When a ship finds itself in a situation where ice is forcibly pressing on both sides, it is said to be "nipped".

While searching for the Northwest Passage, more than 30 vessels were severely nipped - they were trapped and spent winters in the Arctic. Several were crushed or disappeared altogether.

• Henry Hudson's ship "Discovery" spent the winter of 1610-11 in the ice of James Bay. By spring, his crew were so snarly they mutinied and set him adrift in a lifeboat. He was never found.

• William Parry's ships the "Hecla" and the "Griper" were stuck in 1821 - becoming the first Royal Navy ships to winter in the North American Arctic.

• Sir John Ross and his crew were stranded in 1829 (for four winters) when the "Victory", his paddle-wheeled vessel, was crushed.

• Sir John Franklin's ships, the "Terror" and the "Erebus" were beset by ice and deserted in 1848. They have never been found.

• The Canadian RCMP vessel St. Roch spent two winters in the Arctic while making the first west-east trip through the Northwest Passage (1940-42).

• While searching for the Franklin Expedition, the British ship HMS Resolute got stuck in the ice. The crew abandoned it and returned to England.

• Getting frozen in the ice at high latitudes was so predictable, that Fridtjof Nansen designed a crush-resistant ship. Once frozen in, it was hoped the moving ice cap would eventually take it to the North Pole.