%2c_side_view.jpg) USS Trigger (SS-564) | |
| History | |
|---|---|
 United States | |
| Name | USSTrigger |
| Builder | Electric Boat Company |
| Laid down | 24 February 1949 |
| Launched | 14 June 1951 |
| Commissioned | 31 March 1952 |
| Decommissioned | 2 July 1973 |
| Stricken | 2 July 1973 |
| Identification | SS-564 |
| Fate | Transferred to Italy 10 July 1973 |
 Italy | |
| Name | Livio Piomarta |
| Commissioned | 1973 |
| Decommissioned | 28 February 1986 |
| Identification | S 515 |
| General characteristics | |
| Class & type | Tang-classsubmarineAttack submarine |
| Displacement |
|
| Length | 269 ft (82 m) |
| Beam | 27 ft (8.2 m) |
| Draft | 17 ft (5.2 m) |
| Speed |
|
| Complement | 88 officers and men |
| Armament | 8 ×21 inch (533 mm)torpedo tubes (6 forward, 2 aft) |
USSTrigger (SS-564), aTang-classsubmarine, was the second ship of theUnited States Navy to be named for thetriggerfish.
Her keel was laid down on 24 February 1949 atGroton, Connecticut, by theElectric Boat Company. She waslaunched on 14 June 1951 sponsored by Mrs.Roy S. Benson, andcommissioned on 31 March 1952.
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Following shakedown training offRio de Janeiro,Brazil, the attack submarine returned to her home port,New London, Connecticut, and participated in local operations for the remainder of the year. She was back in theCaribbean Sea in February, returned to New London on 28 March, and continued East Coast operations until 16 August 1957. She then joinedsubmarineNautilus and proceeded to theArctic Ocean. The submarine spent ten days at the ice pack in the northGreenland Sea and made several short trips under the ice pack. From 16 September to 1 October, she participated in theNorth Atlantic Treaty Organization (NATO)Operation "Strikeback". She then called atPortland,England andLe Havre,France, en route back to New London to resume normal operations.
On 14 January 1958,Trigger entered thePortsmouth Naval Shipyard inKittery, Maine for major alterations. Her four troublesome high-speed diesel engines were replaced by three reliable medium-speed engines. The submarine was cut in two and lengthened by nine feet to accommodate the large, easier-to-maintain engines. 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 atFaslane,Scotland, and returned to her home port in late April.
On 1 August,Trigger joinedSubRon4 atCharleston, 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. In 1964 she was overhauled in the Charleston shipyard with an emergency blow of straight 3000 psi air bypassing reducing valves. During the shakedown cruise to test the emergency blow from 150 feet her sail forced the boat to list almost 90 degrees to port and swung back to almost 90 degrees to a starboard list. No damage to the safety of the crew was encountered.
She was deployed to theSixth 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 theSUBSAFE program; and, from 3 January 1968 to 6 June 1969, her hull was again lengthened to accommodate the PUFFSsonar equipment.
On 10 August 1970,Trigger departed Charleston for the west coast and assignment to the Pacific Fleet. She called atMontego Bay,Rodman, andAcapulco en route, and arrived atSan Diego, California, her new home port, on 6 September to joinSubRon 3. On 18 November, the submarine got underway forBangor, Washington, to spend a month testing theMark 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 theHunter's Point Naval Shipyard from July 1971 to April 1972, she made a voyage to theNanoose Bay Acoustic Test Range and returned to San Diego on 25 May.
On 17 October,Trigger stood out to sea on her first WestPac deployment. She called atChristmas Island on 31 October and arrived atAuckland, New Zealand, on 10 November. The operational control ofTrigger was shifted to the Commander,Seventh Fleet; and she participated in Exercise "Longex 7," a combined fleet problem utilizing ships from the navies of theUnited States, New Zealand,Canada, andAustralia. The submarine departedAuckland on 1 December and arrived atSubic Bay on 18 December. From 29 December 1972 until 25 January 1973,Trigger was underway conducting special submarine operations. She left thePhilippines on 3 February and, after calling atHong Kong, participated in a joint United States-Canadian exercise offTaiwan. The ship sailed forYokosuka on 20 February and remained in Japan undergoing repairs until getting underway for theUnited States on 16 March.
The submarine arrived atSan Diego, California, on 5 April. On 25 June, she started training a crew of theMarina Militare to operate the ship.Trigger was decommissioned and transferred toItaly on 10 July 1973. She was struck from theNaval Vessel Register on 2 July 1973.
Ex-Trigger served asLivio Piomarta until she was decommissioned on 28 February 1986.
This article includes information collected from theDictionary of American Naval Fighting Ships.
