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USS Observation Island (EAG 154) on 12 July 1962.

USS Observation Island (EAG 154) on 12 July 1962. Her single missile test tube is the white bump on the starboard side of the flight deck.
Click on this photograph for links to larger images of this class.

Design: MA C4-S-1a
Displacement (tons): 16,076 full
Dimensions (feet): 563.7' oa, 528' pp x 76' max x 29' load, (as AGM 23) 27' limit,
Armament: (1969) 4-20mmT; (1974) none
Accommodations: 17 officers and 248 enlisted; (as AGM 23) 92 officers and 465 enlisted
Speed (kts.): 20
Propulsion (HP): 17,500
Machinery: Geared steam turbines, 2 boilers (600psi/875deg), 1 screw

154OBSERVATION ISLAND10 Sep 1956New York SB15 Sep 195215 Aug 19535 Dec 1958

EAGNameTOOSStrikeDisposalFateMA Sale
154OBSERVATION ISLANDTr29 Sep 197231 Mar 20148 May 2014MA/T3 Apr 2018

Class Notes:
On 8 November 1955, after much inter- and intra-service wrangling, the Secretary of Defense established "a joint Army-Navy IRBM program having the dual objective of achieving an early shipboard ballistic missile capability and providing an alternative to the Air Force IRBM program." The Army-Navy missile was the Army's Jupiter and the Air Force's missile was the Thor, both liquid-fueled. CNO Admiral Arleigh Burke, a strong supporter, set up a Special Projects Office under Admiral William F. Raborn to manage the program. On 16 February 1956 Burke formally authorized the conversion of three MARAD Mariner-class (C4-S-1a) cargo ships to support the naval Jupiter IRBM program. The ships, which had been referred to Mariner No. 1, No. 2, and No. 3, were tentatively designated YAG 56, 57, and 58 by BUSHIPS pending formal action by SECNAV. Mariner No. 1/YAG 56 became COMPASS ISLAND (EAG 153), q.v., while Mariner No. 3 became EAG 155 and was then cancelled.

As early as early December 1955 it was understood that BUSHIPS intended to furnish Guidance Contract Plans and Contract Specifications to the conversion shipyard of Mariner No. 2. On 22-23 March 1956 an IRBM Launching and Handling Committee including representatives from BUSHIPS and many other organizations met at the Chrysler Missile Operations Division, Detroit, Michigan (the Army's production contractor for Jupiter which the Navy's Special Projects Office had also designated as its weapon system contractor), for the purpose of conceiving the basic plan and parameters of a shipboard launching system for the Jupiter IRBM missile (also called the FBM for Fleet Ballistic Missile). Topics covered included elevator-platform and catatpult-type launchers (the former being favored) and a myriad of safety and technical issues. On 22 May 1956 CNO changed the classification of the three Mariners from YAG to EAG (miscellaneous auxiliary, experimental), and BUSHIPS tentatively designated them EAG 153, 154, and 155. In May 1956 the process of producing Ships Characteristics for Mariner No. 2 was initiated. The ship was to be a Jupiter firing test ship capable of expansion by moderate re-conversion into an operational FBM attack ship. On 14 June 1956 BUSHIPS notified NSY Norfolk that the preparation of working drawings and the planning and conversion of a Mariner-type ship to EAG 154 under FY 1957 for the IRBM program was assigned to it, along with design work for EAG 155 in FY 1958. One Mariner from the Maritime Reserve Fleet at Mobile, Ala., and one from the James River reserve fleet were reserved for these conversions, although the specific ship assignments were still pending. The conversions would be in general accordance with contract plans and specifications that BUSHIPS expected to complete around 1 October 1956. (This date was still the target on 31 August 1956). EAG 154 would differ from EAG 153, then being converted by NSY New York, by the installation of additional berthing facilities for launching, handling, servicing and fueling for one missile, together with necessary damage control features. Conversion of EAG 154, a FY 1957 ship, was to start on 1 April 1957 and complete on 28 February 1958. Funds for EAG 154 would be forthcoming during August 1956. On 3 July 1956 an internal BUSHIPS memorandum stated that the Mariners to be converted to EAG 154 and 155 were EMPIRE STATE MARINER (MA hull 28, at Mobile) and PRAIRIE MARINER (MA hull 29, in the James River).

Preliminary characteristis for EAG 154 dated 10 July 1956 stated that her mission was to provide a means of evaluating launching, handling, servicing, and guidance equipment for the Fleet Ballistic Missile on board ship. Her primary task was to demonstrate the feasibility of launching and guiding the FBM from a seagoing vessel. Her secondary task was to develop detailed procedures for safe handling, serviding, launching, and guidance of the FBM on board ship. Space would be reserved for a prospective second stage conversion to a combatant (tactical vessel) with facilities for handling and launching of six FBM's. The design as described in these characteristics and in a report of a meeting held on 26 July 1956 provided for two elevator launchers with a servicing tower on a third elevator. These were to be on the port side, with a hangar type structure on the starboard side. A new superstructure would be installed well forward at frames 36-57 in the ship to house primary ship control, a combined weapon control station and CIC, a missile operations station, a telemetering station, a navigation information center, and a data reduction room. The original Mariner bridge amidships would be eliminated and the space reassigned. The stack would be removed and the uptakes diverted to provide exhausts on both sides of the ship. A damper would be installed so that exhaust could be quickly directed away from a missile launch. A heavy armoured deck (1.5", full width, frome 105 to stern) would be installed above the magazine area and forward and aft of the launching area. There would be a helicopter landing platform on the stern. Seakeeping capability would be improved by installation of ballast to compensate for light loading, activated fin stabilizers to reduce roll, and fixed fin stabilizers to reduce pitch.

As of 18 July 1956 the surface FBM program consisted of four ships: EAG 153 (navigation, to be ready for sea 2 Jan 1957), EAG 154 (2 FBM, to start contract design Jun 1956 and be ready for sea 30 March 1958), EAG 155 (6 FBM, to start contract design Feb 1957 and be ready for sea 30 Apr 1959, and BBG #1 (probably KENTUCKY, with 16 FBM, to start contract design in mid-1956 and be ready for sea on 15 January 1961). The first live Jupiter launch from EAG 154 was to be in early 1959.

A BUSHIPS memorandum for file dated 7 August 1956 stated that EAG 154 was designed primarily to prove the feasibility of launching the Jupiter missile from a ship. There were vague plans to convert the ship later to a combatant carrying 6 missiles, but this was not to interfere with its ability to carry out its primary mission. By 22 August 1956 the concept of the mission of Mariner No. 2 had been changed whereby the ship would not be converted into a Mariner No. 3 type (combatant) in the foreseeable future. It was expected that once the conversion was completed in March 1958 that the ship would operate in the vicinity of Patrick Air Force Base so the Navy could use the Air Force facilities there and its range across the West Indies for testing, loading, and tracking the test missiles. BUORD also wanted to design into the ship tracking capabilities for the first stage of flight.

On 14 September 1956 Commander Fifth Naval District directed NSY Norfolk to accept custody of SS EMPIRE STATE MARINER upon arrival at the shipyard around 20 September (she arrived on 21 September) and to place her out of service in reserve for conversion. EMPIRE STATE MARINER had been operated by United States Lines from delivery on 24 February 1954 until going into reserve at Mobile, Alabama on 9 November 1954. She was towed from Mobile by ATAKAPA (ATF 149). On 25 October 1956 an officer responsible for the conversion of EAG 154 indicated that it was desirable for the purpose of facilitating correspondence with the conversion shipyard that a name be assigned to the ship at an early date. The name OBSERVATION ISLAND was proposed on 6 November 1956, and on 5 December 1956 SecNav approved the classification EAG 154 and name OBSERVATION ISLAND for the ship. As of 7 November 1956 NSY Norfolk hoped to start work on 15 January 1957 on known structural and habitability work.

In the meantime, in the summer of 1956 a conference of experts at Nobska Point at Woods Hole, Mass., confronted with the size and weight of the cumbersome Jupiter-S (the solid-fueled alternative to the liquid-fueled Jupiter), which were driven in part by the size of its warhead, demonstrated that the Navy could build a much smaller ballistic missile and warhead long before the planned entry into service of Jupiter-S in 1965. In early September 1956 the Special Projects Office began to investigate the NOBSKA missile, now called Polaris, as a substitute for the unfinished Jupiter-S. On 8 December 1956 the Secretary of Defense authorized the Navy to initiate development of the Polaris FBM and terminated all collaborative efforts with the Army on either the liquid or solid versions of the Jupiter missile.

On 11 December 1956 BUSHIPS informed NSY Norfolk that a major reorientation of the FBM program necessitated stopping work on all projects in support of the liquid Jupiter missile. It directed stopping all design, material procurement, and productive work on the EAG 154 conversion. The EMPIRE STATE MARINER was to be closed up and placed in a maintenance status. The Bureau recommended the yard arrange berthing for her in the Elizabeth River reserve fleet for about nine months. The EAG 154 plans and specifications would require major revision because of the change in concept. An internal BUSHIPS memorandum dated 13 December 1956 explained that the Bureau had been notified that the liquid Jupiter missile was no longer contemplated in the Navy's Fleet Ballistic Missile Program and that the Polaris missile was being substituted. Therefore all codes in the Bureau were requested to stop all procurement action on those items which were applicable to the liquid Jupiter missile and the Jupiter mock-up installation. Alerted in advance to the decision, Buships by 5 December 1956 was drawing up preliminary characteristics for the new EAG 154 (POLARIS), with target dates of 1 April 1957 for contract plan signature, 1 October 1957 for start of conversion (changed by hand to 3 January 1958), and 1 October 1958 for completion of conversion. It was believed that all hull contract plans for the Jupiter EAG 154 would have to be withdrawn and that at least 75% of the hull sections of the specifications would have to be revised extensively. In short, the Polaris AG 154 was a completely different ship from the Jupiter AG 154.

The mission and tasks for USS OBSERVATION ISLAND (EAG 154) as a Polaris test ship were forwarded to CNO on 12 August 1958 for approval. Her mission was to provide development and test facilities for the Fleet Ballistic Missile (FBM) Weapon System at sea. Approved characteristics for a FBM Weapons System (POLARIS) Test Ship (EAG), SCB Project No. unknown, were promulgated on 8 December 1958 as the ship approached completion. The ship arrived at the Eastern Test Range 2 February 1959 to support the Polaris testing program, the first Polaris launch was on 27 August 1959 (A-1) and the last one on 20 January 1964 (A-3) with a total of 25 missiles launched. These included the first at-sea launch of the Polaris A-2 on 1 March 1961 and the A-3 on 17 June 1963. OBSERVATION ISLAND commenced an extensive ten month conversion on 24 June 1968 at the Norfolk Naval Shipyard in preparation for support of the Poseidon C-3 missile program and was the platform for first at-sea firing of the Poseidon missile in July 1969. OBSERVATION ISLAND was decommissioned 1 January 1972 and transferred to MARAD custody in the Suisun Bay Reserve Fleet on 26 January 1973. The ship was briefly transferred back to Navy custody on 18 August 1977 for stripping and was returned to Suisun Bay on 2 May 1978.

On 13 April 1979 OBSERVATION ISLAND was permanently transferred from MARAD to MSC at the request of the United States Air Force for use as a tracking ship, soon designated T-AGM 23. She underwent major modifications between 1979 and 1982 that included the installation of the AN/SPQ-11 COBRA JUDY passive electronically scanned array radar, which was used for monitoring compliance with strategic arms treaties and collecting data on missile tests. In the 31 years that followed, she averaged 260 days a year at sea in support of this monitoring mission. The ship was operated by MSC for the Air Force Technical Applications Center at Patrick Air Force Base. She was relieved in early 2014 by the new USNS HOWARD O LORENZEN (T-AGM 25).

Ship Notes:
154OBSERVATION ISLAND28(ex-EMPIRE STATE MARINER, completed 24 Feb 1954). Operated by the U.S. Lines for MSTS 24 Feb 1954 to 10 Sep 1954, then to NDRF, Mobile. Tentatively designated YAG 57 Feb-May 1956, then EAG 154. Transferred from MA 10 Sep 1956. Formally designated and named 5 December 1956. Conversion completed 5 Dec 1958. On 11 March 1968 effective 1 April 1968 EAG 154 was reclassified to AG 154. Decom. 25 Sep 1972, to MA custody 26 Jan 1973 and permanent 26 Jan 1974. From MA to MSC (permanent transfer) 13 Apr 1979. To T-AGM 23 1 May 1979. To MA custody 29 Mar 2014. Departed 3 May 2018 under sales contract.

Page Notes:
Compiled: 18 Oct 2021
© Stephen S. Roberts, 2021
Special sources: NARA: RG 19 Item S-15 Entry UD 1024-AD Box 1; Harvey M. Sapolsky, The Polaris System Development, Harvard University Press, 1972, pp. 21-34.