US Navy Auxiliary Ships: Big Horn (AO-45)

USS Big Horn (AO-45) on 22 July 1942
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Class:        BIG HORN (AO-45)
Design        Tanker, 1936
Displacement (tons):        4,150 light, 16,200 lim.
Dimensions (feet):        441.7' oa, 425.0' wl x 64.0' e x 28.8' lim.
Original Armament:        5-4"/50 (1942)
Later armament:        2-3/50 2-40mmS 8-20mm (1945, as IX)
Complement        --
Speed (kts.):        12.5
Propulsion (HP):        3,080
Machinery:        1 screw, Westinghouse turbine

Construction:

AO	Name	Acq.	Builder	Keel	Launch	Commiss.
45	BIG HORN	31 Mar 42	Sun SB & DD	30 Nov 35	2 May 36	15 Apr 42

Disposition:

AO	Name	Decomm.	Strike	Disposal	Fate	MA Sale
45	BIG HORN	6 May 46	3 Jul 46	22 Nov 46	MC/D	7 Jul 47

Class Notes:
FY 1942. GULFDAWN was one of a pair of medium sized tankers ordered by the Gulf Oil Co. from Sun on 20 Aug 35 and delivered in 1936, the other being GULFBELLE. Four very similar ships, GULFCOAST, GULFTIDE, GULFWAVE, and GULFDISC, were delivered by the Bethlehem Steel yard at Sparrows point in 1937 and 1938.

Following U.S. entry into World War II in December 1941 German submarines began to inflict serious damage on the U.S. merchant marine along the Atlantic seacoast. Somewhat in desperation the American government decided to try the use of submarine decoy ships or "Q-ships." The idea of using "Q-ships" during World War II reportedly originated with President Franklin D. Roosevelt during a meeting with the Navy leadership on 19 Jan 42. "Q-ships" appeared to be innocent merchant vessels but carried a heavy concealed gun battery with which they would engage an attacking submarine. The Navy ultimately deployed as "Q-ships" USS ATIK ("AK-101"), ASTERION ("AK-100," later AK-63), EAGLE (AM-132), IRENE FORSYTE (IX-93) and BIG HORN (AO-45) in the Atlantic and ANACAPA (AG-49) in the Pacific. Priority was given to the first two of these; for their history see USS ASTERION (AK-63).

On 23 Mar 42 the Auxiliary Vessels Board, undoubtedly responding to correspondence of higher classification, recommended "the acquisition by purchase of a suitable 10-1/2 knot tanker of approximately 80,000 barrel capacity to meet the immediate Naval demand for a tanker of these characteristics." The War Shipping Administration allocated S.S. GULFDAWN to fill this requirement, and on 27 Mar 42 CNO's office instructed BuShips to acquire her. The ship was accepted at New York on 31 Mar 42 and given the usual conversion for Navy use by Bethlehem Steel Co., 56th St., Brooklyn. She was commissioned on 15 Apr 42 and completed this initial conversion a day later. BIG HORN departed New York on 22 April and arrived at the Boston Navy Yard the next day for additional conversion to a Q-ship. Gun cards maintained by the Bureau of Ordnance indicate that one 4"/50 gun was mounted on the ship at New York on 26 Mar 42 and six more were placed on board at the Boston Navy Yard on 25 Apr 42, two of which were to have been installed while the others were "cargo." It seems likely that one of the two guns was installed aft, replacing the gun installed at New York, while the second was installed on the bow, both of these being visible. One of the six new guns was removed on 11 Jun 42, probably from the bow. According a description left by her Coast Guard commanding officer, the ship had a single 4"/50 gun visible on the stern, two more 4"/50 concealed behind quick-release plating on the bridge deck abaft the pilot house and a probable two more behind plating within the lengthened forecastle structure. The ship also received one ASW projector on 10 Jul 42 and two on 21 Sep 42, all at Boston. Her reconversion back to a tanker in 1945 included removal of the 15,000 empty drums in the cargo tanks and wing spaces, restoration of the summer tanks by removing watertight doors and relocating the working spaces there, and removing the excess armament and associated structure.

The ship conducted her first post-conversion sea trials on 22 Jul 42 and began her first operational cruise as a Q-ship on 27 Sep 42. It was hoped that U-boats would be unable to resist a single tanker straggling behind a convoy, but there are no confirmed reports of BIG HORN engaging any enemy submarines. She concluded her last Q-ship voyage by 7 Oct 43. In late 1943 the need for weather ships in the Atlantic became urgent, and on 16 Dec 43 CominCh ordered the ship to proceed to Boston for transfer to the Coast Guard, which operated the weather ships. On 24 Dec 43 CNO directed the transfer to the Coast Guard for weather duty of three ships, PG-72, AO-45, and AK-63. AO-45 was physically transferred on 17 Jan 44 and stricken from the Navy Register on 22 Jan 44. The Coast Guard used the designations PGCG-30 and WAO-124 for the ship. The Q-ship fittings of AO-45 and AK-63 were retained when the ships were equipped for their new duty as weather ships.

During 1944 twelve frigates of the new TACOMA (PF-3) class were fitted during construction for weather patrol duty, and in June 1944 CominCh directed that as soon as enough these were available the miscellaneous ships then performing this duty be reassigned. The cutters CONIFER, EVERGREEN, and SORREL and some 180-foot minesweepers were to return to their regular employment, ASTERION (ex AK-63), NOURMAHAL (ex PG-72), MANHASSET (ex AG-47), and BIG HORN were to report to the Commandant, Coast Guard, for disposition, and ZIRCON (ex PY-16) and SEA CLOUD (ex IX-99) were to report to the nearest Naval District for disposition. BIG HORN was released from weather duty on 2 Dec 44 and was moored at Boston, where she and AK-63 took up nearly all of the Coast Guard's deep-draft mooring space. Following Coast Guard complaints, CNO on 7 Dec 44 ordered an insurv inspection of the ship to determine if she could be restored for use as mobile floating storage. The Board inspected the ship on 22-23 Dec 44 and reported that her characteristics were far in excess of the minimum standards for storage tankers, in that she was relatively new and had demonstrated that she could maintain 11.5 knots cruising speed in maximum loaded condition. On 22 Jan 45 CNO asked the Coast Guard to transfer the ship to the Navy, and the transfer was effected on 1 Feb 45. She was reclassified from a Coast Guard ship to USS BIG HORN (IX-207) on 3 Feb 45 effective 1 Feb 45. Restoration of the ship as an oil tanker began at the Boston Navy Yard on 1 Feb 45, the ship was underway for the Caribbean on 11 Mar 45, and she reported for duty to CINCPAC on 22 Mar 45. She operated as a shuttle tanker in the central and western Pacific between May and August 1945 and then served as station tanker at Nagoya, Japan, from October 1945 to February 1946.

Ship Notes:

AO	Name	Notes
45	BIG HORN	Ex merc. GULFDAWN (ID-4976, completed Jul 36). Acquired as Q-ship, completed conversion 16 Apr 42 by Bethlehem Steel, 56th St., Brooklyn, N.Y. and further converted at the Boston Navy Yard. Transferred to USCG 17 Jan 44 for weather patrol duty as BIG HORN (WAO-124), stk. 22 Jan 44. Relieved of weather duty by new frigates (PF) 2 Dec 44. Transferred from Coast Guard and back on list 1 Feb 45 as IX-207 (Coast Guard-manned) and converted by General Ship & Eng. Works, Boston, to station tanker (19 Jan to 4 Mar 44). Merc. C. B. WATSON 1947. Scrapped 1960 as OSWEGO TRADER.