Page:Encyclopædia Britannica, Ninth Edition, v. 20.djvu/264

Rh 246 RAILWAY twelve minutes was accomplished with a train of sixteen carriages, making a speed of 75 miles per hour. The engine has taken a train of thirty-three carriages full of passengers from Doncaster to Scarborough and back at an average speed of 45 miles per hour. It is capable of moving a gross weight, including engine, tender, and train, of 356 tons on a level at a speed of 45 miles per hour. The average results of the regular performance of seven engines of this class between Doncaster, Peterborough, and London for the third quarter of 1884 show that a train of twelve six-wheeled carriages weighing 13 tons each was taken at a speed of from 50 to 53 miles per hour, for a consumption of 25J ft of coal per mile run and five pints of oil per 100 miles run. Other Four-coupled locomotives, having the cylinders inside, and four locomo- wheels coupled " in front," with a pair of hind or trailing wheels, lives. are known as "mixed engines," tnat is to say, engines adapted for either passenger traffic or goods traffic, a generally useful type. In one example the cylinders are 16 inches in diameter, with a stroke of 22 inches ; the coupled wheels are 5 feet in diameter. The weight of the engine is 24 tons, of which 20 tons are driving weight. The next engine to be noticed is a generally useful engine, four- coupled "behind," for passenger traffic, such, for instance, as that with inclined fire-grate and sloping fire-box designed by Mr J. J. Cudworth for service on the South-Eastern Railway. On a wheel- base of 15 feet the weight of the engine 30 tons is so distributed that 10 tons fall at each pair of driving-wheels and 9J tons at the leading wheels. The cylinders are inside, 16 inches in diameter, with 24 inches of stroke and 6-feet driving-wheels. Another express passenger locomotive, having inside cylinders and four -coupled wheels behind, for service on the London and North-Western Railway, has cylinders 17 inches in diameter, with 24 inches of stroke, and 6 feet 7 inch driving wheels. The engine weighs 29 tons, of which 11 are at the middle wheels, 8| at the hind wheels, and 9 at the front ; thus the driving weight amounts to two-thirds of the total weight. This engine can move a gross weight of 293 ton?, comprising engine, tender, and train, on a level at a speed of 45 miles per hour, with a working pressure of 120 R> per square inch in the boiler. With trains averaging ten carriages the consumption of coal is 26J ft per mile run. A tank locomotive is an engine which carries its supply of fuel and water with it on its own frame, dispensing with the tender. Such engines are much used for short traffic, as well as for shunting and marshalling trains. The four-coupled tank engine (fig. 41) used for the passenger FIG. 41. Tank locomotive ; Metropolitan Railway. traffic of the Metropolitan Railway has four wheels coupled behind and a bogie in front. This engine weighs in working order 45 tons, of which about 35 tons are utilized as driving weight, making 17 tons for one pair of wheels, about the greatest load on one pair of wheels anywhere. The regular duty of this engine is to take a train of six carriages capable of holding in all 432 passengers, and weighing in themselves 13 tons each, at an average speed, including stoppages, of 18 miles per hour, consuming 37 lb of Welsh coal per train mile run. Whilst passing through the tunnels or covered ways the exhaust steam from the engine is condensed in large tanks carried on the engine, filled with cold water. The quantity of condensing water consumed is 900 gallons for half the journey, or every 6 miles ; it is raised to 200 Fahr. temperature. The eight-wheeled tank engine (fig. 42) has been designed by Mr FIG. 42. Tank locomotive ; Great Eastern Railway. T. W. Worsdell to work the heavy suburban metropolitan traffic of the Great Eastern Railway, the ordinary trains in tliis service being composed of fifteen or twenty close-coupled carriages, taken over steep gradients and sharp curves. For this purpose the fore and hind axles are radially mounted, as before explained, to take the curves with facility, the engine running either end first. The engine weighs 52 tons in working order, and of these 30 tons are driving weight placed on the two pairs of coupled driving-wheels. With large cylinders 18 inches in diameter, and driving-wheels only 5 feet 4 inches in diameter, the engine is adapted for starting promptly, which it is required to do in order to keep time between closely placed stations. Every stop is made by the Westinghouse brake, with which the engine is fitted. Locomotives for drawing heavy goods trains, though not heavier than the most powerful passenger locomotives, can take goods trains of great weight. Six-coupled goods engines, with 17-ineh cylinders and driving-wheels 5 feet in diameter, weighing 32 tons in working order, can take a train weighing 360 tons on a level at a speed of 25 miles per hour, consuming from 40 to 45 lt> of coal per mile run with trains. The Fairlie engine (fig. 43) is placed on FIG. 43. The Fairlie locomotive. two bogies or swivelling trucks, the foremost 'of which carries the cylinders and propelling gear and the hindmost the tank and coal- boxes. The longest distance run without stopping, combined with the Rates o highest speed, is performed on the Great Northern Railway, between speed. Grantham and King's Cross, 105^ miles, in 1 hour 58 minutes, at the rate of 53 miles per hour. The Great Western Company run from Paddington to Swindon 77J miles in 1 hour 27 minutes, being at the rate of 53 miles per hour. On the London and North-Western Railway the distance 77J miles from Willesden to Rugby is run in 1 hour 28 minutes, at the rate of 52f miles per hour. The average rate of express and mail passenger trains on this line is 40 miles per hour or more. Parliamentary trains, call- ing at all stations, run at an average speed of from 19 to 28 miles per hour. Express goods trains attain a speed of from 20 to 25 miles per hour. The speed of coal trains is limited, as far as possible, to 15 miles per hour. The coal trains on the London and North - Western, Midland, Coal and Great Northern Railways generally consist of from thirty to trains. thirty -five waggons, weighing from 5 to 5i tons each, and carry- ing a load of 8 tons of coal. At this rate the total load of coal for thirty-five waggons weighs 280 tons, and, adding the weight of the brake-van at the end of the train, 10 tons 17 cwt, the maximum gross weight of train is 483 tons 7 cwt., as on the Great Northern Railway. This train is taken by a goods engine with six -coupled wheels 5$ feet in diameter, having two steam cylinders 17 inches in diameter, with a stroke of 26 inches, and a pressure of 140 Ib per square inch in the boiler. The loco- motive weighs in working order 36 tons 18 cwt., and the tender with fuel and water 30 tons 17 cwt, making together 67 tons 15 cwt. for the locomotive and tender. The gross weights are as follows : Tons, civt* Train, thirty-five vehicles (waggons, load, and brake-van). .483 7 Engine and tender, in full working order .................. 67 15 Engine, tender, and train 551 2 These large coal trains are taken at a speed of IS miles per hour, on ascending inclines of 1 in 178 at 10 miles per hour. The con- sumption of coal as fuel in the engine is at the rate of 45 ft> per mile run, including the coal consumed in getting up steam. Mi' Patrick Stirling, the locomotive engineer of the Great Northern Railway, has also designed and constructed still more powerful engines, having six -coupled 5 -feet wheels, with cylinders 19 inches in diameter and of 28 inches stroke. These engines are capable of taking a train of forty-nine loaded coal-waggons, weighing with brake-van 672^ tons. Including the weight of the engine and tender the total gross load is, say, 740 tons, taken with a consump- tion of 50 ft of coal per mile run. This is probably the most extraordinary example of a dead pull on an ascending incline of 1 in 178. It is equivalent to a gross weight of 1816 tons on a level. It was found that this train was too long for some of the sidings, besides fouling both the level crossings in the city of Lincoln ; hence the train was reduced in number to forty-five waggons. Six-coupled goods - engines of the usual proportions, working at full power, exert a tractive force of from 5 to 6 tons in the direction of the rails, equal to the movement of a gross weight of engine, tender, and train of from 1240 to 1500 tons on a level straight line at a speed of 15 miles per hour, or to from 386 to 463 tons on a level