Endurance (1912 ship)

Endurance trapped in pack ice during the Imperial Trans-Antarctic Expedition
History
Norway
Name:	Endurance
Builder:	Framnæs shipyards, Sandefjord, Norway
Launched:	1912
Out of service:	1915
Fate:	Crushed by pack ice in the Weddell Sea in 1915 and sunk in a hole of ice in 1915
General characteristics
Tonnage:	348 grt
Length:	144 ft (44 m)
Beam:	25 ft (7.6 m)
Propulsion:	350 hp Coal fired steam and sail
Speed:	10.2 knots (18.9 km/h; 11.7 mph)
Complement:	28

Endurance was the three-masted barquentine in which Sir Ernest Shackleton sailed for the Antarctic on the 1914 Imperial Trans-Antarctic Expedition. She was launched in 1912 from Sandefjord in Norway and was crushed by ice, causing her to sink three years later in the Weddell Sea off Antarctica.

Designed by Ole Aanderud Larsen, Endurance was built at the Framnæs shipyard in Sandefjord, Norway and fully completed on 17 December 1912. She was built under the supervision of master wood shipbuilder Christian Jacobsen, who was renowned for insisting that all men in his employment were not just skilled shipwrights but also be experienced in seafaring aboard whaling or sealing ships. Every detail of her construction had been scrupulously planned to ensure maximum durability: for example, every joint and fitting was cross-braced for maximum strength.

The ship was launched on 17 December 1912 and was initially christened Polaris (eponymous with Polaris, the North Star). She was 144 feet (44 m) long, with a 25 feet (7.6 m) beam and measured 348 tons gross. Though her black hull looked from the outside like that of any other vessel of a comparable size, it was not. She was designed for polar conditions with a very sturdy construction. Her keel members were four pieces of solid oak, one above the other, adding up to a thickness of 85 inches (2,200 mm), while its sides were between 30 inches (760 mm) and 18 inches (460 mm) thick, with twice as many frames as normal and the frames being of double thickness. She was built of planks of oak and Norwegian fir up to 30 inches (760 mm) thick, sheathed in greenheart, a notably strong and heavy wood. The bow, which would meet the ice head-on, had been given special attention. Each timber had been made from a single oak tree chosen for its shape so that its natural shape followed the curve of the ship's design. When put together, these pieces had a thickness of 52 inches (1,300 mm).