Liberty Ships

Disaster loomed. The RAF had blunted Reichsmarshal Hermann Göring’s blitz, but by September 1941 VADM Karl Dönitz’s Type VII U-Boats were regularly decimating Atlantic convoys. It was becoming increasingly obvious that the German submarine offensive was maintaining its horrifying 1940 record and even increasing the rate at which it sank the merchant ships that were so essential to Britain’s war effort. Local shipyards could not keep pace. It was decided that UK ship builders would concentrate on warship construction. Meanwhile, America would be asked to help with the construction of new merchant ships.

In 1940 the British Government ordered 60 tramp steamers from the USA and the first of these, the Ocean Vanguard, was launched 16 August 1941.

This basic design evolved into the highly successful Liberty and Victory classes. One Liberty ship even fought back and sank a German Armed Merchant Cruiser.

The original design, by J.L. Thompson and Sons of Sunderland, UK, dated back to 1879. It was a simple tramp, cheap to build and operate, and therefore popular with the shipowners. It had an obsolete but reliable 2,500 hp triple expansion reciprocating engine fed by two coal-fired boilers. In a 135 x 17.3 x 8.5 metres, 7,200 tons hull. The ships carried a good-sized cargo of 9,000 tons at a steady 11 knots. The American order specified a displacement boost of 800 tons and 18 inches (457 mm) more draught. The design was further modified by the United States Maritime Commission to include oil-fired boilers, welding instead of rivets and prefabricated modules to speed construction.

Expendable

The ships were expendable in that they had a planned life of only five years. Even so, some were still plodding their salt-caked smoke stacks around the ocean 20 years later. They sailed chiefly under British and American flags but also under many others, including Canada’s, during World War II. Two have been preserved as museum ships. One is based in Baltimore MD, the other in San Francisco, CA. Another survives as a floating cannery in Alaska.

A conglomerate of six shipbuilders responded to the original work order. These were headed by Henry J. Kaiser, who had a great reputation for building infrastructure such as roads and massive dams on time and under budget, but he had no shipbuilding experience. Under his general direction, early ships spent nearly 230 days on the stocks, but he steadily reduced this to 42 days. By 1943, three Liberty ships were being launched every day. One ship, the Robert E. Peary, was constructed and launched as a publicity stunt only four days and 15.5 hours after its keel was laid. Concomitantly, Australian shipyards required 12 to 18 months to build an 800-ton Bathurst class corvette.

Liberty Ship, sectioned.

 The first 14 Liberty ships were launched on what President Roosevelt decreed “Liberty Fleet Day”, 27 September, 1941. Roosevelt himself launched the Patrick Henry, named in honour of the eloquent “give me liberty or give me death” Virginian attorney and Declaration of Independence signatory. Between 1941 and 1945, a largely unskilled workforce numbering 7000,000 (including 30 per cent women), produced 2,751 of these ships in 18 American shipyards. This made the Liberty easily the most prolific of any major ship class ever built.

This obsolete but reliable 2500 hp triple expansion steam engine, originally designed by the North Eastern Marine Engineering Company, Sunderland, powered most of the Liberty Ships.

Although any ship can be damaged through stormy weather or bad load distribution, nearly 1500 Liberty ships reported significant brittle hull fractures. A total of 19 ships broke in half without warning, some after grounding or being subjected to similar mistreatment. Inexperienced shipyard welders were blamed, but Cambridge University research suggested the cold weather experienced in the North Atlantic was more likely, in that it enabled an “embrittlement” process of the particular grade of steel plate used in construction. This was akin to the then little understood metal fatigue problem associated with the January 1954 Comet jet airliner disaster over the Mediterranean.

Modifications

Nevertheless, the welding process did contribute to the problem, in that it permitted cracks to pass unimpeded from one plate to the next. The ship’s stiff frame also contributed to cyclic stress building up in critical areas, such as sharp cargo hatch corners. Various modifications were incorporated during construction and the succeeding Victory class was built stronger and less stiff. Hull frames, for instance, were spaced at 914 mm in the follow-on Victory class versus 762 mm for the Liberty class.

In early 1942, plans were commenced for a 15-knot Victory class ship and the first of this 534-strong class, the United Victory, was launched on 28 February 1944. Based on the general layout of the Liberty ship, it was a little larger (139 x 19 x 7.6 metres), it had a steam turbine engine that developed 6,000 hp (AP2 version) or 8,500 hp (AP3) and its cargo capacity was 10,850 tons. Variations included one with diesel propulsion and others built as tankers, attack transports and aircraft transports.

American Liberty ships carried a crew of about 44 plus 12 to 25 “Naval Armed Guard”. The size of the naval party depended chiefly on the armament fitted, which might comprise a single three- four- or five-inch gun aft with sometimes a similar weapon forward. These might be supplemented by six to ten 20 mm cannon plus two 37 mm anti-aircraft weapons. About 200 Liberty ships were lost due to enemy action during World War II, and this included the Luckenbach Steamship Company of New York’s Stephen Hopkins, Liberty Hull number 247, launched by the Permente Metal Corporation, Richmond, CA, on 14 April 1942.

Surprise encounter

Under the command of CAPT Paul Buck, 13 days out of Cape Town, at about 0900, Sunday 27 September 1942, in ballast for Paramaribo, Dutch Guiana, Hopkins stumbled upon the 7800-ton tender Tannenfels replenishing the 4778-ton German auxiliary cruiser Stier in the South Atlantic.

Stier probably carried two of only six Arado 231 seaplanes ever built. They had a six-cylinder 160 hp engine and measured 10.16 x 7.8 x 3.12 metres. Designed for submarines, the Ar231 folded into a tidy package (left) but it had limited utility. It required calm seas to operate, it had a maximum speed of only 91 knots and could barely fly 270 miles without refuelling.

Stier measured 134 x 17.3 x 7.2 metres and her seven-cylinder 3750 hp two stroke MAN diesel drove her at 14.5 knots. Her 325 well-trained crew worked well together and since fighting their way clear of the British blockade around her home waters in May, Stier‘s crew had sunk four British and American merchant ships.

Jammed RRR

All three ships were equally surprised when Hopkins suddenly emerged from a heavy rain shower less than one mile away. Third Mate Walter Nyberg, on Hopkins‘s bridge, ordered the helm hard over to port and called the Captain who sounded the general alarm and steadied with his stern to the enemy. His radio officer broadcast the RRR alarm, but this was jammed by Tannenfels. Within six minutes, Hopkins was receiving well-directed and systematic 150 mm broadsides from about 1000 yards range, while Stier‘s 37 mm and both Stier‘s and Tannenfels‘s 20 mm cannon kept peppering away.

Ensign Kenneth Willett had been severely wounded on his way to his action station, but he responded gallantly with Hopkins‘s single four-inch gun. He stuck to his post, firing over open sights in gale force winds, driving rain and rising seas. Others swung Hopkins‘s twin 37 mm and six 20 mm cannon into action.

Boiler room hit

It was not long, however, before a 155 mm shell exploded in Hopkins‘s boiler room, smashing major steam pipes and killing men. MIDN Edwin O’Hara, driven from his engine room by fire, joined Ensign Willett at the stern gun. As she lost speed, another shell destroyed Hopkins‘s steering gear.

Helpless before a vessel with vastly superior firepower, Willett and O’Hara were rewarded by seeing, through the driving rain, their shells smash home. They destroyed Stier‘s generators, which led to total engine, steering, fire pump and armament direction failure. As Hopkins was being reduced to a blazing wreck, Willett and his crew scored a total of about 35 hits on the equally aflame Stier, 15 of them below the waterline. Meanwhile, Stier‘s guns maintained rapid fire in local control.

About 0950 a shell hit Hopkins‘s after magazine, killing most of the gun’s crew. However, the gun still functioned, so MIDN O’Hara single-handedly loaded and fired the last five shells he found in the ready use locker. By now, Hopkins‘s forward 37 mm guns had also been destroyed. CAPT Buck, with his ship sinking and aflame from stem to stern, ordered abandon ship around 1000.

Landfall Brazil

One lifeboat carrying 19 men cleared the wreckage. They eventually sailed 1860 miles due west until they made landfall in Brazil, 31 days later. By that stage there were only 15 emaciated survivors left of the original 56 aboard Hopkins. They did not include CAPT Buck, Ensign Willett or MIDN O’Hara.

Stier fared a little better, but not much. About four hours after the action her captain ordered abandon ship before scuttling.  The tender Tannenfels rescued all but three of her crew.

References:

Edwards, B.E. Salvo! Classic naval gun actions. Brockhampton Press: London, 1999.
Lane, F.C. A history of shipbuilding under the U.S. Maritime Commission in World War II. Johns Hopkins University Press: Baltimore, 2001.
Morison, S.E. History of the United States Naval operations in World War II. Vol 1. The Battle of the Atlantic, September 1939-May 1943. Little Brown and Company: Boston, 1950.
Sawyer, L.A. and W.H. Mitchell. The history of the “emergency” type cargo ships constructed by the United States during World War II. Cornell Maritime Press: Cambridge, 1970.