Editing Queen Elizabeth 2 (section)

===Machinery===
[[File:20-QE2 Re-engine.jpg|thumb|''Queen Elizabeth 2'' being re-engined at [[Bremerhaven]], November 1986]]
[[File:21-QE2 Re-engine.jpg|thumb|''Queen Elizabeth 2''<nowiki>'</nowiki>s original funnel, removed while being re-engined; some of its panels were recycled to create QE2's new funnel.{{citation needed|date=September 2021}} Her old fixed-pitch propellors are visible in the lower left of the photo.]]

''Queen Elizabeth 2'' was originally fitted out with a [[steam turbine]] propulsion system using three Foster Wheeler E.S.D II boilers, which provided steam for the two Brown-[[Parsons Marine Steam Turbine Company|Parsons]] turbines. The turbines were rated with a maximum power output figure of {{convert|110000|shp}} (normally operating at {{cvt|94000|hp|disp=or}}) and coupled via double-reduction gearing to two six-bladed fixed-pitch [[propeller]]s.

The steam turbines were plagued with problems{{Citation needed|date=August 2012}} 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 After seventeen years of service, the availability of spare parts was becoming difficult due to the outdated design of the boilers and turbines and the constant use of the machinery which was mainly due to Cunard's cost-saving deletion of the originally planned 4th boiler while the ship was still on the drawing board.

The shipping company decided that the options were to either do nothing for the remainder of the ship's life, re-configure the existing engines, or completely re-engine the vessel with a modern, more efficient and more reliable 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 while giving the vessel a minimum of another twenty years of service, whereas the other options would only provide short-term relief.<ref name="Rob Lightbody">{{cite web| url=http://www.roblightbody.com/liners/qe-2/1987_Refit/ |publisher=Rob Lightbody |title=QE2's Major 1986–1987 re-engining refit |access-date=8 February 2011}}</ref> Her steam turbines had taken her to a record-breaking{{citation needed|reason=Failed verification at the given citation.|date=June 2024}} total of 2,622,858 miles in 18 years.<ref name="The Cunarders">{{cite web |url=http://www.thecunarders.co.uk/QE2%20History.html |publisher=The Cunarders |title=QE2 History |access-date=23 March 2011 |archive-url=https://web.archive.org/web/20101213081103/http://www.thecunarders.co.uk/QE2%20History.html |archive-date=13 December 2010 |url-status=dead}}</ref>{{failed verification|date=June 2024}}

During the ship's 1986 to 1987 refit, the steam turbines were removed and replaced with nine German [[MAN SE|MAN]] 9L58/64 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 {{convert|28.5|kn|km/h}} was now maintained using only seven of the diesel-electric sets. The maximum power output with the new engine configuration running increased to 130,000&nbsp;hp, which was greater than the previous system's 110,000&nbsp;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 modified into a wider one to accommodate the exhaust pipes for the nine MAN diesel engines.

During the refit, the original fixed-pitch propellers were replaced with [[variable-pitch propeller (marine)|variable-pitch propellers]]. The old steam propulsion system required astern turbines to move the ship backward or stop her moving forward. The pitch of the new variable pitch blades 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.<ref name="Rob Lightbody"/> These were free-spinning propeller blades fitted behind the main propellers, with long vanes protruding from the centre hub. The Grim Wheels were designed to recover lost propeller thrust and reduce fuel consumption by 2.5 to 3%. 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. The wheels were removed and the project was 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 seawater to produce 1000 tons of freshwater daily. There is also a sanitation system and sewage disposal plant, air conditioning plant, and an electro-hydraulic steering system.<ref>{{cite web|url=http://www.qe2.org.uk/engine.html |title=The engine room |publisher=QE2 |access-date=14 July 2010}}</ref>