Engineering Wonders of the World
Volume III

THE ELECTRIC POWER-STATIONS OF LONDON. 231 ONE OF THE SIX PARSONS STEAM TURBINES INSTALLED AT THE LOKS ROAD POWER-STATION, CHELSEA. Top of casing removed to show drum and blades. Each turbine has an output of 8,000 kilowatts at 1,000 r. p.m. (Photo, Parsons Steajn Turbine Company, Limited.) steam turbines, each coupled to an alternating current dynamo, which combination is usually known as a “ turbo-alternator 1 ne Each machine is capable of Generators. _ . t . , , producing, at normal load, 5,500 “ kilowatts." We should remark here that the Board of Trade unit, the standard by which electricity is sold, is equal to 1 kilowatt for one hour. At the low price of one penny per unit the gross earnings per machine would be nearly £25 an hour. As a matter of fact, the output stated can be exceeded to the extent of 50 per cent, if required, and space is provided for two more sets of the same, and one of half the capacity. With the extra boilers the full equipment of the station will therefore consist of eighty boilers and eleven turbo-generators, with a total output of 57,700 kilowatts at normal load. Besides this, and the auxiliary ma- chinery already referred to, there are four “ exciter ” sets for producing the direct cur- rent needed for energizing the field magnets of the alternators, for charging batteries, and for other purposes. In conclusion we may, in imagination, fol- low the distribution of the current from the station. Generated at 11,000 volts, it is con- ducted through. 285 miles of main cables in- sulated with paper, lead-sheathed, and drawn through earthenware conduits laid in concrete. There are twenty-three sub-stations at various points on the different railways. At each sub- station the high-tension alternating current is reduced from 10,000 to 370 volts, and then converted to a direct current at 600 volts for the electric locomotives, each of which is fitted with two 200 horse-power motors. [Note.—The writer begs to express his indebtedness to Garcke's “ Manual of Electrical Undertakings ” for many of the figures contained in this articled]