The second Sierra (AD-18) was laid down on 31 December 1941 by the Tampa Shipbuilding Co., Tampa, FL; launched on 23 February 1943, sponsored by Mrs. F. M. Earle; and commissioned on 20 March 1944, Capt. P. B. Koonce in command.

Sierra completed fitting out at Tampa and, on 13 April sailed for Hampton Roads, VA, via Key West, arriving there on 18 April. The next day, she began a 10-day shakedown cruise in the Chesapeake Bay area and a subsequent yard availability period in the Norfolk Navy Yard from 28 April to 17 May.

On 18 May, Sierra stood out of Norfolk en route to San Diego, via the Panama Canal Zone. She was in San Diego for five days and, on 7 June, departed for Pearl Harbor. The destroyer tender rendered services to destroyers and destroyer escorts at Pearl Harbor from 13 June to 3 September 1944.

With the need for fleet repair units at advance bases to support the forthcoming invasion of the Philippine Islands, Sierra proceeded to Seeadler Harbor, Manus Island, Admiralty Islands. She was attached to the 3rd Fleet and serviced its ships until February 1945. Her most outstanding accomplishments were the replacement of a complete 5-inch gun mount on California (BB-44) and rebuilding the starboard stern of Claxton (DD-571) which had been severely damaged by a kamikaze in Leyte Gulf.

Sierra was underway from Seeadler Harbor on 18 February en route to Purvis Bay, Solomon Islands. She repaired a fleet of LST’s in preparation for the assault on Iwo Jima and then proceeded, on 15 March, to Ulithi, Caroline Islands. She serviced units of the 5th Fleet there until 25 May when she departed for San Pedro Bay, Leyte Gulf, P.I.

Sierra repaired landing craft support ships and destroyers for the anticipated strikes against the Japanese mainland, but the end of hostilities with Japan ended the assignment. The ship sailed from the Philippine Islands on 6 September for Buckner Bay, Okinawa, Jinsen, Korea; and Shanghai, China. She arrived at Shanghai on 12 October 1945 and remained there until 6 February 1946 when she sailed to San Francisco for yard availability.

Sierra was deployed to the Western Pacific two more times in the next three years. Her last assignment terminated at San Diego on 8 April 1949 and, two months later, she sailed for Norfolk, VA, which was her new home port, arriving there on 29 July 1949. She serviced ships there until 6 January 1950 when she was deployed to the 6th Fleet in the Mediterranean as relief of Shenandoah(AD-26), returning to Norfolk on 24 June. The tender was deployed to the 6th Fleet again from 12 June to 6 November 1951.

Upon her return to Norfolk, Sierra moored at Pier 21 Convoy Escort Piers. On 7 November, she was designated the flagship of Commander, Destroyer Flotilla 4 and retained this honor until 1 July 1962 when she was assigned flagship for Commander, Cruiser Destroyer Flotilla 4. Sierraremained at Norfolk until 1959, aptly coping with the heavy demand by destroyers for repairs which was her primary duty. For other than local operations, the longest period of time that she was away from the Convoy Escort Piers was when her services were required for Operation “Springboard” from 6 January to 2 March and again from 9 November to 4 December 1953.

Sierra sailed for the Mediterranean on 30 June 1959 for her third deployment with the 6th Fleet and returned to Norfolk on 13 December to continue her work as destroyer tender. She was deployed to Guantanamo Bay from 23 October to 14 December 1961 to tend the reserve training ships recalled to active duty during the Lebanon Crisis. She entered the Norfolk Naval Shipyard on 27 March 1962 for conversion under the FRAM II program. Sierra was out of the yard and able to resume her normal work routine on 15 September. From 1963 through December 1973, Sierra serviced ships of the fleet at ports along the east coast of the United States but, primarily, at Norfolk. On 5 January 1974, she moved to Charleston, SC, and served there until she was decommissioned in 1993.