PRESIDENTIAL ADDRESS. 703 



may say that to start from rest a train weighing, including the engine, 300 tons, 

 and to attain a speed of thirty miles per hour in thirty seconds, requires about 

 1,350 i.h.p. During the period of acceleration the engine must exert an average 

 tractive pull of nearly fifteen tons. 



Mr. James Holden, until recently locomotive engineer of the Great Eastern 

 Railway, built an engine to produce an acceleration of thirty miles per hour in 

 thirty seconds with a gross load of 300 tons. The engine weighed T8 tons, and 

 was supported on ten coupled wheels each 4 feet 6 inches diameter. There 

 were three high-pressure cylinders, each 18^ inches diameter and 24 inches 

 stroke. A boiler was provided with 3,000 square feet of heating surface and a 

 grate of 42 square feet area. Boiler pressure, 200 pounds per square inch. This 

 engine practically reached the limit of the construction-gauge. 



An acceleration of thirty miles per hour in thirty seconds is considerably below 

 what may be applied to a passenger without fear of complaint. But it is clear that 

 it is just about as much as a locomotive can do with a train of reasonable weight. 

 Even with a gross load of 300 tons nearly one-third of it is concentrated in the 

 locomotive, leaving only 200 tons to carry paying load. The problem of quick 

 acceleration cannot therefore be properly solved by means of a steam locomotive. 

 But with electric traction the limitations imposed on the locomotive by the con- 

 struction-gauge and by the strength of the permanent way are swept away. 



The equivalent of the boiler power of a dozen locomotives can be instan- 

 taneously applied to the wheels of the electric train, and every axle in the train 

 may become a driving axle. Thus the whole weight of the stock, including the 

 paying load, may be utilised for tractive purposes. If, for instance, the train 

 weighed 200 tons, then a tractive force equal to one-fifth of this, namely, forty 

 tons, could be exerted on the train, but uniformly distributed between the several 

 wheels, before slipping took place. The problem of quick acceleration is therefore 

 completely solved by the electric motor. 



Electric Raihvays. 



December 18, 1890, is memorable in the history of railway enterprise in this 

 country, for on that date the City and South London Railway was opened for 

 traffic, and the trains were worked entirely by electricity, although the original 

 intention was to use the endless cable system of haulage. This line inaugurated 

 a wonderful system of traction on railways in which independent trains moving 

 at different speeds at different parts of the line are all connected by a subtle 

 electric link to the furnaces of one central station. 



Since that epoch-marking year electric traction on the railways of this country 

 has made a gradual if somewhat slower extension than anticipated. But electri- 

 cally operated trains have in one branch of railway working beaten the steam 

 locomotive out of the field and now reign supreme — that is, in cases, as indicated 

 above, where a quick frequent service is required over a somewhat short length 

 of road. The superiority of the motor over the steam locomotive, apart from 

 questions of cleanliness, convenience, and comfort, lies in the fact that more power 

 can be conveyed to the train and can be utilised by the motors for the purpose of 

 acceleration than could possibly be supplied by the largest locomotive which could 

 be constructed within the limits of the construction-gauge. There are many other 

 considerations, but this one is fundamental and determines the issue in many 

 cases. 



A few facts relating to the present state of electric railways in the United 

 Kingdom may prove of interest. At the end of 1908 there were in the United 

 Kingdom 204 miles of equivalent single track worked solely by electricity and 

 200 miles worked mainly by electricity, corresponding to 138 miles of line open for 

 traffic. Of this 102 miles belong to the tube railways of London and 201 miles 

 to the older system formed by the District and the Metropolitan Railways and 

 their extensions; 



It is not an easy matter to ascertain exactly how much capital is invested 

 in these undertakings for the purpose of electric working alone, since some of 

 the lines originally constructed for a steam locomotive service have been converted 

 to electric working. On the converted lines there is the dead weight of capital 

 corresponding to the locomotive power provided before electrification took place. 



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