World War II Day by Day

South Portland, Maine • May 6, 1943

On this date the New England Shipbuilding Cor­por­a­tion laid down the keel of SS Jere­miah O’Brien. Named after a Scots-Irish Revo­lu­tionary War hero from Maine (then part of Massa­chu­setts), the SS Jere­miah O’Brien was one of 2,710 emer­gency cargo (EC)‑class freight­ers built in 18 dif­fer­ent ship­yards across the United States. The South Port­land ship­builder built 236 of these cargo-carrying ships in a ship­yard specif­i­cally laid out to pro­duce what became known as “Liberty” ships for the War Ship­ping Admin­is­tra­tion. The WSA was the oper­a­ting divi­sion of the U.S. Marit­ime Com­mis­sion, an agency of the U.S. govern­ment tasked with pur­chasing and allo­ca­ting ship­ping ton­nage to the U.S. Army, Navy, and nomi­nally civil­ian mer­chant marine during World War II. At one time the East and West Yards of the South Port­land ship­yard employed just under 30,000 peo­ple, of which 3,700 were women. The final out­put of both South Port­land ship­yards was 266 EC‑class cargo ships—236 Liber­ty ships ordered built by the WSA and 30 of 60 British “Ocean”-class freight­ers, i.e., the British vari­ant of U.S. Liberty ships that were ordered and built under a British con­tract for the British Ministry of War Trans­port. The Oceans were replace­ments for British-owned mer­chant ships sunk by enemy actions (U‑boats, E‑boats, com­merce raiders, Luft­waffe bombings, etc.) during the dark days of the Battle of the Atlantic. The Jere­miah O’Brien was assem­bled in 56 days, launched on June 19, 1943, and placed in service on July 3, 1943. The ship was valued at $1,750,000 (under $42 mil­lion in 2024) and oper­ated under a cost-plus ser­vice agree­ment with the U.S. govern­ment by the civil­ian steamship company Grace Line, Inc.

Interestingly enough, it was the British Mer­chant Ship­building Mis­sion in Septem­ber 1940 that brought their own plans for a ship design and dropped them in the lap of a con­sor­tium of Amer­i­can con­struc­tion and naval engi­neering firms. One look at the simple design of the hull and the uncom­pli­cated recip­ro­cating engine and steam boilers of the Ocean-class freight­er showed they meshed nicely with Amer­i­can ship­building inge­nu­ity and new tech­niques that stressed quick pro­duc­tion turn­around and low con­struct­ion and assem­bly costs for large-scale projects; they facil­i­tated simul­ta­neously building multi­ple cargo ships in indi­vid­ual slip­ways in one enor­mous ship­yard, lifting these pre­fab­ri­cated, pre­shaped, and pre­assembled sec­tions (e.g., trans­verse bulk­heads, bows, and mid­ships) into place using giant cranes, and welding, not riveting these sec­tions together to build out ships under con­struc­tion. (Welding saved 600 tons in ship weight com­pared to using rivets, reduced labor costs by a third, but sacri­ficed strength.) Former Assis­tant Sec­re­tary of the Navy (1913–1920) and now U.S. Pres­ident Frank­lin D. Roose­velt (1933–1945) looked at the Ocean design, called it “a real ugly duck­ling” of a ship while admitting it was most cer­tainly capa­ble of “carry[ing] a good load” to meet the needs of the war effort. In February 1941 the presi­dent announced the new con­struc­tion of 200 EC-class cargo ships, later increasing the figure to 2,300 for all of 1942 and 1943. On Septem­ber 27, 1941, the first of 14 EC-class cargo­men launched was the SS Patrick “Give me liberty or give me death” Henry. Thus was born the legen­dary Liberty and Amer­i­canized Ocean fleet of cargo ships. Over time the ves­sels were delivered to Allied mer­chant marines and navies in suf­fi­cient num­bers that U‑boat sinkings were un­able to staunch the flow of these newly con­structed trans­atlantic freight­ers into what had once been rich hunting grounds of the Kriegsmarine.

U.S. Liberty ships and 531 successor Victory ships of a slightly more modern design were the main­stay of the Allied logis­tic effort during World War II. They deliv­ered troops, muni­tions, vehicles of all types, air­craft, artil­lery, and other mili­tary neces­si­ties, food­stuffs, petro­leum pro­ducts, coal, iron ore, metals, and ani­mals (horses, mules, and cattle) to name the most com­mon cargoes. The Liberty and Vic­tory ships com­ple­mented British-flagged and British-built freight­ers. With­out the mili­tary and civil­ian cargoes deliv­ered by these ships and men, vic­tory over the Axis powers in Europe and the Pacific would likely to have been more costly and drawn out.

Liberty Ships’ Indispensable Role in Allied Victory in World War II

Above: Line drawing of a typical Liberty cargo ship. The double-bottom cargo ship was 441 ft 6 in/­134.57 m in length, powered by 2 cargo oil- or fuel oil-fired steam boilers, driven by a 2,500 hp/­1,900 kW single-screw, 4‑bladed pro­pel­ler, and trav­eled at a rela­tively slow speed of 11–11.5 knots/­20.4–21.3 km/h/­12.7–13.2 mph. Cargo capacity of a single Liberty ship was equal to that of 300 rail­road freight cars. ­One ship could carry 2,840 Jeeps, or 440 light tanks, or 230 mil­lion rounds of rifle ammu­ni­tion, or 3,440,000 C‑rations. The Liberty’s design was easily adapt­able. Sixty-two hulls were modi­fied to carry petro­leum pro­ducts, more than 100 were built or con­verted to troop­ships, 8 were con­verted to ani­mal trans­ports, and 6 to hos­pi­tal ships. Typ­i­cal ship com­ple­ment for freight-carrying Libertys was 36–62 U.S. volun­teer Mer­chant Mariners and 21–40 U.S. Navy Armed Guard sea­men among whom were the all-impor­tant gun crews who manned the dual-purpose stern-mounted 5 in/­127 mm and bow-mounted 3 in/­76 mm deck guns for use against sur­faced sub­marines and eight 20 mm machine guns. Like all mer­chant ships, Liberty ships were priority tar­gets of Axis sub­marines, sur­face raiders, and air­craft and thus in con­stant danger of attack. At 11 knots per hour, the ship had a range of 19,000 nau­ti­cal miles/­21,865 miles/­35,188 km. Orig­i­nally designed to have a 5‑year life­span, a Liberty ship, if it delivered just one cargo load, paid for itself. Of the 2,710 Libertys built during the war fewer than 200 were lost (7 percent). One in 26 U.S. Mariners serving aboard mer­chant ships in World War II died in the line of duty—a greater per­cent­age of war-related deaths than all other U.S. services.

Left: Sliding down West Yard slipway number 1 on launch day, June 19, 1943, in a South Port­land, Maine, ship­yard is Liberty ship SS Jere­miah O’Brien, 56 days after her keel was first laid down. Fifty-six days set no ship­yard pro­duc­tion record—the median pro­duc­tion time per ship was 39 days by 1943. The pro­duc­tion record holder—surely a pub­lic­ity stunt—was SS Robert E. Peary built in 4 days and 15½ hours; she sailed 3 days later. Over 300,000 men and women working 3 shifts 24/7 in 18 Amer­i­can ship­yards com­pleted on aver­age 3 Liberty ships every 2 days, accounting for the 2,710 Liberty ships produced during World War II.

Right: SS Jeremiah O’Brien’s wartime exploits included 7 voyages, 4 nerve-wracking round-trip trans­atlantic con­voy crossings under escort begin­ning with her maiden voy­age (July 10 to Septem­ber 11, 1943), and 11 shuttle mis­sions, aka “bus runs,” between June and Septem­ber 1944 from England to the French Nor­mandy coast and back again (Oper­a­tion Over­lord). Their prin­ci­pal dis­charge: troops (3,492) and vehicles (1,746). Walter W. Jaffee tells this exciting story of the Jere­miah O’Brien from the time before her keel was laid down to her pre­sent-day status as, first, a living memo­rial to the men and women who built, sup­plied, served on, and defended Liberty ships and, secondly, a floating museum dedi­cated to pre­ser­ving and teaching the his­tory of Liberty ships and their con­tri­bu­tion to vic­tory over the Axis powers. As recounted by Jaffee, Allied Supreme Com­mander in Europe Dwight D. Eisen­hower was ful­some in his praise: “When final vic­tory is ours there is no orga­ni­za­tion that will share its credit more deservedly than the Mer­chant Marine.” Gen. Doug­las Mac­Arthur, whose war­time baili­wick was the South­west Pacific, said: “I hold no branch in higher esteem than the Mer­chant Marine Ser­vices.” One of two oper­a­tional Liberty ship sur­vi­vors, the SS Jere­miah O’Brien is moored at The Embar­ca­dero, Pier 35, in San Fran­cisco Bay, Cal­i­for­nia. The other sur­viving oper­a­tional Liberty ship is the SS John W. Brown berthed in Balti­more, Mary­land, on the U.S. East Coast. The O’Brien occa­sion­ally steams around the bay with a boat­load of guests. Volun­teer crew­members can be reached at 1-415-544-0100. To purchase Jaffee’s fine history of the Jere­miah O’Brien, click either Amazon, AbeBooks, or IberLibro.

Liberty Ships: Key Ingredient in Winning World War II (May want to skip first minute)