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USS Serpens (AK 266) as offered for sale in 1960 showing her Korean stack markings.
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Class: ALCHIBA (AK 261, N3-S-A2)
Design: MC N3-S-A2
Displacement (tons): 1,276 light, 4,040 full
Dimensions (feet): 259' oa, 250' wl x 42' e/wl x 19' max nav
Accommodations: 9 officers, 24 other
Speed (kts.): 11
Propulsion (HP): 1,300
Machinery: Steam 6-cylinder compound reciprocating by Ajax Uniflow of Corry, Pa., 2 boilers, 1 screw
|261||ALCHIBA||12 Jun 1951||Ingalls IW, Decatur||30 Dec 1944||29 May 1945||--|
|262||ALGORAB||12 Jun 1951||Pennsylvania SY, Beaumont||6 Sep 1943||31 Oct 1943||--|
|263||AQUARIUS||12 Jun 1951||Walter Butler SB, Duluth||5 Oct 1943||24 Nov 1943||--|
|264||CENTAURUS||12 Jun 1951||McCloskey, Tampa||2 Oct 1944||25 Mar 1945||--|
|265||CEPHEUS||12 Jun 1951||Avondale Marine Ways, Westwego||13 Nov 1944||21 Feb 1945||--|
|266||SERPENS||12 Jun 1951||McCloskey, Tampa||16 Oct 1944||17 Jun 1945||--|
|261||ALCHIBA||--||1 Feb 1960||12 Jun 1951||Trf.||--|
|262||ALGORAB||--||1 Feb 1960||12 Jun 1951||Trf.||--|
|263||AQUARIUS||--||1 Feb 1960||12 Jun 1951||Trf.||--|
|264||CENTAURUS||--||1 Feb 1960||12 Jun 1951||Trf.||--|
|265||CEPHEUS||--||1 Feb 1960||12 Jun 1951||Trf.||--|
|266||SERPENS||--||1 Feb 1960||12 Jun 1951||Trf.||--|
In 1941 a British Shipbuilding Mission visited the US, stressed to the Maritime Commission that more tonnage would be required to offset and supplement losses to U-boats, and suggested that the shipbuilding potential of the Great Lakes be drawn on for the construction of small cargo ships. The result was the N3-S type, which was very similar to the 'Norwegian' type coasters built for the Baltic timber trade, even having their derricks stepped high to clear deck cargoes. They were also similar to the World War I lakers including EFC Design 1020 that were also based on the 'Norwegian' type. Of the two variations on the N3-S type, the N3-S-A1 type was coal-fired for British service, Britain having a wartime shortage of oil, while the N3-S-A2 type was oil fired.
Two types of steam reciprocating machinery from three different engine builders powered the 36 ships of the N3-S-A1 and the 59 ships of the N3-S-A2 types. 27 conventional triple expansion sets came jointly from the Pacific Bridge Co., San Francisco (9) and the Prescott Co. of Menominee, Michigan (18) and 68 6-cylinder "uniflow" sets came from Ajax Uniflow of Corry, Pa., who built a generic version of Skinner's "Unaflow" engine. The horsepower of each set was 1,300 giving a top speed of 10.5-11 knots. The triple expansion engines probably all went to N3-S-A1 ships (MC 399-416 and 452-460). On each crank in the Ajax Uniflow engines was mounted a low pressure cylinder and piston, single acting, working on the down-stroke, with above it a high pressure cylinder and piston, single acting, working on the up-stroke. A complete compound uniflow cycle was obtained with a single valve, from admission to the condenser, with continuous uninterrupted expansion of the steam on each crank independently of the others. The design permitted a variable number of cylinders to be used up to a practical maximum, and the company ultimately developed the engine in various sizes from 18 inches to 36 inches stroke, 100 to 300 RPM, and 400 to 4,000 HP. The six cylinders in the 1,300 HP engines in the N3-S-A2 ships would have been on three cranks as in a conventional triple expansion engine.
As of 31 August 1948 the Army was operating eight small N3-S-A2 cargo vessels in the Korean Program of its XIV Corps (later USAMGIK and FECOM) on bareboat charter from the Maritime Commission. Title to the eight ships was transferred to the Army on 23 February 1949 under Public Law 766. One of them, EBEN H LINNELL, was acquired by the Army on 12 Jun 1946 in Japan, grounded on 25 January 1948, was towed to Pusan on 6 June 1948 for dry-docking, beached at Yokohama in February 1949, and declared a constructive total loss in July 1949. She was in the process of disposal as scrap in November 1949 and on 3 July 1950 was delivered to the Japanese Ministry of Trade to be scrapped "as is, where is." Another, KIMBALL R SMITH (ex NORTHERN CAPTAIN), was acquired by the Army on 17 Jun 1946 at Pusan and was loaned to ECA Korea on 1 August 1949 with the other six, then under repair, scheduled to follow (see below). ECA Korea was the Economic Cooperation Administration, formed to help Korea rebuild its economic system.
On 5 May 1951 the Army notified the Navy that it had six small N3-S-A2 cargo vessels in the Far East that were required for use by the Republic of Korea for civil relief and support of the Korean economy. The Army felt that the functions of these ships fell under the responsibilities of MSTS and wanted the Navy's Commander, Naval Forces, Far East to take control of the ships while they were so employed. In June 1951 they were transferred from the Army to the Navy and simultaneously loaned to the Republic of Korea for operation. On 20 June 1951 CNO asked the Bureau of Naval Personnel for names for ten cargo ships whose transfer to the Navy had been approved, AK 257-266. On 3 July 1951 BUPERS proposed the names DENEBOLA, REGULUS, RIGEL, SIRIUS, SPICA, and VEGA for AK 261-266, but on 12 July 1951 BUPERS cancelled this recommendation, having been informed that AK 261-266 were to be operated by "the Japanese government," and substitued the names that were approved on 26 July 1951 for the six "Baltic coasters." The ships having served their purpose, the Secretary of the Navy on 1 December 1959 approved their disposal and on 8 January 1960 MA authorized the Navy to do so but only by scrapping. The ships were returned to Navy custody at Sasebo, Japan, advertised for sale on 23 May 1960, and along with six similarly employed former Army FS freighters (see AKL 37-42), sold on 27 June 1960 to the Hong Kong Rolling Mills.
|261||ALCHIBA||2597||Ex merc. CHARLES F WINSOR, ex-NORTHERN COURIER, completed 23 Jul 1945. To Army 3 Jun 1946 at Pusan, Korea. Loaned by the Army to ECA Korea 20 Mar 1950. Sold 27 Jun 1960 to Hong Kong Rolling Mills.|
|262||ALGORAB||1624||Ex merc. ELISHA WHITNEY, completed 25 Apr 1944. To Army 10 May 1946 at Yokohama. Loaned by the Army to ECA Korea 13 Jan 1950. Sold 27 Jun 1960 to Hong Kong Rolling Mills.|
|263||AQUARIUS||1638||Ex merc. JOHN D WHIDDEN, completed 31 May 1944. To Army 21 Jun 1946 at Pusan. Loaned by the Army to ECA Korea 10 Mar 1950. Sold 27 Jun 1960 to Hong Kong Rolling Mills.|
|264||CENTAURUS||2516||Ex merc. NORTHERN EXPLORER, ex-NAT BROWN, ex-NORTHERN EXPLORER, completed 4 Jun 1945. To Army 27 May 1946 at Pusan. Loaned by the Army to ECA Korea 3 Jan 1950. Sold 27 Jun 1960 to Hong Kong Rolling Mills.|
|265||CEPHEUS||2545||Ex merc. RICHARD W DIXIE, completed 18 May 1945. To Army 6 Jun 1946 at Pusan. Loaned by the Army to ECA Korea 31 Mar 1950. Sold 27 Jun 1960 to Hong Kong Rolling Mills.|
|266||SERPENS||2520||Ex merc. WILLIAM LESTER, ex-NORTHERN YEOMAN, completed 30 June 1945. To Army 20 May 1946 at Pusan. Loaned by the Army to ECA Korea 20 Jan 1950. Sold 27 Jun 1960 to Hong Kong Rolling Mills.|
Compiled: 7 Aug 2021
© Stephen S. Roberts, 2021