To do this to the best advantage, alike to owner and employee, can be
learned only by practice under the tuition of an experienced person.
The “trick” or unwritten science of the duties of the skillful fireman
must be communicated to the beginner, by already experienced engineers
or firemen or from experts who have made the matter a special study.
_Let it be understood that the art of firing cannot be self taught._
The importance of this knowledge is illustrated by a remarkable
difference shown in competitive tests in Germany between trained and
untrained firemen in the matter of securing a high evaporation per
pound of coal. The trained men succeeded in evaporating 11 lbs. of
water, as against 6.89 lbs. which was the best that the untrained men
could obtain.
It is certain that a poor fireman is a dear man at any price, and that
a competent one may be cheap at twice the wages now paid. Suppose,
for instance, a man who burns three tons a day is paid $2.00 for such
service, and that in so doing he is wasting as little as 10 per cent.
If the coal cost $4.50 per ton the loss will be $1.35 per day, or what
is equivalent to paying a man $3.35 per day who can save this amount.
The late Chief Engineer of Philadelphia Water Works effected an annual
saving to the city of something like $50,000; and recently the weekly
consumption of a well established woolen mill was reduced from 71 to 49
tons, a clear saving of 22 tons by careful attention to this point.
It is apparent that any rules or directions which might be given for
one system would not apply equally to other forms of boilers and this
may be the principal reason that the art is one so largely of personal
instruction. Some rules and hints will, however, be given to the
beginner, which may prove of advantage in fitting the fireman for an
advanced position; or to assure him permanence in his present one.
_No two boilers alike._ It is said that no two boilers, even though
they seemed to be exactly alike—absolute duplicates—ever did the same,
or equal service. Every steam boiler, like every steam engine, has an
individuality of its own, with which the person in charge has to become
acquainted, in order to obtain the best results from it.
The unlikeness in the required care of steam engines which seem to
be exactly the same, is still more marked in the different skill
and experience demanded in handling locomotive, marine, stationary,
portable boilers and other forms of steam generators.
BEFORE LIGHTING THE FIRE under the boiler in the morning, the engineer
or fireman should make a rapid yet diligent examination of various
things, viz.: 1. He should make sure that the boiler has the right
quantity of water in it—that it has not run out during the night or
been tampered with by some outside party; very many boilers have been
ruined by neglecting this first simple precaution. 2. He should see
that the safety-valve is in working order; this is done by lifting by
rod or hand the valve which holds the weight upon the safety valve rod.
3. He should open the upper gauge-cock to let out the air from the
boiler while the steam is forming. 4. He should examine the condition
of the grate-bars and see that no clinkers and but few ashes are left
from last night’s firing. 5. And finally, after seeing that everything
is in good shape, proceed to build the fire as follows:
ON LIGHTING THE FIRE. When quite certain that everything is in good
condition, put a good armful of shavings or fine wood upon the grate,
then upon this some larger pieces of wood to form a bed of coals, and
then a little of the fuel that is to be used while running. Sometimes
it is better to light before putting on the regular fuel, but in any
case give it plenty of air. Close the fire doors, and open the ash pit,
giving the chimney full draught.
When the fire is well ignited, throw in some of the regular fuel, and
when this is burning add more, a little at a time, and continue until
the fire is in its normal condition, taking care, however, not to let
it burn too freely for fear of injury to the sheets by a too rapid
heating.
It is usually more convenient to light the fire through the fire door,
but where this cannot be done, a torch may be used beneath the grates,
or even a light fire of shavings may be kindled in the ash pit.
At the time of lighting, all the draughts should be wide open.
As soon as the steam is _seen_ to issue from the open upper gauge-cock
it is proof that the air is out. It should now be closed and the steam
gauge will soon indicate a rise in temperature.
When the steam begins to rise it should next be observed that: 1. All
the cocks and valves are in working order—that they move easily. 2.
That all the joints and packings are tight.
In the following two cuts are exhibited in an impressive way the
difference between proper and improper firing.
[Illustration: Fig. 1.]
Fig. 1 represents the proper mode of keeping an even depth of coal on
the grate bars; the result of which will be, a uniform generation of
gas throughout the charge, and a uniform temperature in the flues.
[Illustration: Fig. 2.]
Fig. 2 represents a very frequent method of feeding furnaces; charging
the front half as high, and as near the door, as possible, leaving the
bridge end comparatively bare. The result necessarily is that more
air obtains access through the uncovered bars than is required, which
causes imperfect combustion and consequent waste.
The duties of the fireman in the routine of the day may thus be summed
up:
1st.—_Begin to charge the furnace at the bridge end and keep firing to
within a few inches of the dead plate._
2d.—_Never allow the fire to be so low before a fresh charge is thrown
in, that there shall not be at least three to five inches deep of
clean, incandescent fuel on the bars, and equally spread over the
whole._
3d.—_Keep the bars constantly and equally covered_, particularly at the
sides and the bridge end, where the fuel burns away most rapidly.
4th.—If the fuel burns unequally or into holes, _it must be leveled,
and the vacant spaces must be filled_.
5th.—The large coals must be broken into pieces not bigger than a man’s
fist.
6th.—When the ash pit is shallow, it must be the more frequently
cleared out. A body of hot cinders, beneath them, overheats and burns
the bars.
7th.—The fire must not be hurried too much, but should be left to
increase in intensity gradually. When fired properly the fuel is
consumed in the best possible way, no more being burned than is needed
for producing a sufficient quantity of steam and keeping the steam
pressure even.