RAIL TRANSPORT

New Zealand Herald, Volume LXXIII, Issue 22509, 28 August 1936, Page 15

RAIL TRANSPORT

ELECTRIC TRAINS COMPARISON WITH STEAM COSTS AND ECONOMIES By IS I'. MSA MS, M.A., LL.B., D.Sc., m.Com., r.s.s. No. IV. In flic first article of this scries it was shown that the Auckland-Morning-side cut-oil would include two doubleline funnels of an aggregate length of 11 <j chains. Electrification, though desirable, is not absolutely essential for such conditions. A longer double-line tunnel than either of those proposed for the Morningside deviation is operated bv steam under similar conditions as regards gradients and volume of traflic between C'avershani ami Uurnside on the main line south and inland from Dunedin. The case for electrification is strongest: (1) On routes where lengthy tunnels exist and the elimination of the smoke nuisance is important. (2) On routes where there are heavy gradients. Owing to the greater drawbar pull of the electric locomotive at low speeds it is relatively much more ellicient than the steam locomotive, both on heavy gradients and in accelerating from rest. (.'>) On routes where the tra (lie is especially heavy—if the extra cost ol overhead and other equipment rendered I necessary by electrical operation is recouped by the resulting economies, some of the principal of which are: (a i Attracting extra tra (lie through taster services (due mainly to the more rapid acceleration of electric locomotives) —a most important factor on suburban routes, (h) Lower maintenance costs of electric as compared with steam locomotives. The simplicity of the electric locomotive leads to ,a substantial reduction in the costs of repairs and maintenance, and experience in other countries lias shown that these costs are reduced to one-third, and in some cases to one-quarter, of those of the steam locomotive. Similarly, engineshed expenses are much reduced. On the other hand, maintenance of overhead equipment is a slight addition to the cost of electrical operation. Limitations of Steam (e) The steam locomotive is subject to certain limitations arising from the fact that it must carry coal and water; a consideration which affects - weight, dimensions, general design and operating efficiency (including costs of repairs and maintenance). The electrical locomotive is free from many of these restrictions. (d) The more rapid electric transport means lower aggregate wages in proportion to the total volume of business handled and economy in rolling stock. (c) The use of the regenerative braking system, whereby on a falling gradient the motors on the locomotives are converted into generators and exert a retarding force while returning electric energy to the distribution system, effects a marked increase in the efficiency of electric working as compared with steam railway operation, where the potential energy of the descending train is wasted in brake-block friction (f) Fuel bills are reduced. , (g> Compensation claims for wayside fires are eliminated. (M Coal-handling plant, watercolumns, and pumping plant are reduced in number, if not altogether j eliminated: and, 011 account of the absence of smoke, savings can be effected in the painting of stations • overbridges and rolling stock. Ci 1 ) There are minor economies to be effected in the lighting, heating and ventilating of electric trains. (j) There are certain other economics if the multiple unit vehicles instead of separate electric locomotives are used. Incidental Advantages Apart from the various matters referred to above, there arc other incidental advantages of railway eleetrifiea tion which cannot easily be brought into a balance-sheet of operating costs or revenue. The removal of the steam locomotive must necessarily have a favourable effect on the comfort of travel. The capital cost per mile of an electric railway is much higher than for a steam railway, but where the traffic is sufficiently heavy the savings in operating costs just enumerated pay the interest on the extra capital outJay. The exact point when the change becomes desirable depends in large measure 011 the relative costs of coal and electricity, 0.g., the absence in Switzerland of readily accessible coal and the cheapness of hydro-electricity account for the wholesale electrification of railways in that country. Economies of Capital When, however, a railway is changed over from steam to electric working there are certain economies of capital which tend to offset the extra 'capital cost of'the electric railway: (a) Release of steam locomotives for other work. (b) Curtailment of rolling-stock building programmes 011 account of quicker movements of rolling stock and cutting out of coal haulage to • locomotive depots. (c) Postponement of need for effecting grade easements, inserting extra crossings or duplicating or quadruplicating lines. (But for electrification the Lyttelton tunnel would have had to be duplicated before now.) (d) Reduction of provisions for water tanks, coal-handling facilities, etc.. and locomotive depots.