What was the name of the third and final Olympic-class liner?

Britannic was the third and final Olympic-class liner.

Built by Harland and Wolff for the White Star Line, Britannic followed Olympic and Titanic in the famous trio of sister ships. Her keel was laid in Belfast in 1911, and she was launched on 26 February 1914. She was originally intended to enter transatlantic passenger service, but the First World War began before that plan could be completed.

Britannic was requisitioned as a hospital ship and entered service as HMHS Britannic in 1915. Lessons from Titanic’s sinking led to important safety changes, including a wider hull, additional watertight protection and improved evacuation arrangements. She became the largest hospital ship in the world at the time.

On 21 November 1916, Britannic struck a naval mine near the Greek island of Kea in the Aegean Sea and sank in less than an hour. Thirty people died, while more than 1,000 survived. Unlike Titanic, Britannic never operated as a regular passenger liner, making “final Olympic-class liner” a more precise description than simply “Titanic’s sister.”