USS Jimmy Carter (SSN 23) underwent a deperm at Naval Base Kitsap Bangor's Magnetic Silencing Facility (MSF) Aug. 16 to minimize its magnetic signature and detection by marine mines.
A vessel slowly acquires its own magnetism from the mechanical stress of being used and constant exposure to the Earth’s magnetic field. Deperming, also known as degaussing, is a process to eliminate that magnetism.
The Bangor MSF has a drive-in cage for conducting deperm or signature measurement events. The cage consists of two cable loops below and around the submarine to generate high intensity vertical and horizontal magnetic fields.
Three tugboats and more than 50 linehandlers were on hand to get Jimmy Carter into the cage.
Jimmy Carter, commissioned Feb. 19, 2003, is the third of the Seawolf-class of attack submarines and is homeported in Bangor, Wash. Its mission is to seek and destroy enemy submarines and surface ships; intelligence collection, special forces delivery and anti-ship and strike warfare. Seawolf is designed to be exceptionally quiet, fast and well-armed with advanced sensors. It is a multi-mission vessel, capable of deploying to forward ocean areas to search out and destroy enemy submarines and surface ships and to fire missiles in support of other forces.
Source: Military.com