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tons of coal into the firebox every hour. Three and a half tons is generally regarded as the limit of a fireman's capacity, but this has been greatly exceeded on the fastest trains.

To turn from the general to the particular, one of the Lake Shore's monster Pacific type locomotives, weighing 266,000 pounds, hauling the west bound Twentieth Century Limited with seven cars in the train on a test run December 5, 1909, made the run between Toledo and Elkhart in 2 hours and 4 minutes at an average speed of 65 miles per hour. In this short time 834 tons of coal were shoveled into the firebox. The average scoop used on a locomotive holds 14 to 15 pounds of coal. Taking the latter figure as the average scoop load the fireman had to reach out into the tender, a long stretch, get a shovel full of coal, swing it around and throw it into the firebox, not anywhere, but on the particular spot on the 56

square feet of

FIRE DOOR OPEN. The Hayden Stoker.

grates that happened to need it most at that instant, every 6.3 seconds from start to finish. This is the most remarkable feat of firing for which authoritative figures are available, and it may also be submitted as a marvelous feat of physical endurance.

But this is not all the story. The heat from the open fire door is so intense that it not infrequently blisters the fireman's side, while the white hot glare sears his eyes until seventeen per cent. of firemen are disqualified for further service in the first three years on account of defective vision.

So much for the fireman's side of the stoker problem. For the railroad company the question is even more serious. Already there are many locomotives in service which never do anywhere near what they are capable of doing, for the simple reason that the man never lived who could keep one of them hot while working at maximum capacity. Take,

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A MALLET COMPOUND LIKE THIS COULD BURN 12.000 TO 15.000 POUNDS OF COAL PER HOUR

IF DESIRABLE OR NECESSARY

There is no way, however, of getting it into the firebox.

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for example, a Mallet articulated compound locomotive weighing 445,000 pounds and having a grate area of 99.85 square feet. In the series of tests on the Lake Shore already referred to, the average consumption of coal was 129.6 pounds of coal per square foot of grate area per hour; the maximum, 150 pounds. Some locomotives crowded to the limit have been found capable of burning 200 pounds per square foot of grate area per hour. At the average consumption for the Lake Shore test the big Mallet would burn 61⁄2 tons per hour or one-half more than the Pacific type locomotive burned. At the maximum for the Lake Shore tests the consumption would be 71⁄2 tons, while at the highest recorded rate of consumption it would eat up 10 tons of coal per hour. It is hardly necessary to point out the utter impossibility of any mortal getting even the smallest of these quantities into the firebox in an hour. As a matter of fact a Mallet locomotive of the size mentioned in a test run in pusher service on the Delaware and Hudson burned 5,781 pounds of coal per hour. This was not the measure of the engine's possibilities but of the fireman's capacity under the circumstances.

It is not possible for two firemen to work at once because there is barely room for one man to swing himself on the narrow deck. The C., N. O. & T. Railroad tried the experiment of putting two firemen on one of its Mallet locomotives on a Kentucky division with heavy grades. The men relieved each other at short intervals, each working with his utmost speed when his turn came, but they could not keep up steam. Besides, the constant blasts of cold air through the open fire door caused the flues to leak so badly that they had to be caulked at the end of every trip. Then the company put on a Hanna mechanical stoker and invited the University of Kentucky to send some of its young men to make a forty days test. The first effect noticed was that the flues did not have to be touched during the forty days. The other results when figured out and tabulated were so favorable that twelve more stokers were ordered.

From all this it may be gathered that the call for an automatic stoker that will

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meet the requirements of all the varying conditions of road service in America is urgent. In Europe where the locomotives are small and the trains light the necessity for an automatic stoker is not so apparent and so practically nothing has been done to develop one.

In the United States a number of automatic stokers have been tried out with varying degrees of success; but with possibly a single exception none is yet regarded as entirely satisfactory. As in the case of every other important device used on a railroad, there has been a weary road to travel between the first conception of the idea and its practical working out.

Locomotive mechanical stokers are of two general types, the overfeed and the underfeed. Of the former, which was the first developed, the greatest number

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have been tried out. Of the latter, but two have been attempted and but one of these developed.

The first automatic stoker was invented a dozen years ago by J. W. Kincaid, an engineer on the Chesapeake and Ohio, where it had been found next to impossible to keep up steam in the hundred-ton locomotives to enable them to haul their full tonnage over long divisions. The original stoker was worked by hand at first, then a steam motor was applied. It did very well but was unpopular with the firemen, just as the injector, the air brake, sight feed lubricator and all other improvements were at first.

This original stoker, developed under the name of the "Victor," consisted of a

hopper standing on a frame attached to the boiler head and supported on three wheels. Two conveyor screws in the bottom of this hopper worked the coal forward on to a stoking plate in front of a plunger. This plunger, which was wedge shaped, forced the coal over an upward sloping deflector, thus spreading the coal. By means of three valves operated in rotation the plunger made a rapid, a medium, and a slow stroke, to throw coal to the forward end of the firebox, the middle and the back end. The apparatus was worked by a steam engine beneath the hopper.

At first coal was thrown into the hopper by hand so that the only thing it did was to protect the fireman from the heat, and the flues from the cold draughts.

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The Crosby stoker, which originated on the Chicago and Northwestern, had a screw conveyor in a trough in the floor of the tender to convey coal to the firedoor where it dropped into a small receiving hopper at the bottom of which were steel blades revolving horizontally at high speed forcing the coal through a nozzle into the firebox. This nozzle was jointed so that it distributed coal down the left side of the firebox from front to back, then up the middle and down the right side, completing the cycle every thirty seconds. The spreader could be stopped anywhere to build up a thin spot in the fire. The stoker was operated by a small steam turbine disk upon which four small steam jets impinged. The other end of the shaft drove the conveyor through a cone gear by which the speed could be varied. The attempt to develop the Crosby and the Victor stok

ers to an efficient working basis has been abandoned.

The Strouse stoker has a conveyor to deliver coal from the tender to a hopper above the firedoor from whence it is distributed by means of a plunger much like that of the Victor. The firebox door is replaced by a special door hinged at the top and opening inward which can be taken off and replaced by the regular door for firing by hand. This seems to be the most advanced of the plunger type of stoker, for it is in use on twenty-two locomotives on the Chicago, Burlington and Quincy and two on the Iowa Cen

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On one trip on the Burlington a locomotive equipped with a Strouse stoker hauled five hundred tons more than its rated capacity at an average speed of seventeen miles per hour over the division. The steam pressure did not vary more than four pounds and there

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was very little blowing off. At the end of the trip the fire was in such good condition that the engine could have gone. back over the division without having the fire cleaned.

The Erie Railroad has been experimenting with two stokers, the Black and the Hayden. The former delivers coal from the tender by means of a worm conveyor into a hopper above the firebox door from which it falls on a shelf. Two four-bladed wheels running at 250 revolutions per minute spray the coal over the fire over a tilting shelf which directs the spray of coal to any part of the grate.

The Hayden stoker, which has been tried on six Erie locomotives, is in two separate parts, each driven by its own.

engine. The first part is a mechanical coal heaver on the tender which by means of bucket on endless chains elevates the coal from the tender to a trough six feet above the floor. A worm conveyor in this trough delivers the coal into a hopper on the stoker proper. A slide operated by hand lets the coal from the hopper on to a shelf 5 inches wide and 2 feet long inside the firebox. Intermittent steam blasts from five radially directed nozzles blow the coal off the shelf into all parts of the firebox. The intermittent blasts are regulated by twin engines with cylinders 1.5 by 1.5 inches turning a small gear wheel on which is a striking pin with beveled head which strikes the end of a bell crank lever

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REAR VIEW OF LOCOMOTIVE WITH THE STREET STOKER,

This stoker is of the scatter type, in which crushed coal is driven into the firebox by steam jets.

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