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Kennebec-class oiler
USS Winooski
Class overview
Name: Kennebec
Builders: Bethlehem Sparrows Point Shipyard
Sparrows Point, Maryland
Sun Shipbuilding & Drydock Co.
Chester, Pennsylvania
In commission: 1942 - 1970
Completed: 16
Active: 2 in commercial service as lake freighters
Lost: 1
General characteristics
Class & type: Kennebec class oiler
Type: MARAD T2
Tonnage: 15,910 DWT
Displacement: 21,077 tons
Length: 501 ft 8 in (152.9 m)
Beam: 68 ft (20.7 m)
Draft: 29 ft 8.5 in (9.1 m)
Depth: 37 ft (11.3 m)
Installed power: 12,000 shp (8,900 kW)
Propulsion: geared steam turbine
single screw
Speed: 16.5 knots (30.6 km/h)
Range: 8,000 nmi (15,000 km; 9,200 mi)
Capacity: 130,000 bbl (~18,000 t)
Complement: 214–247
Armament: 1 × 5"/38 caliber gun mounts
4 × 3"/50 caliber gun mounts
8 × 40 mm AA gun mounts
8 × 20 mm AA gun mounts
2 × depth charge projectors
General characteristics
Class & type: Mattaponi class oiler
Type: MARAD T2-A
Tonnage: 16,400 DWT
Displacement: 21,750 tons
Length: 520 ft (160 m)
Beam: 68 ft (21 m)
Draft: 29 ft 11.5 in (9.131 m)
Depth: 37 ft (11 m)
Installed power: 12,000 shp (8,900 kW)
Propulsion: geared steam turbine
single screw
Speed: 16.5 knots (30.6 km/h)
Range: 7,200 nmi (13,300 km; 8,300 mi)
Capacity: 133,000 bbl (~18,000 t)
General characteristics
Class & type: Chiwawa class oiler
Type: MARAD T3-S-A1
Tonnage: 16,543 DWT
Displacement: 21,077 tons
Length: 501 ft 7.75 in (152.9017 m)
Beam: 68 ft (21 m)
Draft: 29 ft 10.5 in (9.106 m)
Depth: 37 ft (11 m)
Installed power: 7,000 shp (5,200 kW)
Propulsion: geared steam turbine
single screw
Speed: 15.3 knots (28.3 km/h)
Range: 14,500 nmi (26,900 km; 16,700 mi)
Capacity: 133,800 bbl (~18,000 t)

The Kennebec-class oilers were sixteen United States Navy medium oilers built during World War II to three related designs at Bethlehem Sparrows Point Shipyard of Sparrows Point, Maryland and Sun Shipbuilding & Drydock Co. of Chester, Pennsylvania, all of which survived the war. Two are still in commercial service as of 2011.

All of the ships of the class initially were to be built for private companies, but the outset of World War II, the ships were transferred to the United States Maritime Commission and given new names. Later, when allocated to the U.S. Navy, they were renamed again.[1]

In some cases the Kennebec class is divided into three classes, the Kennebec class (AO-36 to AO-40, AO-48), the Mattaponi class (AO-41 to AO-44, AO-47) and the Chiwawa class (AO-68 to 72). The first two classes were of the T2 and T2-A designs, built by different shipbuilders, and the Chiwawas were of the T3-S-A1 design, mainly differing in having only a 7,000 shp engine and a top speed of 15.3 knots.


One of the first acts of the War Shipping Administration, established in February 1942, was to address the Navy's pressing need for oilers by requisitioning five tankers in service or under construction for civilian companies. Three of these were 16.5-knot Type T2 "national defense tankers" designed by the Maritime Commission with potential militarization in mind and built by Bethlehem Steel for Socony-Vacuum Oil Co: the Corsicana, Caddo and Calusa. A month later the WSA requisitioned six more: Socony's Colina and Conastoga, together with four similar ships building at Sun Shipbuilding and Drydock for Keystone Tankships to an enlarged design, later called T2-A: Kalkay, Ellkay, Jorkay and Emkay. Corsicana was commissioned as USS Kennebec, becoming the lead ship of the class; Kalkay was renamed Mattaponi and gave that name to the T2-A subclass. In June the WSA moved to acquire the remaining member of each group, Aekay and Catawba.

The T2 design had itself been based on two ships built by Bethlehem Steel in 1938-39, Mobilfuel and Mobilube; the T2's principal difference was MarCom's inclusion of more powerful engines to produce the Navy's desired 16.5 knots. In the meantime MarCom under the State of Emergency had ordered thirteen duplicates of Mobilfuel for the merchant marine; the first of these were nearing completion in late 1942 when the Navy, still very short of oilers, requisitioned the first five starting with Samoset (ex-Mobiloil), renamed USS Chiwawa. Other than being limited to 15 knots, the Chiwawas were effectively identical to the Kennebecs, despite being assigned the confusing design code T3-S-A1.

All sixteen ships survived the war, but were decommissioned shortly afterwards in favor of the larger, faster Cimarron class. Kennebec, Merrimack, Kankakee, Mattaponi, Monongahela, Tappahannock, and Neches were recommissioned for the U.S. Navy after World War II. Mattaponi and Tappahanock were reactivated four times, serving until 1970.

Tappahannock off Vietnam in 1969, refueling USS Oriskany (CVA-34) and USS Wiltsie (DD-716).

Chiwawa (now Lee A. Tregurtha) and Neshanic (now American Victory) are still in commercial service on the Great Lakes.[1]

Ships of the class

Name Original name Commissioned Final decommission Fate
USS Kennebec (AO-36) Corsicana 4 Feb 1942 1 Apr 1970 scrapped, 1982
USS Merrimack (AO-37) Caddo 4 Feb 1942 29 Nov 1957 scrapped, 1982
USS Winooski (AO-38) Calusa 27 Jan 1942 30 Apr 1946 sold commercial 1947, scrapped 1965
USS Kankakee (AO-39) Colina 4 May 1942 27 Jun 1968 scrapped, 1976
USS Lackawanna (AO-40) Conastoga 10 Ju 1942 14 Feb 1946 sold commercial 1947, scrapped 1967
USS Neosho (AO-48) Catawba 16 Sep 1942 13 Dec 1945 sold commercial 1947, scrapped 1964
USS Mattaponi (AO-41) Kalkay 10 May 1942 30 Sep 1970 scrapped, 1973
USS Monongahela (AO-42) Ellkay 11 Sep 1942 22 Aug 1957 scrapped, 1982
USS Tappahannock (AO-43) Jorkay 22 Jun 1942 6 Mar 1970 scrapped, 1987
USS Patuxent (AO-44) Emmkay 22 Oct 1942 21 Feb 1946 sold commercial 1947, scrapped 1985
USS Neches (AO-47) Aekay 16 Sep 1942 1 Oct 1970 scrapped, 1973
USS Chiwawa (AO-68) Samoset, ex-Mobiloil 24 Dec 1942 6 May 1946 converted to Great Lakes ore carrier, 1961; still in service
USS Enoree (AO-69) Sachem 23 Jan 1943 22 Oct 1957 scrapped, 1982
USS Escalante (AO-70) Shabonee 30 Jan 1943 12 Dec 1945 sold commercial 1947, sunk 1960
USS Neshanic (AO-71) Marquette 13 Mar 1943 19 Dec 1945 converted to laker; still in service
USS Niobrara (AO-72) Citadel 20 Feb 1943 12 Nov 1957 scrapped 1982

See also


  1. 1.0 1.1 Wharton, George. "Great Lakes Fleet Page Vessel Feature -- Lee A. Tregurtha". Great Lakes and Seaway Shipping. Retrieved 2008-01-07. 
This article incorporates text from the public domain Dictionary of American Naval Fighting Ships.

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