The survivors of Pearl Harbour

There have been many amazing stories of the longevity of many Limitorque actuators around the world over the years but none of them compare with Limitorque GS-350 actuator, that survived the attacks on Pearl Harbour during World War 2.

The Limitorque GS-350 actuator that is on display at Lynchburg Limitorque Museum was mounted on a 78″ x 84″ sluice gate, one of 4 that were used to flood the dry dock so they could bring in a ship for repair. The actuator shipped in mid-year 1941 and was installed in November of 1941. It was in operation when Pearl Harbor was bombed, and survived the attack. The actuator was in continuous service on the dry dock sluice gate until it was removed from service in May, 2012 – an operating history of 70 years, 6 months!!








Pearl Harbor Attack, 7 December 1941

USS Pennsylvania, Cassin, and Downes

When the Japanese raiders arrived over Pearl Harbor, the battleship Pennsylvania was in the Pearl Harbor Navy Yard’s large drydock and therefore was beyond the reach of the torpedoes that inflicted such devastation on four of the fleet’s other heavy ships. Though bombers of the second wave attacked her, Pennsylvania was directly hit only once, by a bomb that struck amidships, putting some of her five-inch guns out of action but generally causing only minor damage to the heavily-constructed ship.

Also in the drydock, side-by-side ahead of Pennsylvania, the destroyers Cassin and Downes were hit by bombs, puncturing their thin hulls with fragments, releasing fuel oil and starting major fires that badly strained their structure. They were further damaged by exploding ammunition and the detonation of one of Downes’ torpedoes, which blew a large hole in her mid-ships port side. Finally, when the drydock was partially flooded as a precaution against an attack on its entrance caisson, Cassin came partially afloat and capsized against her consort. The fires caused additional, but superficial, damage to Pennsylvania’s bow, and the two destroyers were almost completely wrecked.

Photo#: 80-G-19943
Pearl Harbor Attack, 7 December 1941
Official U.S. Navy Photograph, National Archives Collection / National Archives and Records Administration, College Park, Maryland (80-G-19943) Last Updated: 22 May 20

The wrecked destroyers USS Downes (DD-375) and USS Cassin (DD-372) in Dry Dock One at the Pearl Harbor Navy Yard, soon after the end of the Japanese air attack. Cassin has capsized against Downes.
USS Pennsylvania (BB-38) is astern, occupying the rest of the drydock. The torpedo-damaged cruiser USS Helena (CL-50) is in the right distance, beyond the crane. Visible in the center distance is the capsized USS Oklahoma (BB-37), with USS Maryland (BB-46) alongside. Smoke is from the sunken and burning USS Arizona (BB-39), out of view behind Pennsylvania. USS California ( BB-44) is partially visible at the extreme left. This image has been attributed to Navy Photographer’s Mate Harold Fawcett.

Photo#: NH 64482
USS Cassin (DD-372) (capsized, right) USS Downes (DD-375) (left)
Official U.S. Navy Photograph, NHHC Collection

The Limitorque GS-80, GS-200, and GS-350 actuators were supplied to the US NAVY for the following sluice gates and valves in the Pearl Harbor dry docks:


  • (6) 16″ parallel seat, double disc gate valves


  • ( 4) 54″ gate valves


  • (2) 78″ x 84″ sluice gates
  • (3) 84″ x 58″ sluice gates
  • (2) 72″ x 84″ sluice gates
  • (2) 48″ x 72″ sluice gates
  • (1) 96″ x 96″ sluice gate
  • (1) 72″ x 72″ sluice gate
  • (1) 84″ x 84″ sluice gate

In Dry Dock #1 at the Pearl Harbor Navy Yard on 7 December 1941, immediately following the Japanese attack. Both the USS Cassin and USS Downeshad been severely damaged by bomb hits and the resulting fires.

In the background, also in Dry Dock Number One, is USSPennsy/vania(BB-38), which had received relatively light damage during the attack.

Acrodyne Newsletter

Monthly news on the latest products, case studies, how to’s and industry events. (* indicates required)