The Ethan Allen SSBN class, were the first US Navy submarines really designed from the outset to launch ballistic missiles. They were constructed using submarine design SCB-180 and were built with Hy 80 high-strength steel, which allowed them to reach greater depth than any previous submarine. Five submarines comprised this class that entered service between 1961-62, making their first deterrent patrols at the end of 1962. They were armed with sixteen Polaris A-2 missiles, being replaced by the Polaris A-3 in 1965, which would be replaced in mid of the 70’s by the Polaris A-3T. In 1983 these submarines withdrew from service, except 2 units, which were converted into nuclear attack submarines (SSN) especially fitted to carry out Special Operations missions with the US Navy SEALs until 1992, when they were definitively withdrawn.

ETHAN ALLEN class gallery and more info


Información adicional

Ficha Completa
Country of origin

United States


General Dynamics Electric Boat


Ballistic missile nuclear powered submarine

Entered service




Displacement, (full load)

Surfaced: 6,955 tonnes – Submerged: 7,880 tonnes

Dimensions (length x beam x draught)

125.00 x 10.00 x 9.75 meters

Power plant

1 x Westinghouse S5W PWR reactor, 2 geared steam turbines

Power, (total)

15,000 shp

Shafts - Screws

1 shaft – 1 screw


Surfaced: 16 Knots (30 km/h) – Submerged: 22 Knots (41 km/h)

Diving depth, (maximum)

400 meters


4 x 533mm torpedo tubes with 12 torpedoes

SLBM launcher

16 x Polaris A2/A3 missiles


5 boats: Ethan Allen – John Marshall – Sam Houston – Thomas A. Edison – Thomas Jefferson