Empress had an overall length of, a beam of, and a draught of. She displaced and was rated at. Each of the ship's three sets of direct-drive steam turbines drove one propeller shaft. The ship's six boilers generated enough steam to produce from the turbines. The ship had a designed speed of, but she made a speed of during her sea trials with. Empress carried of coal, enough to give her a range of at.
Service
Built as a fast packet for the South East and Chatham Railway Co., Empress was requisitioned for service during the First World War by the Admiralty on 11 August 1914, and was commissioned on 25 August. During that month, the ship transported equipment for the Eastchurch Squadron of the Royal Naval Air Service to Ostend, Belgium. Beginning on 30 August, she was converted by Chatham Dockyard to carry and operate three seaplanes. One aircraft was stowed forward and two aft, housed in canvas hangars, and handled with newly fitted cargo booms. During her career with the RN, the ship operated Fairey Hamble Baby, Short Admiralty Type 74, Short Type 184, Sopwith Schneider and Baby floatplanes. Two or three quick-firing two-pounder guns also were fitted at this time. Upon completion of the modifications on 30 September, Empress was assigned to the Harwich Force along with and. On Christmas Day 1914, nine aircraft from all three ships took part in the Cuxhaven Raid on hangars housing Zeppelin airships. Seven of the nine seaplanes successfully took off for the attack, but they inflicted little damage. Only three of the aircraft returned to be recovered, but the crews of the other three ditched safely and were recovered by a British submarine and the Dutch trawler Marta van Hattem. From 9 May to 18 July 1915, the ship was modified by Cunard at Liverpool with a permanent, four-aircraft, hangar in the rear superstructure and a pair of cranes were mounted at the rear of the hangar to hoist the seaplanes in and out of the water. The 2-pounders were apparently removed during this refit and four QF 12-pounder 12 cwt guns, each with 130 rounds, and two VickersQF 3-pounder anti-aircraft guns, each with 65 rounds, were fitted. Empress was transferred afterwards to Queenstown for the rest of the year, before moving to the Mediterranean. She arrived there in January 1916 and was assigned to the East Indies and Egypt Seaplane Squadron with the carriers,, and. The squadron was under the command of the General Officer Commanding, Egypt and its primary duty was watch and to attack Turkish positions and movements in southern Palestine and the Sinai in early 1916. In April, Empress was detached from the squadron to support operations off the Aegean coast of Bulgaria, where her aircraft observed for several naval bombardments. After a refit at Genoa, the ship rejoined the squadron and supported operations off the Syrian and Palestinian coasts until November. In January 1918, she was assigned anti-submarine duties, first at Port Said and later at Gibraltar. She was returned to her owners in November 1919 and was sold to the Société Anoynyme de Gérance et d'Armament of France in 1923. On 12 January 1926, Empress collided with the British schooner in the English Channel and sank her. Empress was scrapped in France in 1933.
