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FIGHTING SHIPS OF THE WORLD
UNITED STATES OF AMERICA
SUBMARINES
ETHAN ALLEN nuclear powered ballistic missile submarines (1961 - 1963)


Photo



Thomas Jefferson 1977

Ships


No Name Yard No Builder Laid down Launched Comm Fate
SSBN608, 9.1980- SSN608 Ethan Allen 154 Electric Boat, Groton 14.9.1959 22.11.1960 8.8.1961 attack nuclear-powered submarine 9.1980, stricken 4.1983
SSBN609, 11.1980- SSN609 Sam Houston 548 Newport News SB 28.12.1959 2.2.1961 6.3.1962 attack nuclear-powered submarine 11.1980, stricken 9.1991
SSBN610, 10.1980- SSN610 Thomas A. Edison 155 Electric Boat, Groton 15.3.1960 15.6.1961 10.3.1962 attack nuclear-powered submarine 10.1980, stricken 4.1986
SSBN611, 5.1981- SSN611 John Marshall 549 Newport News SB 4.4.1960 15.7.1961 21.5.1962 attack nuclear-powered submarine 5.1981, stricken 7.1992
SSBN618, 3.1981- SSN618 Thomas Jefferson 555 Newport News SB 3.2.1961 24.2.1962 4.1.1963 attack nuclear-powered submarine 3.1981, stricken 4.1986


Technical data


Displacement standard, t 
Displacement normal, t

6946 / 7884
Length, m

125.1
Breadth, m

10.1
Draught, m

8.40
No of shafts

1
Machinery

2 sets General Electric geared steam turbines, 1 Westinghouse S5W nuclear reactor
Power, h. p.

15000
Max speed, kts

16 / 21
Fuel, t

nuclear
Endurance, nm(kts)

practically unlimited
Armament

16 Polaris A-2 SLBM (UGM-27B), 4 - 533 Mk 65 TT (bow, 12)
Electronic equipment

BPS-9 radar, BQS-4, BQR-7, BQR-15, BQR-19 sonars
Complement

110
Diving depth operational, m

400


Standard scale images


<i>Ethan Allen </i>1971
Ethan Allen 1971
<i>Sam Houston </i>1990
Sam Houston 1990
<i>Ethan Allen </i>1979
Ethan Allen 1979


Graphics


<i>Thomas Jefferson </i>1977
Thomas Jefferson 1977
<i>John Marshall </i>1991
John Marshall 1991


Project history

The first US ballistic missile submarines designed as such, these ships, like the George Washingtons could not be refitted with the Poseidon missile and were therefore retired as attack submarines. All were originally armed with Polaris A-2, later refitted with A-3; they have towed array passive sonars for self-protection. They were, in effect, ballistic missile submarine versions of the Threshers, sharing their deeper-diving hull material and superior silencing. Physical changes on re-designated as SSN submarines began under the FY82 programme: missile tubes were filled with concrete, and missile fire control system removed. Proposals to install Tomahawk vertical launchers were abandoned.

Modernizations

late 1960s, all: - 16 Polaris A-2 SLBM (UGM-27B); + 16 Polaris A-3 SLBM (UGM-27C)

1982, Ehan Allen; 1984, Sam Houston, Thomas A. Edison; 1985, John Marshall, Thomas Jefferson: - 16 Polaris A-3 SLBM (UGM-27C)

1985, Sam Houston, John Marshall: + double DDS, accommodation for 67 SEALs, SDV

Naval service

No significant events.