USS TRIGGER (SS-564)
second Trigger (SS-564) was laid down on 24 February 1949 at Groton,
Conn., by the Electric Boat Co.; launched on 14 June 1951; sponsored by Mrs. Roy S. Benson; and
commissioned on 31 March 1952, Comdr. Edward L. Beach in command.
shakedown training off Rio de Janeiro, Brazil, the attack submarine returned to her home
London, and participated in local operations for the remainder of the year. She was back in the
February, returned to New London on 28 March, and continued east coast operations until 16
She then joined Nautilus (SSN-571) and proceeded to the Arctic. The submarine spent 10 days
at the ice
pack in the north Greeland Sea and made several short trips under the ice pack. From 16 September to 1 October, she
participated in the North Atlantic Treaty Organization (NATO) Operation "Strikeback."
She then called at Portland, England, and Le Havre, France, en route back to New London
14 January 1958, Trigger entered the Portsmouth (N.H.) Naval Shipyard for
major alterations. Her four high-speed diesel engines were replaced by three medium-speed engines. The
submarine was cut in two and lengthened by nine feet. On 15 August, she got underway
for New London and refresher training. She stood out of New London on 2 February 1959 for extended operations in the North
Atlantic. She called at Faslane, Scotland, and returned to her home port in late April.
1 August, Trigger joined Submarine Squadron (SubRon) 4 at Charleston,
S.C., her new home port, and, in late September and early October, participated in NATO Exercise
"Fishplay." The submarine conducted operations out of Charleston for the next
decade. She was deployed to the 6th Fleet in the Mediterranean during the periods: 10
April to 6 August 1962; 7 July to 29 October 1966; and 7 October 1969 to 2 February 1970. From 6 January to 6
August 1964, she underwent modifications in connection with the SUBSAFE program; and, from 3 January
1968 to 6 June 1969, her hull was again lengthened to accommodate more sonar equipment.
10 August 1970, Trigger departed Charleston for the west coast and
assignment to the Pacific Fleet. She called at Montego Bay, Rodman, and Acapulco en
arrived at San Diego, her new home port, on 5 September to join SubRon 3. On 18 November, the submarine got underway for Bangor, Wash., to spend a month testing the Mk 48 torpedo. From 3 March to 7 June 1971, Trigger returned to Bangor to
participate in Mk 48 Torpedo
Selection Test Plan operations. Following
yard work at the Hunter's Point Naval Shipyard from July 1971 to April 1972, she made a voyage to the Nanoose Bay
Acoustic Test Range and returned to
San Diego on 25 May.
17 October, Trigger stood out to sea on her first WestPac deployment. She
called at Christmas Island on the 31st and arrived at Auckland, New Zealand, on 10 November. The operational
control of Trigger was shifted to the Commander, 7th Fleet; and she participated in Exercise "Longex 7," a combined
fleet problem utilizing ships from the
navies of the United States, New
Zealand, Canada, and Australia. The submarine departed Auckland on 1 December
and arrived at Subic Bay on the 18th. From 29 December 1972 until 25
January 1973, Trigger was underway
conducting special submarine
operations. She left the Philippines on 3 February and, after calling at Hong Kong, participated in a joint United States-Canadian exercise
off Taiwan. The ship sailed for
Yokosuka on the 20th and remained in
Japan undergoing repairs until getting underway
for the United States on 16 March.
submarine arrived at San Diego on 5 April. On 25 June, she started training a crew of the Italian
operate the ship. Trigger was decommissioned and transferred to the
Government of Italy on 10 July 1973. She was struck from the Navy list on 2 July 1973 and served the Italian
Navy as INS Livio Piomarta (S-515).
[Note: The above USS TRIGGER (SS-564) history may, or may not, contain text provided by crew members of the USS TRIGGER (SS-564), or by other non-crew members, and text from the Dictionary of American Naval Fighting Ships]