Abstract :
The paper reviews 40 years of experience in the design, construction and maintenance of traction substations on British surface railways. It draws attention to the effect that the hazard of short-circuit over many miles of conductor rail has upon the arrangement and design of plant and apparatus. The number, size and type of converting unit are the main factors that dictate the design of the building, and in the approximate period 1915¿1930 this influence was almost wholly determined by the rotary convertor. This unit has now been completely outmoded by the mercury-arc rectifier, and the consequential effects on the design and layout of the substation are discussed. The Southern Region of British Railways uses both types of installation, of which the rotaryconvertor section, although nearing the end of its life and scheduled for replacement, is still working to capacity at a reasonable cost. The increase in the capital cost of plant and building since 1915, and the manner in which the relative costs have been affected by the different type of converting plant, are discussed. The operation and maintenance of the two systems of conversion are compared, costs of operation are analysed, and the influence of supervisory control is disclosed. The experience so far gained is applied to a suggested design for substations of the future.
