USS San Francisco (SSN 711) departed Puget Sound Naval Shipyard and Intermediate Maintenance Facility (PSNS & IMF) April 7, after more than three years of maintenance work to her bow, forward ballast tanks and associated mechanical and weapon systems. The challenging maintenance involved PSNS and IMF cutting more than one million pounds from the now decommissioned USS Honolulu (SSN 718) forward ballast tanks and sonar sphere. The bow restoration also involved many piping systems, mechanical linkages, combat systems components used for torpedo systems and sonar sounding equipment that facilitates control and operation of the submarine. San Francisco arrived at PSNS in September 2005 following a 5,600-mile open ocean surface transit from Guam. On Jan.