Twin-screw steam launch (length 42 ft., beam 7 ft., depth to underside of rail 4 ft., draught forward 2 ft. aft 2ft. 6 in., displacement 8.5 tons) built by Messrs. Thomas Brassey and Co., Canada Works, Birkenhead, and fitted with twin inverted vertical marine engines each having two cylinders 5 in. in diameter with a 6 in. stroke, operating on steam supplied at 70 ponds per square inch supplied by a locomotive boiler, driving two 2 ft. 3 inches in diameter propellers with a pitch of 3 ft.