Both These Ships Were Already Outsized, For Today the Keel of the Massive Imperator Was Being Laid."
Construction of the Imperator
As the new millennium rounded its first decade, it was an exciting time in the ocean liner industry. The competition between the British and the Germans to have the best liners in the world was at a new high and the matched or exceeded the excitement generated by the launching of every new vessel.
It was 18 June 1910, just months before the RMS Olympic, the first of the three White Star Line giants was set to be launched, while the Titanic, the second in their line, was already one year into her construction. For all intent and purpose, however, both the Olympic and Titanic were already outsized, for on this day at the Vulcan shipyards in Hamburg, the keel of the massive Imperator known only at this point as Hull 314 - was being laid. She would be the first ship ever to exceed 900 feet and 50,000 tons and the first German liner to have four screws. Similarly, she would have public rooms of greater size, height, and luxury than any other ship in the world, and as such can now lay claim to carrying more passengers than any liner in history (before or after). In the process of her construction, she required 25,000 tons of steel, 1500 tons of rivets, and 5600 cubic meters Americas finest, clear, vertical-grain Oregon Fir. The shipment of 47,444 pieces was shipped rough and then cut and fitted in Germany.
The Imperator's core innovation begins deep inside the ship with the design of the hull, the turbines, and the boilers, all which will be refined for the Imperator's soon-to-come sisters, the Vaterland and the Bismarck.
The Imperator's immense superstructure is built around 654 steel ribs (327 a side), with a weight of a single rib being a ton and a third. As the Imperator neared completion, the sinking of the Titanic shocked the world. Determined to never to have such a incident discredit the reputation of the world's biggest shipping company, Ballin had a "second skin" fitted five feet in from the Imperator's outer skin or hull, effectively making her a ship within a ship. This second skin runs the length of the hull and its bulkheads is of exceptional strength and height. There are twelve watertight bulkheads and thirteen transverse watertight compartments. The watertight bulkheads have been outfitted with thirty-six watertight doors and rise to H deck, 55 feet above the keel, between the forward engine room and the collision bulkhead. Twenty three of those thirty-six watertight doors are operated hydraulically using the patented Dorr system. This system makes it possible for the watertight doors to be closed from either the Commander's bridge or by auxiliary controls on the upper deck. In addition, electric enunciators enable our Captain and his officers to ascertain whether their orders have been correctly received and carried out. Similarly, station bells that can locate the number and position of each crewmember on board enables a completely organized force, able to immediately attend to any situation.
The ship's bulkheads are supported by sturdy I-beams, which weigh between 2,200 pounds and 9,900 pounds, and other shapes that can withstand the pressure that would arise from maximum submersion of the ship due to underwater damage. By dividing the vessel into various watertight compartments, safety is assured even if two or more adjacent compartments become filled with water. To prove the effectiveness of our bulkheads, the Vulcan Shipyard had the Hamburg Fire department use one of their fire tenders to fill several compartments in the inner hull.
The longitudinal bulkheads are alongside the four boiler rooms and produce immense side bunkers that contain about 8,500 tons of coal, which is shoveled into furnaces by 422 men. The Imperator's huge coalbunkers extend from just in front of the first stack to just behind the second stack and are above the boilers on decks 4 and 5. There is also a huge coalbunker deep down on deck 7 below the bridge. To handle the waste that accumulates from the burning of coal for fuel, there are five ash ejectors on deck 4 adjacent the bunkers. Together these ash ejectors are capable of disposing of 180 cbm of ash waste an hour.
The Imperator's four boiler rooms extend the breadth of the ship and measure 74 feet 9 inches long (22.6 meters). These boiler rooms house forty-six naval pattern Yarrow single-ended water tube boilers. The boilers are rated at 235lb/sq.inch with forced draught feeding a quadruple set of direct-drive Curtis AEG Vulcan steam turbines. The turbines are the Parson-type-direct acting triple expansion turbines. The high pressure and intermediate pressure turbines drive the two inner propeller shafts while the low-pressure turbines drive the two outer shafts.
The uptakes from the boilers are connected to the first two funnels. The third funnel is a dummy and used to ventilate the boiler rooms. Drawing the air through vertical trunks using electric fans does this. After that, four ventilators with blower wheels of 2.5 3 meters in diameter ventilate the air out through the third funnel. The Imperator's water-tube boilers are indeed an innovation in big ocean liners. Before the Imperator, shipbuilders for the merchant marine had installed the Scotch boiler in their liners - a fine boiler and reliable. Naval engineers, however, have long since discarded the Scotch boiler in favor of the more reliable water-tube type. By installing these boilers on the Imperator, Hamburg Amerika is the first merchant shipping line to accept the word of naval engineers and to put these boilers into practice and performance on a super liner.
The Imperator has two engine rooms. The forward engine room is 65 feet long and separated into three waterproof rooms by two longitudinal bulkheads. On the starboard side is the refrigeration machinery. The rear engine room is 95 feet long and split by one longitudinal bulkhead. As in the boiler rooms, three wheel ventilators operate by one steam engine assure ventilation in the engine rooms.
The forward engine room houses the two low-pressure turbines. They weigh 380 tons each and have a combined power output of 33,500 horsepower. The rear engine room holds the high pressure and intermediate pressure turbines. They are 135 tons each and together generate 22,500 horsepower. The high-pressure turbines in the rear engine room are fitted with 50,000 blades; the largest was 2 feet long. The casing of the turbines is 18 feet in diameter and 25 feet long. To maintain the efficiency of the Imperator's turbines, six oil pumps work to keep all of them lubricated.
In case of any necessary repairs, the rear engine room is equipped with a garage and a machine shop that has a drill machine, lathe, planer, sandstones, and a vice.
The engines of the Imperator are quite innovative indeed. Hamburg Amerika decided on water-tube boilers and turbine propulsion so that the massive Imperator would be able to reach a service speed close to that of Cunard's speed queen, the Mauretania, and faster than White Star's Olympic-class liners Olympic and Titanic that were built with a combination of old-style reciprocating engines and low-pressure turbines. In operation, steam from the water tube boilers passes through the high-pressure turbines and then is evenly spread and sent through the low-pressure turbines. The turbines generate 72,000-horse power (35,000 in reverse) and drive the Imperator at an average speed of 22 ½ knots across the Atlantic. Each of the four propeller shafts is 1 ½ feet in diameter, and each of the four Turbadium-bronze propellers are 16 feet in diameter and at full ahead power run at 185 rpm. In the event of trouble with the boiler plant, each propeller can run independently, using isolated valves. The various castings and materials used in the construction of the machinery were subjected to hydraulic pressure tests to determine their strength and to locate any possible weakness.
On the portside of the aft engine room there are five turbo-generators, each of 2,000 amperes. These five generators produce 110 volts to power the engines, the lifeboat winches, the ventilating system, the ship's entire lighting design, and all heating in the saloons and staterooms. An emergency petrol-operated 100-ampere generator is on the boat deck.
As construction proceeded, the Imperator was initially called the Europa. Hapag chairman Albert Ballin himself chose the name, though he originally intended it for a previous liner that ended up being called Kaiserin Auguste Victoria. In the end, the name Europa was again be passed on when the German Kaiser suggested that Ballin name the first of the Hamburg Amerika giants, Imperator.
As the Imperator's superstructure was being fleshed out there was little doubt among the shipping industry that the new Hamburg Amerika liner would be the heaviest ever built. The Imperator's rudder alone weighed 90 tons and the sternpost and its jackshafts weighed 110 tons. In dry dock, the Imperator was so big that two docks had to be fitted together to support her. Even still, whether she would be the longest liner in the world was another question altogether. At the time, the Cunard line was drawing up the plans for their third liner, the Aquitania, and her dimensions, particularly her length, were being kept under strict secrecy. Regardless, Albert Ballin was confident that his new liner would be the longer, but he did not take any chances.As an ingenious insurance plan for the length of his new liner, Ballin commissioned Dr. Bruno Kruse, one of the finest sculptors in Berlin, to sculpt a 10.3-foot gold and bronze German eagle that would have a huge globe in its claws and a wingspan of 16 meters. Radiating out from behind the globe would be eighteen rays that would secure the massive figurehead to the stem. On a banner running the circumference of the globe the Hamburg Amerika motto, Mein Felt ist die Welt (The World is My Field) would be emblazoned. Upon completion, the eagle was fashioned onto the prow of the ship, thus making her 919.3 feet, which clearly solidified Ballin's bid to make the SS Imperator the longer liner.
