mm/50-caliber deck gun, plus a 40-mm and 20-mm cannon.

After the war

When World War II ended, the Gato was essentially obsolete. With a test depth of just 300 feet, the Gato was already behind the times—despite being just two to four years old—a consequence of the rapid technological development made during World War II. The surviving Gato submarines were still put to use, however. Some of the Gatos were used as radar pickets while others were converted to transport oil. One Gato, meanwhile, was converted to fire the Regulus cruise missile. Still more Gatos were sent abroad, for operation in foreign navies (Brazil, Turkey, Greece). Today, the last remaining Gatos are on display in museums around the United States.

Harrison Kass is a defense and national security writer with over 1,000 total pieces on issues involving global affairs. An attorney, pilot, guitarist, and minor pro hockey player, Harrison joined the US Air Force as a Pilot Trainee but was medically discharged. Harrison holds a BA from Lake Forest College, a JD from the University of Oregon, and an MA from New York University. Harrison listens to Dokken.

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