The third of White Star's great Olympic-class of four stackers,
Britannic was built by Harland & Wolff, Belfast, in the same slip where
Olympic had been built several years earlier. Laid down in November
1911, she was extensively modified while still on the stocks to correct
the fatal design flaws that had contributed to Titanic's disaster. But,
like her ill-fated sister, Britannic was destined never to complete a
single fare-carrying voyage for her owner and, in fact, sank more
quickly than Titanic even with her new safety modifications.
Soon after she was launched on 26 February 1914, World War I began and her completion was delayed. In November 1915, shortly before her fitting out was completed, she was requisitioned by the British Admiralty for use as a hospital ship and was quickly refitted for that purpose. She made her maiden voyage in that capacity on 23 December 1915, from Southampton to Naples and then on to Mudros, Greece.
After three trips to the Mediterranean, Britannic was laid up in April 1916 and decommissioned a month later. However, before she was completely refitted for passenger service, she was recalled to hospital ship duty and resumed that service in September.
On her third trip after being recalled, she struck a mine off Kea Island on 21 November 1916 and sank 55 minutes later. Various sources give the number of deaths as between 21 and 41; all occurred when two lifeboats were shredded by the ship's still turning propellers. Fortunately, no patients were aboard; the balance of the 1,125 medical staff and crew were rescued.
The ship's original name continues to be a matter of dispute. Before the Titanic disaster, she was frequently referred to as "Gigantic," a name which would seem to be in keeping with her sisters'. White Star, however, later denied that she was to have be called "Gigantic" and late in May 1912 it was officially announced that she would be named Britannic, a name which was considered "lucky" due to the stellar career of White Star's first Britannic.
Sources: Mills' HMHS Britannic: The Last Titan; Anderson's White Star; Haws' Merchant Fleets; Eaton & Haas' Falling Star; The New York Times, various dates 1910-1912.