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details of the pockets proper, which style of pockets can be used either with the style of coal-chuteshown in Fig. 295, delivering the coal by shovelling from cars, or with a regular high-chute dumpingthe coal from hopper-bottomed cars, as shown in Fig. 299.
The issue of the Railroad Gazette mentioned above contains the following remarks on thesubject:
The change in this chute from the older methods in taking off the weight of the apron by a counter-weight, whose vertical resultant shall vary the same as that of the weight of the apron, was a markedadvance from the dead weights formerly used. The apron and arms are built of oak, and to the ends of thelatter are fastened cast-iron blocks of about fifty pounds weight each, which may be moved forward or backto adjust the proper balance. In taking coal the fireman pulls a small latch at the top of the apron, which,when slipped, allows the easy lowering of the apron, because it is balanced. As the counterweighted armrises it comes in contact with the tail of a pivoted latch, which releases the inner or retaining coal door.The sides of the apron are spread wider than this coal-door, and are formed by the forward end of thecounterweight arm. To the lower part of the apron the hinges on which it and the arms are swung arefastened, there being a slight drop to the coal as it passes out of the pocket on to the apron.
Fig. 299.—Cross-section with High-chutes.
Back of the fulcrum line, about 2 ft. on each arm, is fastened a small ratchet plate, into which works aii-in. pawl, bent out 5 in. at the inner end, and held to a 2-in. flat strap by a split key, the strap being held to
the door-frame with bolts. The retaining door-latch is offset 3 in., and, by means of a notch at the forward
end, engages with the flat strap. A guide for this pawl is provided, which is made up of four pieces, pivotedtogether and fastened back by the short end pieces to the frame.
The sides of the apron are shod with 2-in. x i-in. x J-in. channel iron, which is also used for stiffeningbetween the sides and bottom, with several 24-in. strips bent at right angles at the middle.
This arrangement of catches (with the exception of the one at the top of the apron) is entirelyautomatic, and all the pieces have been made of such proportions as to especially provide for durability.This point requires special attention in the design of any structure of this character, as it is not desirable tobe obliged to have any mechanism liable to break or get out of order at outlying coaling stations. There isnot only the expense of taking down the parts and sending them to the shops for repairs, but the breakmay occasion the delay of trains either in getting coal or in the inability to close the pocket properly.
In Fig. 298 a special form of pocket is shown, for taking part or all of the coal, as,is needed. The