A. A locomotive boiler is cylindrical in form, it usually has a
rectangular shaped fire-box at one end and a smoke-box at the other, and
flues extend through the cylindrical part, and, like the fire-box, are
surrounded by water.
16. Q. How does the wide fire-box type of boiler differ from the
ordinary boiler, and what are its advantages?
A. The wide fire-box type of boiler is built so the fire-box is above
the frame and extends out over the driving wheels. The advantages of
this are to obtain a larger grate area in the same length of fire-box
and to give a slower rate of combustion per square foot of grate
surface. The deep fire-box is limited in width to the distance between
the frames, while the shallow fire-box sets on top of the frames and
between the driving wheels.
17. Q. Why have two fire-box doors been placed in the large type of
locomotive boilers?
A. For convenience of the fireman on account of the greater width of the
fire-box, so that coal can easily be distributed to all parts of the
fire-box.