(DD-725: dp. 2,200; l. 376'; b. 41'1"; dr. 15'8"; s. 34 k.; cpl. 336; a. 6 5", 2 21" tt., 6 dcp; cl. Allen M. Sumner)
The fourth O'Brien (DD-725) was laid down by Bath Iron Works, Bath, Maine, 8 December 1943 and launched 12 July 1943; sponsored by Miss Josephine O'Brien Campbell great great-great granddaughter of Gideon O'Brien and commissioned at Boston Naval Shipyard, Comdr. P. F. Heerbrandt in command 25 February 1944.
After shakedown out of Bermuda, B.W.I. and Norfolk, Va. O'Brien joined convoy forces 14 May 1944 enroute to Scotland and England. Following patrol and escort duty near England, she participated in shore bombardment of Cherbourg, and the invasion of Normandy. On 25 June while supporting minesweeps well inshore of Texas (BB-35), which was engaging German shore batteries at Cape Levi, near Cherbourg, O'Brien's own gunfire was so accurate that enemy gunnery positions shifted from Texas to O'Brien. She received a direct hit just abaft the bridge, but was able to stay on station long enough to lay a smoke screen for Texas. Thirteen men were killed and nineteen wounded. Following temporary repairs in Portland, England, O'Brien escorted a convoy to the Boston Naval Shipyard where she underwent extensive work.
After training in the Boston and Norfolk areas, she escorted Ticonderoga (CV-14) to the Pacific via the Panama Canal and 6an Diego for carrier operations with the 3d Fleet east of the Philippines. In early December, she joined 7th Fleet assault forces at Ormoc Bay, P.I. While under continuous air attack, O'Brien crewmen attempted to extinguish oil fires in Ward (APD-16) caused by Japanese suicide planes until ordered to sink the stricken transport by gunfire. O'Brien's commanding officer, Comdr. W. W. Outerbridge, had been in command of Ward when she had sunk a Japanese submarine off Pearl Harbor 7 December 1941. On 15 December 1944, O'Brien fought fires in LST-472 caused by suicide planes, and rescued 198 survivors.
Following a brief patrol period at Mindoro Strait she proceeded to Lingayen Gulf for the invasion of Luzon. On 6 January 1945, a Japanese aircraft crashed into the port side of her fantail causing slight damage. After several days of escort duty and shore bombardment during the landing of Army assault troops, she proceeded to Manus Island, Admiralties, for repairs. She joined fleet carrier forces 10 February 1945 for air strikes against Tokyo, Iwo Jima, and the Bonin Islands. Aircraft attacked her off Kerama Retto 27 March while U.S. forces secured an advance logistics base for the attack on the Japanese home islands. One plane crashed into the water as a result of gunfire while another, a "Val" suicide plane carrying a 500 pound bomb, crashed into the port side amidships exploding a magazine. Fifty were killed or missing and seventy-six wounded in the valiant crew.
During the summer, the ship underwent repairs at Mare Island Naval Shipyard and training in San Diego. As the war ended in mid-August 1945, she returned to the 3rd Fleet for patrol duty in Japanese water. O'Brien operated in the eastern Pacific, Hawaii, the Marianas, and Australia through the first half of 1947. She returned to the west coast in the summer and decommissioned at San Diego, Calif., 4 October 1947.
Three years later she recommissioned at San Diego, on 5 October 1950, Comdr. C. W. Nimitz, Jr. in command, and became the flagship of Destroyer Division 132.
During the Korean War she first joined the TF 77 carrier group in early March 1951. Later that month she joined TF 95, the United Nations Blockading and Escort Force, and participated in the siege of Songin. On 17 July 1951, at Wonsan harbor, shore batteries opened on O'Brien, Blue and Cunningham from three sides in a futile attempt to drive UN vessels from the harbor. The ships went at once into the "War Dance", an evasive maneuver in which ships steamed in an ellipse at 22 knots firing on batteries in each sector as their guns came to bear. This four and a half hour engagement became known as the "Battle of the Buzz-saw".
In July and August O'Brien provided covering fire for LSMR bombardment, and co-ordinated rescue operations which saved three downed Navy pilots and one Air Force pilot. Although both Radio Moscow and Radio Peking reported O'Brien sunk by the North Korean Peoples Army, she returned to San Diego for repairs in late September 1951. On 23 July 1952, she returned to Korea as part of TF 95 and participated in shore bombardment, interdiction and patrol duties near Wonsan Harbor. Ordered to the 7th Fleet with Helena (CA-75), she provided search and rescue protection for carrier aircraft and shore bombardment fire on the east coast of Korea in September. The ship joined Operation "Feint", a mock invasion of Kojo 12-16 October 1952, in which UN forces attempted to lure the enemy into the open. At the end of the month, she left the Korean area for exercises and repairs in Japan before returning to San Diego in mid-January 1953.
From the end of the Korean action through 1960, O'Brien made annual operational cruises to the western Pacific. In late January and early February 1955, she operated with Wasp when the 7th Fleet discouraged Communist resistance to the Nationalist Chinese evacuation of the Tachen Islands off the Chinese mainland.
February to October 1961 was spent in Mare Island Naval Shipyard, Vallejo, Calif. for FRAM II conversion. The ship now specialized in antisubmarine warfare procedures and periodically deployed to the western Pacific. In May 1965 operating with Antisubmarine Warfare Group 1, she was one of the first ships successfully to refuel a helicopter in flight. In June O'Brien successfully refueled a helicopter from Hornet off San Francisco while it made a pioneer nonstop helicopter flight from Seattle, Wash to Imperial Beach, Calif.
The ship sailed for 7th Fleet duty in August and was assigned to Taiwan patrol. On 14 November 1965, while patrolling the Taiwan Straits, the ship was ordered to the aid of a Chinese Nationalist patrol craft under attack by Communist torpedo boats. Arriving after the vessel had sunk, she rescued all fifteen survivors, and was praised by Commander in Chief, Nationalist Chinese Navy.
A week later 22 November 1965, more than 600 miles from the rescue, O'Brien saw her first action in the Vietnam War. Called to the aid of a surrounded outpost at Thach Teu, Quang Ngai province, the ship's accurate fire helped turn back a North Vietnamese regiment. In January and early February 1966, she supported carrier operations, conducted search and rescue missions in the Tonkin Gulf, and provided gunfire support for the amphibious landing near Cape Batangan, Operation "Double Eagle."
O'Brien returned to her homeport March 1966 and operated on the west coast for the next eight months. During a port visit to The Dalles, Ore., in July O'Brien became the largest vessel to use the locks at the Bonneville Dam and to transit the Columbia River to The Dalles.<>
The destroyer got underway again for the troubled western Pacific 5 November 1966. Following antisubmarine warfare exercises in Hawaii and the eastern South China Sea, O'Brien became flagship for Operation "Sea Dragon," the surface action task unit off North Vietnam. With Maddox (DD-731), she was ordered to interdict enemy coastal traffic. More than twenty vessels carrying enemy war supplies to the Viet Cong were sunk or damaged by O'Brien. On 23 December 1966, the ship received three direct hits from coastal batteries north of Dong Hoi. Two crewmen were killed and four wounded. After repairs at Subic Bay, P.I., she provided support for air strikes from Tonkin Gulf while guarding five different carriers in January 1967. In February and March, she was assigned to Taiwan patrol. The ship returned to the Tonkin Gulf in late March first as a carrier escort and then on "Sea Dragon" operations. Again as flagship for Commander, Destroyer Division 232, she was instrumental in significantly slowing coastal supply traffic. She was taken under fire by shore batteries seven times during this period.
The ship returned to her homeport of Long Beach, Calif., in May 1967. In July 1967 she made a second trip to The Dalles, Org., before entering Long Beach Naval Shipyard for overhaul. Following refresher training at San Diego, she was assigned to destroyer squadron 29 on 1 Feb. 1968. She returned to the 7th Fleet operations in the spring of 1968.
O'Brien (DD-725) received 6 battle stars for World War II service, five battle stars for Korean Conflict service, and three battle stars for Vietnam service (1967).