HMS Pirouette was the last of a pair of steel twin tunnel screw steam tugs ordered from Rennie Forrestt at Wivenhoe by the War Office for the Royal Engineers Inland Water Transport Department for use in Mesopotamia. These vessels part of a large number ordered from several small shipyards were ‘named’ T 90, and T 91. They were of exceptionally shallow draft for their size and power as they were intended for towing barges up and down the Euphrates and Tigris Rivers to supply the British and Indian troops fighting the Turks.
These tugs were 130′ long 26’3″beam and 7’0″depth, on a 3’6″ draft. Powered by two compound 2 cylinder engines made by Plenty & Son Ltd at Newbury with a total of 450ihp, they had a speed of 9½ knots. The propellers were in “tunnels”, hollows in the bottom plating of the ship so that large propellers could deliver the necessary power without grinding on the river bed. The power and speed were needed to overcome the strong currents in the rivers. T 90 yard number 1307 was completed in 1917 and sent out to Basrah, but when yard number 1308, T 91 launched in September of that year was it was clear that the war against Turkey would be over before she got there; she was therefore transferred to the Royal Navy and completed as a ‘Dance’ Class minesweeper HMS Pirouette and soon set to the task of clearing away the many mines that the war had left behind. In 1920 HMS Pirouette was returned to War Office for disposal and was probably sold like many of her sisters for use as a tug.