needed to meet growing demands. The first liners were small and overcrowded, leading to unsanitary conditions on board. Eliminating these phenomena required larger ships, to reduce the crowding of passengers, and faster ships, to reduce the duration of transatlantic crossings. The iron and steel hulls and steam power allowed for these advances. Thus, Great Western (1,340 GRT) and Great Eastern (18,915 GRT) were constructed in 1838 and 1858 respectively. The record set by Great Eastern was not beaten until 43 years later in 1901 when (20,904 GT) was completed. The tonnage then grew profoundly: the first liners to have a tonnage that exceeded 20,000 were the Big Four of the White Star Line. The s, first completed in 1911, were the first to have a tonnage that exceeded 45,000. , completed in 1935, had a tonnage of 79,280. In 1940, raised the record of size to a tonnage of 83,673. She was the largest passenger ship ever constructed until 1997. In 2003, became the largest, at 149,215 GT. In the early 1840s, the average speed of liners was less than 10 knots (a crossing of the Atlantic thus took about 12 days or more). In the 1870s, the average speed of liners increased to around 15 knots the duration of a transatlantic crossing shortened to around 7 days, owing to the technological progress made in the propulsion of ships: the rudimentary steam boilers gave rise to more elaborate machineries and the paddlewheel gradually disappeared, replaced first by one screw then by two screws. At the beginning of the 20th century, Cunard Line's and reached a speed of 27 knots. Their records seemed unbeatable, and most shipping companies abandoned the race for speed in favor of size, luxury, and safety. The advent of ships with diesel engines, and of those whose engines were oil-burning, such as the Bremen, in the early 1930s, relaunched the race for the Blue Riband. The Normandie won it in 1935 before being snatched by in 1938. It was not until 1952 that set a record that remains today: 34.5 knots (3 days and 12 hours of crossing the Atlantic). In addition, since 1935, the Blue Riband is accompanied by the Hales Trophy, which is awarded to the winner. Passenger cabins and amenities The first ocean liners were designed to carry mostly migrants. On-board sanitary conditions were often deplorable and epidemics were frequent. In 1848, maritime laws