SS ''Rochambeau'' was a French Transatlantic crossing, transatlantic ocean liner of the Compagnie Générale Transatlantique (CGT). She was launched in 1911 and was the first French ship to be powered by a combination of Marine steam engine, reciprocating steam engines and Steam turbine#Marine propulsion, steam turbines. She was named after the Jean-Baptiste Donatien de Vimeur, comte de Rochambeau, Comte de Rochambeau, a French Aristocracy (class), aristocrat and List of Marshals of France, marshal who led an army in the American Revolutionary War.

Combining reciprocating and turbine engines

A turbine is smaller, simpler, lighter, faster, smoother and more reliable than an equivalent triple- or quadruple-expansion piston engine. United Kingdom of Great Britain and Ireland, UK shipyards had built the first turbine-powered commercial ship, , launched in 1901, and the first turbine-powered transatlantic liners, Allan Line Royal Mail Steamers, Allan Line's and ''SS Drottningholm, Virginian'', both launched in 1904. But a turbine consumes more fuel than an equivalent triple- or quadruple-expansion piston engine. It cannot run in reverse, and does not run well at low speed. Another limitation was that early turbines drove their propeller shafts directly, as satisfactory Gear train, reduction gearing had yet to be developed. The speed at which a turbine runs efficiently is several times faster than that at which a marine propeller runs efficiently. UK shipyards responded by developing steamships that combined reciprocating and turbine engines. The first was the Reefer ship, refrigerated cargo liner , closely followed by the transatlantic liner , both launched in 1908. ''Otaki'' and ''Laurentic'' each had three Propeller, screws. The port and starboard screws were each powered by a Marine steam engine#Triple or multiple expansion, triple-expansion engine. Exhaust steam from their low-pressure cylinders fed a single low-pressure turbine amidships that drove the middle screw. ''Otaki'' and ''Laurentic'' could go astern, slowly forward or manoeuvre using only their piston engines. For higher speeds they could use the turbine as well, increasing both power and fuel efficiency. ''Laurentic'' proved both more economic and more powerful than her sister , which had twin Marine steam engine#Triple or multiple expansion, quadruple-expansion engines and no low-pressure turbine. The comparison influenced Harland and Wolff to apply the same triple screw, reciprocating and turbine combination in the White Star Line, White Star Olympic class liners.

Building and early service

Chantiers de l'Atlantique built ''Rochambeau'' at Saint-Nazaire, launching her on 2 March 1911. Her design was an enlargement of the , which Chantiers de l'Atlantique had launched in 1907 and completed in 1908. ''Rochambeau'' was launched on 2 March 1911 and completed later that year. Unlike ''Otaki'', ''Laurentic'' and the s, ''Rochambeau'' had four screws: two driven by four-cylinder triple-expansion engines and two by low-pressure turbines. Her piston engines ran at 115 Revolutions per minute, RPM and her turbines (when in use) ran at 350 RPM. Nine boilers supplied steam at 200 Pounds per square inch, lb_f/in² to her piston engines. Chantiers de l'Atlantique designed ''Rochambeau'' to achieve a speed of . ''Rochambeau'' was designed with berths for 420 first & second class passengers and 1,450 steerage class. ''Rochambeau'' left Port of Le Havre, Le Havre on her maiden voyage to New York City, New York on either 30 August or 16 September 1911. CGT was satisfied with its choice of four screws instead of three. On CGT's advice, Swan Hunter, Swan, Hunter and Wigham Richardson adopted the same arrangement when it built the liner for Compañía Transatlántica Española in 1912–13. Experience with ''Rochambeau'' also influenced the design of CGT's launched in 1913 and ''SS Mexique, Lafayette'' launched in 1914. By 1914 ''Rochambeau'' was equipped for wireless telegraphy. She operated on the standard 300 and 600 metre wavelengths. Her Maritime call sign, call sign was FTR.

First World War

After the outbreak of the World War I, First World War the List of ambassadors of the United States to France, US Ambassador in Paris, Myron T. Herrick, chartered ''Rochambeau'' and another CGT liner, , to repatriate US citizens from Europe. ''Rochambeau'' was booked to leave Le Havre on 28 August 1914 carrying 1,200 US citizens. When Herrick retired as US Ambassador in November 1914, he too returned to New York on ''Rochambeau''. CGT kept ''Rochambeau'' on the same route until March 1915, despite the extra pressure on Le Havre as a port supplying the British Expeditionary Force (World War I), British Expeditionary Force and the danger from Imperial German Navy, German Navy U-boats operating in the English Channel. CGT transferred ''Rochambeau''s sailings to Bordeaux in April 1915. ROCHAMBEAU LOC 16348392195

In the war the Allies of World War I, Entente Allies Armed merchantman, defensively armed their merchant ships, generally with a single naval gun on the stern. The United States in World War I, USA was neutral until April 1917, but from September 1914 its United States Department of State, Department of State allowed an armed merchant ship of a belligerent country to use US ports on condition that she was armed with no more than two guns, they were not more than calibre, no guns were mounted on the forward part of the ship, her cargo excluded war Materiel, materiél, and her passengers as a whole were not suitable for military service. On 8 November 1915 en route from New York to Bordeaux a fire broke out aboard ''Rochambeau''. Her officers held an investigation but failed to determine the cause. In February 1916, 11 people in Bordeaux were convicted of either stealing valuables from CGT passengers' luggage or handling the stolen goods. The stolen items included a jewel box from ''Rochambeau'' insured for $4,000, and items from passengers aboard ''Chicago'' and ''Espagne''. From February 1915 Germany had waged unrestricted submarine warfare against Entente merchant ships. Therefore by March 1917 ''Rochambeau''s armament was increased to two guns. As well as the usual gun on her poop deck she had a gun on her forecastle. The latter breached the USA's rule, but the State Department allowed her to continue to use the Port of New York and New Jersey, Port of New York. On 29 April 1917 ''Rochambeau''s gunners opened fire on a "suspicious object" astern, and then off her starboard beam at a range of about 800 yards. About 12 shots were fired, but it was misty and it was not clear whether the object was a submarine or a whale.

Post war service

In 1919 after the First World War ''Rochambeau'' brought service personnel home to the USA. On one crossing in January she repatriated 883 men of the 337th and 339th Field Artillery Branch (United States), field artillery, 88th Infantry Division (United States), 88th Infantry Division and medical units. On another in September she brought home 245 Czech Americans and Slovak Americans who had served in the Czechoslovak Legion in France. ''Lafayette''s westbound crossing in January 1919 was marred by engine trouble three days out of Bordeaux, which reduced her speed to . She then stopped in Halifax, Nova Scotia for four days for bunkering. She reached New York 17 days after leaving Bordeaux. The ship carried 554 civilian passengers on the voyage as well as 883 US troops, and her Master mariner, Master imposed rationing to ensure her supply of food lasted for the prolonged voyage. ''Rochambeau'' last sailed from Bordeaux in January 1919 and reverted to Le Havre in February. Also in 1919 her first and second class accommodation was refitted as 475 berths for "cabin class", a new concept that the CP Ships, Canadian Pacific Steamship Company had pioneered in the First World War. On 15 August 1924 ''Rochambeau'' suffered a broken crankshaft en route from Le Havre to New York. She continued under her own power at reduced speed. On the morning of 21 February 1925 ''Rochambeau'' collided with the Anchor Line (steamship company), Anchor Line liner in New York Harbour, damaging both ships above the waterline. The two ships were at anchor, and as they swung with the turn of the tide ''Rochambeau''s stern struck ''Tuscania''s bow. Damage to ''Rochambeau'' was assessed at $100,000. ''Rochambeau'' sustained storm damage at sea on 30 December 1925. CGT took her out of service, sent her to Toulon for repairs and announced that it would use the occasion to have her converted from coal to oil fuel. The Immigration Act of 1924 limited migration to the USA, which reduced steerage class traffic. Therefore while ''Rochambeau'' was at Toulon, CGT had her steerage berths replaced by "tourist class". She returned to service in August 1926. Her accommodation was revised again in December 1927 to three classes: cabin, tourist and third. In June 1931 the United Press International, United Press Association reported that ''Rochambeau'' collided with a vessel called ''Uncheria'' off Ushant. UPA reported that ''Uncheria'' was sunk, ''Rochambeau'' suffered slight damage, and ''Rochambeau'' rescued all 29 crew from ''Uncheria''. Numerous newspapers published the story, but the ''Waikato Times'' noted that there was no vessel called ''Uncheria'' in ''Lloyd's Register''. ''Rochambeau'' made her final Le Havre – Port of Vigo, Vigo – New York crossing in July 1933. In 1934 her code letters OSAN and original wireless call sign were superseded by the call sign FNTW, but by then she was waiting to be scrapped. She was broken up at Dunkirk.

References

Bibliography

External links

* * – postcards of ''Rochambeau'' {{DEFAULTSORT:Rochambeau, SS 1911 ships Ocean liners Passenger ships of France Ships built by Chantiers de l'Atlantique Ships of the Compagnie Générale Transatlantique Steamships of France World War I passenger ships of France