HMS Calgarian was an armed merchant cruiser of the Royal Navy

Royal Navy

The Royal Navy is the naval warfare service branch of the British Armed Forces. Founded in the 16th century, it is the oldest service branch and is known as the Senior Service...

. She was sunk by the U-boat

U-boat

U-boat is the anglicized version of the German word U-Boot , itself an abbreviation of Unterseeboot , and refers to military submarines operated by Germany, particularly in World War I and World War II...

  off Rathlin Island

Rathlin Island

Rathlin Island is an island off the coast of County Antrim, and is the northernmost point of Northern Ireland. Rathlin is the only inhabited offshore island in Northern Ireland, with a rising population of now just over 100 people, and is the most northerly inhabited island off the Irish coast...

, Northern Ireland

Northern Ireland

Northern Ireland is one of the four countries of the United Kingdom. Situated in the north-east of the island of Ireland, it shares a border with the Republic of Ireland to the south and west...

 on 1 March 1918. The initial strike did not sink her and the crew managed to contain the damage. The U-boat torpedoed her again, despite the protection of other ships. She was hit by 4 torpedoes and quickly sank with the loss of two officers and 47 ratings.

SS Calgarian, was originally built for the Allan Line

Allan Line Royal Mail Steamers

The Allan Shipping Line was started in 1819, by Captain Alexander Allan of Saltcoats, Ayrshire, running dry goods from Greenock to sell in Montreal and returning with Canadian produce to sell back in Scotland, a route which quickly became synonymous with the Allan Line...

, making her maiden voyage from Liverpool to Canada on 8 May 1914. Her sister ship was the Alsatian

RMS Empress of France (1914)

RMS Empress of France, formerly the SS Alsatian was an ocean liner built in 1913-1914 by William Beardmore and Company at Glasgow in Scotland for Allan Line....

.

On 15 September 1914 Calgarian was taken over as an armed merchant cruiser. Her naval career saw her take part in the blockades of the ports of Lisbon and New York and acts as a troop and passenger transport across the Atlantic.
Calgarian was at Halifax

City of Halifax

Halifax is a city in Canada, which was the capital of the province of Nova Scotia and shire town of Halifax County. It was the largest city in Atlantic Canada until it was amalgamated into Halifax Regional Municipality in 1996...

 when the Halifax Explosion

Halifax Explosion

The Halifax Explosion occurred on Thursday, December 6, 1917, when the city of Halifax, Nova Scotia, Canada, was devastated by the huge detonation of the SS Mont-Blanc, a French cargo ship, fully loaded with wartime explosives, which accidentally collided with the Norwegian SS Imo in "The Narrows"...

 took place on December 6, 1917. Her crew assisted with rescue and medical relief.

She was officially transferred to Canadian Pacific in July 1917 on its acquisition of Allan. However, she continued in Royal Navy use until her sinking.