USS Rigel (AF 58) circa 1956.
Click on this photograph for links to larger images of this class.
Class: RIGEL (AF 58).
Design: SCB Project No. 97 and MA R3-S-4a.
Displacement (tons): 7,950 light, 15,150 full
Dimensions (feet): 502' oa, 475' wl x 72' e/wl x 29' max nav
Armament: 4-3"/50T; (58: 1963, 59: 1969) 2-3"/50T
Accommodations: 20 officers, 330 enlisted
Speed (kts.): 21
Propulsion (HP): 16,000
Machinery: Geared steam turbines, 2 boilers (615psi/850deg), 1 screw
Construction:
| AF | Name | Ord | Builder | Keel | Launch | Comm |
| 58 | RIGEL | 13 Aug 1953 | Ingalls SB, Pascagoula | 15 Mar 1954 | 15 Mar 1955 | 2 Sep 1955 |
| 59 | VEGA | 13 Aug 1953 | Ingalls SB, Pascagoula | 24 May 1954 | 26 Apr 1955 | 10 Nov 1955 |
Disposition:
| AF | Name | T | Decomm/Cust | Strike | Disposal | Fate | MA Sale |
| 58 | RIGEL | Tr | 9 Sep 1992/C | 16 May 1994 | 1 Apr 1998 | MA/T | Jul 2008 |
| 59 | VEGA | 29 Apr 1977 | 29 Apr 1977 | 2 May 1977 | MA/T | 21 Dec 1977 |
Class Notes:
On 19 April 1951 CNO's Director of Fleet Operation (Op-33) wrote that the Navy then had 14 active stores ships (AF), but seven of these were small 10-knot ships and three were bulk carriers for MSTS point-to-point service. The fleets therefore had only four fast issue ships against a requirement for 16. One acquired ship (AF 55) was then being converted to a fleet issue stores ship with FY 1951 funds and two more (AF 56-57) had been included in the FY 1952 program, but with these the fleets would still be short nine AFs capable of underway replenishment. On 13 February 1951 Op-33 had recommended including in the FY 1953 building program four conversions of existing merchant type hulls or new construction fast fleet issue reefers (AF) to replace present slow AF's. An AF prototype was included in a SCB draft of the FY 1953 program dated 24 May 1951. BUSHIPS on 30 July 1951 commented that the requirements for this ship, SCB Project No. 97, in which the basic design of the C3-S-DX1 (Freedom class, see SCHUYLER OTIS BLAND, AK 277) would be revised to eliminate present criticisms, were generally feasible. The four stores ships (AF) in the FY 1953 program were reduced to two new construction ships during the summer of 1951, prompting a protest on 4 Sepember 1951 from Op-33 that the reduction meant that "we must expect a dangerous shortage in this type."
An internal BUSHIPS memorandum of 7 September 1951 reported a discussion three days earlier with MARAD concerning possible modifications to the Maritime Administration's C3-S-DX1 design for naval use. Modifications under consideration were the substitution for the experimental 850 psi - 890 degree F main propulsion plant in BLAND of a proven 600 psi - 850 degree F main plant and the substitution for BLAND's 120/240 electrical DC generating plant of a 440-volt AC plant (a change already made in the design of MARAD's C4-S-1a Mariner design). No change to the basic hull or propeller design was contemplated, and the cargo handling facilities were considered to be excellent. The speed and performance of BLAND to date were also considered encouraging. But for the proposed FY 1953 AF (and AKV) Navy designs it was felt that greater utilization of space could be accomplished by modifying the 'tween deck spacing and hull depth of the C3-S-DX1 and that some re-spacing of main transverse bulkheads and the addition of some ballast might be required to achieve satisfactory subdivision and stability. It was also recommended that Navy rather than commercial specifications for materials and component parts be used throughout as was then being done for the new AO 143 design. The basic hull and machinery design modifications accepted for the AF design in the 1953 program were expected to be satisfactory for any later auxiliaries to be built by the navy of this type or of the AE, AK, AKS, AVS, and AKST types. In view of the degree and extent of the design modifications proposed for the AF type it was recommended that it be considered strictly new construction, and it was expected that it could be built at little additional cost over that of construction to a modified C3-S-DX1 design which would then require extensive alterations. The memo reaffirmed, however, that the present selection of the C3-S-DX1 as a prototype for mobilization naval conversions from merchant vessels (as opposed to new construction) for AE (SCB 99), AF (SCB 100), AVS (SCB 102), AK (SCB 105), AKS (SCB 106), and AKST (SCB 108) type ships remained firm.
On 1 October 1951 the Ship Characteristics Board circulated for information and study its first preliminary characteristics for a stores ship (AF), Project No. 97. It noted that, in contrast to the mobilization AF (SCB 100) that would be obtained by conversion of a MC C3-S-DX1 hull, this project envisioned an AF design that would be eminently suited to the Navy's needs without compromising military features. The general configuration of the design was to be similar to the C3-S-DX1 in tonnage, length, beam, and draft (14,330 tons full load, 477' oa x 66' x 26' full load), and it was also envisaged to be suitable for use as the basic design for all new construction vessels of the AE, AF, AK, AKS, and AKST classes destined for use in the Logistic Support Force. The design would provide a 20 knot stores ship whose entire cargo stores space was capable of being put under refrigeration and in which the sectinalization by insulated bulkheads and decks would ensure that breakout from any particular space would have a minimum effect on adjoining spaces. The ship was to be provided with the most modern transfer at sea gear and be capable of maintaining a formation speed of at least 15 knots while discharging cargo at maximum rate to ships alongside. Armament was to be six 3"/50 twin mounts. The ship was to be capable of operating three transfer-at-sea stations per side simultaneously. No aviation facilities were specified. Accommodations were for 20 officers and 275 enlisted.
On 5 January 1952 BUSHIPS informed the Administrator of the Maritime Administration, retired Vice Admiral E. L. Cochrane, USNR (the wartime chief of BUSHIPS), that it was possible that the Navy Shipbuilding and Conversion Program for FY 1953 might include two new naval refrigerated stores ships (AF). Based on its earlier analysis, BUSHIPS listed the expected characteristics, including a 20 knot trial speed, a single screw powered by a steam turbine, and principal hull characteristics resembling the MARAD C3-S-DX1 design ship but with significant modifications including decks without sheer and modified deck spacing. BUSHIPS stated that if the ships were included in the 1953 program it was considering having them built for the Navy Department by the Maritime Administration with Navy funds, resulting in a design suitable for the merchant service and readily convertible into various types of naval auxiliaries. If the military requirements militated against the use of the design for merchant ships, it would still have merit as a prototype for mobilization construction of naval auxiliaries. MARAD agreed to participate in the project on 14 January 1952. On 27 February 1952 BUSHIPS specified that the Navy would produce the design and contract drawings with assistance from commercial design agents as required. The design would be based on merchant ship standards except where Navy standards were mandatory. Construction of the ships and approval of all working plans, however, would be by MARAD.
The New York firm of George G. Sharp, Inc., was retained as design agent for the two new Stores Ships (AF) in the FY 1953 program and started work on 7 February 1952. On 19 February 1952 Sharp delivered preliminary basic design data for its project V-5019, which it updated on 7 and 24 March following a conference at BUSHIPS on 25 February 1952. The first preliminary characteristics of 1 October 1951 were circulated by the SCB for review on 14 March 1952 and updated on 19 March 1952. The length overall was changed from 477' to 500' by Sharp in order to give required deadweight and capacities, resulting in a ship measuring 500' oa, 475' pp x 72' beam and 27' full load draft for a full load displacement of 16,020 tons (thus departing from the C3-S-DX1 model). Trial speed was 20 knots and service speed 18.5 knots. The design had a capacity of 360,000 cubic feet of refrigerated cargo with 40% frozen and 60% chilled and a crew, as before, of 295 men. DCNO (Operations) on 8 April 1952 reduced the 3"/50 armament from six to four twin mounts, all on the centerline (deleting two amidships). BUPERS recommended changing the enlisted complement from 275 to 301 based on manning requirements for an increase from five to six holds recommended by the SCB. On 25 April 1952 Sharp received a contract to prepare and furnish design studies and a circular of requirements for the new AF. On 19 May 1952 BUSHIPS provided comments on the 19 March SCB characteristics, noting that the sustained speed of the ship was then estimated at 19.4 knots and recommending that the specified trial speed be raised from 20 knots to 20.5 knots, to be run at a trial displacement of 11,000 tons. (Trials were rarely if ever run in full load condition.) On 22 May 1952 the SCB circulated revised second preliminary characteristics dated 20 May for Project No. 97 to be reviewed at a meeting on 27 May 1952. They still stated that the general configuration of the new design (tonnage and dimensions) would be similar to the MARAD C3-S-DX1 design although the enlarged dimensions were cited. It was potentially to be the basic design for new construction AE, AF, and AKS types but references to new construction AK and AKST types were deleted.
Approved characteristics for a new construction Stores Ship (AF), SCB Project 97, were promulgated by the SCB on 21 July 1952 with a final change on 25 March 1957. The armament was confirmed at four 3"/50 twin mounts on the centerline, the trial speed was 20.5 knots at the trial displacment of 11,000 tons, and the ship was to maintain a 19.4 knot sustained speed at replenishment displacement (14,730 tons). The cargo was still 40% frozen (0 degrees F) and 60% chilled (30 degrees F). The complement was now 20 officers and 330 enlisted. On 21 July 1952 Sharp produced a "Memo Summary of Design for Refrigerated Stores Ship (AF) Shipbulding Project No. 97," that was discussed in a conference at BUSHIPS on 29 July. Basic characteristics were now 500' oa, 475' pp x 72' beam and 26.5' full load draft and a trial speed without cargo (10,939 tons) of 20.8 knots at 15,200 SHP, a sustained speed at full load replenishment displacement (14,730 tons) of 19.6 knots at 15,200 SHP, and an endurance speed at full load displacement (15,670 tons) of 18.5 knots at 11,900 SHP. Maximum continuous SHP was 16,000. Sharp completed their design work on the ship on 30 August 1952. The MARAD specifications for the ships were dated 3 November 1952 and were revised on 12 January 1953. The two ships, MARAD hulls 36 and 37, were the first ordered by MARAD after the Mariner class cargo ships. Designated R3-S-4a by MARAD, they were then the largest American pure refrigerated ships at 15,540 tons full load.
As of 20 November 1952 two more Project 97 AFs were included in the initial FY 1955 program to replace two that fell below the cutoff point for the FY 1954 program, but the FY 1955 program recommended by CNO to SECNAV on 9 January 1954 included no auxiliaries except for four YAGRs (later AGRs). On 19 July 1955 CNO approved a FY 1957 program drafted on 21 April 1955 that included another Project 97 AF. At a meeting on 23 August 1955 following the trials of AF 58 the Ship Characteristics Board reviewed the characteristics of SCB Project No. 97 for their suitability for use in connection with the FY 1957 building program. The Board determined that a new set of characteristics under a new project number would be appropriate in view of the "minor but significant" changes in the hull form proposed by BUSHIPS while designing the similar AE 21 class. In addition, the Bureau of Supplies and Accounts wanted a revision of the frozen and chilled percentages and a reduction in the temperature of freeze spaces from zero to minus 10 degrees F. On 29 August 1955 BUSHIPS Code 300 reported that for the FY 1957 AF it appeared that a rework of contract plans and specifications would be required as a result of the trials of AF 58 and the just-completed SCB review of the AF characteristics. It recommended assigning this job to Sharp with an estimated award date of October 1955. In early October SECNAV returned the draft FY 1957 program to CNO for cost reductions resulting in the deletion of two AO. Preliminary characteristics for a new construction AF (now called a store ship), SCB Project No. 156, were distributed on 21 October 1955. These were essentially a reproduction of the Project 97 characteristics redrafted to utilize the basic hull and machinery design being developed for the Project 114 AE. Dimensions were 512' oa x 72' x 26.5' full load for a full load displacement of 15,600 tons. The entire cargo space was to be capable of being placed under refrigeration, 55% being freeze space at minus 5 degrees F and 45% chill space at plus 30 degrees F. Approved characteristics for a new construction store ship (AF), SCB Project No. 156, were promulgated on 28 November 1955 with a final change on 25 March 1957. Between 5 October and 18 November 1955 the FY 1957 AF was changed from Project 97 to Project 156, but by 23 November 1955 the AF had been deleted from the program. On 20 August 1957 CNO approved a draft FY 1959 program that included one new construction AF but it was deleted on 17 September 1957. On 20 October 1958 the SCB requested BUSHIPS to initiate a design study for a new type of store ship, the AFS (Combat Store Ship, q.v.), which combined the features of the AF, AKS, and AVS into one hull.
VEGA was used from March to November 1960 for at-sea tests of a ram-tensioned sliding-block ammunition and cargo transfer system called STREAM (Standard Tensioned Replenishment Alongside Method), which was installed in half of an M-frame transfer station then being developed for the AOE 1 class. The STREAM system was integrated into the more complex FAST system of the 1960s and began to replace it in 1970 when FAST proved to be a maintenance nightmare. (See the AOE 1 class for a description and history of FAST.) The improvised M-frame stayed on VEGA for several years because SERVPAC thought they might want the experimental STREAM rig for service use. In the meantime RIGEL in 1961 was fitted with an experimental Helicopter Extended Area Platform (HEAP), an inexpensive cantilever beam that extended 25 feet over the starboard side forward of the bridge and from the end of which helicopters could pick up cargo for delivery to other ships. Two years later, that platform was replaced by a conventional helicopter platform on her fantail (displacing two of her four 3"/50 twin gun mounts), a modification soon applied to much of the Navy's underway replenishment fleet. VEGA received her platform aft in 1969. RIGEL served in the Atlantic while VEGA served in the Pacific. At the decommissioning ceremony for VEGA in 1977, Commander Service Group One explained that "This type of ship with booms, hatches and masts is doomed." Unlike VEGA, RIGEL in 1975 found a second career in MSC with her guns and other military equipment removed.
Ship Notes:
| AF | Name | MA | Notes |
| 58 | RIGEL | 36 | FY 1953. Decomm and to MSC 23 Jun 1975. To MA custody 9 Sep 1992, title accepted by MA 1 Apr 1998 for disposal. Transferred back to Navy for disposal as required by the FY 2008 Defense Authorization act (with TRUCKEE and KALAMAZOO). Sold by Navy Jul 2008 to All Star Metals, Brownsville, TX. Departed MA custody 28 Aug 2008 enroute Brownsville. |
| 59 | VEGA | 37 | FY 1953. To MA custody 2 May 1977. Sold 21 December 1977 to Union Metals & Alloys for non-transportation use (probably as a processing ship). BU 1988 at Kaohsiung. |
Page Notes:
Compiled: 22 July 2021
© Stephen S. Roberts, 2021
Special sources: NARA: RG 19 Entry P 39 Boxes 2-3, RG 19 Entry P 37 box 67; Marvin O. Miller, Designing the U.S. Navy's Underway Replenishment System, Naval Surface Warfare Center, Port Hueneme, Cal., 1996.