THE ELECTRIC RAILROAD.

Dominion, Volume 1, Issue 91, 10 January 1908, Page 4

THE ELECTRIC RAILROAD.

- RECENT PROGRESS. (London "Daily Telegraph," JSovomber 21-.): It is an ago of acceleration. Changes in modes of transport tako placp so rapidly that wo have' no .time to consider the possibilities of a new system beforo-it is put iiito actual practice. It seemed as if, for many years, tho Londoner thought only of the horse-drawn omnibus. And, then, almost. in ,a fow hours, ho awokd and rubbed 'liis eyes Vat the sight of the various flcots of mechanically-driven vehicles, which now. ply for hiro. -It is sometimes argued that these new methods of locomotion are not a blessing, but a curs'o. It has beon stated tl-nt men, wero happier "in' the good old <hys." But (luring the last century -wo have acquired a. wider knowlodgo of tho world, and .that, larger universo of which 1 it, is but a part, than in all tlio sixty or hundred centuries preceding it. Tlio coming of tin calculus, tlio. chemist's , test tubo, tho slide-rule, the-; iron-horse, and the dynamo .lias lessened for many, tho struggle for existence, ' ancl has opened up a .realm for thousands who enjoy a. fulness of life .unknown in other days. The logo of darkness and narrowed, bigotry can never return. For if tho light .of learning should flicker and :!io out in one land, :it will be burning brightly, iu7;another. It is th'o greatest blt-saitiu of-, tho. age that, knowledgo can bo sd easily cbinmunicatcd. . A discovory niado in this country .is'at onco known in America and on tho'Continent, and. a thousand, other minds are instautly. iocusscd upon tho subject. ..Tqgothor„ tliby ' build up . something .which wo call 1 an "invention." For, groat inventions, aro never tho Work of one man, but of many...... ' One of tho most fascinating' problems for. the workers in applied science is .that .of the-electrification of tho railroads!,.Wo aro' now so used to tho advantages of electri-cally-operated trnmcars. that perhaps wo do not fully appreciate .them. It is estimated tbac in this, country there aro at present SOtin mile 3. ol'. electrically-operatcd track. Over 20,000 motor tramcars are in use. The importance of electricity, a£- a lighting agent has now, been eclipsed by its extended uso for. motive ■ power. Perhaps the greatest venture was tho recent conversion 'to clec r trie traction of- the Metropolitan .Underground Railway. - Tho Londoner is familiar with ; his "tube" railways. But of tlio advantages of electric railways for suburban work he has had no practical experience. Ho will not have to wait long. The London, Brighton, and South Coast Railway will soon provido him with an object lesson. It is .tho last word'.' in 'electric .traction' at this present dato; it will influehco the design ot tho equipment for, othor lines.'

CHECKING THE DRIVERS. Interest has been of late awakened in the question ""of effecting economios in the,'consumption of current by tramcars. Meters have been installed. Not only do-they absolutely record the amount of energy consumod'by 'each car, but thoy form a chock on the way in which a driver handles his car. Ihey also give a record of tho con.dition of the electrical apparatus. It has been noticod that this automatic check on the driver has resulted in a saving of from 10 to 20 per cent, of the energy' consumed. Arrangements are also made so, that when tho car is running ,down hill.the electric motor may act as a dynamo and return current to the line. In this' system there are several notches on the controller. ; rJSach ■notch corresponds to a certain definite speed,, •which varies within quite narrow.; Ijiiiita. W hon tbo handlo js placcd l at a cbrtaiiv notch the car runs at a .definite speed;'what-, over may be the' gradiont.' The advantage' of running the'electric motors as generators during, a descent is not limited. to the econ-. omy of; current.-' Thero.' is at tho'driver's command a powerful braking effect, and it will not look the' wheels'.' Thero is thus a saving on brakes''and wheels/ ; , RAILWAY "LIVE". RAILS.

Tho i'dbal system of supplying'/electricity for , railway work'seeriis to be'by means of tho insulated third rail, which'is "live,"" or electrically chargod, whilo the system is at' work. Tho voltage employed is from 500 to 600 volts—amply sufficient to causo death by shock, especially in wet weather. This is the Bystem of working' for all the London underground and tube ■ railways, although there-aro differences in tho method of generating power.' The advent of the steam turbine has not only revolutionised shipbuilding and design, but ii: has mado a great difference to central station design. Tho men in tl;o street will be glad to know that it has spelt economy and reduced tariff Jor electricity. '

It is a 1 much more difficult mattor to arrange for a railway train to collect, current than is tho case-with a tramcar. Currents cannot bo easily collected by means of tho ordinary trolley-wheel at high speeds, owing to the jumping of tho wheel at the points of suspension of the trolley-wire. The outcome . ha 3 been the development of sliding collcctors. Tho simple collector consists of a cast-iron block, which rests on 1 the rail. No mechanical pressure, beyond that of its own weight—some 301b. to 401b. —is exerted. A system is now being used, two i.livo rails being/placed at the side, of tho track, the running-rails being used as middle /wire. A pressure of 1000 volts exists beI tween the insulated rails.

"REGENERATIVE" CONTROL. Referonce : has been made to a system' of regenerative control on tramcars, but somo remarks on what might bo called a gravitational regenerative railway, used on the Central London Railway, will not bo out of place. On the Liverpool overhead system it was found that of the total energy supplied to the rails-only 21 per cent, was expended in actual driving, 29 per ccnt. was spent in the motors, gearing, and starting resistances, and oO per cent, on the brakes. Tho question naturally arose as to tho'method of rahicingthcsc losses. One method was seen, and as a result tho station's of tho Central London Railway were each placed at tho top of a■ little hill; the energy stored in going up the. hill helped to brake the train,, and was available for restarting. In the driving'of the heavy trains on suburban railways the master controller has been introduced. Tho currents which havo •to bo dealt with aro so largo that the .ordinary tramway controller is quite unsuitable. In, order, therefore, to make all. regulating gear compact, tho switches aro placed beneath tho'car, and aro operated indircctly, either by pneumatic or magnetic control. Tho trains are operated on tho multiple unit system, every other coach on the train being a motor coach.

In the so-called rheostatic control of direct current motors there arc considerable losses which, aro inherent to.the system. In alternating current working a great portion' of these losses can-be eliminated. Alternating current systems arc chiefly used abroad for mainline work. For this class of transport higli voltages aro absolutely neecssary. and for high voltaren overhead lines are almost essential. The three-phase system has a iiumber of advantages which Have led to its wido adoption. The.necessity of using a low voltage,is avoided, and the commutator—tho most delicate part of a motor, and one vorv likcly to get out of order when working under tho arduous conditions of railway work—is abolished. . It also lends itself readily to l exonerative braking. The main disadvantage is that two overhead wires aro required. There aro two or threo different kinds of collectors used in these wires. Oil tho_ Valtellina Electric Railway a speciallydesigned trolley wheel is used, but general practice seems to favour Hie "bow" eollcetor, in which a spring in the form of a bow presses against the wire. The Simplon tunnel electric locomotives are fitted with a modification of this collector.

Tho latest ami most advanced stop in tlio evolution of elcetric traction is tlic singlephase, svsteni. Lt lias been largely tlic ontcnnie of experiments made in Milan by Dr. Tinaq ill 1003. Since that date, considerable activity lias been displayed on tlio Continent anil in tlio United States towards developing jtho single-phase commutator motor. The first- installation in America war, commenced in 190-1 liv tlie Cincinnati and Indianapolis Traction Company. The current is supplied directly to the-rails from tlio generator without any intermediate transformation. One of the great advantages of this system

is its simplicity, only one overhead wire being noeded. At the same time.'that, it rivals the simplicity of the direct current system, over long distances it affords thi flexibility and economy of alternating current transmissions. The total cost of tlio single-phase alternating enrrent "equipment- isless than that of direct current; and tho alternating method' is rrforo efficient.

In th'o ease of'an electrified overhead, system tho lines liavo to bo' protected from lightning discharges. Lightning arresters aro arranged along tho line, tlio per mile depending upoii the; exposure I of 1 the lino. The'function of the arrester is to convey aiiy disch'argo to earth' through a suit-, r.blo path, instead'of allowing the'discharge to pass through the machines. The ideal arrangement- for' an electrified 'locomotive is. for it to be'perfectly self-con-tained,, carrying not only its motors, but its sourco of electrical''energy. Such'a locomotive could be" placed on oxisting steam roads, : .and 110 expense would, be incurred'by the erection of ovorhcad conductors, with' their necessary feeders, etc.' Secondary batteries, each consisting of a sufficient'number of cells' ;to supply tho necessary voltage'.for. tho •motorsj and of a size sufficient to supply the full load current for'at least a complete journey, seem i necessary for a practical 'solution of the problem. Asthere would be no niain& to consider, the battery, could bo a, low voltage oho, 'individual cells, being very ,larp:o. The difficulty is that such ; a battery would bo exceedingly unwieldy, and a considerable proportion of tlio energy expended would be required t'o carry the-battery itself-. With such a battery of secondary cells speed regulation could be easily and efficiently:obtained, • and ' regenorativo: braking would bo much simplified. '•■' Unfortunately, • the -.ideal battery for'isuch.a purpose remains yet'to ,bo produced. Wo may :look. for progress in this direction.Sometimes such 'progress is' made rapidly ; ■ sometimes it ; is' disappointingly slow. ; ' .. • • ■ . 1