USS America Undergoes Deperming
The amphibious assault ship USS America (LHA 6) completed a magnetic treatment, known as deperming, at Naval Base Point Loma Magnetic Silencing Facility (MSF) May 21.
Deperming reduces the ship’s magnetic signature by flashing the ship’s hull with electricity in order to help avoid detection and to minimize marine mine attraction to the steel hull.
America is the first amphibious warship of its class to undergo this process.
America’s crew took part in hauling on board 152 600-foot cables weighing about 1,200 pounds each. Each cable is two inches in diameter, twice the size of cables used to deperm destroyers which use only 68 cables.
Once the cables were placed and connected, they were energized with 250 volts direct current (DC) for three-minute intervals in a four to six-hour process.
In order to help reduce the risk of injury to personnel or equipment, the evolution was completed in increments.
Once the deperming was complete, the crew began disassembling and removing the cables.
The ship returned to Naval Base San Diego following the successful evolution.
Image: US Navy