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USS <I>YAG 36</I> with <I>YAG 37</I> and <I>YAG 38</I> in reserve in Japan.

USS YAG 36 with YAG 37 and YAG 38 in reserve in Japan (NavSource).
Click on this photograph for links to larger images of this class.

Class: YAG 36 (YAG 36)
Design: MC EC2-S-C1
Displacement (tons): 3,900 light, 13,710 full
Dimensions (feet): 442' oa, 416' pp x 57' e/wl x 28' max nav
Armament: none
Accommodations: 4 officers, 34 enlisted
Speed (kts.): 11
Propulsion (HP): 2,500
Machinery: Steam triple expansion reciprocating, 2 boilers (220psi/450deg), 1 screw

36YAG 36 (ex FLOYD W SPENCER)21 Apr 1952Delta SB17 May 19441 Jul 1944--
37YAG 37 (ex-JOHN L SULLIVAN)12 May 1952Permanente Metals #22 May 194326 May 1943--
38YAG 38 (ex EDWARD KAVANAGH)3 May 1952New England SB14 Nov 194324 Dec 1943--

YAGNameTInactStrikeDisposalFateMA Sale
36YAG 36--1 Jun 19608 Nov 1960Navy sale--
37YAG 37--5 Mar 195627 Feb 1958MA/S--
38YAG 38--1 Jun 19608 Nov 1960Navy sale--

Class Notes:
On 22 October 1951 CNO informed BUSHIPS that an urgent need existed for three Guinea Pig ships in the operating forces and asked that BUSHIPS prepare at high priority a design and cost estimate for the minimum necessary alterations and activation of Liberty-class ships in the MARAD reserve fleet. The design work was to be conducted at a rate that would permit requesting the funds for the actual work in a supplemental FY 1952 budget estimate. The general requirements and considerations involved in altering and operating the ships were contained in Mine Countermeasures Emergency Instructions dated 30 December 1948. An alternative study was also to be conducted for altering and activating USS HOLLAND (ARG 18) for this role. At a lower priority, CNO also asked BUSHIPS to prepare plans of a more general nature for the alteration of other merchant vessel typess to Guinea Pig ships. The types selected were to be those most plentiful and most likely to be available for conversion at the scene of an emergency.

On 26 March 1952 the Navy informed the Commerce Department that it had an urgent requirement for three Liberty ships for highly classified operations. The Navy requested the transfer at Yokosuka in March and April 1952 of PARK BENJAMIN, FLOYD W SPENCER, and EDWARD KAVANAGH. The Commerce Department approved the transfer on 11 April 1952, but on 18 April PARK BENJAMIN was reported to be aground and the navy asked for the substition of JOHN L SULLIVAN. The three requested ships were then all in commercial operation in the Far East under MSTS control and had to be redelivered by their operators to MARAD before transfer to the Navy. COMNAVFE accepted custody from MARAD and placed in caretaker status FLOYD W SPENCER on 21 April, EDWARD KAVANAGH on 3 May, and JOHN L SULLIVAN on 12 May 1952. On 3 June 1952 the three ships received the Navy classifications of YAG 36 (ex-FLOYD W SPENCER), YAG 37 (ex-JOHN L SULLIVAN), and YAG 38 (ex-EDWARD KAVANAGH). The Naval Vessel Register (NVR) shows YAG 36 going into "reserve in service" status in April 1952 upon acquisition and the other two in May 1952. According to the NVR YAG 36 and 38 were never activated before disposal in 1960.

Normally vessels whose classification began with the letter "Y" were service (formerly called yard) craft that were not placed in commission but were commanded by non-commissioned personnel and assigned an In-Service status under the Commandant of a Naval District. Therefore their operation was not charged to personnel ceilings as established for Fleet Operations. YAG's were only in commission as miscellaneous auxiliaries for experimental purposes. The YAGR radar picket ships (later AGR, q.v.) were also so designated so that their personnel did not count against a fleet ceiling.

CNO on 8 April 1954 suggested the possibility of utilizing large ships (Guinea Pigs) as universal or all influence minesweepers. YAG 37 was placed in service at Yokosuka on 24 June 1954 and taken from Japan to Panama City, Fla., where custody was accepted on 17 October 1954. Technical tests were then conducted at the U.S. Navy Mine Defense Laboratory to determine the nature and extent of her influence fields. Following the tests YAG 37 arrived at the MARAD reserve fleet at Beaumont, Tex., on 8 December 1955 and custody was transferred to MARAD there on 9 December 1955. At the Navy's request she was given the EC2-S-22a conversion as part of MARAD's reserve fleet refurbishment program (see the YAG 45 class) at Mobile, Ala. from 8 December 1955 to 23 March 1956 and she was then laid up in permanent MA custody in the MA reserve fleet at Mobile, Ala.

An internal BUSHIPS memorandum of 26 October 1955 requested a feasibility study of the use of aircraft engines to propel Guinea Pig minesweepers, and a response on 30 January 1956 reported that the idea appeared feasible. On 17 February 1956, anticipating satisfactory results, an internal BUSHIPS memo noted that a redesign of the Guinea Pig conversion to an actual minesweeper appeared warranted. It seemed to be the most practical method for sweeping combination pressure influence mines, and it would have the immediate capability of sweeping any type of influence mine to be developed in the future. Costs were to be kept down, as if they proved effective large numbers of Guinea Pigs would be required. The Guinea Pig would have topside propulsion by turbo propeller aircraft engines (two forward and one, later two, aft, the after ones also serving as a rudder). These engines would enable the ship to retain mobility even after an explosion that would disable any machinery mounted in the hull. The original machinery spaces would be filled with buoyant material and water ballast in the same manner as the hold compartments, the original propulsion equipment would be either left in place or removed, the screw would be removed, and the rudder would be locked amidships. The vessel would be operated by remote control in waters which had already been cleared of moored mines. The project to test the feasibility of propelling and controlling a large pressure minesweeping vehicle (a Liberty ship with aircraft engines) was named Project DUMBO.

The 17 February 1956 memo asked that a design study be conducted with plans and specifications to be prepared by 1 June 1956 (soon changed to 29 July 1956) and a prototype be tested in an explosion test series being planned for early 1957. The design was to be a conversion of an existing YAG, and no project number was assigned to the study. Four 5,000 hp Pratt and Whitney T-34 turboprop aircraft engines with their Hamilton Standard electronically governed propellers were removed from a Lockheed Constellation aircraft in which they had been mounted for test flights. They were to be mounted on the ship on 40mm gun mounts which could be controlled from a central station. The Naval Air Station at Jacksonville, Fla., designed the installation of the engines on the gun mounts while the Bethlehem Steel Corp. at Baltimore designed the ship installation. The Navy asked for temporary transfer of YAG 37 for a special project on 4 September 1956 and she was withdrawn from the Mobile reserve fleet on 24 April 1957. The conversion work was put out for competitive bids early in 1957, Rawls Brothers Shipyard in Jacksonville, Fla., won the bidding, and they completed the installation and dock trials on 19 June 1957. According to the NVR, YAG 37 returned to "active in special service" status in June 1957, and as of 22 June 1957 she was enroute to Panama City where she was to be tried on the tracking range of the U.S. Navy Mine Defense Laboratory for maneuvering capability. These tests were completed by the end of August, the ship attaining speeds up to 7 knots and proving sufficiently maneuverable. The ship was then towed from Norfolk to the Maryland Shipbuilding and Drydock Co. at Baltimore for repairs, the original steam propulsion machinery was removed, some internal structural changes were made to improve resistance to underwater explosions, and the ship was then tested in a series of underwater explosions in October. Taken by the Navy to Newport News, Va, after the tests, the now severely damaged YAG 37 was "transferred to another agency" (to MARAD for sale) in March 1958.

Following the October 1957 tests, a BUSHIPS internal memorandum dated 8 November 1957 suggested the use of diesel powered outboard propulsion and steering units as a lower priced and easier maintained alternative to the aircraft engines tested under Phase I of project DUMBO. This idea had been rejected for YAG 37 because of inadequate power and expected vulnerability of the machinery to explosion damage, but it was estimated that two 400-hp units mounted on an enclosed watertight platform at the stern of a YAG would produce a speed of about 8 knots and that the idea appeared worth reconsidering. The Ship Characteristics Board began to develop characteristics for a Guinea Pig (SCB 195) in March 1958, which after many delays ultimately resulted in the MSS-1 of FY 1966, a Liberty ship (ex HARRY L GLUCKSMAN) classified as a "device" that used outboard diesels and underwent tests between 1969 and 1973.

Ship Notes:
36YAG 362802(ex FLOYD W SPENCER, compl. 22 Aug 1944). FY 1953. To USN custody 21 Apr 1952 in Japan. In USN reserve 1952-60. Title to Navy 31 May 1956. Disposal approved by SECNAV 20 May 1960. Sold by the Navy to T. Yamamoto & Co., Japan, and delivered in Japan 8 Nov 1960 to BU.
37YAG 371121(ex-JOHN L SULLIVAN, compl. 7 Jun 1943). FY 1953. To USN custody 12 May 1952 in Japan. In USN reserve 1952-54. In service 24 Jun 1954 for minesweeping tests, to MA temporary custody 9 Dec 1955, struck 5 Mar 1956, to MA permanent custody in the Mobile, Ala., reserve fleet after an EC2-S-22a conversion 12 Mar 1956. To Navy custody at Mobile 24 Apr 1957, in service Jun 1957 for more tests, which resulted in severe damage. Sold by MA 27 Feb 1958 at Newport News, to buyer 19 Mar 1958, BU at Wilmington, NC, 1958.
38YAG 382207(ex EDWARD KAVANAGH, compl. 5 Jan 1944). FY 1953. To USN custody 3 May 1952 at Yokosuka. In USN reserve 1952-60. Title to Navy 31 May 1956. Disposal approved by SECNAV 20 May 1960. Sold by the Navy to Ridgefield Navigation Co. Ltd. of Liberia (U.S. owned), and delivered in Japan 8 Nov 1960 to BU.

Page Notes:
Compiled: 20 Oct 2021
© Stephen S. Roberts, 2021
Special sources: NARA: RG 19 BUSHIPS Confidential Corresp 1946-61 File C-FS-S1-ARG18 (22 Oct 1951), RG 19 Entry UD 1024-H Box 6 (YAG 37), RG 19 Entry P 62 Boxes 73, 95 (MSS 1, 1958-1964)