At the time of her entry into service on 2 April 1912, Royal Mail Ship (RMS) Titanic was the second of three[b] Olympic-class ocean liner sister ships, and was the largest ship in the world. She and her sister, RMS Olympic, were almost one and a half times the gross register tonnage of Cunard's RMS Lusitania and RMS Mauretania, the previous record holders, and were nearly 100 feet (30 m) longer. Titanic could carry 3,547 people in speed and comfort, and was built on an unprecedented scale. Her reciprocating engines were the largest that had ever been built, standing 40 feet (12 m) high and with cylinders 9 feet (2.7 m) in diameter requiring the burning of 600 long tons (610 t) of coal per day.
Her passenger accommodation, especially the First Class section, was said to be "of unrivalled extent and magnificence", indicated by the fares that First Class accommodation commanded. The Parlour Suites (the most expensive and most luxurious suites on the ship) with private promenade cost over US$4,350 (equivalent to $112,935 in 2018) for a one-way transatlantic passage. Even Third Class, though considerably less luxurious than Second and First Classes, was unusually comfortable by contemporary standards and was supplied with plentiful quantities of good food, providing her passengers with better conditions than many of them had experienced at home.
Titanic's maiden voyage began shortly after noon on 10 April 1912 when she left Southampton on the first leg of her journey to New York. A few hours later she called at Cherbourg in northern France, a journey of 80 nautical miles (148 km; 92 mi), where she took on passengers. Her next port of call was Queenstown (now Cobh) in Ireland, which she reached around midday on 11 April. She left in the afternoon after taking on more passengers and stores.
By the time she departed westwards across the Atlantic she was carrying 892 crew members and 1,320 passengers. This was only about half of her full passenger capacity of 2,435, as it was the low season and shipping from the UK had been disrupted by a coal miners' strike. Her passengers were a cross-section of Edwardian society, from millionaires such as John Jacob Astor and Benjamin Guggenheim, to poor emigrants from countries as disparate as Armenia, Ireland, Italy, Sweden, Syria and Russia seeking a new life in the United States.
The ship was commanded by 62-year-old Captain Edward John Smith, the most senior of the White Star Line's captains. He had four decades of seafaring experience and had served as captain of RMS Olympic, from which he was transferred to command Titanic. The vast majority of the crew who served under him were not trained sailors, but were either engineers, firemen, or stokers, responsible for looking after the engines; or stewards and galley staff, responsible for the passengers. The six watch officers and 39 able seamen constituted only around five percent of the crew, and most of these had been taken on at Southampton so had not had time to familiarise themselves with the ship.
The ice conditions were attributed to a mild winter that caused large numbers of icebergs to shift off the west coast of Greenland.
A fire had begun in one of Titanic's coal bins approximately 10 days prior to the ship's departure, and continued to burn for several days into the voyage, but it was over on 14 April. The weather improved significantly during the course of the day, from brisk winds and moderate seas in the morning to a crystal-clear calm by evening, as the ship's path took her beneath an arctic high pressure system.