LOCOMOTIVE, DESIGN AND CONSTRUCTION

through it, a draft is produced when the locomotive is at rest.

BOILER. The vessel in which the steam used for driving the locomotive and operating its various auxiliary appliances, is generated.

BOILER-JACKET. See Jacket.

BONNET. The wire cap or netting placed over the chimney or smoke-stack to restrain the sparks and cinders.

BOXES. The bearings which rest upon the journals of the axles.

a

BRAKE. The appliance by which a locomotive or
train is brought quickly to a standstill. Ordinarily,
it consists of a flexible piece of strap-iron lined with
wooden blocking which is applied to the tires of the
wheels by means of rods and levers actuated by the
pressure of compressed-air, or by hand.
BRAKE PIPE. The pipe through which compressed-air is
conducted from the various air-reservoirs connected
with the air-pump, to the brake-cylinders of the loco-
motive, the tender, and the cars composing the train.
Each car has its own brake-pipe and brake-cylinder.
When the cars are made up into a train, these pipes
are connected with each other and with those of the
tender and the locomotive, by means of flexible hose,
and when thus connected, it is called the train-pipe.
BRANCH-PIPE.- The pipe which connects the injector
check-valve with the boiler.

BRASSES. The boxes on the cross-heads and the crank-
pins.

BRICK-ARCH.- - A slab of brickwork placed across the
front end of the furnace, directly over the fire, to
hold the smoke and gases in contact with the fire until
they become thoroughly mixed.
BUMPERS or BUFFERS.-

Massive pieces of timber bolted to the front end of the engine frame, and to the rear end of the tender.

BUMPER BLOCKS.-Pieces of timber bolted to the bump-
ers for the purpose of reducing the shock of impact
when the cars come together.
BUMPER SHEET. A sheet of metal placed on the front
end of the frame, to cover the space between the
bumper and the cylinders.

CAB. The hood or house placed on the back end of the
boiler, and over the foot-plate, for occupancy by the
engineer and fireman.

CAB HANDLES.- Handles attached to the sides of the cab for the use of the engineer and fireman, in getting on or off the engine.

CELLARS. Recesses or chambers in the jaws of the boxes, which hold the oil for lubricating the journals. CENTRE-CASTING. The cast-iron plate which connects the truck bolster to the front-end of the boiler. CHECK-CHAMBER. A chamber attached to the waist of the boiler, through which the water passes from the connecting pipe to the boiler.

CHECK VALVE.A wing-valve inserted in the feed-pipe
between the feed-pump and the boiler, to prevent the
return of the water from the boiler to the pump.
CONNECTING-PIPE. The feed-water pipe which connects
the pump with the check-valve.

CONNECTING RODS or MAIN-RODS. The rods or bars at-
tached to the piston-rods, and by means of which the
power developed in the cylinders is transmitted to the
driving-axles. They convert the rectilinear recipro-
cating motion of the pistons into the rotary motion of
the crank-pins of the main driving-wheels.
COUNTER-BALANCES or COUNTER-WEIGHTS.

Large blocks

of iron cast on or otherwise secured in place between two or more spokes of each driving-wheel, opposite the crank-pin, for the purpose of balancing the weight of the parallel and main rods, and to steady the motion of the engine by equalizing the forces or ments around the revolving axle. COUPLER. See Draw-bar.

mo

COUPLING-RODs. The rods by which the crank-pins on
adjoining driving-wheels are connected together, so as
to cause the wheels to revolve in unison.
COW-CATCHER or PILOT. A triangular structure
wood, or iron bars, or curved sheet-metal, attached to
It is provided for
the front end of the locomotive.

of

the purpose of removing stray cattle and other ob-
structions from the track, and thus prevent them
from getting under the wheels.

CRANK-PINS. The pins or movable journals which unite
the connecting-rods with the cranks or shafts of the
driving-wheels.

CROSS-HEADS.-Blocks which move in guides and unite
the piston and connecting-rods, and slide-blocks to-
gether.

The pins in the cross-heads to which
CROSS-HEAD PINS.-
the main-rods are attached.
CROWN-BARS. Bars placed on the upper side of the
crown-sheet in the water-space, with their ends rest-
ing on the edge of the furnace-sheet, to strengthen
the crown-sheet.

CROWN-SHEET. The top sheet of the furnace, to which
It is placed directly
are attached.
the crown-bars
over the fire.
of steam into the cylinders. The point of cut-off is
CUT-OFF. The termination of the period of admission
regulated by the amount of lap on the slide-valves.
CYLINDERS. Steam-tight, metal receivers attached to
the front end of the boiler on each side of the lower
part of the smoke-box. They contain the pistons,
which are actuated by the steam obtained from the
boiler. There may be two, four, or eight of them,
according to the type of locomotive-simple-engine,
compound-engine, and tandem-compound engine, re-
spectively. They are called high-pressure, or low-
pressure cylinders, according to the manner in which
the expansive energy of the steam is utilized therein,
and are given the additional designations - outside, or
inside cylinders, according to their position relatively
to the engine frame.

CYLINDER-COCKS. Small cocks placed on the lower parts
of the cylinder-ends, to drain off the water of con-
densation, prior to starting the engine, and thus pre-
vent the possibility of blowing out the cylinder-ends.
CYLINDER-ENDS or CYLINDER-HEADS. The front and back
ends of the cylinders. The latter hold the stuffing.
boxes through which the piston-rods move.
DAMPERS. The doors in the front and rear ends of the
ash pan, by which the air admitted to the furnace is
regulated.
DAMPER-HANDLE. The bar which passes through the
foot-plate, and by which the dampers are opened and
closed.

DASHERS. The sheet-iron plates attached to the inside
shell of the boiler, opposite the pump-check, to pre.
vent the cold water from drenching the tubes.
DEFLECTOR. A bell-shaped or trumpet-mouthed opening
used in the furnace to effect a mixing of the air and
gases so as to cause the latter to ignite and thus ren
dome-shaped
der the combustion of the fuel more perfect.
DOME STEAM-DOME. The elevated,
or
The steam
chamber on the top of the boiler, from which the sup-
ply of steam for the cylinder is taken.
being partially superheated, it is consequently hotter
and drier in the dome than elsewhere, and when used
from the dome, diminishes the tendency to priming
in the boiler.

DOME BODIES. The sheet-iron jackets which envelop the
dome outside of the wooden "lagging."
DOME-STAYS. The braces attached to the crown-bars
and the dome, to strengthen the dome and the crown-
sheet.
DCME-COVER or DOME-TOP. The covering which encases
the dome, and to which the safety-valves and the
whistle-stand are attached.

-

DRAW-BAR or COUPLER. The bar attached to the front
of the pilot, by means of which the locomotive may
or to another locomotive. The
be attached to cars
name is also applied to the rod or bar by which the
locomotive is coupled to its tender.

dis-
and steam
DRIP-COCK or DRIP. The receptacle placed under the
gauge-cocks, to receive the water
charged from the cocks, and drain it into a discharge
pipe.

DRIVING-SADDLES. The yokes which straddle the frame
and support the driving-springs.
DRIVING-SPRINGS. See Springs.

DRIVING-AXLES. The axles which communicate the mo-
tion of the connecting-rods directly to the driving.
wheels.

"

DRIVING-WHEELS or DRIVERS. The wheels which are
The driving-wheel ar-
attached to the driving axles.
rangement of a locomotive may consist of the 4-
of the
coupled, 6-coupled, or of the 8-coupled wheel type.
They form what is called the "wheelbase
locomotive. The tractive power of a locomotive is
derived from the adhesion of the driving-wheels to
the rails, and depends upon the weight of the locomo-
tive and the area of the wheelbase.
on the driving-axles or crank-
ECCENTRIC. The cams
shafts of engines by means of which the rotary motion
of the axles or shafts is converted into the rectilinear
reciprocating motion which operates the slide-valves.
This change in motion is effected by giving the cam
"throw " or eccentricity equal in amount
a definite
A locomotive
to one-half of the travel of the valve.
has two pairs of eccentrics and their attachments.
One eccentric of each pair is set on the shaft in such
a position that the operation of the valves will run
the engine in one direction, and the other one is set
so as to operate the valve to run the engine in the
They are referred to by various
opposite direction.
and
"backward
"forward eccentric
terms, such as
and "back-up
"go-ahead eccentric
eccentric
eccentric." according to the direction of the motion
given to the locomotive by their action on the valves.
The ends of each pair of eccentrics are attached to a
"link"
by means of which either of the eccentric-
rock.
rods is engaged with or disengaged from the

or

LOCOMOTIVE, DESIGN AND CONSTRUCTION

FOOT-PLATE. A cast-iron plate bolted to the back end
of the frame opposite the fire-door.
FRAME. The strong metal skeleton which supports the
boiler, machinery, and axles of the locomotive. It is
usually made in two parts the back part to which
the driving boxes, axles and wheels are attached, be
ing called the main-frame, and the front part to which
the cylinders are bolted, being called the front-frame.
When formed of plates of sheet-metal, it is called a HAND-HOLD.
plate frame, and when composed of iron bars it is HAND-HOLES.

consists

LOCOMOTIVE, DESIGN AND CONSTRUCTION

of the furnace near the ring, through which deposits of rust or dirt in the water-legs of the furnace are removed. HAND-RAILS. Brass or iron pipes attached by brackets or studs to the upper part of the boiler, and extending from the cab to the smoke-box. They are used by the engineer in getting on or off the running-board. HEADLIGHT.A large lamp placed on the front end of the locomotive to illuminate the track in front and It thus disclose any obstructions that may exist thereon, and to signal the approach of the locomotive. surmounted by an of an oil-reservoir all Argand burner, and a parabolic "reflector," case," which is of which are enclosed in a metal placed on the top of the smoke-box, or supported on "brackets," with a shelf between, bolted to the front of the smoke-box. HEATER-COCKS.- Cocks attached to the back end of the boiler, by which steam is blown through the feedpipes, to prevent them from freezing in cold weather. HOLLOW-STAYS.- Hollow stay-bolts inserted through the inside and outside sheets of the furnace near the crown-sheet, through which air is admitted to the furnace to increase the combustion.

two

""

HOUSE. See Cab.

66

HOUSE-BOARDS. The boards attached to the sides of the
boiler, upon which the house or cab rests.
HOUSE-BRACKETS. Brackets attached to the back-bumper,
to support the house-boards.

INDUCTION-PORTS. The passages

in the

valve-seats, is admitted to the cylinders.

through which steam See Steam-parts. INJECTOR. A mechanical device by means of which a continuous supply of feed-water is given to the boiler. It acts on the principle, that if a jet of high-pressure steam issuing from a boiler at a high velocity, is brought into contact with a body of cold water, the steam will partially condense and combine with the water and thus impart a portion of its velocity to the water, and induce a current of water to flow into the same boiler against the pressure of the water in the boiler. Partial condensation of the steam is The injector will not feed essential to efficient action.

water too hot to condense the steam.
INJECTOR OVER-FLOW or INJECTOR-NOZZLE. The pipe
which connects the overflow-space in the injector. If
more water has been supplied to the jet of steam
than it is capable of carrying into the delivery-tube
of the injector, a part of the water will escape through
the overflow-nozzle. On the other hand, if too little
water has been supplied, air will be drawn in through
the nozzle, and carried into the boiler.
arrangement by which the
INJECTOR-THROTTLE. The
water passage between the steam-nozzle and the com-
bining-tube of the injector is changed in size auto-
matically or by hand, to suit the changes of steam-
pressure in the boiler.

JACKETS. The outside coverings of the cylinders and
the boiler. The boiler jacket is composed of layers
about seven-eighths of an
of wood called "lagging
inch in thickness, felt, and Russia iron, placed around
the boiler to prevent the loss of heat by radiation and
convection.

JAM-NUTS. Lock-nuts used for setting-out the spring.
packing in the piston-heads.

JAWS. The parts of the frame formed by the frame-
legs, and which hold the axle-boxes.
JOURNALS. That part of the axle on which the weight
The journals are situated on
of the locomotive rests.
the inner side of the wheels, and turn on brass "jour-
nal-bearings" which resist the friction of the revolv-
ing axle. The bearings are held in cast-iron or steel
"axle-boxes."
or
boxes called "journal-boxes
straps
KEYS. The wedges employed to tighten the
at the ends of the connect-
which hold the "brasses
ing-rods. As these keys are very liable to loosen and
fall out, they are secured in place either by screws
and nuts, or by a set-screw on the other side of the
rod.

66

KING-BOLT or CENTRE-PIN. The bolt or pin which passes through the centre-casting and the centre of the truck, thus making a flexible connection between the engine and the truck, enabling the latter to turn about the king-bolt so as to allow the axles to assume positions approximating the radii of the curves of the track.

KNUCKLE-JOINTS.- The joints on the valve-rods, which allow the rods to vibrate freely with the radius of the rocker-arm.

LIFTING SHAFT. See Eccentric.

LINK. A variable-radius expansion-gear by means of
See Eccentric.
which the slide-valves are operated.
LINK-BLOCK.- A block which fits into the curved slot
of the link, and moves freely from one end to the
other thereof.

LINK-BLOCK PIN.- The pin which connects the link-
block to the lower rocker-arm of the valve-gear.
LINK-HANGERS. Rods or bars by which the links are

suspended to the horizontal arms of the lifting-shaft by two pins, the upper one being attached to the arm, and the lower one to the link-saddle bolted to the link.

LOWER RAIL FRAME. See Frame.

LUBRICATOR. The valve through which oil or tallow is
admitted to the cylinders for the purpose of lubrica-
tion. These valves communicate with the cylinders
or through a pipe
either through the steam-chests
The lubricators placed in the
leading from the cab.
In these lubri-
cab are called sight-feed lubricators.
cators, the weight of a column of water displaces the
oil in the cup, causing it to flow upwards drop by
drop, through water in glass tubes, to the pipes leading
The flow of the oil is thus placed
to the steam-chests.
constantly in sight of the engineer, and enables him
to know whether the lubrication is continuous and
regular or otherwise.

MAIN-FRAME. See Frame.

MAIN RESERVOIR. The main air-reservoir of the loco. motive. It is usually located on the front of the main frame, and immediately behind the cylinders. MAIN-RODS. See Connecting-rods.

64

MAIN-ROD CONNECTIONS. See Connecting-rods.
MAIN-ROD FRONT-STRAP. See Connecting-rods.
MUD-DRUM. A cylinder attached to the under side of
the
waist "
of the boiler, to receive the deposits
This material is discharged
from the feed-water.
from the drum by means of a valve called the "mud-
cock."
MUD-HOLES.- Openings provided in the back end of the
fire-box, through which the accumulations of mud in
These openings
the lower water-space are removed.

are usually closed by means of brass plugs.
MUD-RING. The wrought-iron ring which unites the
inner and outer shells of the fire-box; completely sur
rounding the inner shell and closing the water space
between the two shells.

NETTING.- Wire netting placed in the front end of the
smoke-box, and in the chimney or smoke-stack. This
netting acts as a sieve, arresting the sparks and cin-
ders, but allowing the smoke to escape freely.
NOZZLES. The contracted tube called the "steam-noz-
zle in the injector, through which the jet of steam
from the boiler is conducted to the combining-tube of
the injector. Also, the outlets of the exhaust-pipes,
called " exhaust-nozzles," in the smoke-box.
NOZZLE-STAND. The supports of the exhaust-nozzles in
the smoke-box.

NOZZLE-TIPS. The rings or bushes fitted into the tops
of the exhaust-nozzles. They are held in place by
means of set-screws so as to permit of their being
readily removed and others with larger or smaller
openings substituted, to adjust the size of the blast
orifices so that they will be small enough to produce
the required draft, and yet be as large as possible to
reduce the amount of back-pressure.

OIL-CUPS. Cylindrical metal receptacles with glass lin-
ings, employed to contain oil, and to distribute it to
moving contact surfaces, for the purpose of lubri-
cating them. Such cups are attached to the guides
and the connecting rods above the bearings and the
crank-pins. The oil-cup for lubricating the main or
slide valves is placed in the cab where it is under the
control of the engineer. See Sight-feed Lubricator.
PACKING. The hempen, metallic, or other substance
used in the stuffing-boxes, and in the steam and pump
cylinders, to make the moving parts of the pistons
steam and water tight.
PETTICOAT or DRAFT PIPE. The pipe through which
the exhaust-steam is conducted to the exhaust-nozzles
in the smoke-box, thus creating a partial vacuum in
the smoke-box, which sucks the smoke and gases out
of the flues with great power, and forces them out
into the open air by the blast or the action of the
exhaust steam.

PILOT. See Cow-catcher.
PISTON-HEAD.-The solid or hollow disc-like plunger in
the cylinder which is moved with a reciprocating or
forward and backward movement by the action of the
steam, thus converting the energy of the steam into
the motion which drives the engine.
PISTON-PACKING. The packing by means of which the
piston-rods are made steam tight.
rings of cast-iron,
PISTON PACKING-RINGS. The
wrought-iron, steel, or gun-metal which form the pe-
ripheral portions of the piston-heads, and make a
steam-tight joint between the piston-heads and the in-
side surface of the cylinders. They are made thin and
turned slightly larger than the bore of the cylinders,
and thicker on one side than on the other so as to act
as a spring when they are slotted diagonally across
and forced into the cylinders between the piston
After being placed in position, their elasticity
tends to thrust them outwards and thus maintain a
steam-tight joint with the bore of the cylinder.
PISTON-ROD. The rod attached to the piston-head, and

covers.

LOCOMOTIVE, DESIGN AND CONSTRUCTION

by means of which the motion of the piston-head is
communicated to the connecting-rod or crank. It
works through a packed stuffing-box which prevents
the leakage of the contents of the cylinder.
PRIMER. The valve by means of which the air in the
water-space of the pump is expelled, and a partial
vacuum produced so as to cause an inflow of water
vto start the action of the pump.
PUMP-GOVERNOR.- See Governor.

QUADRANT. A slotted curved bar which holds the
verse-lever in the proper position by means of a re-
hoverse-latch. Also, a toothed bar located in the cab, by
means of which the variable-exhaust is regulated.
RADIAL STAY-BOLTS, Stay-bolts screwed into the outer
shell of the boiler radially to its cylindrical form, and
as nearly as possible at right-angles to the surface of
the crown-sheet which they are designed to support.
RADIUS-BAR. The angle-bar attached to the back end
of the truck frame and to the radius-bar cross-tie by
Imeans of a pin.vn

which are cast in channels called "steam-passages lowing manner: The steam is admitted through two called the valve-seat." The valve-seat has two openthe cylinder, and terminate in a smooth, flat surface, ings called "steam-ports" for the admission of steam ated between the steam-ports, and communicates with and a cavity called the "exhaust-port" which is situ to the open air through pipe connections leading into onthe exhaust-pipes in the smoke-box. A valve called a a cavity in its under side, is fitted on the valve-seat re-slide-valve," made of cast-iron, and provided with in such a manner, that when it is moved backwards and forwards, it will alternately cover and uncover to the front end of the cylinder and exhausting it the two steam-ports, simultaneously admitting steam the back end of the cylinder and exhausting it from from the back end, and then admitting the steam to the front end. This reciprocating motion of the valve axles of the locomotive, which is converted into recis derived from the rotary motion of the drivingtilinear reciprocating motion by means of the "eccenand the "valvelink," the "rocker bo tric, the REACH-ROD. The rod which connects the reverse-lever with the reverse-arm of the reverse-shaft. axle, and connecting the latter with the stem of the RECEIVING-PORTS or STEAM-PORTS. The passages in the rod" placed between the cylinder and the driving valve.sond seats of the slide-valves through which the steam is SMOKE-BOX. A cylindrical chamber at the front end of admitted to the cylinders from the steam-chests.dar the boiler, which is utilized to contain the "archexhaust-pots," the REVERSE-LATCH.-The tongue which fits into the notch pipes," the "lifting-pipes," the steam-pipes" and the "exof the quadrant by which the reverse-lever is held in exhaust-nozzles," the the right position.19 09/07qm to b958 haust pipes." It also forms a convenient receptacle REVERSE-LEVER or REVERSING-LEVER. The lever by which nl for the smoke before it escapes into the open air the direction of motion of the locomotive can be od through the smoke-stack. The" smoke-arch ring changed, and the travel of the valves increased or no divides the smoke-box proper from that portion of 97decreased. It is located in the cab within easy reach tai paille the smoke-box which is commonly known as the The and into which it opens through the of the engineerine sanood ni "front-end," ROCKERS. The double-cranks connected with the linkblocks at one end and the valve-rods at the other, and ed front-end gives the additional room required to con20through which the valves receive the motion of the smoke arch door" in the "smoke arch front." nadw botnsvni 26W Otain the "deflector" and the wire netting which comeccentrics and links.9270 SADDLE-PIN. A pin by which the link-hangers are atSMOKE-STACK. The chimney through which the smoke tached to the saddle-plate, and by means of which theprise the spark arresting appliances. To Tie link is raised or lowered. L SADDLE-PLATE. The plate which fits into and slides escapes from the smoke-box. Smoke-stacks are made in the slot of the link.

SAFETY-HANGERS.-Chains fastened to the front-bumper and to the front end of the truck-frame, to prevent the truck from swinging around and breaking the links in case the locomotive happened to run off the oldina totor Spring-valves attached to the domecover, by which the steam-pressure in the boiler is prevented from exceeding a certain limit. Usually there are two of these valves, so as to provide against the contingency of the breakage of one of them. SAND-BOX. The cylindrical or dome-shaped box attached to the top of the boiler to contain the sand used for the purpose of sanding the rails in order to increase the adhesion, and prevent the driving-wheels from slipping at starting, or when hauling a heavy load, or when running up a heavy grade.

StrackLVES aninh

SAND-BOX LEVER. A lever located in the cab, and
which communicates with the rod by means of which
the sand-valves are operated by the engineer.
SAND-PIPES. The pipes on each side of the locomotive
through which the sand from the sand-box is con-
veyed to the rails in front of the driving-wheels.
SHAKE-LEVER STUB.-The cab end of the lever of the
grate shaking-rig. velob anoibs
SIDE-RODS or PARALLEL-RODS. See Coupling-rods.
SIGHT-FEED LUBRICATOR. See Lubricator.
SIGNAL-PIPE. The air-pressure pipe by means of which
the engineer communicates with the trainmen, bron
SIGNAL-WHISTLE. A steam-whistle attached to the top
of the dome. It consists of an inverted metal cup,
usually made of brass, which is placed immediately
enover the annular opening of a hollow valve-stem
screwed into the top of the dome. Communication
with the steam-space within the dome is effected by
opening or by closing a valve attached to a spindle
which extends upwards into the valve-stem. The
valve is operated by the engineer by means of a rod
which connects the operating lever of the valve with
the cab. When the valve is opened, the steam escapes
20through the annular opening in the valve-stem, strikes
against the edges of the inverted cup, and produces
the sounds which are utilized to give signals to the
trainmen, to warn people off the track, and to signal
the approach of the train to stations and crossings.
SLIDE-VALVES. The

to and from the cylinders.
and exhaust of teaves which control the admission
They are operated by the rotary motion of the axles
-oofo the driving-wheels which is converted into recti-
linear reciprocating motion on the valves in the

STAND-PIPE. See Steam Pipe.h2 52
outer shells of the fire-box at frequent intervals,
STAY-BOLTS.-The bolts screwed through the inner and
usually about four and a half inches apart, to connect
the shells together and enable them to resist the full
pressure of the steam."
ders, and which contain the slide-valves through which
STEAM-CHESTS. The boxes located on top of the cylin
the steam is admitted to the cylinders. A steam-chest
usually consists of two castings the steam-chest
casing" which rests on the top of the cylinder casting
to which it is united with a steam-tight joint, and the
steam-chest casing cover," made of cast-iron and
STEAM-GAUGE.-A gauge attached to the back end of
held down by bolts screwed into the cylinder casting.
the boiler, in the cab, to indicate the pressure of
steam per square inch, in the boiler.
ducted from the boiler to the steam-chests, thence
through the openings in the seats of the slide-valves
STEAM-PIPE.- The pipe through which steam is con-
tends vertically downwards until it clears the vertical
to the cylinders. Starting at the dome, the pipe
walls of the dome, this vertical part is called the
makes a bend called the throttle-pipe "; then it ex-
stand-pipe." The stand-pipe is connected to the
which extends to the top of the smoke-
"T-pipe," the
22 box where it is connected to the
dry-pipe

connecting with the steam-chests. steam-pipes STEAM-PORTS. See Receiving-ports. mool mort STEAM-VALVE. The valve inserted in the steam-pipo fol-connecting the boiler with the injector. Toisilivio

LOCOMOTIVE ENGINE