when she joined the 4th Destroyer Flotilla based at Portsmouth. In October that year, the Tribals were officially designated the F class, and as such the letter "F" was painted on the bows of the class. In February 1914, the Tribals (including Tartar), as their range was too short for effective open sea operations, were sent to Dover, forming the 6th Destroyer Flotilla. On 8 September 1915, the destroyer was involved in a collision with a transport in the English Channel, suffering a badly damaged bow. She was towed stern first back to Dover, assisted by Tartar, and the tug Lady Crundall. On the night of 26/27 October 1916, German torpedo boats of their Flanders Flotilla carried out a large scale raid into the English Channel, hoping to attack the drifters watching the anti-submarine nets of the Dover Barrage, and to sink Allied shipping in the Channel. Six Tribal-class destroyers (Tartar, Mohawk, Viking, , and ) were being held at readiness at Dover as a fast response force, at readiness in Dover harbour, and when the German 5th Half Flotilla attacked the drifters and sank the old supporting destroyer , they were ordered to intervene. The destroyers split up as they left Dover harbour, with Viking leading Mohawk and Tartar from the Western entrance to the port, while the other three destroyers left by the Eastern entrance and failed to join up with Vikings group. Nubian and Amazon separately ran into the German 17th Half Flotilla, on its way home after sinking the merchant ship Queen, with Nubian first being badly damaged by a torpedo and Amazon then heavily hit by German shells. Vikings group then encountered a third German formation, the 18th Half Flotilla. Mohawk, second in line of the three British destroyers, was hit by German shells which caused her steering to jam, and turn out of line. Tartar followed Mohawks turn, while Vikings attempts to pursue the German torpedo boats were thwarted when her course was blocked by Mohawk. All the German torpedo boats that took part in the nights operations escaped successfully. Tartar struck a German mine on 24 June 1917, killing 43 of her crew, including her newly appointed Captain, G. K. Twiss, but was towed to safety. By November 1917, Tartar had joined the 11th Destroyer Flotilla, based at Blyth, Northumberland. On 18 February 1918, Tartar collided with the merchant ship Ardgantock off West