Type C3-class Cargo Ships (1940)

C3 Type Cargo

US Maritime Commission 1940-45: 238 Built

Foreworld: US Maritime Commission Fleet

The United States Maritime Commission (MARCOM) was an independent executive agency of the U.S. federal government created by the Merchant Marine Act of 1936, abolished on May 24, 1950. Created at first to replace WWI vintage vessels of the United States Merchant Marine and operate ships under the American flag. It formed the US Maritime Service for training officers and from 1939 until 1945, funded and administered the largest and most successful merchant shipbuilding effort in world’s history with 5,777 oceangoing merchant and naval ships total.

♆ Liberty ships♆ Victory ships – ♆ Freighters Type C1C2C3C4 – ♆ Tankers T1T2T3

The C3 Cargo Type: Faster than U-Boats

SS Mormac Isle

The more famous and far more numerous “Liberty Ships” derived for an, early standard cargo defined by MARCOM in 1938 to replaced WW1 vintage standard vessels. Three types were designed, the largest of which became the Type C3-class, third type designed. With preliminary plans largely circulated and communicated to civilian yards for comment. The design presented was adaptable to all trade route and bulk palleted payloads, a large general purpose ship modular enough to be later modified for specific uses. In total 162 C3 ships were built in 1939-1946, but many more hulls (238 in all) were constructed (so 76 more) to be later declined into several variants among which many escort aircraft carriers.

Development design

USS Hercules, the 1940 prototype

The Long Range Shipbuilding Program paired by an ambitious 500-ship goal conducted the U.S. Maritime Commission to turn to standardization and shorting the usual practice of shipping lines designing their own tailored vessels to service said routes. The Commission ambition was to unit all the needs by making an easily adaptable, modern but also safe and well-appointed vessel that would be in addition efficient and fast in order to defeat potential submersibles.

The Commission rated the basic need along three basic designs called “C1,” “C2,” and “C3” denoting increasing capacity and length. They also differed by having different powerful engines, steam turbine for the C3 and and diesels for the C1/2. It was combined with modern cargo equipment, fire-retardant fixtures, and improved crew and passenger living spaces, made the vessels popular with both commercial operators and the U.S. Navy. In fact, many of the navy’s auxiliary ships during World War II were Maritime Commission “C” ships.

The C3 was larger and faster than the C1 and C2 at 492 feet (150 m) overall, versus 459 feet for the C2. More than that, they were designed with a more powerful propulsion in order to make 16.5 knots (30.6 km/h; 19.0 mph) versus 15.5 knots for the C2, and thus, allowing them to out-pace the known surface speed of U-Boats. Later it was downgraded on the Liberty ships (11–11.5 knots). Like the C2 however they were fitted with five cargo holds. The hulls proved even more popular as 465 were built between 1940 and 1947, all in US Yards and then transferred via lend-lease.

The C3 was 492 ft long, 69.5 feet wide, with a 28.5 foot draft. They registered at 7,800 gross tons and 12,000 deadweight tons. Of the 465 built until 1947 and if most were equipped with a turbine rated for 8,500 hp and from 16.5 to 18 knots they wete used by the following lines:

  • American Export Lines
  • Newport News Shipbuilding & Drydock
  • Seas Shipping
  • American South African Line
  • United States Maritime Service
  • Four Aces
  • American President Lines
  • Moore-McCormack Lines

Hull and facilities

Liberty ship in comparison. I could not find blueprints for the C3 as a cargo

Although there was a base design, many varianst existed (see below). The basic, initial model had a “clipper stern” with some flare, but this was simplified over time. As usual freeboard was high, with a prow capable of dealing with heavy weather, twice as high on its forecastle compared to the amidship’s freeboard. This made them good seaboats, albeit somehwat stiff. They were divided into eight modules and this never changed but after postwar civilian reconstructions:

  1. Forcastle, crew’s quarters
  2. Main deck, first hold
  3. Main deck, second hold
  4. Main deck, third hold
  5. Island (main superstructure)
  6. Main deck, fourth hold*
  7. Main deck, fifth hold*
  8. Stern quarters

*Note: Part of the machinery space and fuel tanks were located below the holds and the waterline to mitigate a torpedo blast.

2 plan view, note much the larger island compared to the Liberty ship. She could also carry passengers with extensive facilities.

The holds were served by no less than seven ladder-type poles operating each two cranes or more (four for the ladder masts). The fore and main masts were attached to these ladder porticos fore and aft.
The C3 were powered as said above by a single compact turbines located in the aftermost section, turning a single large propeller with a short shaft. The type of steam turbin use varied among yards, but the Allis-Chalmers type proved the most popular. Fed by two admiralty type double-ended small tubes boilers running on oil, the powerplant delivered 8,500 hp, enough for runs at 18 knots and more when needed, but cruise range was down to 12 knots.

Armament-wise, each ship, albeit having a civilian crew, was complemented by a small Navy personal to operate the armament aboard. This varied greatly among ships, from nothing at all to a heavier armament for those converted. In general however, they were less well armed than Liberty Ships. If armed, they likely had a single 12-in/38 main artillery piece, generally located on the forecastle, four or more single 40 mm/70 and 20 mm/70 Oerlikon AA guns.

C3 Variants

Illustration of a C3-E, private design of the American Export Line, with its Export-Line-stern. Drawing from usmaritimecommission.de

C3: 12,595 tonne: USS Anne Arundel
C3-A: 10,000 tonnes: USS President Polk
C3-E: 9,514 tonnes: USS Hercules
C3-P&C: 10,000 tonnes Some Avenger-class CVE
C3-S-A1: 12,595 tonnes: CVE HMS Tracker, some Bogue-class
C3-S-A2: 12,595 tonnes. USS DuPage
C3-S1-A3: 12,595 tonnes, Funston class APDs
C3-S-A4: 11,000 tonnes, as the six “President” ships
C3-S-A5: 11,800 tonnes: HMS Chaser CVE.
C3-S1-BR1: 9,900 tonnes (3 built: Del Norte, Del Sud & Del Mar)
C3-S-BH1: 12,600 tonnes, 5 built: Tillie Lykes, Almeria Lykes, Lipscomb Lykes, Norman Lykes & Doctor Lykes
C3 Mod.: 12,430 tonnes. Ex. USS Euryale

Proper Navy Variants

USS Dorothea, Operation Husky, Sicily

The Navy had its fair share of extra hulls to be turned into specialized versions, coming as part of the vast fleet of 465 vessels. The 75 “proper C3” hulls were mostly used as base fo escort carriers;

Long Island/Charger class escort carriers

USS Long island (CVE-1) was like HMS Audacity a quick conversion of the C3 USS Mormacmail, the firsr USN light “auxiliary”, or escort aircraft carrier (CVE), designed in peacetime for the sole purpose of convoy escort in the Atlantic, for the US leg of convoy escort. USS Long Island was the first conversion of that kind, without island and a small hangar. She was superseded by the far better USS Charger (CVE-30) in 1942. The latter is artifically considered in the same class but was in reality very different, including a larger hangar and proper island. She became the prototype for the Bogue class ans almost 75 conversions, mostly destined lend-lease.

Bogue-class escort carriers

USS Bogue in Bermuda, Feb. 1945

Derived from USS Charger (CVE-2), first with an island, the Bogue class were about eleven vessels retained in USN service during the war, based on C3-S-A1 and C3-S-A2 ships. The other eleven went to the Royal Navy as the Attacker class. Laid down in 1941 and converted at that time, they were commissioned from August 1942 to May 1943 and saw active service in the Atlantic, and Pacific from 1945.

They were typically 8,390/13,980 tonnes FL, for 495 ft 8 in (151.08 m) in lenght, 82 ft (25 m) at flight deck level for a maximum draft of 26 ft (7.9 m). Their single Allis-Chalmers turbine connected to two Foster-Wheeler boilers working at 285 psi (1,970 kPa) provided 8,500 shp (6,300 kW) for 18 knots (33 km/h; 21 mph) and the amazing range of 26,300 nmi (48,700 km; 30,300 mi) at 15 knots, based on 2,400 long tons of fuel oil.

As CVEs they were well armed, with two 5 in/51 and ten 20 mm Oerlikon AA guns (it varied over time and type); Air facilities comprised a single hydraulic catapult and two elevators and their hangar housed from 19 to 24 aircraft.

Archer-class escort carriers

HMS Archer, a clone of Long Island.

After the leasing of HMS Archer, an island-less early CVE, the conversion of Mormacland by the Sun shipbuilding yD. Converted at the Atlantic Basin Iron Works at Brooklyn New York and comm. on 6 May 1942, she was followed by many more carriers based on other C3 cargo versions:
Avenger class: Same design as Archer but new specifications and arrangements: HMS Avenger, HMS Dasher, HMS Bitter (launched 1940)
Attacker class: New design with larger flight deck and hangar for 24 aircraft, elevators and catapults. 11 built and commissioned until June 1943 (same serie as the 11 Bogue).
Aleer class: Or “ruler class”, 23 vessels like the Bogues buot at Seattle-Tacoma Shipbuilding Corporation but built in three specialized groups.

HMS Attacker, lead vessel of its class.

Windsor-class attack transports (APD)

USS Windsor, APA-55

The class comprised 16 vessels total, with for the Windsor, Leedstown, Adair, Dauphin, Duchess, Queens, Shelby and for Funston, O’Hara, Griggs, Grundy, Guiford, Stika, Hamblen, Hampton, Hannover.

The first class nine entered service between 1943 and 1945, and can carry 150,000 cu ft (4,200 m3), 1,600 tons. They had a single 5″/38 caliber gun mount and light 20 mm AA. They only served in the Pacific. USS Windsor and Leedstown earned collectively five battle stars. The Funston served mostly in the Atlantic. Five arrived too late to see any combat but took part in “magic carpet” and also carried occupation troops in Japan, China and Korea and after 1946 they were all sold on the commercial market though many were scrapped in the 1970s.

USS James O’Hara, APA-90 in the Atlantic, June 1943.

Bayfield-class attack transports (APD)

USS DuPage APA-41, 13 Oct. 1943

Actually the first large standard of assault transports based on the C3. Numbers varied from 28 to 34: USS Bayfield, Bolivar, Callaway, Cambria, Cavalier, Chilton, Clay, Custer, Du page, Elmore, Fayette, Fremont, Henrico, Knox, Lamar, Alpine, Barnstable, Burley, cecil, Dade, Medocino, montour, Riverside, Westmoreland, Hansford, Goodhue, Goshen, Grafton, or APA-33-48, 92, 93, 95, 96, 99-102, 104, 106-109. They were well armed thanks to a massive island with passengers accomodations. They were armed with two single 5-in 38, four twin 40 mm Bofors and 12 single 20 mm AA.

The two cargo holds amidships were converted into accommodation facilities with prefabricated floors and walls with three decks each devided into five high bunks beds and passageways, 30-in wide. Troops had their their own galley and mess hall separated from the Navy crew. They also had a sick bay and dental clinic. Concrete was used as ballast at the bottom of the holds for stability.

Single propeller but steam geared turbine coupled to more powerful boilers, allowing them to reach 17-18 knots for some time, to evade a surfaced U-Boat, at about 17.7 knots for the Type VII. Their real force resided in their payload, in general 12 LCVPs, four LCM and three LCP(L) plus a 4,500–4,800 tons cargo. The crew was quite extensive for a “civilian” freighter, with 51 officers and 524 sailors due to all their armament and additional facilities, while carrying some 80 officers and 1,146 privates.

Klondike-class destroyer tenders (APD)

USS Klondike
USS Klondike (AD-22) at ancho August 1945

These four vessels were all built in Todd, San Pedro Cal.: USS Klondike (AD-22) (launched 30 July 1945, comp. 15 December 1970) as AR-22, USS Arcadia (AD-23) comm. 13 September 1945, USS Everglades (AD-24), comm. 25 May 1951 and USS Frontier (AD-25) and comm. 2 March 1946. They were sold for BU in 1974 but 1991 for USS Everglades.

Displacing 8,165 long tons (8,296 t)/11,755 long tons FL for 492 x 69 x 27 ft 3 in they were powered by the same C3 Geared turbines delivering 8,500 shp (6,338 kW) for 18.4 knots. They were well armed, with a single 5 in/38, four 3 in/23, four 40 mm AA and twenty 20 mm guns.

Also based on the same hull were the next Shenandoah-class (9 ships, commissioned 1945 or after the war) and Hamul class (AD-20). Like the former they saw little service in WW2, arriving too late.

Euryale/Aegir class submarine tenders (AS)

USS Apollo late 1944 (navsource)

There was the USS Euryale, sole of her class (Displacement: 13,830 tons FL, 492’6″ x 69’6″ x 23’2″ 8,500 shp and 16.5 knots). Built at Federal-Kearny as a modified C3 type and comm. as AS-22 in 1943. There were also the following Aegir Class based on the C3-S-A2 type and comprising AS-23 USS Aegir, AS-24 USS Anthedon, AS-25 USS Apollo and AS-26 USS Clytie (Displacement 16,000 tons FL, 492′ x 69’6″ x 28’6″, 8,500 shp and 16.5 knots also with turbine engines). They were built in Federal-Kearny and commissioned in 1944, 1945 for the last one.

Chandeleur class seaplane tenders (AV)

USS Chandeleur, AV-10

The lead ship was launched on 29 November 1941 and completed on 19 November 1942 in this role. She was pusrpose-built by the commission for this role, sole of the C3-S1-B1 type within its own shipbuilding program.
She was built by Western Pipe and Steel Company and earned 5 battle stars in the pacific. She had a large crane on her stern to fish aircraft from the sea and also a large aft desk space to repair aircraft. A successful type, many later C3 were converted on this standard. One of her seaplanes spotted IJN Yamato.

⚙ C3 class specifications

Dimensions 492 ft (150 m) x 69.5 ft (21.2 m) x 28.5 ft (8.7 m)
Displacement 7,800 gross tons, 12,000 deadweight tons.
Crew Varying: Ex. 129 for USS Hercules
Propulsion Installed power turbine developing 8,500 hp
Speed 16.5 knots (30.6 km/h; 19.0 mph) (designed)
Range Varying among ships, avg. 11,000 nm at 12 kts;
Armament USS Hercules: 5 in/38 (127 mm) DP, 4x 3 in (76 mm) DP guns.

Wartime use

The C3 cargos were put into their transport tasks as soon as available, and lessons learned from the design, perhaps too complex and costly led to the Liberty Ship standard, cheaper and much simplified. Still, the C3 rendered amazing service to Atlantic convoys, with their main davantage being their speed. In many occasions, captain spotting U-Boats were racing out of the formation to escape attacks. Unfortunately, Convoys rarely comprised only C3 cargos, and in that case, due to their range, they could not have sped up to max speed all along their trip, but perhaps the infamous “black hole” uncovered by smaller escort vessels and aviation in the middle of the Atlantic. C3 were mixed with every other cargo available, and had to comply to the slowest demonimator, to the captain’s frustration.

Other than that, turbines also had their dowside, and their were known gas-guzzlers. Although their range was enough to cross the Atlantic, high speed runs in case of attacks could jeopardize their ability to reach the desired range.

Theere were many losses, like Express (C3-E) torpedoed and sank off the coast of Madagascar on 30 June 1942, Almeria Lykes (C3) later Empire Condor, torpedoed and sank off Tunisia on 13 August 1942, Rio Hudson (C3-P&C)sunk as HMS Avenger off Gibraltar on 15 November 1942, a C3-S-A1 converted as USS Block Island (USN CVE-21) torpedoed and sank near the Azores and Canary Islands on 29 May 1944, Rio de Janeiro (C3-P&C) now the Avenger-class HMS Dasher sunk in the Lower Clyde in Scotland 1943 due to an accidental explosion, or USNS Card, sunk on 2 May 1964 in Saigon by the North Vietnamese frogman Lam Son Nao like the WW2 Italoan frogmen of old. Some vessels had an extensive carrer with the USN as cargoes and were awarded multiple times:

USS Hercules (AK-41)

USS Hercules, AK-41

AK-41 was responsible for delivering goods and equipment to ships and stations in a war zone and was the ex-SS Exporter launched 18 July 1939 by Fore River Shipbuilding Co. in Massachusetts. She was ordered originally bt American Export Lines Inc. She was acquired by the Navy 15 July 1941 and kept her civilian crews until 30 November 1942 before commission at San Francisco under command of W. H. Turnquist. Her career is typical of WW2 USN-operated C3 cargos:

After reaching Noumea, New Caledonia, on 6 January 1943 to discharge her cargo she was back to San Francisco on 20 February and made a second run from 11 March to 5 July. She was in Pearl Harbor 6 August and became flagship, Admiral Willis A. Lee, CTF 11, while off Baker Island during the Army occupation. She made a crossing next to Pearl Harbor and then to San Francisco. On 13 October she was discharging her cargo to Funafuti, Ellice Islands and on 14 November at Pearl Harbor. After other trips she was in Pearl on 28 January 1944 for maintenance.

Next, she made two round-trips with cargo and passengers to San Francisco and in June, sailed with the Saipan invasion force, and from D-Day, discharging cargo, until the 24th. She was attacked several times by IJN aviation but was never hit. After a run back to Pearl Harbor she transport troops and cargo to Guadalcanal and sailing from there on 8 September to take part in the invasion of Peleliu in the Palau Islands. Next she carried goods to Hollandia, New Guinea and by mid-October was taking part in the Philippines invasion. She made several trips there until the invasion of San Pedro Bay 20 October and Lingayen Gulf landings on 9 January 1945.

Back in Ulithi 24 January 1945 she carried troops and cargo to Iwo Jima. She was hold in the retirement area until 27 February, disembarking reserve troops on the beach and received wounded soldiers. From 20 March she departed with many U.S. Marines and their equipment aboard for Pearl Harbor. Next she haded for Guam and Eniwetok and was back in San Francisco 22 June 1945 for her major overhaul. The war ended but she returned to the Pacific on 24 October 1945, loading ammunition in the Philippines and Admiralty Islands to reach Norfolk in Virginia on 26 March via Panama. She was decommissioned on 28 June 1946, transferred back to the Maritime Commission 18 July for merchant service as SS Exermont and SS Bostonian. She was scrapped in 1971, a common date for these C3s. For her Pacific wartime service she earned 5 battle stars.

USS Hercules, AK-41

She was President Jackson-class attack transport, converted from a MCV Hull Type C3-P&C, MCV Hull No. 110. She started her career as SS President Polk (1941 – 4 October 1943) with a civilian crew, then was requisitioned by the Navy as a transport, and started her service commissioned as USS President Polk AP-103 from 4 October 1943 – 26 January 1946, earning 6 battle stars for her service.

As an attack transport she was far better armed as converted in 1943, than other C3 cargos acting as simple transport (AK): She had a more extensive crew of 354, parft of which manned her single 5″/38 caliber gun forward, four 3″/50 caliber dual-purpose gun mounts and four Bofors 40mm gun mounts. Launched 28 June 1941, she was acquired by the War Shipping Administration (WSA) on 5 December 1941, American President Lines operating as agent. She started her semi-civilian service in the Pacific, making particularly critical delivery to Hawaii on 19 December 1941 with a tanker and two freighters, in Brisbane in Australia (12 January 1942), 55 P-40E and 4 C-53 aircraft and their pilots plus 20 million of .30 caliber, 447,000 of .50 caliber, and 30,000 three-inch AA and 5,000 75 mm rounds of ammunition plus carloads of torpedoes and 615,000 pounds of rations, 178 officers and men to continue the war from Australia. Back, she transited via Townsville and Soerabaja with again, ammunition, bombs, airplanes, and rations for the KNIL.

She would also carry the 7th Naval Construction Battalion (7 officers, 433 enlisted men) from Samoa to Espiritu Santo in the New Hebrides in August. Her acquisition on 6 September 1943 and conversion by the Navy as assault transport meant she was transferred to the Naval Transportation Service, carrying her first battalion from Port Hueneme, California to Pearl Harbor by late 1943. She took part in the invasion of Tarawa, and stayed there to receive casualties, being back to Pearl Harbor 11 December. Next she operated at Kwajalein and became again an emergency hospital ship back to San Francisco. She also ferried troops to New Caledonia and Admiralty Islands.

In July 1944 she carried reinforcements to Guam and later to New Guinea. She was sent to Bougainville Island before the invasion of Luzon and disembarked troops at Lingayen beaches on 11 January 1945. She latter carried from Leyte, and was in Ulithi, taking Marines at Iwo Jima to Hawaii. After a stay in San Francisco she carried fresh troops to Okinawa on 24 July. After the war she was in Apra Harbor, Guam before proceeding back to San Francisco. She carried troops from Seattle to Tinian and took part in Operation Magic Carpet from October 1945, to and from Espiritu Santo and Manila. Decommissioned, she was transferred back to the War Shipping Administration , struck from the USN 25 February 1946 and continue her civilian service until 15 July 1965, sold to Ganaderos del Mar as “Gaucho Martin Fierro” anbd later “Minotauros”, then scrapped in 1970 in Taiwan.

USS Euryale (AS-22))

USS Euryale at Sasebo in November 1945 with I-401, I-14 and I-400 just surrendered nearby.

USS Euryale was originally the civilian “SS Hawaiian Merchant” ordered to Federal Shipbuilding and Drydock Company, Kearny, New Jersey, by the Matson Navigation Company, launched 12 April 1941 and completed by April 1941. She was to serve alongside Hawaiian Planter and Hawaiian Shipper but under the USA Transportation Corps charter, and then War Shipping Administration, until purchased on 15 April 1943 by the USN, recommissioned on 2 December 1943 as the submarine tender USS Euryale (AS-22).

After reaching Brisbane in Australia she headed for NYC on March 1944, loading provisions and supplies for Milne Bay in New Guinea. Until 26 May she refitted submarines and repaired surface ships as well. She was seen at Manus in May-August, staying anchired as a forward base and rest camp for submariners. her personal and equipment helped clearing the island and constructing buildings. She helped refitting 26 submarines, and was back to Brisbane on 16 August 1944 to load cargo to Fremantle.

She tended US submarines in Fremantle until 11 April 1945, then at Pearl Harbor until 16 August 1945 and on the 28th sailed to Guam as submarine base/rest camp. On 16 September she was in Okinawa, and later at Sasebo to work with Japanese submarines for disposal. She sailed then to Pearl Harbor with two Japanese submarines, one towed and proceeded to San Francisco (22 February) to be decommissioned on 7 October 1946. Unlike other C32 vessels she did not returned to civilian service but stayed in fleet reserve until 9 August 1972, whe she wass delivered back to the Maritime Administration at Bremerton, purchased by American Ship Dismantler for scrappng. During her service she was typically armed with a single 5 in/38 and four 3 in (76 mm) DP guns.

Post-ww2 service

A postwar C3 model, the Var

A postwar C3, the Loulea cutout

A postwar C3 with an extensive carrer: M/V Rose Schiaffino

Most C3 cargos not modified extensively for specialized roles returned promptly to civilian service, and for some were still around in 1980s “in their juice” after a few overhauls. But it was rare to reach that age. Most were scrapped in the 1970s. Other however were modernized extensively in the 1950s or 1960s and saw extensive service until the 1990s for some. However at the time, container ships were really the bulk of cargo transport, but not all harbours on the planet could accept these. Like most bulk carriers, these C3s still operated on these smaller harbours around the planet.

Sime of these vessels were designed as mixed cargos, like the six of Mississippi Shipping Co. built in Bethlehem Steel Co. started in December 1938 and completed in late 1940. A private design they served between Gulf ports and the East coast of South America with extensive Passenger accommodation for 67 in 26 staterooms on the shelter deck and two other complete decks. Later acquired by the USN so serve as AP and APA’s.

Some had amazing carrers, such as SS Barnes converted as CVE 7, then HMS Attacker (D 02), sold 1950 and rebuilt as the passenger ship “Castel Forte”, later “Fairsky”, then “Philippine Tourist” and scrapped in 1980. But the rcord goes to Cadmus (a C3 Modified, delivered on 23-Apr-46 to the USN as AR 14, and later resold to Taiwan in 1974 as Yu Tai (AR 521) and eventually scrapped in 1995, or St. George also a C3 Mod. from Tacoma, deliovered on 24 July 1944 and used by the USN as AV 16 and resold to Italy 1968 in service with the Marina Militare as Andria Bafile (A 5314), and also scrapped in 1995. Unfortunately, no C3 has been preserved to this day, unlike the Liberty and Victory ships. Unlike the first two, they were far less standardized and mass-built, making less understandable for the general public, and less desirable as museum ships. They not even survived indirectly through some CVE, unlike USS lunga Point, a Casablanca class.


So, all in all, between the 238 vessels completed as C3 cargos, far more hulls were converted: 45 Bogue-class escort carriers, 59 Attack transports (3 Arthur Middleton class, 4 Crescent City class, 2 Frederick Funston class, 9 Windsor class, 34 Bayfield class and 7 President Jackson class), 7 Submarine tenders (Euryale, 2 Griffin-class, 4 Aegir-class), 2 Delta-class repair ships (AR-9, AR-12) and 2 Amphion-class repair ships, so 115 extra C3 hulls for conversions, so 353 total.

USS Euryale
USS Euryale (AS-22) 21 August 1944

USS Sea Tarpon
USS Sea Tarpon in construction at Ingalls. She was a C3-S-A2 type.

USS Deucalion
USS Deucalion (AR-15) remair ship

USS Cascade
USS Cascade AD-16, destroyer supply ship

USS Anne Arundel
USS Anne Arundel

Links and sources

A stranded C3, Dominator, tossed over the reefs in 1961, from Life magazine.


Sawyer, L.A.; Mitchell, W.H. (1981). From America to United States: The History of the Long-range Merchant Shipbuilding Programme of the United States Maritime Commission. London: World Ship Society.


On usmaritimecommission.de
Full list on shipbuildinghistory.com, 162 built in five variants and 75 to other designs by size group.
C3 bases sub tenders
usmm.org full list of C3 vessels
ss-african-mercury shipsnostalgia.com
Mormacisle on shipspotting
about thge C3 based USN Comet, first Ro-Ro (1957)
USS Chandeleur on maritime.dot.gov
May 1941 review of Hawaiian Merchant/Skipper
Matson navigation vessels


3D models

On maritime.dot.gov

Model kits

Revell’s Merchant fleet kit, C3 freighter and T3 tanker
1947 Beavercove (499′ Long) On nscaleships.com
modelwarships.com review
RC model

T2 Tankers (1940-1945)

T2 Tankers

US Maritime Commission 1940-45: 533 Built

Foreworld: US Maritime Commission Fleet

The United States Maritime Commission (MARCOM) was an independent executive agency of the U.S. federal government created by the Merchant Marine Act of 1936, abolished on May 24, 1950. Created at first to replace WWI vintage vessels of the United States Merchant Marine and operate ships under the American flag. It formed the US Maritime Service for training officers and from 1939 until 1945, funded and administered the largest and most successful merchant shipbuilding effort in world’s history with 5,777 oceangoing merchant and naval ships total.

♆ Liberty ships♆ Victory ships – ♆ Freighters Type C1C2C3C4 – ♆ Tankers T1T2T3

The T2 Tankers: Bedrock of oil supply in WW2

Assembly and Construction of T2 Navy Tankers: Mission Santa nez, Suisun Bay Reserve Fleet, Benicia Solano County, CA

Was the allied effort ever in jeopardy because of oil tanker losses in the Atlantic ? Absolutely. Apart old merchant vessels dating back from the WWI emergency fleet and still running on coal the allied war machine from 1939 depended on oil. From tanks to planes and ships, and virtually all power from field generators for communication or lighting, oil, and oil again.

The axis knew it, and when possible, U-Boat in the Atlantic targeted tankers. In all, 2,603 merchant ships had been sunk (13. 5 million tons) and among these, in almost each convoy, oil tankers were present.

Was the Pacific war winnable without oil tankers ? Absolutely not. The while Pacific fleet out at sea depended on oil for operations at any level, special supply and repair fleets played a huge role having task forces resupplied at sea by fleet tankers, an art perfected in 1942-45, allowed a great degree of flexibility. They fit in a galaxy of fresh water generators, floating freezers, hospital ships, floating drydocks, workshops and repair ships.

Thus we can say, without a doubt, that the 900+ oil tankers (including 500 T2) of all types built in WW2 played a vital part in this allied effort, being the largest standardized oil tanker armada ever built. While these ships had their problem, notably related to a hasty construction and associated structural issues, they still were highly dependable and just the required size to enter most ports and carry their liquid cargo, as well as dispensing it wherever manageable.

Basic design Development

Outboard Profile, T2 Navy Tanker Lines

The T2 were a first of the three main types of oil tankers designed, built and used during WW2, the other two being the larger T3 mostly used as fleet oilers, and the coastal T1s. The T2 were subdivided into several classes (see below) but they all depended on the same basic design. Alteration mostly were in powerplants. Based on the Kannebec class oilers (MARAD T2), these T2 “national defense tankers” designed by the Maritime Commission from February 1942 started with three prototypes based on a typical “two islands” design of the late 1930s.

First Prototypes: The 1938 “Mobil”

Profile of the SS Mobil Fuel (1939-55) Src aukevisser.nl

The T2 design had its root in two vessels built by Bethlehem Steel in 1938–39: SS Mobil Fuel and Mobil Ube. MarCom took the basic design, well proven, and just included more powerful engines as per the Navy’s spec of 16.5 knots. Under the State of Emergency, thirteen duplicates of these vessels were also ordered for the merchant marine, first of which were completed in late 1942. By then the Navy wanted more oilers and requisitioned the first five/ This became the Samoset class (ex-Mobiloil was the lead ship, renamed USS Chiwawa). These were however pre-modification vessels limited to 15 knots with their VTE engines, but otherwise identical to the Kennebecs. Design code chosen was rather confusing, T3-S-A1.

The Kennebec class

USS Kennebec (AO-38) off Winoosky, Vermont, showing her two-tone measure 22 livery.

They were tailored for potential militarization with freed spaces fore and aft and reinforced decks to mount ordnance in platforms. The three prototypes were built by Bethlehem Steel for Socony-Vacuum Oil Co, SS Corsicana, Caddo and Calusa. A month later six more were requisitioned, SS Colina and Conastoga and four similar ships which were in completion at the time at Sun Shipbuilding & Drydock for the company Keystone Tankships. These were the “preserie”, an enlarged design later called T2-A: The SS Kalkay, Ellkay, Jorkay and Emkay. SS Corsicana was eventually commissioned as USS Kennebec, lead ship of the T2 class and thus, the whole T2 Type. SS Kalkay was renamed USS Mattaponi, making for the T2-A subclass. In June 1942 SS Aekay and Catawba were also acquired. All sixteen Kennebec class vessels survived the war, decommissioned to make way for the faster Cimarron class. Some were recommissioned and the very last was scrapped in 2018 in Turkey.

Hull & Equipments

The T2 had a gross tonnage (DWT) of 15,910 tons, but displaced 21,077 tons. They were called ‘500 footers’ also, as having a 501 ft 8 in (152.9 m) overall lenght, 68 ft (20.7 m) beam, and 29 ft 8.5 in (9.1 m) draft for a maximum depth of 37 ft (11.3 m) fully loaded; They carried 130,000 bbl (~18,000 t) on oil total. Due to this, when fully loaded, their tonnage was 39,000 tonnes. Tis required extra care for strenghtening their double hull. Complement was 214–247.

The basic design had a forecastle, a three storey bridge, two masts on decks fore and aft with booms to lift the heavy oil pipes (notably for refuelling at sea), pumps at all holds, separated into nine cargo tank, occupying the whole forward section, down to the aft island. The latter part was reserved for the crew’s quarters, above the machinery space, with the turbines and turbo generator. The ship had extra fresh water tank, used to flush and clear the fuel tanks after operation. The single funnel was raked and located aft.


With their installed power of 12,000 shp (8,900 kW) thanks to two geared steam turbines fed by two standard boilers, mated on a single screw propeller, they reached 16.5 knots (30.6 km/h; 19.0 mph), which was enough to left behing most U-Boats, even surfaced. Range was a comfortable 8,000 nmi (15,000 km; 9,200 mi).

Armament (AO fleet oilers)

USS Abatan, LCM AW4, ONI photos and description. She was modified as a fresh water distilling plant (Pasig class).

All fleet oilers (AO) were armed, and somewhat well armed, with typically a single standard 5″/38 caliber gun mount provided on the poop platform, usable both for antiship and AA combat, four 3″/50 caliber gun mounts (76 mm) of which two were placed o the forecastle forward and two aft. This was colmpleted by eight 40 mm AA gun mounts, generally in single monts and eight 20 mm AA gun mounts, also single. They were also given two depth charge projectors for ASW warfare but no sonar.

From 1943-44, all vessels gradually received either more AA and/or radars. The addition of the Navy personal to man the guns made the original crew of about 60-80 rose to 214 and even up to 247.

SS Sulphur Queen, sank by broking in two in the 1950s

USS Abatan at Guantanamo Bay today. She was one of the longest-service Fleet Oiler in the USN, being only retired after the Vietnam war and disposed of as a target, in early 1980.

⚙ T2 class specifications

Dimensions 144 x 13.2/14* x 4.4/4.5* m (472 x 46-47* x 16.5 feets)
Displacement 4,850 tons standard, 5,925 tons Fully Loaded
Crew 450/469 wartime
Propulsion 2 shafts Parsons turbines, 6 Yarrow boilers, 40,000 hp.
Speed 29 knots (42 km/h)
Range 2300 nm @ 27 knots.
Armament None


Keystone Tankships company ordered five tankers in 1940 from Sun Shipbuilding & Drydock of Chester, Pennsylvania, based on the T2 but longer and with increased capacity; Marcom would designate this design T2-A. Bigger but faster, they were 526 ft (160.3 m) in total length, displaced about 22,445 tons, and were rated at 10,600 tons gross with 16,300 DWT — yet they attained a top speed approaching 16+1⁄2 knots (30.6 km/h; 19.0 mph). All five were requisitioned by the Navy during the war and converted to fleet oilers as the Mattaponi class.

⚙ T2-A class specifications

Dimensions 144 x 13.2/14* x 4.4/4.5* m (472 x 46-47* x 16.5 feets)
Displacement 4,850 tons standard, 5,925 tons Fully Loaded
Crew 450/469 wartime
Propulsion 2 shafts Parsons turbines, 6 Yarrow boilers, 40,000 hp.
Speed 29 knots (42 km/h)
Range 2300 nm @ 27 knots.
Armament None


A T2 SE A1 Hat Creek at sea, 16 August 1943.

By far the most common variety of the T2-type tanker was the T2-SE-A1, another commercial design already being built in 1940 by the Sun Shipbuilding Company for Standard Oil Company of New Jersey. They were 523 ft (159.4 m) long, 68 ft (20.7 m) abeam, with 10,448 gross register tons (GRT) and 16,613 DWT. Their (steam) turbo-electric transmission system delivered 6,000 shaft horsepower (4,500 kW), with maximum thrust of 7,240 horsepower (5,400 kW), which produced a top-rated speed of about 15 knots (28 km/h; 17 mph) with a cruising range of up to 12,600 miles (20,300 km).

After Pearl Harbor, the United States Maritime Commission ordered this model built en masse to supply U.S. warships already in accelerated production, and provide for the fuel needs of US forces in Europe and the Pacific, as well as to replace the tanker tonnage being lost at an alarming rate to German U-boats.

481 were built in extremely short production times by the Alabama Drydock and Shipbuilding Company of Mobile, Alabama, the Kaiser Company at their Swan Island Yard at Portland, Oregon, the Marinship Corp. of Sausalito, California, and the Sun Shipbuilding and Drydock Company of Chester, Pennsylvania. During that period, average production time from laying of the keel to “fitting out” was 70 days. The record, however, was held by Marinship, which had Huntington Hills ready for sea trials in just 33 days.

⚙ T2-SE-A1 specifications

Built by Alabama DD. & SB. Co., Mobile, Alabama. *after modernization

Dimensions 159.6 m (168.25 m*) x 20.7 m (22.92 m*) x 9.1 m
Displacement 10,172 tons GRT (12,532*), DWT 16,613 tons
Crew 30 ?
Propulsion Main engine: 5,399 kW
Speed 15 knots
Range as T2
Armament as T2

T2-SE-A2 and -A3

The fleet oiler USS Onaganset (AO-86) fractured in port. A T2-SE-A2 model, she had a measure 2 camo graded, Dark, Ocean and light Gray.

These were built by Marinship of Sausalito Yard. Nearly identical to the T2-SE-A1 but with an output of 10,000 hp (7,500 kW) rather than 7,240. The A3 was a naval oiler from the start, not converted later as A2s. They had the full equipment for refuelling at sea and a powerful defensive armament.

⚙ T2-SE-A2/A3 specifications

Propulsion Main engines: 10,000 hp (7,500 kW)
Speed 16 knots?


T3-S-A1s were built by Bethlehem Sparrows Point Yard, for Standard Oil, New Jersey. They were identical to the original T2s but with downgraded powerplant, of just 7,700 hp (5,700 kW). 25 of such ships were ordered by the Maritime Commission, five later used as fleet oilers, the Chiwawa class. These WERE NOT the actual T3 design

⚙ T2-SE-A2/A3 specifications

Propulsion Main engines: 7,700 hp (5,700 kW)
Speed as T2


The T2-A-MC-K were smaller, with a M.C. deadweight tonnage of 16,300 tons, and fully loaded, 22,445 tons. They were shorter at 526 ft (160 m), narrower at 68 ft (21 m) with a draft ranging up to 30 ft 10 in (9.40 m) max. Their new turbine produced 12,000 hp (8,900 kW) for 17.5 knots (32.4 km/h; 20.1 mph), making them the fastest Oilers at the time. could hold 117,400 Bbls of oil and 595,000 gal of gasoline. Crew of 23 officers and 329 enlisted men. Armament: one single 5’/38 cal dual purpose gun mount, four single 3″/50 cal dual purpose gun mounts, four twin 40 mm AA gun mounts and twelve single 20 mm AA gun mounts. The first was commissioned in 1942 and USS Patuxent, a Kennebec-class oiler, was a good example.

⚙ T2-SE-A2/A3 specifications

Dimensions 526 ft (160 m) x 68 ft (20 m) x 30 ft (9.4m)
Displacement 16,300 tons GRT, 22,445 tons FL
Propulsion Main engines: 12,000 hp (8,900 kW)
Speed 17.5 knots (32.4 km/h; 20.1 mph)
Armament See notes
Range as T2

Wartime Career of notorious T2 ships

USS Macoma, AO 83, in dark blue livery.

USS Suamico, AO-49, in dull marine gray. ONI photo showing her bow 5-in and Oerlikon AA guns, and surface radar alteration of 1943. Mare Island Arsenal, July, 31, 1943.

Controversial hull structure weakness

USS Schenectady in January 1943.

In WW2, USS Schenectady broke in two at 11 pm on 16 January 1943, a few days after completing her sea trials. It happened while lying at the outfitting dock in Portland, Oregon in pristine weather. The hull failure was sudden, and heard a mile away. The Kaiser Shipyard oiler was the first and most notorious catastrophic T2 hull failure. The failure started on the deck between two bulkheads, ran down to the keel, initiative by a defective weld present in stress concentration point of the design.

It was compounded by poor welding procedures, cited later by the investigating committee. It contributed but was not critica in itself. Mass-production and metallurgical welding issues were not fully understood at the time, combined to a competing, challenging need to out-do other yards by production time. This ended with a serie of equally critical ship’s breaking up accidents, fuelling a relatively poor reputation, but most losses were simply from enemy action, with the critical failure added as aggravating factor. Indeed many oilers survived one of even several torpedo impacts due to their double, or even triple hulls in some cases, showing amazing resilience.

  • SS Caddo (1942) sank on 23 November 1942 (hit by torpedo U-518, North Atlantic)
  • SS Esso Gettysburg sank on 10 June 1943 (from U-66)
  • SS Bloody Marsh sank on 2 July 1943 (from U-66), on “Bloody Marsh”, maiden voyage
  • US Touchet sank on 3 December 1943 (from U-193) in the Gulf of Mexico while en route to New York from Houston
  • SS McDowell sank on 16 December 1943 (from U-516) off Cuba.
  • SS Fort Lee sank on 2 November 1944 (from U-181), Indian Ocean.
  • SS Jacksonville sank on 30 August 1944 (from U-482) off Ireland, convoy CU 36
  • USS Ponaganset: Accident: Broke in two at pier in Boston
  • SS Nickajack: Sank 30 March 1946 in Eniwetok Harbor underway to Yokohama
  • SS Glenn’s Ferry: Sank on 6 October 1945 at Batag Island, Philippines, bound to Manila after explosion

Postwar Civilian Career

Since some of the T2 were completed after the end of WW2, there was no way to have been scrapped afterwards. The USN curtailed its fleet oilers (AO) fleet, most being sold to civilian owners, just like other T2 exploited by MARCOM. They were sold quickly at low prices due to the double concerns of the Commission and state to still own these ships under US taxpayer expenses, and their known safety concerns, as all mass-produced ships in wartime. Indeed, the T2 were soon notorious for many accidents in the 1950-60s. They were used to transport fuel oil, diesel fuel, gasoline and sometimes black oil-crude oil. Many were also sold to foreign companies and served well into the 1980s despite their age and issues.

Fro example, SS Bemis Heights sank on 5 November 1948 off Quoin Point, South Africa, SS Pendleton, broke in two on 18 February 1952, same for SS Fort Mercer on 18 February 1952, SS Salem Maritime exploded on 17 January 1956 while unloading fuel in Lake Charles, Louisiana. SS Midway Hills sank on 2 October 1961, broke in two from after an engine room explosion off Jacksonville, Florida. Also SS Marine Sulphur Queen (disappeared, causes unknown, 4 February 1963), SS Bunker Hill (6 March 1964, explosion, broke in two), SS White Bird Canyon (sank 17 December 1964, bad weather in the Aleutians), SS Rainier (wrecked and sank 22 December 1965, SS Fort Schuyler engine room fire, sank 24 October 1966), SS Ninety-Six (sank 3 March 1971, leaking in storm, Indian Ocean), SS V. A. Fogg (lost 1 February 1972), SS Belridge Hills (Sank 24 December 1972, gale off Japan), SS Marine Floridian (1977 collision with a drawbridge), SS Marine Electric (sank 1983 storm), Delta Conveyor (sank in the Mississippi River Louisiana, raised 2003).

Ideal X was one of the most famous tanker postwar, being the very first container ship. The former Marinship Corporation’s Potrero Hills, she was later purchased by Malcom McLean’s Pan-Atlantic Steamship Company, and made history. She could carry 58 containers, inside her holds and on deck platforms, making intermodal transport way faster.

Fleet Oilers’s cold war Career

Being that recent, many fleet oilers still in the USN were put to good use to refuel the USN armada deployed off the coast of southern Korea duing the Korean War. Better so in 1966, the US Army reactivated 11 T2 tankers and converted them into floating electrical power generation plants (alongside those used for refuelling the fleet). Their propulsion systems with electrical turbines generate current for on-shore use, based on their classic tubines and own fuel (150,000-barrel holds). These giant generators could in that case stay in place for two years, continuouslt providing electricity, without ever refueling. This is a rarely spoken of contribution to the Vietnam War. USNS French Creek was in fact the first to arrive, in June 1966, followed by USS Kennebago, both berthed at Cam Ranh Bay.


A Former T2 in Curaçao, Willemstad Port.

Details on the deck of SS Fort Lee, Feb. 1945 at Mare Island, California

USS Ranger refuelled underway at sea by SS Council Grove, 1974.

USS Pasig, water distilling ship, one of the four ever built in WW2, and lead ship.

USS Pasig (AW-3, Pasig class) ONI Mare Island, 6 January 1945

Tanker Esso, Manhattan, underway with PT-boats in 1943

Richfield Oil Corporation type T2-SE-A1 David E Day in port, circa 1950

USS Cohocton, with a two-graded Type 2 measure camouflage, 1942

SS Marine Electric, a former T2 converted as bulk carrier

SS Fort Mercer prior to sinking

Dutch Tanker at Rotterdam, HAL Company

A Tanker postwar for a Dutch Company CPIM in Curaçao

SS Pendelton sinking

Links and sources

www.nytimes.com/1943/03/18/archives ship-failure-laid-to-steel-welding-investigators-report-that