USS Squalus

1939

The first deep-sea submarine rescue Location: Atlantic Ocean, off the Isles of Shoals, New Hampshire · Coordinates: 42.87°N 70.58°W · Casualties: 26 · Survivors: 33 · Depth: 73 m (raised) · Cause: valve failure — Main induction valve failed to close during her fourteenth test dive on the morning of 23 May 1939. Water flooded the aft torpedo room and engine room in seconds. She settled to 73 metres; 26 men drowned in the flooded compartments, 33 were trapped alive forward. · Fate: raised · recommissioned as USS Sailfish · Type: submarine · Porpoise class · Tonnage: 1,450 tons · Crew: 59 · Flag: United States · Launched: 1938 American Porpoise-class submarine on her fourteenth trial dive off the Isles of Shoals on 23 May 1939. A main induction valve failed to close; water flooded the aft compartments in seconds. Twenty-six drowned; 33 trapped alive at 73 metres were lifted out by the first successful deep-sea submarine rescue in history. Raised in September and recommissioned as USS Sailfish, she sank a Japanese aircraft carrier in 1943. The Vessel USS Squalus (SS-192) was an American Sargo-class submarine of the United States Navy, built at the Portsmouth Naval Shipyard, Kittery, Maine, between 1937 and 1939 and commissioned on 1 March 1939. She was 94 metres long, 1,450 tons surfaced displacement (2,350 tons submerged), and armed with eight 21-inch torpedo tubes (four bow tubes, four stern tubes) plus one 4-inch deck gun. Her propulsion was a conventional diesel-electric configuration: four diesel engines for surface operation and two electric motors for submerged operation. The Sargo-class was among the most modern US Navy submarine designs of the late 1930s, substantially advanced beyond earlier US submarine classes in habitability, range, and operational endurance. Squalus was specifically designed for the emerging long-range Pacific operational role: extended patrols of 60-75 days' duration, long operational range, and sustained submerged endurance. Her master on her final voyage was Lieutenant Oliver F. Naquin, 35, a career career submariner who had commanded Squalus since her commissioning. Her complement on the final voyage was 56 US Navy crew plus 3 civilian observers from the Portsmouth Naval Shipyard - a total of 59 aboard. The specific mechanical issue relevant to the disaster was the main engine air-induction valve system. The Sargo-class submarines were equipped with large main engine air-induction valves that admitted air to the diesel engines during surface operation; these valves were required to close The Disaster The seawater entering through the open induction valve flooded the aft engine room and the aft torpedo room at approximately 30 tonnes per minute. The submarine lost approximately 40 tonnes of positive buoyancy within approximately three minutes of the dive command. Lieutenant Naquin's immediate response was to order emergency blow of ballast tanks and immediate surfacing. The ballast tank emergency blow was executed, but the progressive flooding of the aft compartments exceeded the ballast tank's buoyancy-restoration capacity. The submarine's aft trim progressively increased; her forward section rose while her aft section settled; by approximately 08:45 on 23 May 1939, the submarine was trimmed approximately 10 degrees down by the stern and continuing to sink. Naquin's second response was to abandon the aft compartments and to close the forward watertight bulkhead door, isolating the flooded aft sections from the still-dry forward sections. The bulkhead door was closed at approximately 08:47 on 23 May 1939, trapping 26 of the 59 aboard in the flooded aft sections of the submarine. The 26 trapped personnel drowned over the subsequent minutes as the aft compartments continued flooding. USS Squalus settled to the Atlantic seabed at approximately 08:50 on 23 May 1939 in approximately 74 metres of water, her forward section dry but her aft section fully flooded. The 33 remaining survivors (29 crew plus 3 civilians, including Lieutenant Naquin) were trapped in the forward section,