Parbuckle salvage

In 1943, the USS Oklahoma was rotated nearly 180 degrees to upright after being sunk in the attack on Pearl Harbor, and the Italian cruise ship Costa Concordia was successfully parbuckled off the west coast of Italy in September 2013, the largest salvage operation of that kind to date.

[1] A major concern during salvage is preventing rotational torque from becoming a transverse force moving the ship sideways.

As the Utah was rotated, however, its hull did not catch on the harbor bottom, and the vessel slid toward Ford Island.

In order to increase the leverage, the wire passed over a wooden strut arrangement (a bent) which stood on the bottom of the ship about 40 feet (12 meters) high.

It was indicated that the soil under the aft part of the ship prevented sliding, whereas the bow section rested in soupy mud which permitted it.

During righting, excess soil under the starboard side was washed away by high-pressure jets operated by divers.

[3] Following its capsizing and sinking in January 2012, the hull of Costa Concordia lay starboard side to the seaward face of a small outcropping very near the mouth of the harbor of Giglio, Italy, resting precariously on the incline to deeper water.

To right the vessel, four key pieces of apparatus were required: Tensioning the cables started the roll of the ship.

At about the halfway-to-vertical position the sponsons were filled with seawater, and Costa Concordia completed its roll to upright upon the ledge.

[5] The grout bags contained an "ecofriendly cement," and were built with eyelets to aid post-recovery cleanup.

This phase began when the strand jacks exerted force and the ship started to return to an upright position.