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USS Mount Whitney (LCC 20) ca. 1990.

USS Mount Whitney (LCC 20) ca. 1990.
Click on this photograph for links to larger images of this class.

Design: SCB Project Nos. 400.65 and 400.66
Displacement (tons): 13,038 light, 18,874 full (LCC 19)
Dimensions (feet): 620' oa (original), 580' wl x 108' e, 82' wl x 27' max nav
Armament: 2-3"50T; (1974) 2-3"50T, 2-MK25 (Sea Sparrow) MLS; (19: 1985, 20: 1987) 2-3"50T, 2-MK25 MLS, 2-CIWS; (1992) 2-CIWS; (1998) 2-25mmS, 2-CIWS
Accommodations: 52 officers and 790 enlisted (LCC 19)
Speed (kts.): 22
Propulsion (HP): 22,000
Machinery: Steam turbines, 2 boilers (600psi), 1 screw

19BLUE RIDGE31 Dec 1964NSY Philadelphia27 Feb 19674 Jan 196914 Nov 1970
20MOUNT WHITNEY22 Aug 1966Newport News8 Jan 19698 Jan 197016 Jan 1971

LCCNameTDecommStrikeDisposalFateMA Sale
19BLUE RIDGEIn Comm. 2022--------
20MOUNT WHITNEYIn Comm. 2022--------

Class Notes:
As of 30 July 1951 one prototype new construction AGC, SCB Project No. 92, based on the P2-SE2-R1 transport hull (see the ADMIRAL W S BENSON, AP 120 class) was under consideration for inclusion in the FY 1953 program but BUSHIPS found major problems with the idea and it was dropped from the proposed FY 1953 program on 1 September 1951. As of 16 March 1954 BUSHIPS intended for the contract plans of a new AGC or a conversion of a Mariner class cargo ship to be completed by 15 September 1955. However no new or converted AGC was programmed during the 1950s.

Serious work on a new construction AGC began during 1960 with extensive discussions on requirements between BUSHIPS and the fleets and CNO plus a quick study based on the Mariner class hull and machinery. This was followed in November 1962 by a single sheet of characteristics from the Ship Characteristics Board accompanied by a request for a feasibility study. This study, now for an AGC, SCB Project No. 248, based on the hull and machinery of the new combat store ship (AFS), found that the superstructure would have to be enlarged to accommodate the vast areas of command and communications spaces but that the elimination of the cargo handling of the AFS would more than compensate for the weight of the enlarged superstructure and the antennas. On 17 April 1963 the Ship Characteristics Board circulated for comment preliminary characteristics for a new construction Amphibious Force Flagship (AGC) based on the AFS 1 hull and propulsion plant, now designated SCB Project No. 400.65. The ship now had a second, contingent, function of serving when not engaged in amphibious operations as a flagship for striking force commanders and numbered fleet commenders in place of the converted World War II cruisers then being used. The primary consideration for topside configuration was to obtain the most effective radiation characteristics and coverage for the communications and radar antenna systems, requiring minimizing vertical topside structures and masts. Armament was to be two 3"/50 twin mounts, one fore and one aft, plus space and weight reserved for two Sea Mauler point defense SAM systems. A helicopter platform and hangar for two small helicopters was to be provided. The ship was to have command facilities and accommodations for amphibious task force, landing force, and air support commanders and their staffs plus facilities for the control and coordination of supporting arms, a joint communications center, and facilities for the control of aircraft and the collection, processing, and dissemination of operationsl intelligence. Total accommodations were to be for 269 officers, 119 CPOs, and 1,077 other enlisted. Boat stowage was to be provided for 4 LCPL, 2 LCVP, 2 40' utility boats, and inflatable lifeboats for 1,400 persons.

On 10 July 1963 the Ship Characteristics Board held a working level meeting to consider revised preliminary characteristics for SCB 400.65. The BUSHIPS Preliminary Design Branch (Code 420) presented its work on the design based on the AFS 1 hull, but the Electronic-Electrical Design Branch (Code 450) announced that it had just decided that it would require a flat-top configuration to provide a ground plane for antenna performance with minimum topside structure and absolutely no running rigging of any sort exposed to electronic radiation. This also required putting the boats in sponsons and locating the helicopter hanger and shops below decks with an elevator. After trying unsuccessfully to adapt the AFS 1 hull, Code 420 shifted to the LPH 2 hull as a more promising basis for the design, giving it a centerline bridge structure instead of an island. The substitution of a conversion, either of an AP 120 class (P2-SE2-R1) troop transport, a CVL-22 class AVT, or CC-3 (ex AVT 6, ex CVL 48) was then considered, but by 20 November 1963 when a full meeting of the Ship Characteristics Board was held on the AGC all work focused on the new construction design based on the LPH 2 hull. Two ships were funded, one in Fiscal Year 1965, the other in 1966. Approved characteristics for an Amphibious Force Flagship (AGC), SCB Project No. 400.65, were promulgated on 24 January 1964 and updated as SCB Project No. 400.66 on 18 September 1964 with a final change on 28 August 1969.

Electronics were a driving factor in the design. The ship had to be able to transmit simultaneously on 40 separate HF channels, which could only be done with broadband antennas. Massive broadband high frequency (HF) discage transmitting and receiving antennas were of primary importance because the ships would rely on HF radio to reach over the horizon to ships and to commands ashore. The ships also carried another kind of HF antenna, working at the upper end of the HF frequency range: a directional log periodic troposcatter antenna mounted atop a lattice mast. A new technology, satellite relay, was just being introduced for longer-haul communications back to the United States, and a structural tower supported on bulkheads on the second deck was provided to ensure a strong and rigid foundation for the MISER (Microwave Space Electronic Relay) satellite relay system. The MISER system included a 12 foot diameter antenna covered by a 20 foot diameter radome, a large operator room located a maximum of 20 feet from the antenna, and a high voltage power supply system located a maximum of 60 feet from the antenna, effectively dictating the structure of the tower. The MISER tower also held a circular array of ECM, VHF (amphibious communications), and UHF (eventually including NTDS) antennas. Geosynchronous communications satellites were still in development following the failure of the ADVENT program (see AG 164) until the sub-synchronous Initial Defense Satellite Communications System (IDSCS) became operational in 1968, and experience with a satellite dish antenna in Arlington (AGMR 1) showed that a firm foundation was needed for gyroscopes to keep the antenna stable while tracking the original low orbiting communications satellites. MISER, which had also been planned for a follow-on ship to Arlington, (the original AGMR 2), failed during development and much lighter SATCOM antennas were ultimately fitted. A height finding radar was also needed for the ship's air control function, and the AN/SPS-48 was ultimately provided along with an AN/SPS-40 air search radar and a masthead Tacan for aircraft navigation. The design also included a pair of Sea Mauler missile launchers, but this was deleted from the characteristics on 10 February 1964 for replacement by a self-defense missile system "to be developed," ultimately two Mk 25 Sea Sparrow launchers that were fitted several years after the ships entered service.

A new study of amphibious flagships conducted between February 1967 and April 1968 resulted in a plan that included construction of a third new AGC under the FY 1969 program. She was to have been designed from the outset for both amphibious force and fleet command functions while the first two were primarily fitted for amphibious forces. However on 9 Feb 1968 a Navy proposal to slip her to FY 1970 was approved and as of early 1969 construction of the third new AGC (now LCC) had not yet been approved for FY 1970, funds being withheld pending a study of alternatives. Ultimately no more new command ships were built, although two LPDs were converted to fleet flagships, LA SALLE (LPD 3) to AGF 3 in 1972 and CORONADO (LPD 11) to AGF 11 in 1980.

On 14 Sep 1968 SECNAV directed the redesignation of AGCs, AKAs, and APAs to LCCs, LKAs, and LPAs. OPNAV notice of 25 September 1968 stated that LCC 19-20, then building, were to be reclassified to LCC on dates determined by NAVSHIPS. A NAVSEA letter of 1 October 1968 requested officials at Newport News and Philadelphia to implement the new system on the AGCs they were building, and 1 October 1968 became the reclassification date for LCC 19-20. In October 1979 BLUE RIDGE relieved the cruiser OKLAHOMA CITY (CG 5) as flagship of the Seventh Fleet at Yokosuka, Japan, and in January 1981 MOUNT WHITNEY relieved ALBANY (CG 10) as flagship of the Second Fleet at Norfolk. Both AGCs were still in commission in 2022 as fleet flagships. MOUNT WHITNEY converted to a mixed USN (military) and MSC (civilian) crew in 2004, BLUE RIDGE remains fully USN-manned.

Ship Notes:
19BLUE RIDGEFY 1965. Name assigned as AGC, to LCC 19 1 Oct 1968. Based at Yokosuka, Japan, in 2022 supporting the US Seventh Fleet.
20MOUNT WHITNEYFY 1966. To LCC 20 1 Oct 1968, name assigned 11 Dec 1968 as LCC. MSC assumed navigational operation of the ship 20 Sep 2004. Based at Gaeta, Italy, in 2022 supporting the US Sixth Fleet.

Page Notes:
Compiled: 29 Jul 2021
© Stephen S. Roberts, 2021
Special sources: NARA: RG 19 Entry P 26 Boxes 7-9; Norman Friedman, U.S. Amphibious Ships and Craft, (Annapolis, 2002).