A steam launch (length 40 feet overall; 37 feet at the water line, beam 8 feet 4 inches overall; 7 feet 3 inches at the water line, draught 3 feet 3 inches; trial speed 10 knots) was built by William Crichton and Co., Abo, for river traffic and fitted with a 6-inch by 6-inch stroke, 6 horsepower (nominal) twin cylinder inverted-vertical simple marine engine operating at 300 revolutions per minute, built by Tangye of Birmingham.