THE COLLIERY GUARDIAN

AND

JOURNAL. OF THE COAL AND IRON TRADES.

Vol. CXV.

FRIDAY, MAY 24, 1918.

No. 2995.

American Methods of Unloading Coal from Car and Barge.

(SPECIALLY CONTRIBUTED.)



It is a matter of importance to the consumer to ,have
the best possible arrangements for the receipt of coal
from the railroad or from the ship or other boat.
Ordinarily a railroad makes delivery by means of
special coal cars, but there are frequent deviations
from this practice, the coal being forwarded in
gondolas or even box cars. The matter is partly a
question of transportation possibilities. Coal shipped
west and north-west from points at the head of navi-
gation , on the Great Lakes will usually go by box
car, because the railroad needs to ship commodities
west and north-west in the very same cars that have
come east and south-east. Box cars handle a large
part of this easterly business on account of the neces-
sity for protecting the grain and other commodities.
On the return trip coal goes into the same cars.

Railway cars discharge through the bottom, over
the side, or through the side door (if a box car).
Naturally, the consumer’s arrangements must take
the method of discharge into consideration.

Where discharge is
through the bottom,
gravity is depended
upon ordinarily to get
the coal into the bins,
pits, or other receiving
chambers. This means
that the top of the
pile must be not higher
than the track or the
bottom of, the car.
Naturally, this neces-
sitates the floor being
at a lower level. Some-
times it will be con-
venient and advisable
to utilise gravity to get
the coal from this floor
to the next point of
delivery. In such event
the height of the rails
above this second point
must be sufficient to
provide for the special
requirements of the
particular case. For
example, the bottom
dump car may deliver
to a bin, and the bin
may independently de-
liver to chutes run-
ning part or all of the
way to the boilers.
We have here two
gravity movements, and
there must be sufficient

height to accomplish both of them. If in the
second movement the coal has to be moved hori-
zontally as well as vertically, then the height allowed
for this movement must be sufficient to leave room for
the slide in the chute. No single simple rule can be
given for chutes. A wooden chute is one thing; a steel
one, another. Curves tend to retard the coal; and
one coal will slide better than another. Also, the time
of year will make a difference, so that in such cases
care must be taken to select the steeper gradient.
The location of the boilers may be sufficiently low to
permit simple gravity movements from the railroad
car to the bins delivering to the boilers. When this
is the case economical movements are obtained.

Now, the switch may be located at the general
level of the railroad or a higher level. It is all a
question of the gravity movements concerned. If the
switch is at the same level as the railroad, or only
slightly higher, then one may ordinarily expect
economical handling of the coal.

There are various ways of arranging details. One
is to locate the receiving point on a side track which
connects at both ends with the railroad. The loca-
tions where discharge is actually made may then very
well be placed a little higher than the railroad. There
may advantageously be an up-grade to the beginning
of the receiving bins and a down-grade over the bins
and on down to the railroad at the far end of the
siding. With this arrangement a loaded car may be
pushed or pulled by the locomotive to the exact point
desired for unloading. The car will stand on a down-
grade leading to the railroad or siding. When this
car has been discharged of its load there will be no
necessity to use a locomotive to get it away, provided
a proper down-grade is used. A man on the car to
handle the brakes is sufficient.

Where only one end of the side track connects with
the railroad, matters may be so arranged that the
up-grade from the railroad continues to the far end
of the delivery location. The loaded car may be moved
up to position by a locomotive, but, given sufficient
gradient, will not need anything but gravity and the
brakeman to make the return to the railroad.

Two per cent, is a sufficient gradient to secure move-

ment of the empty car. Probably less will suffice,
but, naturally, the action of a fair gradient is quicker
than that of a very slight one. The P. and R. R.R.
at Port Reading, N.J., in New York Harbour, has
two piers, and the C.R.R. of N.J., at Port Johnson,
N.J., also in New York Harbour, has one pier where
a I.) per cent, gradient is employed to secure gravity
movements of loaded and empty cars. The deck and
return tracks of the Clinton Street (Canton) pier of
the P.R.R., in Baltimore Harbour, have still slighter
gradients.

A trestle-work will often be required, especially at
the location where cars stand to discharge. This
trestle-work may be of wood, steel, or of reinforced
concrete, all being suitable.

Where cars are discharged by shovel, the coal may
be delivered into a bin or pit alongside. Naturally,
there may be a gravity movement from it. In such
cases the level of the tracks must take into account
this movement and whether it includes a horizontal

A

.

A ■ a .

■

Fig. 1.—Four to Five-ton Grab Bucket.





shift. The case is much the same as that of discharge
through the car bottom.

The bin into which delivery is made, whether cars
discharge through the bottom or not, may often with
advantage be provided with a sloping bottom with the
idea of shifting the coal somewhat. Where coal is to
pass on by chute, it will often be desirable to slope
the bottom on three, or even all four, sides. This
hopper bottom facilitates delivery to the chute.

Where the single incline is used, it may be desirable
to use a screen for the whole of the inclined bottom
oi- for a strip running from one side to the other,
the idea being to force all the coal to pass on to the
screen. The lumps that are too big to go through will
naturally slide on, whilst the portions that are small
enough will, if the passage from the upper to the lower
side is long enough, drop through. If the distance
from the upper to the lower sides is too short, con-
sidering the incline, then some of the fine coal may
be expected to pass ovei- and remain mixed with the
large size.

An open-top car may be unloaded with a grab
bucket. The type to use is that known as the clam
shell (fig. 1). The bucket should, if properly con-
structed, dig into the coal and get its load without
any necessity of dropping it forcibly on to the pile.
In a typical case two ropes run to the bucket, one
being the hoisting rope. As this rope is paid out
and drawn in, the bucket is lowered and raised. It
must be strong enough to lift both bucket and load
and have a large factor of safety. The other rope is
the closing rope, which causes the grab to dig into
the pile and secures the load, and also opens the bucket
to discharge. The effective strength of these ropes
depends largely upon the size of the pulleys and
sheaves over which they run. The smaller the wheel,
the less the effective strength. Usually the diameters
the small in grab-bucket work. It is important to
select a rope suited to the work in hand. As a rule,
the smaller the individual wires in the rope, the
better is the rope able to pass over small pulleys and
sheaves. One way to obtain the desired flexibility is
by selecting a rope made of small wires instead of
large ones, for though a rope of given diameter and

material will have about the same strength, irre-
spective of the diameters of the individual wires in
the strands, wires give flexibility. Thus instead of
seven wires in a strand there may be 19 or 37, or
even more, without any change in the diameter of
the strand. A second course is to select a smaller
diameter for the whole rope by using a sufficiently
high quality of steel to maintain the strength un-
altered. The smaller rope diameter will automatically
necessitate thinner individual wires, though, even so,
the rope should not have less than, say, 19 wires to
the strand. A third course would be to combine the
foregoing two methods.

Wire ropes used on derricks, locomotive cranes, etc.,
for the rapid handling of coal are subjected to con-
siderable external wear. Fine wires are not well
adapted to resist this, but the difficulty may be
overcome by using rope made up of strands, each of
which is protected by a steel sheath consisting of a
flat strip wound in a helix about the strand. Such
rope will have a diameter a trifle larger, say | inch,
than the same rope made from unsheathed strands.

While on the subject of ropes, it may be profitable
to add a few words of useful information. A guy
rope should be arranged as flat as possible. The
steeper the guy rope, the greater the strain induced
by a horizontal pressure against the mast of the
derrick or whatever is being held upright. If a rope
is used as a cableway to support a load—as a trolley
and a loaded grab bucket—then the less slack it is,
the weaker it is. This may appear to be contrary
to the rule about guy ropes. In reality, however,
it is the same rule. The load pulls vertically on the
cableway, but presses horizontally against the mast.
A rope is subject to internal friction by the rubbing
of wire against wire when the load comes on and goes
off, and when the rope runs round a turn. Further-
more, a rope is subject to internal rusting due to the
penetration of moisture. Both these contingencies

Fig. 2.—Steel Guy Derrick.

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I





are provided for by keeping the inside of the rope
thoroughly lubricated, the oil facilitating the move-
ment of wire on wire, and also excluding moisture
from contact with the metal. A rope may lose a good
deal of its effective strength through being attached
wrongly at one or both ends. Thus, if the end of
the rope is to be given a loop and the extreme end
fastened to the rope, there are one or two good
methods and several bad ones. • What should be done
in order to get perfect results is to arrange that when
the rope is in actual use every wire will come into
service just as it does in a straight piece. This is
more or less difficult to effect, since some wires are
almost sure to be shortened—or others lengthened—so
that when the load comes on the shorter wires get
overloaded. One of the best methods of attachment
is to open out the wires in a basket or cup provided
on the fitting that is to be attached, and then fill
the remaining space with spelter. This is not a very
easy job, however, as the basket and the wire ends
need to be chemically clean before the speltei- is
poured; but when this method of attachment is
properly applied, the result develops very nearly the
whole strength of the rope. If, instead of this, the
end can be spliced into the rope and the splicing