NAVYPEDIA

Photo

Haddock 1979

Ships

No	Name	Yard No	Builder	Laid down	Launched	Comm	Fate
SSN593	Thresher		Portsmouth N Yd, Kittery	28.5.1958	9.7.1960	3.8.1961	foundered 10.4.1963
SSN594	Permit		Mare Island N Yd, Vallejo	16.7.1959	1.7.1961	29.5.1962	stricken 6.1991
SSN595	Plunger		Mare Island N Yd, Vallejo	2.3.1960	9.12.1961	21.11.1962	stricken 2.1990
SSN596	Barb (ex-Pollack)	1079	Ingalls, Pascagoula	9.11.1959	12.2.1962	24.8.1963	stricken 12.1989
SSN603	Pollack (ex-Barb)	534	New York SB, Camden	14.3.1960	17.3.1962	26.5.1964	stricken 3.1989
SSN604	Haddo	535	New York SB, Camden	9.9.1960	18.8.1962	16.12.1964	stricken 6.1991
SSN605	Jack		Portsmouth N Yd, Kittery	16.9.1960	24.4.1963	31.3.1967	stricken 7.1990
SSN606	Tinosa		Portsmouth N Yd, Kittery	24.11.1959	9.12.1961	17.10.1964	stricken 1.1992
SSN607	Dace	1080	Ingalls, Pascagoula	6.6.1960	18.8.1962	4.4.1964	stricken 12.1988
SSN612	Guardfish	539	New York SB, Camden	13.2.1961	15.5.1965	20.12.1966	stricken 2.1992
SSN613	Flasher	158	Electric Boat, Groton	14.4.1961	22.6.1963	22.7.1966	stricken 5.1992
SSN614	Greenling	160	Electric Boat, Groton	15.8.1961	4.4.1964	3.11.1967	stricken 4.1994
SSN615	Gato	162	Electric Boat, Groton	15.12.1961	14.5.1964	25.1.1968	stricken 10.1995
SSN621	Haddock	1081	Ingalls, Pascagoula	24.4.1961	21.5.1966	22.12.1967	stricken 4.1993

Technical data

Displacement standard, t
Displacement normal, t	SSN593 - 596, 603, 604, 606, 607, 612, 621: 3705 / 4311 SSN605: 3900 / 4470 SSN613 - 615: 3800 / 4242
Length, m	SSN593 - 596, 603, 604, 606, 607, 612, 621: 84.9 SSN605: 90.5 SSN613 - 615: 89.1
Breadth, m	9.70
Draught, m	7.70
No of shafts	1 SSN605: 1 (2 propellers)
Machinery	2 sets General Electric or de Laval geared steam turbines, 1 Westinghouse S5W nuclear reactor
Power, h. p.	15000
Max speed, kts	15 / 28
Fuel, t	nuclear
Endurance, nm(kts)	practically unlimited
Armament	4 - 533 Mk 63 TT (amidships, 23 torpedoes, including 4 SUBROC UUM-44 ASW rockets)
Electronic equipment	SSN593 - 596, 603 - 607, 612, 621: BPS-5 or BPS-9 or BPS-15 radars, BQQ-2 (BQS-6 + BQR-7) sonar suite, BQS-14 sonar, WLR-1 ECM suite SSN613 - 615: BPS-5 or BPS-9 or BPS-15 radars, BQQ-5 sonar suite, BQS-14 sonar, WLR-1 ECM suite
Complement	94
Diving depth operational, m	400

Standard scale images

Graphics

Project history

This is the largest class of submarines built by the United States since 1945; officially it was subdivided into Thresher/Permit and Sturgeon classes; the original name-ship, Thresher, was lost on diving trials on 10 April 1963. They combine a stronger hull for deeper diving with an advanced long-range BQQ-2 sonar and its associated SUBROC missile; diving depth is reportedly 400m. Later units were lengthened to permit die installation of a BQQ-5 sonar in place of BQQ-2; the extra space is free flooding, and underwater displacement rises by about 200t to 350t (SSN613-615 and most Sturgeon class submarines); ultimately all of these units will have BQQ-5. All will also ultimately receive the Mk 117 fire control system in place of their current Mk 113, providing facilities for Harpoon anti-ship missile control. However, since SUBROC is an analogue rather than a digital weapon, and Mk 117 is a fully digital fire control system, the long-range ASW capability (except as provided by the Mk 48 torpedo) is being lost. SSN613-615 were, in effect, prototype Sturgeons with heavier machinery, taller fins (6.1m rather than 4.2m or 4.6m), improved safety features ('Sub-safe' programme), and lengthened hulls.

As officially described in 1979, Thresher class design compromises included a low sail, inadequate numbers of periscopes and antennas, and limited electronics. The reduced sail height was specifically accepted to minimize the speed loss, given the fixed reactor power of the S5W. The SSN637 class was considerably enlarged for a combination of quieting and additional electronics, as well as improved internal arrangements. Presumably the electronics was a combination of sonar signal processing and torpedo control, one control console being required for each wire-guided torpedo.

These submarines were intended primarily for ASW, with a large spherical sonar array filling their bows, and the torpedo battery, reduced to four tubes, moved aft to abreast the fin, firing diagonally from the hull. One advantage of this arrangement was that a large torpedo room could be provided, permitting a relatively easy choice of weapons for each tube. By the late 1060s, the submarine commander had a choice of long ASW torpedoes, nuclear torpedoes (Astor, or Mk 45, now retired), long anti-ship torpedoes, or SUBROC now there are Harpoon (first tested in Permit in 1976) and, very soon, Tomahawk. Unfortunately total weapon capacity was quite small, figures as low as twenty torpedoes in stowage being reported, so that this variety of weapons is very much a mixed blessing. Indeed, one advantage of the adoption of the Mk 48 torpedo was that it can replace both long ASW and long anti-ship weapons, and the Mk 45 was discarded partly because it consumed valuable space but was unlikely to be used in action.

Since the power plant, the S5W, duplicated that of the earlier Skipjack, and the size of these submarines was much greater (by at least 800t), these ships were considerably slower. There were three attempts within this class id improve propulsion. Jack has contraprops on her single screw, an arrangement never duplicated. Narwhal has a natural convection powerplant (S5G rather than S5W); and Glenard P. Lipscomb had turbo-electric propulsion, both of the last two choices having been made for quietness.

Modernizations

1970s, all: - BQQ-2 sonar suite; + BQQ-3 (BQS-11 + BQR-7) sonar suite

early 1980s, Permit, Plunger, Barb, Pollack, Dace, Flasher, Haddock; late 1980s, Haddo, Jack, Tinosa, Guardfish, Greenling, Gato: - 4 SUBROC ASW rockets (UUM-44); + 4 Harpoon SSM (UGM-84)

late 1980s, many: - BQQ-3 sonar suite; + BQQ-5 sonar suite

Naval service

Thresher sunk 10.4.1963 during diving tests in 220nm E of Boston.