« PreviousContinue »
tons of coal into the firebox every hour. grates that happened to need it most at Three and a half tons is generally re- that instant, every 6.3 seconds from start garded as the limit of a fireman's capac- to finish. This is the most remarkable ity, but this has been greatly exceeded on feat .of firing for which authoritative the fastest trains.
figures are available, and it may also be To turn from the general to the par- submitted as a marvelous feat of physical ticular, one of the Lake Shore's monster endurance. Pacific type locomotives, weighing 266,- But this is not all the story. The heat 000 pounds, hauling the west bound from the open fire door is so intense that Twentieth Century Limited with seven it not infrequently blisters the fireman's cars in the train on a test run December side, while the white hot glare sears his 5. 1909, made the run between Toledo eyes until seventeen per cent. of firemen and Elkhart in 2 hours and 4 minutes are disqualified for further service in the at an average speed of 65 miles per hour. first three years on account of defective In this short time 834 tons of coal were vision. shoveled into the firebox. The average So much for the fireman's side of the scoop used on a locomotive holds 14 to stoker problem. For the railroad com15 pounds of coal. Taking the latter pany the question is even more serious. figure as the average scoop load the Already there are many locomotives in fireman had to reach out into the tender, service which never do anywhere near a long stretch, get a shovel full of coal, what they are capable of doing, for the swing it around and throw it into the simple reasor that the man never lived firebox, not anywhere, but on the par- who could keep one of them hot while ticular spot on the 56% square feet of working at maximum capacity. Take,
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.
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 672 tons per hour or one-half more than the Pacific type locomotive burned. At the maximum THE DISCHARGING HOPPER OF THE CROSBY STOKER. for the Lake Shore tests the consumption would be 712 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
THE CROSBY STOKER WITH THE DEFLECTOR. room for one man to swing himself on
The deflector regulates the feeding of coal. the narrow deck. The C., N. O. & T. Railroad tried the experiment of putting two firemen on one of its Mallet locomo- meet the requirements of all the varying tives on a Kentucky division with heavy conditions of road service in America is grades. The men relieved each other at urgent. In Europe where the locomoshort intervals, each working with his tives are small and the trains light the utmost speed when his turn came, but necessity for an automatic stoker is not they could not keep up steam. Besides,
so apparent and so practically nothing the constant blasts of cold air through the
has been done to develop one. open fire door caused the Aues to leak In the United States a number of auso badly that they had to be caulked at tomatic stokers have been tried out with the end of every trip. Then the com- varying degrees of success; but with pospany put on a Hanna mechanical stoker sibly a single exception none is yet reand invited the University of Kentucky garded as entirely satisfactory. As in the to send some of its young men to make case of every other important device a forty days test. The first effect used on a railroad, there has been a weary noticed was that the flues did not have road to travel between the first concepto be touched during the forty days. The tion of the idea and its practical working other results when figured out and tabu- out. lated were so favorable that twelve more Locomotive mechanical stokers are of stokers were ordered.
two general types, the overfeed and the From all this it may be gathered that underfeed. Of the former, which was the call for an automatic stoker that will the first developed, the greatest number
have been tried out. Of the latter, but hopper standing on a frame attached to two have been attempted and but one of the boiler head and supported on three these developed.
wheels. Two conveyor screws in the The first automatic stoker
bottom of this hopper worked the coal vented a dozen years ago by J. W. Kin- forward on to a stoking plate in front caid, an engineer on the Chesapeake and of a plunger. This plunger, which was Ohio, where it had been found next to wedge shaped, forced the coal over an impossible to keep up steam in the liun- upward sloping deflector, thus spreading dred-ton locomotives to enable them to the coal. By means of three valves ophaul their full tonnage over long divis- erated in rotation the plunger made a ions. The original stoker was worked rapid, a medium, and a slow stroke, to by hand at first, then a steam motor was throw coal to the forward end of the applied. It did very well but was un- firebox, the middle and the back end. popular with the firemen, just as the The apparatus was worked by a steam injector, the air brake, sight feed lubri- engine beneath the hopper. cator and all other improvements were At first coal was thrown into the hopat first.
per by hand so that the only thing it did This original stoker, developed under was to protect the fireman from the heat, the name of the "Victor," consisted of a and the flues from the cold draughts.
The Crosby stoker, which originated ers to an efficient working basis has been on the Chicago and Northwestern, had abandoned. a screw conveyor in a trough in the The Strouse stoker has a conveyor to floor of the tender to convey coal to the deliver coal from the tender to a hopper firedoor where it dropped into a small above the firedoor from whence it is receiving hopper at the bottom of which distributed by means of a plunger much were steel blades revolving horizontally like that of the Victor. The firebox door at high speed forcing the coal through is replaced by a special door hinged at a nozzle into the firebox. This nozzle the top and opening inward which can was jointed so that it distributed coal be taken off and replaced by the regular down the left side of the firebox from door for firing by hand. This seems to front to back, then up the middle and be the most advanced of the plunger type down the right side, completing the cycle of stoker, for it is in use on twenty-two every thirty Seconds.
The spreader locomotives on the Chicago, Burlington could be stopped anywhere to build up a and Quincy and two on the Iowa Centhin spot in the fire. The stoker was op- tral. On one trip on the Burlington a erated by a small steam turbine disk upon locomotive equipped with a Strouse which four small steam jets impinged. stoker hauled five hundred tons more The other end of the shaft drove the con- than its rated capacity at an average veyor through a cone gear by which the speed of seventeen miles per hour over speed could be varied. The attempt to the division. The steam pressure did not develop the Crosby and the Victor stok- vary more than four pounds and there
was very little blowing off. At the end of engine. The first part is a mechanical the trip the fire was in such good con- coal heaver on the tender which by means dition that the engine could have gone. of bucket on endless chains elevates the back over the division without having coal from the tender to a trough six the fire cleaned.
feet above the floor. A worm conveyor The Erie Railroad has been experi- in this trough delivers the coal into a menting with two stokers, the Black and hopper on the stoker proper. A slide the Hayden. The former delivers coal operated by hand lets the coal from the from the tender by means of a worm hopper on to a shelf 5 inches wide and conveyor into a hopper above the firebox 2 feet long inside the firebox. Intermitdoor from which it falls on a shelf. Two tent steam blasts from five radially difour-bladed wheels running at 250 revo- rected nozzles blow the coal off the shelf lutions per minute spray the coal over the into all parts of the firebox. The interfire over a tilting shelf which directs the mittent blasts are regulated by twin enspray of coal to any part of the grate. gines with cylinders 1.5 by 1.5 inches
The Hayden stoker, which has been turning a small gear wheel on which is tried on six Erie locomotives, is in two a striking pin with beveled head which separate parts, each driven by its own strikes the end of a bell crank lever
REAR VIEW OF LOCOMOTIVE WITH THE STREET STOKER,