Engineering Wonders of the World
Volume III

230 ENGINEERING WONDERS OF THE WORLD. companies and borough councils of London. Most of the tramways and railways have their own generating lighting Greater electric stations, but some purchase current in bulk from the supply companies. Thus the Metro- politan Electric Tramways derive their cur- rent from the North Metropolitan Electric Power Supply Company, and the newly elec- trified South London line of the London, Brighton, and South. Coast Railway Com- pany will be supplied with energy by the London Electric Supply Corporation. Five electric railways—namely, the “ Baker- loo,” the “ District,” the “ Great Northern and City,” the “ Hampstead,” and the “ Picca- dilly ”—are worked, from one generating sta- tion ; and to these systems will be added others authorized but not yet constructed. As this station is one of the most modern and by far the largest in London, we propose to take it as an example, and to describe it at some length. This immense power “ factory ” occupies nearly four acres of land adjoining the Thames at Chelsea. On account of its four lofty chim- neys, which are each 275 feet high, it is a very conspicuous, if not picturesque, object in the landscape, and some one has compared its general appearance to an inverted table of Gargantuan proportions. The site, Chelsea Creek, is a fortunate one, as it is fairly well placed relatively to the elec- tric railways concerned, and at the same time has the advantages of a river frontage and proximity to the West London extension of the Railway. Coal can therefore Lot’s Road Power» Station. Coaling Facilities. North-Western be delivered by water or rail, and special facil- ities exist for handling it. In the case of water-borne coal, the barges are received into a tidal basin, spanning which are two travel- ling cranes, each fitted with a 1-ton “ grab.” After being picked up by the grab and raised from the barge, the coal is weighed, and dis- charged on to a travelling belt, which conveys it to the elevators. These elevators raise the coal to the top of the building—140 feet—for distribution to the bunkers by another set of belt conveyors, which discharge their load automatically into any one of a number of large bins. When brought by rail, the coal is tipped from the wagons, and then elevated and distributed as described. From the bun- kers the coal is fed automatically to the fur- naces. The tidal basin gives accommodation for six large barges, the storage capacity of the bunkers is 15,000 tons, and the plant can handle 240 tons of coal per hour. The daily consumption will eventually be about 800 tons. Equally complete are the arrangements for removing the ashes. These are dropped from the hoppers into tip wagons, drawn by an electric locomotive to the water’s edge, and there discharged into barges. One side of the main building is occupied by sixty-four water-tube boilers, and space is reserved for sixteen more. The boilers are on two floors, with the coal bun- kers above and the ash hop- Automatic , i , . Stokers. pers below ; automatic chain grates feed their furnaces'. In a chain grate the fire-bars consist of a series of short links assembled to form a wide flat chain of iron. The ends of this chain are joined, and it is carried on two revolving cylinders, like a belt over pulleys, and so arranged that its upper side travels slowly through the furnace. In this way the coal is conveyed from the bunker to the under-side of the boiler, consumed, and reduced to ashes by the time its journey is completed. Before entering the boilers the water passes through “ economisers.” These consist of a great number of tubes placed _ * , . The Boilers, m the Hues leading to the chimneys in order that the water may absorb heat from the waste gases. The generating machinery consists of eight