The construction of the Imperator was begun in the summer of 1910. She was launched 2 years later in May, 1912. The ship was 919 feet long over all, 879 feet long between perpendiculars, 98 feet beam, 62 feet depth to the uppermost continuous deck, and about 100 feet depth to the boat deck. The boat deck was 100 feet from the keel, and the trucks of the masts raised to a height of 246 feet above the keel. Three funnels were each 69 feet long of oval shape, measuring 29 feet by 18 feet. She had a displacement of about 70,000 tons and a gross tonnage of about 50,000. The main engines were Parsons turbines of about 72,000 horsepower, operating four propellers, which were designed to give the ship a speed of 22½ knots. The propeller shafts were 18 inches diameter, with four-bladed propellers of Turbadium bronze, 16 feet 5 inches diameter. The low-pressure rotors weigh 135 tons. The outer casing inclosing those rotors was 25 feet long and 18 feet wide.

The hull was fitted with a cellular double bottom which extended for nearly the whole length of the vessel. The hull was divided into watertight compartments by both transverse and longitudinal bulkheads. There were 12 transverse bulkheads, those amidships extending from the double bottom to a height of 50 feet, or for a distance well above the waterline. Towards the bow, the bulkheads ran up to a greater height, and the forward collision bulkhead extended to the first deck. Longitudinal bulkheads were fitted in the boiler space to form wing bunkers, and also in the forward engine room, where the wing compartments were used for auxiliaries. In the after engine room, there was a single longitudinal bulkhead on the center line of the ship, the cargo holds, both forward and aft, extended across the full width of the ship. In the bulkheads there were in all 36 watertight doors, which were fitted with an automatic closing system operated by the use of electric and pneumatic power, enabling complete control of all the doors from the navigating bridge. The doors could also be controlled individually at their separate locations. Wing bunkers through the boiler space provided an inner skin, which, together with the double bottom and subdivision of the two engine rooms by longitudinal bulkheads, were designed to protect the ship effectually against disaster from collision. The dimension of the tank was 767 feet 6 inches length, 85 feet width, 6 feet depth, giving a cubic capacity of 291,000 gallons.

Accommodations were provided for about 700 first class, 600 second class, 940 third class and 1,750 fourth class passengers. The crew numbered over 1,000. The appointments of the ship involved many unique features. Besides the main dining rooms there were a Ritz Carlton restaurant, a grill room, tea garden, veranda cafe, a palm garden, ball room and elaborate gymnasium and baths. The arrangement of passenger accommodations in the ship was in keeping with the modern tendency to eliminate the cramped quarters which were formerly found on shipboard. The size of staterooms and of public saloons had been increased. In the first class staterooms the old-time built-in berths were replaced by metal bedsteads, and a large number of single-berth rooms were provided. Similar arrangements had been made in the second class accommodations, and the whole arrangement strongly resembled the accommodations found in first class hotels on shore. All the rooms were provided with electric connections for lighting, heating, ventilation, call bells, etc. Supplementary to the steam heating system electric heaters were provided, and a complete artificial ventilating system was installed which provided for excellent air circulation according to the requirements of each room. Besides the large main stairways between decks, electric elevators provided communication through five decks. There were also small shops to meet the needs of the passengers.

A large amount of deck space in the first-cabin quarters was set aside for promenade decks. The upper promenade deck was enclosed at the front and along two-thirds of the length on each side by heavy plate-glass windows for protection in stormy weather.

Anti-rolling tanks, built according to the Frahm system, were installed to reduce the rolling of the ship. Lifeboats and liferafts were provided sufficient to accommodate all on board. She was fitted with a gyroscopic compass, submarine signals and a powerful wireless outfit. Electric current for lights and power purposes on board the ship were provided by five turbo-generators of 2,000 amperes and 110 volts. An additional generator of 100 amperes capacity was placed above the waterline to provide current for lighting in case the main electric plant was disabled by flooding of the dynamo compartment. She was equipped with a completely fitted machine shop located in the forward engine room, the equipment consisted of lathes, drills, planers and a full equipment of small tools enabling all minor repairs be carried out on board the ship.

The steam fire-fighting apparatus was of the latest and most approved type. In addition, hand extinguishers were conveniently placed throughout the ship, and she had powerful pumps ready for immediate use. As a special protection against fire a number of smoke bulkheads had been constructed in the passenger decks.

Station bells, locating the number and position of each man on board, from the captain down to the last trimmer, no matter what the occasion or stress, was installed to assemble the crew into a completely organized force, able to control any situation. Frequent drills were planned to enable familiarity and breed confidence in this most valuable human factor. Fire and boat drills were held frequently. At night, and during fog, all watertight doors were to be closed. The living quarters of the officers and crew were so arranged and placed that each man would be near to his work, so that even in off-duty periods prompt response to all calls could be made.