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USS YAG 36 with YAG 37 and YAG 38 (Navsource)
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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--

YAGNameTDecomm/CustStrikeDisposalFateMA Sale/Depart
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 26 Mar 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 Cavanaugh. The Commerce Department approved the transfer on 11 Apr 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 Cavanaugh) 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 (Floyd W Spencer), YAG 37 (John L Sullivan), and YAG 38 (Edward Cavanaugh).

Normally vessels whose classification began with the letter "Y" were service (formerly 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's (later AGR's) were also so designated so that their personnel did not count against a fleet ceiling.

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. YAG 37 moved to active status in June 1954 for the first round of propulsion trials described below. Her status was changed to in MA reserve at Beaumont in December 1955, she was refurbished by the MA at the Navy's request (see the YAG 45 class), and then returned to "active in special service" status in June 1957 for the second round of trials. She was "transferred to another agency" (to MARAD for sale) in March 1958.

CNO on 8 April 1954 suggested the possibility of utilizing large ships (Guinea Pigs) as universal or all influence minesweepers. 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. In the meantime YAG 37 had been taken from Japan to Panama City, Fla., where technical tests at the U.S. Navy Mine Defense Laboratory to determine the nature and extent of her influence fields had been completed. 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 latter 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 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 T34 engines with their Hamilton Standard electronically governed propellers were removed from a Lockheed Constellation aircraft in which they had been mounted for test flying. They were mounted 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. YAG 37, then laid up in the Mobile Group of the Atlantic Reserve Fleet after its previous Guinea Pig trials, was made available by MARAD and the work was put out for competitive bids early in 1957. Rawls Brothers Shipyard in Jacksonville, Fla., won the bidding and completed the installation and dock trials on 19 June 1957. As of 22 June 1957 the ship 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 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.

Following these 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 only operational implementation of the Guinea Pig idea, MSS-1 of 1966 (see the YAG 45 page), used such outboards.

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 there 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. Placed in service at Yokosuka 24 Jun 1954, custody accepted at Panama City 17 Oct 1954. Arrived at Beaumont 8 Dec 1955 and custody to MA there 9 Dec 1955. MA repair program 8 Dec 1955 to 23 Mar 1956 (Mobile). Struck 5 Mar 1956, to MA permanent custody 12 Mar 1956. To Navy custody at Mobile 24 Apr 1957. Sold by MA 19 Mar 1958 at Newport News to BU.
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
Sources: RG19 Item S-15 Entry 1024-H(UD)