Sunday, October 18, 2015

Parbuckle salvage

Parbuckle salvage, or parbuckling, is the righting of a sunken vessel by applying leverage to rotate the vessel into an upright position from one where it is either on its side or fully inverted. A common operation with smaller watercraft, parbuckling has been used successfully to right large vessels. In 1943 USS Oklahoma (BB-37) was rotated nearly 180 degrees to upright after being sunk in the attack on Pearl Harbor, TH, and the MS Costa Concordia was successfully parbuckled off the west coast of Italy in the largest salvage operation of that kind to date.
A major concern during salvage is to prevent the rotational torque from becoming a transverse force moving the ship sideways. USS Utah (BB-31), lost like the Oklahoma in the Pearl Harbor attack, was meant to be recovered by a similar rotation after the Oklahoma. As the Utah was rotated, however, its hull did not catch on the harbor bottom, and the vessel slid towards Ford Island. The Utah recovery effort was abandoned.

File:Oklahoma Righting 01.jpg

Shells for 16 inch guns on battleships were stored vertically in the lower part of the gun turret. They weighed about a ton apiece, and were parbuckled to move them sidewise, for both when loaded in port, as well as being moved to the hoist when firing.

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