Ethane Allen class
 The Sam Houston at Pearl Harbor |
|
| Overview | |
|---|---|
| Type | Missile submarine |
| units | 5 built, 0 in service |
| Namesake | Freedom fighter Ethan Allen |
| period of service |
1961 to 1992 |
| Technical specifications | |
| displacement |
7900 ts submerged |
| length |
125.1 meters |
| width |
10.1 meters |
| Draft |
9.1 meters |
| crew |
12 officers, 128 sailors |
| drive |
S5W pressurized water reactor, 15,000 SHP |
| speed |
20 knots |
| Armament |
16 ICBMs, 4 torpedo tubes |
The Ethan Allen class was a class of nuclear powered missile submarines (SSBN) operated by the United States Navy . Five boats of the class were built between 1959 and 1962. At the beginning of the 1980s the boats were reclassified as hunting submarines due to the restrictions of the SALT-I contract and finally all decommissioned by 1992.
history
Planning and construction
The plans for the Ethan Allen class began in the mid-1950s. It was the first class of missile submarines of the US Navy from drawing board to accommodate intercontinental ballistic missiles designed and manufactured, the five boats of the previous class George Washington still had the body of hunting submarines Skipjack class with an additional inserted missile compartment.
Four of the five boats were named after statesmen from United States history, these were Ethan Allen , a freedom fighter from the American Revolutionary War ( SSBN-608 ), Sam Houston , President of the Republic of Texas ( SSBN-609 ), John Marshall , Chief Justice of the United States ( SSBN-611 ) and Thomas Jefferson , third President of the United States ( SSBN-618 ). SSBN-610 , which is named after the inventor Thomas Alva Edison , falls out of the role . Edison was Chairman of the Civil Naval Consulting Board during World War I through which Edison helped establish the United States Naval Research Laboratory .
Construction of the boats began in 1959 and took place at the Electric Boat ( Ethan Allen and Edison ) and Newport News Shipbuilding ( Houston , Marshall and Jefferson ) shipyards . The boats each spent a little over a year in the dry dock, after which the Ethan-Allens were each a little under a year at the equipment pier and were on the shipyard test drives. This meant that there were around two years between keel laying and commissioning. Nothing was known about the construction costs.
period of service
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The five boats of the class were added to the fleet in 1961, 1962 and 1963, where they complemented the five boats of the Washington class . By 1967, 31 Lafayette-class boats (including the James Madison and Benjamin Franklin sub-classes ) were added. These 41 missile submarines made up the so-called 41 for Freedom , the fleet of submarines that carried the US deterrent to the oceans.
When the modern Ohio-class SSBNs came into service in the early 1980s , there was no longer any room in the regulations of the Strategic Arms Limitation Talks for the missiles on board the Ethan Allens , which is why the missile compartment was sealed and the launch tubes made unusable with concrete were. In addition, the missile control system was removed. After that, the boats were reclassified as hunting submarines and given the SSN identification . As such, the boats were mostly used for anti -submarine exercises. Three of the boats were decommissioned by 1985, the other two ( Houston and Marshall ) remained active until 1991 and 1992, respectively, as they had been equipped to transport two Dry Deck Shelters (DDS). Not only were the fastenings for the DDS installed, additional space was also created for the equipment of the special units to be transported.
All five boats were abandoned in the Puget Sound Naval Shipyard in the 1990s . According to the guidelines of the Ship-Submarine Recycling Program, they were first stripped of all radioactive parts and then dismantled.
technology
hull
The hull of a boat of the class was 125.1 meters long and 10.1 meters wide. The draft was 9.1 meters. Thus, each submerged boat displaced around 7,900 ts of water. In contrast to its predecessors, however, the missile section was already planned for during construction, which can also be seen from the lines. The starting shafts are, as is usual with American SSBN, behind the tower . In order to increase the maximum diving depth to about 400 meters, the class was made of HY-80 steel. This means that the steel has a guaranteed "Yield strength" ( yield strength ) of 80,000 psi - equivalent to approximately 5,516 bar - has.
Inside, the boats were divided up similarly to hunting submarines. In front of and under the tower were the torpedo, crew and command rooms, behind it was the rocket silo room - also known as the “Sherwood Forest” because of the log-like launch shafts -, then the reactor chamber and finally the engine room.
drive
The drive of the Ethan Allens consisted of a pressurized water reactor of the type S5W . The S stands for the use on a certain type of ship, here submarine , submarine, the 5 stands for the generation, the W represents the manufacturer, with this type Westinghouse Electric . This reactor delivered around 15,000 horsepower working on a shaft. The maximum submerged speed was 20 knots or less, a few knots slower than hunting submarines. However, a quiet drive system counted more than speed for the SSBN, as their main concern was clandestine patrol driving. The shape of the hull was optimized for underwater travel, which is why the boats only appeared for transit to and from the base. The theoretical maximum speed was around 15 knots.
Armament
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The main armament of the boats of the Ethan Allen class consisted of 16 UGM-27B Polaris A2 submarine-based intercontinental ballistic missiles (SLBM) . These had a range of up to 1500 nautical miles and an accuracy (specified in Circular Error Probable , or CEP for short) of around 900 meters. By 1974, all five boats had been converted to carry the much improved UGM-27C Polaris A3 . Not only was the range increased by 1000 miles, while the CEP was reduced by a third, the A3 could now carry three instead of just one warhead in a multiple reentry vehicle . At the end of the 1970s, the submarine fleet was converted to the new UGM-73 Poseidon ; However, since this was over ten meters long, it was not possible to use it on the Ethan Allens without making expensive structural changes to the boat. For this reason, too, the impending retirement from service was not a major loss for the deterrent concept of the USA.
For self-defense, each boat had four torpedo tubes in the bow. The diameter of 533 mm allowed the launch of the Mark 48 heavyweight torpedo from the introduction of the weapon in 1972 . There was reload capacity for four of the large Mark-48 or eight of the smaller Mark-46 lightweight torpedoes .
electronics
The Ethan Allen-class boats had several sonar systems with which they could detect enemy submarines and surface ships. The main system was the AN / BQS-4 , which could work both actively and passively and is located in the bow together with the pure passive sonar AN / BQR-7 . Since the tip of the bow of the boats was occupied by the torpedo tubes, the sonar system received a small "wing" on the hull to pick up noises. In addition, each boat was equipped with an active AN / BQR-19 that was used for navigation. An AN / BQR-15 acted as a towing sonar for eavesdropping at great distances .
Mission profile
The Ethan Allens were part of the United States' policy of deterring the oceans. With its 16 ICBMs, a boat left its home port under strict security precautions. Hunting submarines and destroyers ensured that the waters around the harbor were clear of enemy submarines so that the SSBN could safely depart. Thereupon the boat remained submerged for about three months without interruption and was in a certain patrol area, the coordinates of which were subject to the highest level of secrecy. After the patrol, the boat returned to port, changed crew - each boat had two complete crews, divided into Blue and Gold - and, after a maintenance period, left for the next patrol with the second crew.
As the most modern class of boomers at the time (as the SSBN was nicknamed in the US Navy), the five boats were stationed in Europe after their commissioning, as they could quickly reach the waters near the pole from there . The reason for the selection of this patrol area is based on the fact that nuclear missiles fired from there could reach the Soviet capital Moscow quickly, ergo the Soviet advance warning time was very short. The base of the five boats was initially Holy Loch in Scotland, then Rota in Spain from the mid / late 1960s . From the mid-1970s, the now relatively old boats were mainly used in the Pacific, home ports were Pearl Harbor on Hawaii and Apra Harbor on Guam .
The lead ship of the class, the Ethan Allen , is the only submarine in United States history that has ever launched a live, nuclear-powered ICBM. In 1962, the boat took part in Operation Dominic I , as part of the exercise Frigate Bird , a Polaris A2 launched from the boat , which detonated in the region of the island of Kiritimati in the Central Pacific.
After their conversion, Sam Houston and John Marshall were able to use the Dry Deck Shelter to transport special forces such as United States Navy SEALs and bring them to targets within enemy territorial waters without being noticed. There the commandos could leave the boat through a pressure lock and re-enter after completing a mission.
literature
- Dale Schoepflin: 41 for Freedom: The FBM Experience. PublishAmerica, 2006, ISBN 1-4137-6734-6 .
Web links
Footnotes
- ^ Stefan Terzibaschitsch : Seemacht USA , Bechtermünz-Verlag, ISBN 3-86047-576-2 , page 494
