In a ship the size of the “Queen Mary” the propelling machinery and auxiliary plant attain enormous dimensions, yet so well has she been designed that her space and power are used to the fullest advantage
FOR THE MAIN MACHINERY SUPPLY SWITCHBOARD in the engine-
THE use of steam turbines and oil-
The size of the Queen Mary is vividly demonstrated by the illustration on page 10. In a similar manner the vast proportions of her power plant may be visualized by bearing in mind that the greater part of the hull below the water-
Not a cubic foot of space is wasted. Right forward are the tanks for some of the water ballast and oil fuel as well as cargo and baggage spaces. Next are the water-
Farther aft are No. 2 boiler-
The boiler installation of the Queen Mary was built by John Brown and Co, Ltd, at Clydebank (Dumbartonshire). In No. 1 boiler-
The air for combustion is heated in nests of tubes placed at each boiler end, and is forced into the ash-
These boilers, with a working pressure of 250 lb, are used for auxiliary purposes in the ship, including the electric turbo-
Fuel oil is heavy and thick and has to be heated before being pumped to the boiler-
THE MIGHTY ATLANTIC RECORD BREAKER. Within little more than three months of her maiden voyage in May 1936, the Queen Mary had broken six Atlantic speed records, and had won the Blue Riband. On August 19, 1936, she left Southampton for New York and covered the distance from Bishop Rock to the Ambrose Light, 2,907 miles, in 4 days 27 minutes, at an average speed of 30·14 knots. She left New York on August 26 and covered the eastbound distance from the Ambrose Light to Bishop Rock, 2,939 miles, in 3 days 23 hours 57 minutes, at an average speed of 30·63 knots. Her speed records include the fastest day’s run eastbound and westbound, the fastest crossing in either direction and the fastest port-
The Queen Mary’s main boilers are of the Yarrow type, and there are twenty-
The air supply is on the closed-
Each main boiler is approximately 31 feet high, including the air heaters -
The working pressure of the main boilers is 425 lb per square inch, with steam superheated to a temperature of 700 degrees Fahrenheit. Steam at this temperature is an intensely hot gas, so that, instead of the analogy of houses in a township, the whole generating plant might be compared with a volcano in full blast.
There are some 2,600 feet of main steam piping in the Queen Mary. Piping for the ahead turbines has an internal diameter of 16-
The stop valve on each boiler is fitted to the superheater outlet and is so designed that should a boiler tube burst, the valve operates to prevent any inflow from the main steam supply.
A particularly interesting feature among the boiler fittings is the type of gauge used to indicate the level of the water. The forged steel body of the gauge is provided with two thick plate-
TWO OF THE TURBINE CASINGS in the Queen Mary's after engine-
Behind these strips are four electric lamps, and their light, passing through the coloured strips, is directed by a lens on to the back of the steam and water space between the covers. Viewed from the front, the steam space appears red, and the water by reason of its bending action on light causes the green illumination to appear. Red and green thus provide a vivid contrast and indicate the water level where the two colours meet.
The illuminated gauges of a group of four boilers are brought to view at a single control point by the use of mirrors. In addition to these indicators there are devices that automatically shut off the fuel supply and sound an alarm whistle should the water fall to a dangerous level.
In addition to their steam generators, all five boiler-
The 168 main oil burners are fed with fuel by a battery of twelve large oil-
A number of revolving steel wire brushes on flexible shafts 26 feet long, operated electrically, are provided for boiler cleaning. In Nos. 1, 3 and 5 boiler-
The two turbo-
Alongside the generators in this compartment are auxiliaries to hotel services boiler plant as well as air compressors and ballast pumps.
The hotel service turbo-
In the after turbo-
THE GIANT EXHAUST TRUNKING from one of the low-
Each of the turbo-
In addition to the turbo-
All the telephones, electric bells, lond speakers, fire alarms and similar apparatus in the Queen Mary are supplied with low-
The distribution of electric power throughout the ship proved a tremendous undertaking. There are 735 miles of main insulated cable and another 3,000 miles of subsidiary cable. The main machinery supply switchboard in the after turbo-
The motors that drive the winches and capstans alone aggregate 2,000 horse-
It is in the two great engine-
Each set has one high-
1,024 Feet of Propeller Shafting
Each of the iron centres of the main reduction gear wheels was cast in one pieee and weighs 51½ tons. The cast iron lower half of the gear case for each of these huge wheels weighs 54½ tons.
The overall length of each set of turbines, including the Michell bearings that take the enormous thrust of the propeller, is 70 feet. The total length of propeller shafting that transmits the power of the Queen Mary’s engines to the giant screws is 1,024 feet.
Each set of turbines can be operated as an independent unit. In addition, the high-
DISTRIBUTION CABLES are held in special clamps bolted to the deck above. These cables carry electric current from one of the Queen Mary's auxiliary switchboards, of which there are thirty-
The important “axial clearance” of the blades is adjustable in conjunction with an electric fore-
The turbines are thus guarded against damage in the event of shaft fracture, loss of a propeller or other emergency. Steam is also shut off automatically should the forced lubrication system fail or cease to function satisfactorily.
Another interesting point arises in connexion with the huge helical reduction gears. In each instance, these are double, to equalize the end thrusts ol the helices and, to ensure resiliency, the pinions are hollow and attached to their shaft at the end farthest from the turbine. The internal pinion shaft is driven by the turbine rotor through a flexible coupling.
In the Queen Mary there are four main condensers, one for each set of engines. The condensers are 28 feet high, nearly 20 feet wide and over 20 feet long. Each condenser comprises a huge casing, similar to a ventilating cowl in general appearance with the opening turned inboard, and containing two separate nests of horizontal tubes. The central lane between the two set? of tubes permits the passage of exhaust steam to the bottom of the condenser, where it mixes with and heats the condensate in the storage reservoir.
There are in each condenser 13,780 tubes of copper-
Part of the tube space provides a pocket for the air which is extracted from the condenser by air-
The circulating pumps that force the cooling sea water through the condenser tubes are of the vertical type with the pump at the foot and the powerful electric driving motor at the top. There are eight of these pumps and they stand 12 ft 6-
Special arrangements are made to maintain a constant supply of boiler feed water from the condensers by adding to or taking from the condensate. The feed water is extracted from the condensers by eight powerful electric pumps, each of which is capable of dealing with 550,000 lb of water every hour.
After having left the electric extractor pumps the boiler feed water is passed through apparatus known as ejector coolers, with the dual function of cooling the condenser air-
These feed water heaters are arranged in sets of four, working in three stages -
Boiler and air heater tubes are kept clean by steam-
It is not possible to catalogue all the auxiliaries and fittings in the engine-
Included in the machinery and equipment of the Queen Mary are a number of interesting and ingenious devices devoted to maintaining the safety of the great ship, her passengers and crew. The subdivision of the vessel into watertight compartments has been thoroughly carried out and the bulkhead doors can be closed by machinery. The doors are built to slide in grooved framework attached to the bulkheads and vary in size from those that will permit of a man’s passing through them to openings large enough to provide a passage-
The watertight door system is divided into two sections, one comprising the doors in the lower part of the ship, the other including those in the passenger accommodation spaces. The sections muv be operated independently or simultaneously and the doors are closed within one minute from a central control on the navigating bridge.
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The doors are operated by hydraulic cylinders supplied with fluid at a pressure of 700 lb by two powerful steam pumps. The pumps are connected with the doors by about two miles of copper tubing. A bell fitted to each door gives warning seven seconds before closing begins.
Steering a ship of the Queen Mary a enormous size calls for the use of really robust equipment. The steering gear that serves the vessel weighs 180 tons and occupies a space about 68 feet long and 25 feet wide. The rudder stock (weighing with its frame 110 tons) comes up through the deck of the steering flat and is fitted with a massive steel yoke 15 feet long.
On either side of the rudder stock, arranged in pairs fore and aft, are four hydraulic cylinders mounted in a massive frame. The steel rams of opposed cylinders unite, on either side of the rudder stock, in massive bearings that encircle the ends of the yoke. Fluid under pressure is delivered to the cylinders by pumps driven by three 250 horse-
The electric pump motors are arranged side by side forward of the operating rams and farther forward is the servo-
In addition to the use ot servo gear and gyro-
In conclusion, there are three steam-
You can read more about “Making Giant Propellers” for the Queen Mary in Wonders of World Engineering