HMHS Britannic

HMHS Britannic (/brɪˈtænɪk/) was the third and final vessel of the White Star Line's Olympic class of ocean liners and the second White Star ship to bear the name Britannic. She was the younger sister of RMS Olympic and RMS Titanic and was intended to enter service as a transatlantic passenger liner. She operated as a hospital ship from 1915 until her sinking near the Greek island of Kea, in the Aegean Sea at position 37°42′05″N 24°17′02″E / 37.70139°N 24.28389°E / 37.70139; 24.28389, in November 1916. At the time she was the largest hospital ship in the world, and the largest vessel built in Britain.

Britannic was launched just before the start of the First World War. She was designed to be the safest of the three ships with design changes made during construction due to lessons learned from the sinking of the Titanic. She was laid up at her builders, Harland & Wolff, in Belfast, for many months before being requisitioned as a hospital ship. In 1915 and 1916 she operated between the United Kingdom and the Dardanelles.

On the morning of 21 November 1916, she hit a naval mine of the Imperial German Navy near the Greek island of Kea and sank 55 minutes later, killing 30 of 1,066 people on board; the 1,036 survivors were rescued from the water and from lifeboats. Britannic was the largest ship lost in the First World War. After the War, the White Star Line was compensated for the loss of Britannic by the award of SS Bismarck as part of postwar reparations; she entered service as RMS Majestic. The wreck of the Britannic was located and explored by Jacques Cousteau in 1975. The vessel is the largest intact passenger ship on the seabed in the world. It was bought in 1996 and is currently owned by Simon Mills, a maritime historian.

The original dimensions of Britannic were similar to those of her older sisters, but her dimensions were altered whilst still on the building stocks after the loss of Titanic. With a gross tonnage of 48,158, she surpassed her older sisters in terms of internal volume, but this did not make her the largest passenger ship in service at that time; the German SS Vaterland held this title with a significantly higher tonnage.

The Olympic-class ships were propelled by a combined system of two triple-expansion steam engines which powered the three-bladed outboard wing propellers whilst a low-pressure steam turbine used steam exhausted from the two reciprocating engines to power the central four-bladed propeller giving a maximum speed of 23 knots.

Britannic had a similar layout to her sister ships. Following the Titanic disaster and the subsequent inquiries, several design changes were made to the remaining Olympic-class liners. With Britannic, these changes made before launch included increasing the ship's beam to 94 feet (29 m) to allow for a double hull along the engine and boiler rooms and raising six out of the 15 watertight bulkheads up to B Deck. Additionally, a larger 18,000 horsepower (13,000 kW) turbine was added instead of the 16,000 horsepower (12,000 kW) units installed on the earlier vessels in response to the increased hull width. The central watertight compartments were enhanced, allowing the ship to stay afloat with six compartments flooded.

Externally the largest visual change was the fitting of large crane-like gantry davits, each powered by an electric motor and capable of launching six lifeboats which were stored on gantries; the ship was designed to have eight sets of gantry davits but only five were installed before Britannic entered war service, with the difference being made up with boats launched by manually operated Welin-type davits as on Titanic and Olympic.

Additional lifeboats could be stored within reach of the davits on the deckhouse roof, and the gantry davits could reach lifeboats on the other side of the ship, providing that none of the funnels was obstructing the way. This design enabled all the lifeboats to be launched, even if the ship developed a list that would normally prevent lifeboats from being launched on the side opposite to the list. Several of these davits were placed abreast of funnels, defeating that purpose. The elevators, which previously stopped at A deck, could now reach the boat deck. The ship carried 48 lifeboats, capable of carrying at least 75 people each. Thus, at least 3,600 people could be carried by the lifeboats, which was well above the ship's maximum capacity of 3,309.^{[citation needed]}