From the desk of the Chief Engineer
Authored by: S.L. Hare Chief Engineer - MV Queen Elizabeth 2
Brought to you by Martin's Marine Engineering Page, comments to email@example.com
I RECEIVE MANY REQUESTS FROM PASSENGERS for, Engine Room visits, but regret that due to the high level of security exercised, and for safety reasons, these cannot be granted.
NEVERTHELESS, I APPRECIATE the great interest that is shown in the technical aspects of QE2 and this short review may serve to answer some of the more commonly posed questions.
QE2'S POWER PLANT IS DIESEL ELECTRIC, a system chosen for its inherent reliability and flexibility. In 1986/87, in an operation costing £100m, nine medium speed MAN L58/64 nine cylinder turbo charged diesel engines were fitted, in place of the aging and fuel thirsty steam plant. The diesel engines drive C.E.C. generators, and each develop 10.5 MW of electrical power at 10,000 volts. Each engine weighs approximately 120 tons. (please see bottom of page for updated information on this - 06.2010)
IN ADDITION TO SUPPLYING AUXILIARY SHIP'S SERVICE and hotel service requirements via transformers, the electrical power generated is used to drive the two main propulsion motors, one on each propeller shaft. The maximum output of each motor is 44 MW giving QE2 a top speed in excess of 32 knots. They are of synchronous salient pole construction, are 9m diameter, and weigh over 400 tons each, representing the largest marine motors ever built.
THE SERVICE SPEED of 28.5 knots, can be maintained using only seven engines, thus allowing essential and routine maintenance to be carried out whilst at sea and without affecting schedules. At this speed a 35% fuel saving is made over the previous power plant, the fuel used being of the same grade - IF 380 (Bunker "C"). This fuel is heated under pressure to 140'C for injection, and is akin to road tar at room temperature.
BESIDES THE MAIN POWER PLANT, the machinery spaces house auxiliary equipment necessary to maintain services around the vessel. There are nine waste heat recovery boilers mounted in the engine exhaust uptakes, coupled with two oil-fired boilers designed to produce steam for fuel heating, domestic fresh water heating, heating of swimming pools and steam for the laundry equipment and kitchens.
THERE ARE FOUR FLASH EVAPORATORS which make fresh water out of sea water for boiler feed make-up, cooling water systems, and for washing and drinking requirements. A Reverse Osmosis unit completes the desalination plant enabling us to produce 1000 tons of fresh water per day. It is then transferred from treatment tanks to service tanks before being heated or chilled and distributed to every part of the ship.
A CLOSED CIRCUIT T.V. SYSTEM is constantly monitoring all machinery spaces.
FIRE-FIGHTING SYSTEMS are housed within the machinery spaces; pressure tanks for the accommodation sprinkler system and continuously running fire pumps ensure that water is always available at sprinkler heads and fire hydrants. Virtually every fire-fighting aid is available, ranging from foam and CO2 to the very advanced Halo injection system, so your safety whilst onboard QE2 is assured.
THE SANITATION SYSTEM and sewage disposal plants, completely self-contained and sealed, are located on 8-deck. Main air-conditioning plant is located in the machinery spaces, as are the pumps for the four sets of stabilizers, the bow thrusters and the electro-hydraulic steering gear.
MAY I TAKE THIS OPPORTUNITY to wish you a pleasant voyage with us, and advise you that my staff will be happy to answer any further questions you may have.
Frequently Asked Questions
What is the total power output of QE2's engines?
95 MW: enough to light the city of Southampton or equivalent to the power output of 3000 medium sized family cars.
What is the fuel consumption?
At the service speed of 28.5 knots, consumption is 380 tons per day: this equates to 50 ft/gall.
What is the diameter of the propeller and shafting?
The propellers are of controllable pitch, have five blades each, and are a little over 6m in diameter. The two propeller shafts are 80m long, are of solid forged steel, and are 590mm in diameter.
How big is each engine?
Each engine, including the sump-pan, is about the size of a double-decker bus. Each has nine cylinders of 580mm bore and 640mm stroke, operating on the 4-stroke cycle.
At what speed do the engines run?
The diesels at 400 rev / min, the propulsion motors at 144 rev / min.
What is the range when all fuel tanks are full?
At service speed, QE2 carries enough fuel for 12 days continuous sailing, but at the slower, more economical speed of 20 knots, she could sail for 30 days or two-thirds of a circumnavigation of the world.
How many personnel are there in the Technical Department?
Engineers, Electrical & Electronics Officers number 24. There are a further 48 technicians, ranging from mechanics, plumbers, carpenters, electricians and air-conditioning mechanics.
How many Engineers actually run the propulsion plant?
The new installation was designed to be unmanned, however one senior Engineer Officer is always on duty in the Control Room, assisted by three technical staff on a rotational basis of 4 hours on and 8 hours off.
When the vessel arrives in port, does everything stop?
Most definitely not! This is the time when repairs can be made and checks carried out. There is always one engine running in port to keep lights on and air-conditioning and galleys functioning.
How do the stabilizers work?
Very effectively! The two pairs of Denny Brown stabilizers cut down rolling by 60%. They are controlled by a gyroscope which uses the effect of precession to generate an electrical impulse, this in turn controls a hydraulic pump that alters the angle of the fin, which is shaped much like an aeroplane's wing. The action of the water over the wing either provides "lift" or "dive" to counter the effects of bad weather. Each fin projects from the ship's side by 12' and is 6'wide.
Are computers used in the machinery spaces?
Extensively. The power management system automatically stops and starts engines as required to ensure the highest efficiency is maintained. There is also a sophisticated alarm & monitoring system which alerts the duty engineer to any function which is outside of established parameters.
Why do Engineer Officers wear gold stripes with purple?
When the Titanic sank, all engineers went down with the ship. King George V decreed that the Royal Purple will be worn from that date on.
Editorial Comment -
It was brought to my attention that the above comments is not accurate, please read on.
" The gold braid insignia of rank worn by British mercantile marine engineer officers on the sleeves of their uniform jackets has a purple background. There is a long held belief that this was decreed by King George V in recognition of the heroism shown by Titanic`s engineers. Although it is a fine story and that heroism certainly deserved recognition, it is incorrect. In 1865 it was decided that British naval engineers would wear a purple background to their gold braid of rank in order to distinguish them from other officers and that colour coding transferred to the British mercantile engineer officers when they started wearing uniforms. Although engineer officers aboard passenger ships wore uniforms the practice was not common aboard cargo ships prior to WWI and so purple was not usually seen. As more engineer officers wore uniforms the purple background became common and the myth associated with the Titanic developed."
Dr. Denis Griffiths
Update, June 2010.
Tony writes us his observations, on an answer, regarding the main engines of the QE2.
" Re the Information Sheet written by QE2 chief engineer - the 'approx engine weight' is not 120 tons.
After travelling on the ship in 2008 I felt the 120 was a 'bit light'. I have checked on the MAN B&W website for these engines, and the actual weight is '208 tons without the flywheel', so the engine is probably closer to 210-212 tons. The QE2's generators were 70 tons each, and the engine/generator bedplates were 15 tons.
The misinformation of 'about 120 tons' was also shown on the old (2010) Cunard website (which Carnival have now destroyed, along with the virtual tour, and along with all references to QE2. Cunard's new, incomplete website is so user unfriendly that people are evidently looking elsewhere for cruises! "