The first RMS Laconia was a Cunard ocean liner built by Swan Hunter & Wigham Richardson, launched on July 27, 1911, delivered to the Cunard Line on December 12, 1911, and began service on January 20, 1912.

On the outbreak of World War I Laconia was turned into an armed merchant cruiser in 1914 and based at Simonstown in the South Atlantic, from which she patrolled the South Atlantic and Indian Ocean until April 1915. She was then used as a headquarters ship for the operations to capture Tanga and the colony of German East Africa. Four months later she returned to the patrolling of the South Atlantic. She was handed back to Cunard in July 1916 and on September 9 resumed service..

On February 25, 1917 she was torpedoed by the German U-50 six miles (11 km) northwest by west of Fastnet while returning from the United States to England with 75 passengers (34 first class and 41 second class) and a crew of 217 under the command of Captain Irvine. The first torpedo struck the liner on the starboard side just abaft the engine room, but did not sink her. Twenty minutes later a second torpedo exploded in the engine room, again on the starboard side, and the vessel sank at 10:20pm. 12 people were killed, 6 crew and 6 passengers, including three American citizens.

For the later ship of the same name, see RMS Laconia (1921).

General Characteristics

• Gross Tonnage: 18,099 tons
• Length: 183m (600 feet)
• Beam: 22m (72 feet)
• Number of funnels: 2
• Number of masts: 2
• Construction: Steel
• Propulsion: Twin screw
• Engines: Eight-cylinder quadruple-expansion engines by Wallsend Slipway Co Ltd
• Service speed: 17 knots (31 km/h)
• Builder: Swann, Hunter & Wigham Richardson, Wallsend-on-Tyne
• Passenger accommodation: 300 1st class; 350 2nd Class; 2,200 3rd Class