Question: The largest ship in the "Imperator" class ocean liners had how many gross register tons?

full_context: Document 1: RMS Homeric (1913): RMS "Homeric", originally launched as "Columbus", was built for Norddeutscher Lloyd and launched in 1913 at the F. Schichau yard in Danzig. "Columbus" was ceded to Great Britain in 1919 as part of German war reparations. She was sold to White Star Line in 1920, which named her "Homeric". Her sister ship "Hindenburg" retained her German ownership and was renamed "Columbus". "Homeric" was operated by White Star from 1922 to 1935.
Document 2: Imperator-class ocean liner: The "Imperator" class ocean liners were a series of three ocean liners designed for the Hamburg America Line, commonly known as "HAPAG". These three ships were commissioned by the chairman of HAPAG Albert Ballin. Namely the "Imperator" (1912), the "Vaterland" (1913) and the largest, the "Bismarck" (1914). These liners were over 50,000 tons, sported three funnels and had a length ranging from 906 ft (276 m) to 955.8 ft (291.3 m). To this day, the "Vaterland" is the largest passenger ship operated by a German shipping company.
Document 3: RMS Queen Mary 2: RMS "Queen Mary 2 (also referred to as the QM2") is a transatlantic ocean liner. She is the largest and only major ocean liner built for the British Cunard Line since "Queen Elizabeth 2" in 1969, the vessel she succeeded as flagship of the Cunard Line.
Document 4: RMS Majestic (1914): RMS "Majestic was a White Star ocean liner working on the North Atlantic run, originally launched in 1914 as the Hamburg America Line liner SS "Bismarck. At 56,551 gross register tons, she was the largest ship in the world until completion of  in 1935.
Document 5: Oceanic (unfinished ship): The RMMV (Royal Mail Motor Vessel) Oceanic was the planned name of an unfinished ocean liner that was partially built by Harland and Wolff for the White Star Line. The ship was to have been the first 1000 ft -long ocean liner. It was intended to be the largest ocean liner for the White Star Line, thus it would have been larger than the earlier White Star giants, "Olympic", "Titanic", "Britannic", and "Majestic".
Document 6: RMS Queen Mary: RMS "Queen Mary" is a retired ocean liner that sailed primarily on the North Atlantic Ocean from 1936 to 1967 for the Cunard Line (known as Cunard-White Star Line when the vessel entered service). Built by John Brown & Company in Clydebank, Scotland, "Queen Mary", along with  , were built as part of Cunard's planned two-ship weekly express service between Southampton, Cherbourg and New York. The two ships were a British response to the express superliners built by German, Italian and French companies in the late 1920s and early 1930s. "Queen Mary" was the flagship of the Cunard Line from May 1936 until October 1946 when she was replaced in that role by "Queen Elizabeth".
Document 7: RMS Titanic: RMS "Titanic" ( ) was a British passenger liner that sank in the North Atlantic Ocean in the early morning hours of 15 April 1912, after it collided with an iceberg during its maiden voyage from Southampton to New York City. There were an estimated 2,224 passengers and crew aboard the ship, and more than 1,500 died, making it one of the deadliest commercial peacetime maritime disasters in modern history. The RMS "Titanic" was the largest ship afloat at the time it entered service and was the second of three "Olympic"-class ocean liner s operated by the White Star Line. The Titanic was built by the Harland and Wolff shipyard in Belfast. Thomas Andrews, her architect, died in the disaster.
Document 8: RMS Mauretania (1906): RMS "Mauretania" was an ocean liner designed by Leonard Peskett and built by Swan, Hunter & Wigham Richardson for the British Cunard Line, and launched on the afternoon of 20 September 1906. She was the world's largest ship until the completion of  in 1911 as well as the fastest until "Bremen" 's maiden voyage in 1929. "Mauretania" became a favourite among her passengers. After capturing the Eastbound Blue Riband on her maiden return voyage in December 1907, she claimed the Westbound Blue Riband for the fastest transatlantic crossing during her 1909 season. "Mauretania" would hold both speed records for twenty years.
Document 9: RMS Republic (1903): RMS Republic was a steam-powered ocean liner built in 1903 by Harland and Wolff in Belfast, and lost at sea in a collision six years later while sailing for the White Star Line. A CQD distress call was issued on the new Marconi radio device, the first recorded, resulting in the saving of around 1500 lives. Known as the "Millionaires' Ship" on account of the number of well-known and immensely rich Americans who traveled by her, she was described as a "palatial liner" and was the flagship of White Star Line's Boston service.
Document 10: Four funnel liner: A four funnel liner, four funnelled liner or four stacker is an ocean liner with four funnels. The SS "Great Eastern", launched on 31 January 1858 (a full 40 years ahead of any comparable ships), was the only ocean liner to sport five funnels. As one funnel was later removed, the "Great Eastern", by default, became the first ocean liner to have four funnels. However, after the Great Eastern became a four funnel ship she never carried passengers so really should not be considered the first four funnel liner. The SS "Kaiser Wilhelm der Grosse", launched on 4 May 1897, was properly the first ocean liner to have four funnels and was one of the first of the golden era of ocean liners that became prominent in the early- to mid-20th century. The most famous four funnel liners are the RMS "Titanic", which sank after striking an iceberg on her maiden voyage on 14 April 1912, and the RMS "Lusitania", which was torpedoed on 7 May 1915 during the First World War.
Document 11: Barbarossa-class ocean liner: The "Barbarossa" class was a class of ocean liners of North German Lloyd and the Hamburg America Line of the German Empire. Of the ten ships built between 1896 and 1902, six were built by AG Vulcan Stettin, three were built by Blohm & Voss, and one was built by Schichau-Werke; all were built in Germany. They averaged  gross register tons (GRT) and featured twin screw propellers driven by quadruple-expansion steam engines.
Document 12: SS Kaiser Wilhelm der Grosse: Kaiser Wilhelm der Grosse (Ger. orth. "Kaiser Wilhelm der Große") was a German transatlantic ocean liner named after Wilhelm I, German Emperor, the first head of state of the German Empire. The liner was constructed in Stettin for the North German Lloyd (NDL), and entered service in 1897. It was the first liner to have four funnels and is considered to be the first-ever superliner. The first of four sister ships built between 1903 and 1907 by NDL (the others being  ,  and  ) she marked the beginning of a change in the way maritime supremacy was demonstrated in Europe at the beginning of the 20th century.
Document 13: RMS Olympic: RMS "Olympic" ( ) was a British transatlantic ocean liner, the lead ship of the White Star Line's trio of "Olympic"-class liners. Unlike her younger sister ships, "Olympic" had a long career, spanning 24 years from 1911 to 1935. This included service as a troopship during the First World War, which gained her the nickname "Old Reliable". "Olympic" returned to civilian service after the war and served successfully as an ocean liner throughout the 1920s and into the first half of the 1930s, although increased competition, and the slump in trade during the Great Depression after 1930, made her operation increasingly unprofitable.
Document 14: Inman Line: The Inman Line was one of the three largest 19th-century British passenger shipping companies on the North Atlantic, along with the White Star Line and Cunard Line. Founded in 1850, it was absorbed in 1893 into American Line. The firm's formal name for much of its history was the Liverpool, Philadelphia and New York Steamship Company, but it was also variously known as the Liverpool and Philadelphia Steamship Company, as Inman Steamship Company, Limited, and, in the last few years before absorption, as the Inman and International Steamship Company.
Document 15: Olympic-class ocean liner: The "Olympic"-class ocean liners were a trio of British ocean liners built by the Harland & Wolff shipyard for the White Star Line during the early 20th century. They were "Olympic" (1911), "Titanic" (1912), and "Britannic" (1915). All three were designed to be the largest and most luxurious passenger ships in the world, designed to give White Star an advantage in the transatlantic passenger trade. Two were lost early in their careers: "Titanic" sank in 1912 on its maiden voyage, after hitting an iceberg in the North Atlantic Ocean, and "Britannic" in 1916, after hitting a mine laid by the minelayer submarine "U-73" in a barrier off Kea in the Aegean Sea during World War I. "Olympic", the lead vessel, had a career spanning 24 years and was retired in 1934 and sold for scrapping in 1935.
ground_truth: 56,551