The White Star Liners "Olympic" and "Titanic"
LECTRICITY, it need hardly be pointed out, is extensively employed in all the departments of the Olympic and Titanic. In addition to the large supply required for lighting purposes, electrical power is used for the deck cranes; cargo, boat, and engine room winches; passenger elevators ; stores, mail, and pantry lifts ; ventilating and stokehold fans ; cabin fans ; motors for the cylinder-lifting gear, turbine-turning and lifting gear, and condenser sluice valves ; the workshop machine tools ; conveyor for marconigrams ; gymnastic apparatus ; kitchen and pantry machinery, such as the ice-rocker, dough-mixers, potato-peelers, roasters, knife-cleaners, mincers, hot plates, and electric irons ; electric heaters ; electric baths ; main steam whistles; sounding machines; stoking indicators ; boiler room telegraphs; clocks ; watertight doors ; helm indicator; illuminated pictures; chimes bells ; loud-speaking and service telephones submarine signalling; and wireless telegraphy. The electrical installation, therefore, may virtually be termed the nerve system of the ship. Indeed the application of electricity is so general that much of the electrical equipment is necessarily described in the other sections of this book.
The central station is situated in a separate watertight compartment, about 63ft. long and 24ft. high, adjoining the after end of the turbine room at the tank top level. The general arrangement of the electrical machinery in this compartment is shown in Fig. 122.
The main generating plant consists of four 400-kilowatt engines and dynamos, manufactured by Messrs. W. H. Allen, Son & Co., of Bedford, and has a collective output of 16,000 amperes at l00 volts, which exceeds in current capacity many large city central stations. The switchboard gallery is at the forward end of the cornpartment at the orlop deck level, and commands a view of the machines.
Main Generating Sets
The engines are of the vertical three-crank compound forced-lubrication type and indicate 580 horsepower each when running at 325 revs. per minute. Each engine has one high-pressure cylinder 17in. diameter and two low-pressure cylinders 20 in. diameter, with a stroke of 13in. Steam is supplied at 185 lb. pressure and is exhausted either into the surface heater, which is the condition at sea, or into the auxiliary condenser, which is the condition in port. Each engine is coupled directly to a compound-wound continuous-current dynamo of the ten-pole type fitted with inter-poles. The equalizer cables are led to the equalizer switches situated below the deck near the centre of the compartment, with a view to minimizing and equalizing the resistance when running in parallel. Illustrations of one of the generating sets are given in Figs. 123 and 124.
The tachometers are driven by Hans Renold silent chains.
Auxillary Generating Sets
In addition to the four main generating sets, there are two 30-kilowatt engines and dynamos situated on a flat in the engine casing at the saloon deck level, well above the water-line. The general features of their design are similar to the main sets, except that the engines are of the two-crank compound type. Each engine has cylinders 9 in. and 12 in. diameter by 5 in. stroke, and runs at 380 revs. per minute. The auxiliary sets are connected by means of a separate steam pipe to boilers situated in either of several boiler rooms, and will be available for emergency use should the main sets be temporarily put out of action.
Current is conveyed from the main dynamos by means of heavy rubber-insulated cables, each of 1.5 sq. in. sectional area and 2-1/4 in. diameter, to the dynamo control switches situated on the front of the switchboard gallery. Of these there are four, one for each dynamo, each provided with five hand levers resembling those commonly seen in a railway signal box; see Fig. 125.
The electrician in charge faces the machinery when operating the switches, and can also communicate his instructions to the engineer below by means of electrically illuminated signals which signify if any particular set is to be started, stopped, or varied in speed. The various switches are interlocked to ensure correct operation. Four ammeters, reading up to 5,000 amperes each, are provided, and there are also four integrating wattmeters, which record the number of units generated by the several dynamos. For guidance in coupling or uncoupling the sets, four revolving voltmeters are mounted on a stand between the dynamo pillars, and indicate the electrical pressure at the lighting and power bus-bars and any individual dynamo.
From the main dynamo switches the current passes by insulated cables below the gallery to the feeder switchboard. The latter consists of 25 black polished.slate panels, upon which are mounted the fuses, automatic cut-outs, and ammeters for controlling each circuit. A general view of the feeder switchboard and its attendant apparatus, which have been constructed by Messrs. Dorman & Smith, of Salford, Manchester, to the shipbuilders' specification, is shown in Fig. 126.
From the feeder switchboard radiate no fewer than 48 cables, ranging in area up to 61/12 S.W.G. The distribution of current is effected on the single-wire system, but the returns are carried back and bonded in such a way as to avoid stray currents. The power and heating supply can be run entirely independent of the lighting supply, there being power and light bus-bars on the switchboard which can be paralleled or otherwise, as may be required. The cables pass vertically up two steel trunkways, one on the starboard and one on the port side, and terminate in master fuse boxes at each deck, from whence branch the individual circuit cables. The latter ramify throughout the vessel along the main passages of the different decks, and feed in turn the distribution boxes, one of which is illustrated in Fig. 127.
From the distribution boxes the current is taken by wiring to the individual lights, motors, heaters, etc. Local switches are, of course, provided for turning off individual lights or machines.
The main cables and branch wires are of tinned copper covered with rubber and heavily braided, except in the machinery spaces, where they are lead sheathed, armoured, and externally braided. In the boiler rooms the cables are run in steel pipes for protection against damp and mechanical injury. All wires leading through a watertight bulkhead are collected together in a steel tube filled with bitumen to ensure watertightness and yet look neat. Some idea of the extent of the electrical system will be gathered when it is stated that considerably more than 200 miles of cable have been fitted on each ship.
The total number of incandescent lamps installed on board the Olympic is about 10,000, ranging from 16 c.p. to 100 c.p., the Titanic having a similar number. Tantalum lamps have been adopted throughout, except in a few cases in the engine room, the metal filament lamps having been found quite suitable for use on shipboard except where there is any pronounced vibration. Their use permitted the voltage to be reduced to 100. The economy secured by the reduced voltage more than compensates for the higher first cost of the metal filament lamps compared with the ordinary incandescent pattern.
In the first-class staterooms, in addition to the usual fixed lights, there are fitted sockets for portable electric lamps or fans. Special dimming lamps with two filaments are also provided so that a light of small candle-power can be kept burning throughout the night, a feature which will appeal to nervous passengers. Emergency lamps on distinct circuits, deriving current from the emergency dynamos, are placed at intervals in all the passages, public rooms, and compartments throughout the vessel, so that, in the unlikely event of an entire extinction of the ordinary lighting, there would still be illumination available at all the points where the passengers and crew would congregate. In fact, anyone could find their way from one end of the vessel to the other at night by means of the lights on these circuits. Many of the electric light fittings in the passenger-accommodation are of majolica, which does not tarnish like metal. The ormolu electric light fittings have been supplied by Messrs. N. Burt and Co., Limited, of London. In the public rooms, main entrances, and suite rooms, these fittings are of a magnificent character, designed to agree in style with the particular period of decoration employed, and ranging from severe Italian Renaissance to elaborate Louis Seize. The main staircase fittings are after original French models. No trouble or expense has been spared in their selection, some having cost many hundreds of pounds each. Illustrations of these fittings will be found elsewhere in the chapter dealing with the passenger accommodation.
The electric bell installation comprises no fewer than 1,500 bell pushes on each ship. In the staterooms the bell pushes are mounted on the same plates with the electric light switches, such a plate being placed within convenient reach of each berth.
The electric heaters, of which there are 520 installed throughout each vessel, are of the Prometheus type, illustrated in Fig. 128.
These heaters take a collective current of over 5,000 amperes.
An idea of the large number of motors required will have been gathered from the numerous types of electrically driven machinery already cited. Altogether there are150 motors on board, varying from 1/2 to 40 H.P. Of these, 76 are employed in driving the ventilation fans, and take a collective current of 5,250 amperes. The method of hand and automatic control adopted for the fan motors has already been dealt with when describing the stokehold fans and the ventilation and heating arrangements. Next in order to the fan motors as regards the amount of power absorbed come the various motor-driven machines and mechanisms in the engine rooms, the cargo cranes and winches, the elevators and hoists, and the domestic machinery.
Electric Cargo Cranes
To secure the minimum of noise and vibration, electrical driving has
been adopted for the cargo cranes and winches in the vicinity of the passenger
accommodation. Eight electric cargo cranes have been supplied to each ship
by Messrs. Stothert and Pitt, Ltd., of Bath, six having a capacity of 2-1/2
tons each and two of 1-1/2 tons each. Two of the 2-1/2 ton
cranes are placed at the third hatch forward (see
Plate III.), and have a radius of 27ft., a height from the deck to
the centre of the pulley of 29ft., and a total lift of 100ft. The
remaining four 2-1/2 ton cranes are placed at the after hatches, Nos. 5
and 6. The radius is somewhat greater than in the case of the forward cranes,
two having a radius of 28ft. and the other two 29ft. ; but the height to
the centre of the pulley is slightly less, being 27ft. and 26ft. respectively
instead of 29ft. In the case of all the 2-1/2 ton cranes the hoisting
motor is of 40 B.H.P. and the slewing motor of 5 B.H.P. The lifting speed
at full load is 160ft. per minute, and the slewing speed 500ft. per minute.
The lifting speed increases automatically for lighter loads. One
of the 2-1/2 ton cranes is shown in Fig.
The two 1-1/2 ton cranes are placed at the after end of the promenade deck, and serve the two small hatches to No.4 hold. Their radius is 2l ft., height between deck and pulley 20 ft., and total lift 80 ft. Each crane is fitted with a hoisting motor of 30 B.H.P. and a slewing motor of 3 B.H.P. The lifting speed at full load is 200 ft. per minute, and the slewing speed is 500 ft. per minute.
Four 3-ton electric cargo winches and four 15-cwt. boat-hoisting winches have been supplied to each ship by the Sunderland Forge and Engineering Co., Ltd., and have been so designed by the makers that vibration and noise are practically eliminated. In the case of both sizes the lifting speed is 100ft. per minute at full load. As the winches are situated on the open decks, the working parts and motors are made totally enclosed and watertight. The warping ends are driven through worm gearing of very substantial construction, the whole being enclosed and running in an oil bath. Ball thrust blocks are provided on the worm shafts.
The motors are series-wound, and equipped with all the necessary control gear. A magnetic brake and also a foot brake are provided on each size of winch, the latter brake being interlocked with the controller to prevent abuse of the motor by unskilled operators.
The controllers and resistances are built with a view to withstanding the roughest treatment. Particular attention has been paid by the makers to the insulation of the current-carrying parts, on account of the damp and salt atmosphere to which the machines will be exposed. One of the winches is illustrated in Fig. 130.
There are also electric winches in the engine room in connection with the lifting gear, which have been supplied by Messrs. Chambers, Scott and Co., of Motherwell.
Elevators and Lifts
The winding gear for each of the first and second-class passenger elevators, which have already been described when dealing with the passenger accommodation, is driven by a motor of the four-pole totally enclosed shunt-wound type, rated at 6 B.H.P. when running at a speed of 500 revs. per minute, the rating being on the basis of a six-hours run with full load and a rise of temperature not exceeding 70 degrees F.
Besides the passenger elevators there is, on each ship, a 3-cwt. electric service lift in the officers' pantry and another in the restaurant pantry. The latter travels from the saloon to the bridge deck, a height of 19ft. 6in., and has a cage l ft. 7in., by 2 ft. 2 in., by 2 ft. 6 in. There is also a 10-cwt. stores lift (depicted in Fig. 131) for carrying provisions, etc., from the storerooms to the saloon cleck, a height of 33ft. 6in., and an 8-cwt. lift forward for raising mail bags.
All the service lifts are electrically controlled by push buttons placed at each deck. Position indicators and speaking tubes are also provided. All the lifts have been constructed and fitted on board by Messrs. R. Waygood & Co., Ltd., of London.
Two electric bathrooms of the most modern type have been arranged adjacent to the Turkish baths at the middle deck level. The type of bath fitted is illustrated by Figs. 132 and 133.
Fig. 132 shows the bath open and Fig. 133 shows the bath closed up and in use.
The clocks, of which there are 48 throughout each vessel, have been supplied by the Magneta Time Co., Ltd., and are all actuated electrically on the Magneta system, which obviates the use of galvanic batteries. They are controlled by two master clocks placed in the chart room, so that they may work in complete unison and each register exactly the same time. One of the master clocks is illustrated in Fig. 134.
As is well known to ocean travellers, the ship's clocks gain over half an hour each day when going westwards and lose a corresponding amount when returning to Europe. To allow for this difference in time the master clocks are set each day at noon by the officer in charge, who puts them backwards or forwards according to the longitude.
Illuminated Signs and Pictures
A number of electrically illuminated signs are distributed throughout the first and second-class accommodation to direct passengers to the respective main entrances and public rooms, while on view in the gymnasium are attractive illuminated multi-coloured pictures of sections of the Olympic and Titanic, and a map of the world with a network of the many White Star steamship routes which encircle the globe.
The telephone installation of the Olympic and Titanic is divided into two sections, viz., the navigating group and the internal system. All the apparatus is of the very latest type and has been installed on the most approved lines. The navigating group provides for communication between the following:--
Except in the chief engineer's cabin, the telephones are of the "Universal" pattern, by which calls are given by means of an interrupter as well as by voice. The apparatus is mounted in special forms to suit the various positions. On the forecastle and poop the instruments are contained within a polished brass casing mounted on a pillar, and the whole fitting is arranged in portable form, so that the apparatus can be used at two alternative positions in the case of the forecastle set and at a second position on the poop. For the crow's nest the telephone is mounted within a metal hood, and this set also is portable. In the wheel house on the navigating bridge four instruments are fitted. Each telephone is provided with an indicating device, and, in addition to a flag showing as is usual, a signal lamp is caused to glow upon a call being received. In the engine room three telephones are employed, and the instrument for communicating with the boiler rooms operates in conjunction with a combined switch and indicator giving both lamp and flag signals, as in the case of the bridge instruments. In each boiler room the telephone is mounted within a metal hood, and a special calling receiver is provided at each station, as well as a visual indicator. The telephone in the chief engineer's room is of the cabin type.
The current for operating the system is obtained from the ship's lighting circuit, which is reduced to a pressure suitable for telephonic work by means of resistances, and the noise of commutation, inherent in the machine-generated supply, is eliminated by the introduction of inductance coils. A standby battery is also provided, and is introduced in the circuit, should the main supply fall, by means of an automatic switch.
The internal system provides for intercommunication between a number of cabins through a central exchange. The exchange switchboard has a capacity of 50 lines, the stations connected being a number of first-class staterooms and also the rooms of the chief officials and various service rooms. The switchboard, which is illustrated in Fig. 136, is arranged to give a lamp signal upon a call being made, and in addition to the usual audible signal a voice call can be given to the exchange from any station in connection, so that rapidity of operation is assured.
The user at one of the cabins has simply to pick up the telephone and say straightaway the station he wishes to speak to and a loud receiver at the exchange gives the instruction. The operator, seeing a lamp glowing corresponding with the calling station, then connects the calling station with the station required, thus obviating the usual delay in communicating with the calling station and ascertaining the position required. The current supply is obtained from the lighting circuit, as in the case of the navigating telephone system, and the automatic switch and standby battery are contained within the exchange switchboard casing. The telephone sets in each cabin are of Graham's intermediate loud-speaking type (Fig. 137), and comprise a hand set with a circular metal push and terminal box.
At the majority of the positions the fittings are silver-plated, and at others of polished and lacquered brass. The wiring of the system has been planned on the most approved principles, and junction boxes have been introduced so as to facilitate testing and extension of the installation.
In addition to the exchange system, a separate group of circuits is provided for direct communication between the following:--
The telephones and fittings have been manufactured by Messrs. Alfred Graham & Co., at their Crofton Park Works, London, and the work of erection on board has been carried out by their own staff.