Queen Elizabeth 2 - Technical

Technical

After the ship was launched, the QE2 was fitted out with a steam turbine propulsion system utilising three Foster Wheeler E.S.D II boilers, which provided steam for the two Brown-Pametrada turbines. The turbines were rated with a maximum power output figure of 110,000 shaft horsepower (normally operating at 94,000 hp) and were coupled to two six-bladed fixed-pitch propellers.

The steam turbines were plagued with problems from the time the ship first entered service and, despite being technically advanced and fuel-efficient in 1968, her consumption of 600 tons of fuel oil every twenty four hours was more than expected for such a ship by the 1980s. After seventeen years of service the availability of spare parts was becoming difficult due to the outdated design of the boilers and turbines, and Cunard decided that the options were to either do nothing for the remainder of the ship's life, re-configure the existing engines, or re-engine the vessel with a more efficient diesel-electric powerplant. Ultimately it was decided to replace the engines, as it was calculated that the savings in fuel costs and maintenance would pay for themselves over four years, and give the vessel a minimum of another twenty years of service, whereas the other options would only provide short-term relief. Her steam turbines had taken her to a record breaking total of 2,622,858 miles in 18 years.

During the ship's 1986 to 1987 refit, the steam turbines were removed and scrapped. The engine rooms were then fitted with nine German MAN L58/64 nine-cylinder, medium-speed diesel engines, each weighing approximately 120 tons. Using a diesel-electric configuration, each engine drives a generator, each developing 10.5 MW of electrical power at 10,000 volts. This electrical plant, in addition to powering the ship's auxiliary and hotel services through transformers, drives the two main propulsion motors, one on each propeller shaft. These motors produce 44 MW each and are of synchronised salient-pole construction, nine metres in diameter and weighing more than 400 tons each. The ship's service speed of 28.5 knots (52.8 km/h) can be maintained using only seven of the diesel-electric sets. Her maximum power output with the new engine configuration running was now 130,000 hp, which is greater than the previous system's 110,000 hp. Using the same IBF-380 (Bunker C) fuel, the new configuration yielded a 35% fuel saving over the previous system. During the re-engining process, her funnel was replaced by a wider one in order to accommodate the exhaust pipes for the nine B&W diesel engines.

Also during refit, the fixed pitch propellers were replaced with variable-pitch propellers. The old steam engines required astern turbines to move the ship backwards or stop her moving forward. The pitch of the new variable pitch blades, however, could simply be reversed, causing a reversal of propeller thrust while maintaining the same direction of propeller rotation, allowing the ship shorter stopping times and improved handling characteristics. The new propellers were originally fitted with "Grim Wheels", named after their inventor, Dr.-Ing. Otto Grim. These were free-spinning propeller blades fitted behind the main propellers, with long vanes protruding from the centre hub. These were designed to recover lost propeller thrust and reduce fuel consumption by 2.5 to 3%. However, after the trial of these wheels, when the ship was drydocked, the majority of the vanes on each wheel were discovered to have broken off, and so the wheels were removed and the project abandoned.

Other machinery includes nine heat recovery boilers, coupled with two oil-fired boilers to produce steam for heating fuel, domestic water, swimming pools, laundry equipment, and galleys. Four flash evaporators and a reverse-osmosis unit desalinate sea water to produce 1000 tons of fresh water daily. There is also a sanitation system and sewage disposal plant, air conditioning plant, and an electro-hydraulic steering system.