Sorting-sidings--Turn-tables--Traversers--Water-Tanks and
Water-Columns.
Sorting-sidings.--On many important long main lines it is necessary
to establish special independent sidings for sorting or arranging
waggons of merchandise and minerals. Where there are only two lines of
rails to serve for the UP and DOWN service of a heavy passenger and
goods traffic, it is imperative to restrict those lines as much as
possible to the actual transit of trains, and not to block them by
unnecessary occupation for shunting purposes. A goods train running a
long distance collects waggons from many roadside stations, and at
some of them several waggons will be taken on, to be forwarded to
various and widely distant destinations. The accumulated train
comprises waggons which must be divided out into groups, to be passed
on either to distant sections of the same railway system, or on to
neighbouring lines. To avoid interruption to the train-working, and
the delay of complicated shunting operations at the roadside stations,
the waggons are attached just as they are dicked up, and the work of
sorting is allowed to stand over until the train arrives at the place
assigned for the purpose. A site for sorting-sidings is generally
selected where the ground and gradient are favourable, and where ample
room can be obtained for a large number of short parallel lines, with
space for future extensions. The arrangement that naturally suggests
itself is that of a series of fan-shaped sidings leading out of main
shunting lines, separate from the main-traffic lines. In some cases
the sorting-sidings are laid down with dead-ends, as in Fig. 434, and
in others they are made as through sidings, connecting at both ends
with shunting lines and main-traffic lines, as in Fig. 435. Each of
the sidings is usually made sufficiently long to hold a complete train
of sorted waggons, and the number of them will depend upon the number 287
of sections to be served, and the amount of waggons to be sorted.
Sometimes the sidings are laid with a slight falling gradient leading
away from the main shunting lines, to facilitate the running out of
the waggons into the respective sidings.
[Illustration: Fig. 434, 435]
An arriving goods train is first drawn out of the main-traffic lines
into one of the shunting lines, and then handed over to the staff of
men in charge of the sorting operations, who at once mark the waggons
according to the number or designation of the particular siding into
which they have to be placed. A suitable engine is generally set apart
for this work, and in a very short time the entire train is divided
out by one or more waggons at a time, and distributed into the various
sidings, representing different sections of the line, or groups to be
handed over to neighbouring railways. When one of these sorting-sidings
contains a full complement of waggons, an engine is attached, and the
train despatched to its destination, leaving the siding clear for
another set of waggons. Where the trains to be sorted are very
numerous, two or more shunting-engines may be engaged working at the
same time on distinct sets of shunting lines and sidings. Sometimes it
may be expedient to have one lot of sorting-sidings leading off the UP
line, and another lot leading off the DOWN line, to meet the
requirements of trains coming and going in both directions. With
sidings well laid out, and fitted with ample facilities, a
well-organized staff can carry out a very large amount of work both
expeditiously and economically. There are several of these
sorting-sidings stations in operation, where from one thousand to two
thousand waggons are sorted and marshalled into trains every
twenty-four hours.
The above diagram sketches merely illustrate the general principle of
the sorting-sidings, and may be modified and enlarged in many ways to
suit the traffic requirements and local surroundings.
Turn-tables.--Turn-tables revolving on fixed centres are made of
various sizes according to their use for engines, carriages, or
waggons. The carrying-beams may be made of cast-iron, wrought-iron, or
steel, but the latter material is the most suitable for tables of more
than 20 feet diameter. For small turn-tables, cast-iron beams will
serve very well, for although more liable to fracture, they will not
suffer so much from rust and oxidization as wrought-iron or steel.288
[Illustration: Fig. 436, 437, 438, 439, 440]
Opinions as to the most convenient position and use of turn-tables 289
have undergone a considerable modification during the past twenty or
twenty-five years. Circular and semi-circular running-sheds for
engines, as in Figs. 436 and 437, are not so often adopted now as
formerly. Although compact and accessible in theory, they possess the
one great drawback that when the turn-table in the centre becomes
deranged by wear or accident, none of the engines on the
standing-lines inside the building can be taken out until the
turn-table is again put into working order. A stock of from twenty to
thirty engines might thus be put entirely out of the service for a day
or more. This objection is considered to be of so serious a nature
that running-sheds are now almost always constructed of rectangular
form, of which Fig. 438 is a type.
With this description of shed, the lines of rails are laid down
parallel to one another, and the engine turn-table is placed on a line
separate and distinct from those lines forming connections with the
shed.
Where there is a large goods traffic, an endeavour is generally made
to so lay down the goods-sheds and approach lines and sidings, that
the full complement of waggons may be shunted in or out of the shed at
one operation. This arrangement, which dispenses with turn-tables
altogether, admits of the ready removal of a central or far-end
waggon, without the necessity of taking out so many others in front
one by one over the turn-table. At the same time, there are large
numbers of these waggon turn-tables in use, and there are many cases
where access to side sheds or detached stores can only be obtained by
turn-tables.
A goods-shed and lines laid down with turn-tables, as in Fig. 439,
will always be more tedious and costly to work than one laid down with
direct through lines, as in Fig. 440. Should either of the turn-tables
shown on Fig. 439 get out of order and become incapable of turning,
then the entire side of the shed controlled by that table will be
rendered useless until the defect be remedied.
Engine turn-tables are rarely made with more than one road on the top.
The most modern types generally consist of two strong wrought-iron or
steel-plate girders well braced together and securely attached to a
middle framework which rests on and revolves round a centre-piece
fixed on a solid foundation To the ends of the girders are attached 290
large roller wheels which travel round a solid iron or steel
roller-path laid down along the circumference. These modern
turn-tables are generally worked on the balancing principle, by
bringing the engine and tender to a stand in such a position on the
rails that the greater portion of the weight is thrown on to the
cup-shaped steel centre, so that a small force applied to the long
outrigged hand-levers at the ends is sufficient to turn one of the
heaviest locomotives. Figs. 441 and 442 give sketch plan and section
of one of these steel-plate girder turn-tables, which has few parts,
and very little to get out of order. The end rollers guide the table
when making any portion of a revolution, and carry such part of the
weight as may not be taken up by the centre. A recess is shown in side
wall to facilitate the inspection of end rollers. In the earlier forms
of engine turn-tables, the revolving movement was effected by
attaching to the upper portion of the girders a strong winch, which
acted upon gearing fixed either to the end rollers, or direct on to a
toothed ring forming part of the roller-path. In cases where the
engine turn-table was in constant use, as in connection with a large
running-shed, the winch was sometimes driven by a small steam-engine
to expedite the movement.
The great increase in the lengths and weights of modern locomotives
has necessitated the removal of many of the old small turn-tables, and
replacing them with others of 45 or 50 feet, or more, in diameter.
[Illustration: Fig. 441, 442, 443, 444, 445]
An engine turn-table is a costly item in railway requirements, not
only in the girder-work, but in the large amount of building in the
side walls and centre pier, and an effort is always made to avoid the
outlay unless the table can be placed where it may be of permanent
use. In the construction of foreign railways, and in our colonies,
where the lines are opened in sections as the work goes forward, the
temporary arrangement shown in Fig. 443 is frequently used instead of
an engine turn-table. The sketch will almost explain itself. On the
main line, A, B, C, D, switches are placed at B and C, from which turn
out curved lines, uniting at the switches E. An engine proceeding from
A, and passing round the curve B, E, G, then round curve G, E, C, and
back along main line, D, C, B, A, will be turned round as efficiently
as on a turn-table. The writer has used this arrangement abroad with
great advantage. It involves very little work or expense beyond laying
down the permanent way, and so soon as the temporary terminus of the 292
line has been advanced further ahead, the rails and sleepers can be
lifted and used again elsewhere.
Figs. 444 and 445 give sketch plan and section of a waggon turn-table
which has been largely adopted. The centre should be securely fixed on
a solid foundation of masonry, brickwork, or concrete. The deep outer
cast-iron ring is made in segments, properly fitted and bolted
together, and fastened down to the foundation course. The stop-checks
are cast on to this outer ring. Two roads, at right angles to each
other, are laid on the turn-table, so that waggons to or from the
goods-shed have only to make one quarter turn of the table. The top is
generally covered with either chequered iron plates or timber to give
good foothold for the men and horses which have to pass over in moving
the waggons. If properly balanced, the table is easily turned by men
pushing at the opposite corners of the waggon, or by a horse and
tail-rope, or by hydraulic power through a capstan. In many cases of
bad or soft foundations these small turn-tables are erected on a
strong framework of creosoted timber.
Carriage turn-tables are now very rarely used. With the old short
four-wheeled carriages the moderate-size turn-table was convenient for
transferring an extra carriage to or from a spare carriage-line
alongside the making-up train at a platform, but modern carriages are
now so much longer, some of them twice the length, or more, than
formerly, that nothing less than an engine turn-table would be large
enough for them. Sometimes a carriage traverser is used for this
station work, but much more frequently these long carriages are
shunted on or off the making-up train by simply running them in or out
through the nearest switches and cross-over road.
[Illustration: Fig. 446, 447]
Fig. 446 is a sketch of a carriage-traverser, of length to suit an
ordinary six-wheeled carriage. The length, however, may be extended to
take on a bogie carriage or any other long carriage. The framing is
made of wrought-iron or steel, well braced together. The carrying
wheels, W, W, run upon rails laid at right angles to the
running-line or siding, and the carriage is moved on to or off the
traverser by means of the hinged ramps shown at R, R. A carriage,
once on the traverser, may be moved across one or several lines of
running road, according to the extent of traverser line laid down; and
this appliance is very suitable for large terminal stations and
carriage-repair shops. It will be observed that the operations of the 294
turn-table and the traverser are quite distinct. With the former a
vehicle can be transferred from one line to another, and also turned
completely round; but with the traverser the vehicles are simply moved
in a parallel direction, from one line to another, and when it is
necessary to turn or change a vehicle end for end, as in the case of a
mail-bag-catching apparatus van or a special saloon, then resort must
be had to a turn-table.
Cranes.--A large portion of the merchandise conveyed on railways
must be lifted into or out of the trucks by cranes. The position,
description, and capacity of these will depend upon the materials to
be handled. Large slow-working powerful cranes will be necessary for
raising heavy castings, large logs of timber, or massive blocks of
stone; while the small quick-acting cranes will be more suitable for
dealing with the lighter packages, casks, and bales.
Fig. 447 shows a gantry or overhead crane, used for lifting heavy
weights out of an ordinary road-waggon, carrying them a short
distance, and then depositing them in a railway truck, or _vice
versâ_. Double-flanged rollers, attached to the ends of the platform
C, C, run upon the rails R, R, which are fixed on
the top of the beams B, B, secured to the verticals A, A.
The working length of the gantry is only limited by the number of the
verticals, and this, being the fixed portion of the work, may be
extended out to any distance required. The travelling or carrying
girders of the platform C, C may be made of wrought-iron, steel,
or timber. They must be strongly framed and braced together as a
platform to carry the lifting machinery and weight lifted, and have
convenient gearing for effecting the transverse or side-to-side
movement, as well as a horizontal movement along the line of rails on
top of the verticals. Where the fixed portion of the gantry is of
considerable length, two or more travelling platforms can be used. In
the sketch given above, the entire gantry is shown as made of timber,
but iron or steel can be equally well adopted, and continuous masonry
or brickwork walls may be built to serve as verticals.
[Illustration: Fig. 448, 449, 450]
Fig. 448 is a sketch of a small handy crane for warehouse work; it is
quick in action, and restricted to weights not exceeding twelve
hundredweight. This form of crane may be strengthened to lift still
greater loads, but in doing so the additional size of the parts, and
the corresponding extra labour in working, detract from its efficiency 296
as a quick-acting crane for light weights.
Fig. 449 shows an ordinary fixed three-ton jib crane, a very
convenient size for general station work. The centre pillar is fixed
into a bed of masonry or a solid block of concrete. The jib is of
wrought-iron or steel, those materials being so much more reliable
than timber, and very little more expensive. This crane must be fixed
so that in one direction the jib may command the centre of a railway
truck, while in the other it can conveniently raise the packages to or
from the carts or loading-bank alongside. In the sketch the crane is
shown as placed on the loading-bank, but it may be placed on the same
level as the rails if preferred. Cranes of this type and strength are
frequently found necessary for the inside work of goods-sheds, where
packages of considerable weight have to be handled. A very similar
class of jib-crane is constantly made for lifting weights of five or
ten tons or more, the different parts being made stronger and heavier
to correspond to the weights to be raised.
Fig. 450 shows a five-ton travelling crane. Although more costly, it
has the advantage over a fixed crane that it can be moved about from
place to place. It is mounted on a very strong waggon framework, and
provided with springs and spring buffers. Instead of moving round a
long deep centre, the jib of the travelling-crane is arranged to work
round a bevelled metal roller-path laid down on the platform of the
waggon, and has a heavy counterweight loaded to correspond to its
capacity. Before commencing to lift any weight strong oak blocks or
filling pieces are inserted between the tops of the axle-boxes and the
under side of main beams of waggon, to relieve the springs of the
pressure which would arise from the weight lifted. From the four
corners of the waggon are suspended chains carrying gripping-hooks to
be attached or clipped round the rails. These gripping-hooks, when
firmly secured to the rails, prevent the crane from tilting over, as
the weight of the waggon and also of the rails and sleepers are
brought into play to counteract any tendency to throw the crane off
its proper balance. With the larger size travelling cranes, capable of
lifting ten or fifteen tons or more, outriggers of joist or
I-iron, moving in slides, are run out at right angles on either
side, and can be loaded with bars of iron or other weights to form a
counterpoise.
A medium-sized travelling-crane is a most useful appliance about a 297
railway station; it has a much greater range of utility than a fixed
crane, but it is not always appreciated as it should be. It merely
requires a line of rails laid down parallel to the rails of siding,
and may be placed either on the same level as the siding, or on the
level of the loading-bank. Being laid flush with the roadway, the
rails do not present any obstacle to the passage of carts or movement
of merchandise. As one waggon on the siding is loaded or unloaded, the
crane can be moved along its own line of rails, and be put to work at
another without the necessity of moving or drawing out any of the
railway waggons on the siding. Five, ten, or twenty, or more railway
waggons can be dealt with in this way, according to the length of
crane-line laid down. The crane can also be readily removed to another
part of the station-yard, or to another station along the line. For
stations with an intermittent or spasmodic traffic in heavy timber,
large blocks of stone, or other unwieldy articles, a travelling-crane
is particularly suitable, as it will meet all the wants so far as the
lifting is concerned, and when the rush of traffic is over, it can be
easily transferred to some other sphere of usefulness. The
crane-siding itself is never very costly, as the rails are generally
old rails taken out of the main line, and laid on good second-hand
sleepers. They have little to do, and merely form a track for the
moving crane.
Fig. 451 is a sketch of an ordinary Goliath crane constructed of
timber. The general arrangement and capabilities of this crane are
somewhat similar to those of the gantry shown in Fig. 447. Both of
them are designed to lift heavy weights, and move them sideways into,
or out of, ordinary road waggons, but the methods of application are
different. In the gantry the verticals are permanently fixed, whereas
in the Goliath the verticals and overhead girders are all attached and
braced together, forming a complete framework which is carried by
double flanged rollers running on the lines of rails R, R. The
winches or gearing for lifting the weights, or slinging them sideways,
or for propelling the crane forward on the rails, are attached to the
verticals as shown, and are worked from the ground-level instead of
the overhead platform, as indicated in the gantry. As each Goliath
crane is complete in itself, there is nothing to prevent two or three
of them working at the same time on a long length of crane-line.
[Illustration: Fig. 451, 452]
Fig. 452 shows an ordinary derrick crane, which, on account of the 299
large and varying sweep of the jib, is found very convenient for
certain classes of work. It occupies a considerable amount of room,
and its adoption is therefore limited to situations where space is of
secondary importance.
All the cranes described above are shown as worked by hand-power, but
they may be worked by steam, hydraulic machinery, or electricity.
Manual power will be the most economical where the use of a crane is
only occasional, but it would be too slow and costly where there is
constant heavy work.
Water-tanks.--A supply of good water forms an important item in
railway working, and ample provision must be made at all principal
stations for the requirements of engines and general station purposes.
According to the locality, the water may either be procured from the
main of some established waterworks company, or be pumped from a well,
or forced up from a stream by a ram, or brought down by gravitation in
pipes from a spring or stream at a distance. Water thus obtained is
conducted into tanks placed at a height of 18 or 20 feet, or more,
above the level of the rails, and forms a storage supply from which
deliveries can be made at a fair pressure and in large volume. The
tanks may be made of cast-iron, wrought-iron, or steel, or even of
wood. In the great timber-producing countries abroad, water-tanks,
some of them of large capacity, are very frequently made of wood, the
circular or half-cask form being preferred; but at home, and on
European lines generally, wooden tanks are rarely used except for
temporary purposes. Cast-iron being less liable to deterioration from
rust than wrought-iron or steel, is much used for water-tanks.
[Illustration: Fig. 453, 454, 457, 455, 456, 461, 460, 459, 462, 463,
464, 458]
Figs. 453 to 457 are sketches of a medium-sized cast-iron water-tank,
to hold about 7800 gallons. The size may be varied both in length,
width, and depth, without in any great measure altering the type. The
lower portion, or tank-house, may be of stone, brick, wood, or iron
framework, and may be utilized as a pump-room, store, or lamp-room. In
the sketch given a row of cast-iron girders are placed across the top
of the walls of the tank-house, to carry the tank, the plate-joints of
the latter being made to coincide with the centre lines of the
girders. The lower and upper edges of the tank-plates are shown curved
in section, the former for appearance and facility of cleaning, and
the latter to check the tendency of the water rippling or splashing 301
over the sides when disturbed during high winds. The large pipe, A,
is securely bolted at the bottom of the tank, and forms a shield or
funnel through which the supply pipe, B, passes upwards into the
tank. C is an overflow, or waste pipe, to carry away any surplus
which may find its way into the tank after the water has risen to its
fixed maximum height. All the contact surfaces of the cast-iron
tank-plates must be accurately chipped or planed, and fitted to ensure
water-tight joints. Stay-rods must be placed at frequent intervals,
connecting the vertical or outer plates to the horizontal or floor
plates. When required to hold more than 20,000 gallons, it is better
to make the tank in two parts, by placing a permanent plate partition
across the middle, in reality making two separate tanks, which can be
connected or disconnected at will. The double tank arrangement gives
additional strength, and possesses the advantage that the one tank can
be emptied and cleaned out while the other remains in service.
Water-tanks constructed of wrought-iron or steel plates are usually
made circular in form, with vertical sides. The floor-plates must be
either carried on small girders, as in the cast-iron tank, or be
strengthened internally with angle-irons, tee-irons, and tie-rods. The
rivetting must be well done, all joints sound and watertight. This
class of tank must be kept well painted, or oxidization will take
place very rapidly. The arrangement of inlet, waste-pipe, and delivery
pipe may be the same as for the cast-iron tank. Although frequently
seen abroad, these circular wrought-iron tanks are not often adopted
at home. By many the appearance of the circular tank is considered
inferior to one of neat rectangular shape, and the form of the round
tower does not lend itself so conveniently for use as a pump-room or
store.
There may be no practical difficulty in constructing a large circular
wooden vat or water-tank, but there cannot be any great actual
economy, except in those countries where suitable timber is very
cheap, and iron very dear. The wooden tank must be made of selected
materials, and by skilled workmen; but however carefully constructed
it cannot be expected to last so long as an iron tank. In many parts
of the United States of America there are excellent examples of the
circular wooden tank, strongly put together, and covered with a light
ornamental roof. Numbers of these wooden tanks have been erected there
in places where the cost of carriage alone of an iron tank would have
been a serious item, and where suitable timber was fortunately 302
close at hand.
In cases where engines are watered direct from a water-tank, a simple
delivery-valve, as shown in the sketch (Fig. 458), will answer the
purpose. This valve has to be pulled open by the chain and lever,
D, and when released falls with its own weight, and is kept closed
by the pressure of the water above. The delivery-pipe should not be
less than 7 or 8 inches in diameter, to accelerate the filling of the
tenders. Where water has to be delivered to engines at two or more
places in a station-yard, and the supply derived from the same
principal tank, the result may be obtained either by laying down 7 or
8-inch main pipes from the principal tank to separate water-columns,
or by erecting two or more pedestal water-tanks, similar to Figs. 459
to 462, each of which holds a little more than the average quantity
for one tender, and can be fed from the principal tank by a
comparatively small pipe of 3 or 4 inches in diameter. It is simply a
question of expense--whether it is cheaper to lay down a long length
of 7 or 8-inch main pipe and ordinary water-columns, or to adopt the
small pipes and pedestal tanks.
Figs. 459 to 462 are sketches of a medium-sized pedestal water-tank to
hold 1200 gallons. The supporting column must have a very wide base,
bolted down to a solid foundation. The tank itself, made circular in
plan, is generally constructed of light plates of wrought-iron or
steel, the lower portion or floor of tank being very securely attached
to the vertical column. Notwithstanding their top-heavy appearance,
these pedestal tanks can be made very firm and steady if enough width
be given to the base-plate, and the tank properly fixed to the column.
Water is led into these pedestal tanks by a small pipe passing up
inside the supporting column, and the delivery may be effected by a
simple valve, as explained for Fig. 458.
Fig 463 shows one type of water column for watering engines. The wide
base-plate is bolted down on to a foundation of stonework, brickwork,
or concrete, and the main supply pipe (not less than 7 or 8 inches in
diameter) is carried up inside the column, and connected with the
screw valve, A, which regulates the delivery to the tenders. The
curved top, which forms the outlet, and carries a leather hose, works
on a swivel joint, and can be swung round, either to the right or
left, for convenience of supplying engines on one or two
standing-lines. The delivery valve can be opened or closed by the 303
small hand-wheel B, which is conveniently accessible to the man on
the tender. On the above sketch (Fig. 463) the water column is shown
placed at an ordinary normal distance from the rails; but in cases
where there is considerable space between the two lines of rails, or
where a platform intervenes, the swinging arm may be extended out to
the necessary length, and counterbalanced as shown in Fig. 464.