The sinking of the USS San Diego may have lessons for today.
The U.S. Navy is probing a warship disaster 99 years after the fact in an attempt to find out what really happened when it sank. The USS San Diego went down in 1917, and it was assumed that it was sunk by a mine or German submarine. Now, nearly a hundred years later, the Navy finally wants to find out what sent the ship to the bottom.
The USS San Diego
The USS San Diego was a Pennsylvania-class armoured cruiser, built at Union Iron Works in San Francisco and commissioned into the Navy in 1907. San Diego displaced 15 138 tons fully loaded, could make 22 knots, and was equipped with four eight-inch guns, fourteen six-inch guns, and 30 light guns. The cruiser served as part of President Theodore Roosevelt’s Great White Fleet. The fleet sailed around the world to promote American seapower from 1907 to 1909.
Upon the United States’ entry into World War I in 1917, the San Diego was used to escort convoys carrying troops and supplies across the Atlantic Ocean. San Diego did not lose a single ship to German u-boats or mines—but may have eventually succumbed to one itself.
The day the warship went down
On July 18th 1918, San Diego left the Portsmouth Naval Shipyard for New York to begin another convoy run. The next day, off Fire Island, New York, sailors onboard the armored cruiser heard an ear-shattering explosion on the port side and the ship began listing badly. Despite this, the captain ordered to begin firing at anything that resembled a periscope, until the guns themselves could no longer be fired. Six crewmen were killed in the sinking, the rest rescued by nearby ships.
The Navy concluded the San Diego had been sunk by mines laid by the German submarine U-156. Thereafter the matter was put to rest. Still, alternate theories have been put forward to explain the ship’s sinking. One explanation looks at an explosive charge smuggled onboard the ship. The captain himself also believed the ship had been struck by a torpedo.
Investigating the disaster
Now, 99 years later, the Navy’s Naval History and Heritage Command is overseeing the a probe that hopes to pin a definitive cause to the sinking, with the work spearheaded by the command’s underwater archaeology branch. The Navy believes that getting to the bottom of the sinking could help modern warship designers build better ships. They will use underwater robotics and sensors to study the port side damage area.