Completed during World War I, she served as a troop ship and was nearly sunk by a German naval mine, but without loss of life.

On 6 February 1917, Tyndareus struck a mine which had been laid by the merchant raider, SMS Wolf, while about 10 miles (16 km) off Cape Agulhas, the geographic southern tip of the African continent.

[3] On board were 30 officers and 1,000 men of the 25th (Garrison Service) Battalion, The Middlesex Regiment, who were bound for Hong Kong, commanded by Lieutenant-Colonel John Ward, who was the Liberal–Labour Member of Parliament for Stoke-upon-Trent.

[4] King George V sent a message to the troops which read: Please express to the officers commanding the Battalion of the Middlesex Regiment my admiration of the conduct displayed by all ranks on the occasion of the accident to Tyndareus.

[7] A memorial stone was commissioned by Lieutenant Colonel Ward recording the gallantry of his men, and was erected on Victoria Peak on Hong Kong Island; it was brought to London in 1994 and is now at the National Army Museum in Chelsea.

[8] Returned to the Blue Funnel Line in 1920, Tyndareus finally began her intended "Trans-Pacific Service" which ran from Hong Kong to Tacoma, Washington, via Japan, Vancouver and Seattle.

[2] In October 1940, she was one of 32 Allied merchant and transport ships that formed Convoy BN 7,[11] which was on passage from Bombay to Suez via Aden with a heavy naval escort.