F. LOCOMOTIVE POWER

Express Passenger Locomotives

The fundamental characteristics of English practice are fairly represented by a few types of locomotives. Take first an express passenger locomotive, which stands on a wheel base—the distance apart of the centres of the extreme axles—of 15 feet 4 inches. The cylinders are inside and are 16 inches in diameter, with a slide of 22 inches. The driving-wheels are 7 feet in diameter. The fire-grate has an area of 18 square feet, and the heating surface of the fire-box and flue-tubes taken together is 1339 square feet. The total weight of the engine in working order is 28 tons 6 cwt., of which nearly 12 tons are driving weight,—the weight at the driving-wheels. The tender stands on three pairs of wheels and weighs about 16 tons, with, in addition, 1780 gallons or 8 tons of water when filled, and 3 tons of coal.

The "Lady of the Lake" is an express passenger locomotive, one of a class which was designed by Mr. John Ramsbottom with special regard to the running of express trains on the northern division of the London and North-Western Railway. The cylinders are "outside"; they are 16 inches in diameter, with 24 inches of stroke, and the driving-wheels are 7 feet 7 inches in diameter. The fire-grate has an area of 15 square feet, and there is over 1000 square feet of heating surface. The engine weighs 27 tons in working order and the tender 17 1/2, together 44 1/2 tons. The tender is fitted with Mr. Ramsbottom’s apparatus for picking up feed-water whilst running: a scoop is let down from the bottom of the tender and dips into water contained in a long open trough laid between the rails, from which it is scooped up into the tanks. The minimum speed at which this operation can be effected is 22 miles per hour. By the aid of the water-lifter this express engine has been enabled to run the whole distance from Holyhead to London—264 miles—in one continuous run, at an average speed of 42 miles per hour, taking a train of eight or nine carriages, and consuming 27 lb of coal as fuel per mile run.





An express passenger locomotive having 18-inch cylinders and four-coupled driving-wheels, 7 feet in diameter, with a four-wheel bogie in front under the smoke-box, was designed by Mr. T. W. Johnson for the traffic of the Midland Railway. The engine stands on eight wheels, forming a base 21 1/2 feet long. It weighs about 42 tons in working order, and with the tender, including coal and water, about 68 tons. The average load taken by engines of this class is fourteen carriages at the time-bill speed of 50 miles per hour, over gradients of from 1 in 120 to 1 in 130, with a consumption of 28 lb of coal per mile run. The engine can take as a maximum load seventeen carriages between Manchester and Derby, over ruling gradients of 1 in 90 and 1 in 100 for 10 miles, at a speed up the inclines of 35 miles per hour, and on levels and falling gradients at 50 miles per hour. The carriages weigh, with passengers, 11 tons each, making up a train of the gross weight of 187 tons.

Fig. 40. Express locomotive: Great Northern Railway.

The express passenger engines on the Great Northern Railway (fig. 40), designed by Mr. Patrick Stirling, have outside cylinders, 18 inches in diameter, and a single pair of 8-feet driving-wheels. It is one of the most recent developments of the single-wheel engine. It is placed on eight wheels, of which the first four are framed in a bogie, or truck, pivoted on a centre under the smoke-box. The cylinders are placed outside, and between the wheels of the bogie at each side. They are 18 inches in diameter, with a stroke of 28 inches,—dimensions which, taken together, exceed in magnitude those of any other engine for English passenger-traffic. The driving-wheels are 8 feet 1 inch in diameter and the bogie-wheels 3 feet 11 inches. The engine weighs 38 tons in working order, the distribution of the weight being as follows:—

The pivot of the bogie is 6 inches nearer the hind than the front axle,—these being 6 1/2 feet apart. By this disposition the bogie appears to lead better than if the pivot were, as usual, equidistant between the axles. The working pressure in the boiler is 140 lb per square inch. There are 217 brass flue-tubes 1 9/16 inches in diameter, presenting a heating surface for evaporation of upwards of 1000 square feet. There is in all 1165 square feet of surface and there is 17·6 square feet of grate surface. Mr. Stirling, on the question of single-wheel versus coupled wheels for passenger locomotives, states that he constructed two classes of engines,—one class with four 6 1/2 feet wheels coupled, the other with a single pair of 7-feet driving-wheels. The boilers of the two classes were alike; also the cylinders, which were 17 inches in diameter, with 24 inches of stroke. The pressure in the boilers was 140 lb. With like trains the single-wheel engine had the better of it; in fact, it generally beat the coupled engine in time, running from King’s Cross to Potter’s Bar, a distance of nearly 13 miles, nearly all uphill, the gradients varying from 1 in 105 for 2 miles to 1 in 200. Engines of the class of the 8-feet-wheel engine travel between King’s Cross and Leeds or York. The steepest gradients on the route are met with on leaving Leeds, ascending 1 in 50, besides the gradient 1 in 105 leaving King’s Cross. Trains of from sixteen to twenty-two carriages are taken from King’s Cross station with ease; and on several occasions twenty-eight carriages have been taken, and time has been kept. On one occasion a distance of 15 miles in 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 25 1/4 lb of coal per mile run and five pints of oil per 100 miles run.





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