[1] Her initial action occurred on 19 December 1939, during deployment in the Firth of Clyde, when she was subject to an unsuccessful torpedo attack by a submarine near Holy Isle.

In February 1940, she was deployed for escort of convoys to Norway based at Rosyth where she sustained structural damage during anti-submarine operations at high speed in heavy weather and was sent to Falmouth for repair.

On completion in May 1940, she took passage to come under the Commander-in-Chief, The Nore to help evacuate personnel from the Netherlands and Belgium but developed a machinery defect and was taken to Portsmouth for two days of repair, where her pennant number for visual signaling purposes changed to G45.

Khartoum and Kandahar detached with other K-class destroyers Kimberley and Kingston for surveillance of Italian warship movements from Massawa on the Red Sea.

[2] Some five and a half hours later, at 11.50am (local time), a torpedo's compressed air chamber exploded, propelling the warhead through the deck house of number 3 4.7-inch mount.