Glossary of Common Railway Terms
(With contributions from Art Clowes and Don Grove)
Terminology varies by country, and also often by railroad. The following are general terms as usually understood in Canada. (qv) = please refer to
agent – an employee of the railway appointed to be in charge of a station. The agent was responsible for conveying train orders to train crews, and for staffing and operating the station. This included ticket sales, freight way bills, dispatch and receipt of express parcels and LCL (less than a car load of) merchandise, the operation of the station telegraph, maintenance of the station area, provision for the well-being and direction of passengers, and the safety and accuracy of freight shipments. A person of standing in the local community along with the banker, priest, postmaster and head teacher.
air brake – a power braking system with compressed air as the operating medium.
aspect – the visual appearance of the signal which indicates its meaning (e.g., danger, proceed with caution, clear), especially of a colour light signal.
bad order (track) – a track to hold cars requiring minor repairs, usually in a marshalling yard.
baggage – a passenger’s luggage, carried with the passenger or conveyed in the baggage compartment and (where required) stored in the baggage room at the station.
baggage car – a car for the transportation of passengers' baggage, sometimes also closed mail (qv), parcels and express.
ballast – crushed stone or slag put down to form a level bed for the track and to facilitate drainage of the roadbed.
bend the rail – slang for throwing a switch (qv).
big hook – slang for a breakdown crane capable of righting a derailed locomotive.
bridge – a structure consisting of plate girder or truss spans, intermediately supported, if needed, by piers at longer intervals than those of a trestle.
(See also the Trestles, Bridges and Culverts Glossary below.)
brakeman/trainman – an employee of the railway. These terms are interchangeable. The word brakeman dates from the days before air brakes when the brakes had to be applied by hand to stop the train. When the engineer wanted to stop the train he blew one short blast of the engine whistle. This was the signal for the brakemen to climb on top of the cars and apply the hand brakes. To apply the brakes a long brake club was used. A brake club was the size and shape of a pick handle and this gave the leverage to apply the brake. Also sets switches, couples and cuts off cars, and performs running maintenance on car mechanical problems, and otherwise assists the conductor.
buffer stop or bumper post – the barrier installed at the end of a dead-end track to prevent rail vehicles from proceeding further.
B&B – Building and Bridge (Department).
cab – the enclosed space of a locomotive that is the work station of the engineer and fireman.
caboose – see conductor’s van.
car – any piece of rollingstock (qv) that can form part of a consist.
check rail – see guard rail.
class – see under engines and trains.
clearance (clearance form) - In addition to a train order, train crews needed a clearance when leaving their initial station and at any station where they receive a train order. A clearance is a verification that the crew has received all the orders it is supposed to receive.
closed mail – mail in bags sealed by the post office for transportation only, i.e., not to be sorted in a railway post office car (qv).
coal car – obsolete term for the locomotive tender (qv).
coal chute – a structure next to, or over a railway track, used to place coal into the locomotive tender.
conductor – an employee of the railway in charge of a train.
conductor’s van – a car at the rear of a freight train that acted as the conductor’s office and crew accommodation, and as a look-out to ensure that nothing untoward was occurring to the train, of which the head-end crew might be unaware.
consist – the rolling stock assigned to an engine at any particular time on any particular run.
controlling gradient – see gradient.
cornfield meet – slang for a head-on collision.
couple up, (to) – to couple up cars or cuts of cars to each other; or onto a train.
crossing (diamond) – a track formation where two tracks cross at grade. Where this is between two different railways, usually protected by an interlocking tower. (See also Tower, interlocking.)
crossover – where a pair of switches allows a train to move over from one (parallel) track to another.
culvert – a constructed opening under a railway track, usually to allow water to flow from one side to the other, either for drainage or for unimpeded flow of a smaller water course. Larger culverts may also be to allow passage between two fields separated by the railway. It may be constructed of wood, brick, stone, or latterly of concrete. (See also the Trestles, Bridges and Culverts Glossary below.)
cut of cars – a number of cars coupled together (in the UK, a rake).
cut off, (to) – to separate any car or cut of cars from each other or from the train, i.e., to uncouple.
cutting – the excavation of high ground to provide a level grade for the track.
derail – a single rail point switch on a spur or siding that can be opened to prevent a car from rolling onto the mainline in the event of brake failure.
diamond (crossing) – see crossing (diamond).
dispatcher – an employee of the railway responsible for coordinating and controlling train movements and issuing train orders on designated subdivisions or at terminals (qv).
district – a Grand Trunk Railway term for a subdivision. See also Subdivision.
diversion – a temporary or permanent track re-alignment. A temporary track by-pass or siding is usually laid during nearby construction or after an accident, in order to maintain railway service (also known informally as a “shoo-fly”).
division – a major operating segment of a railway’s network. Its size was often defined by geography and/or the railway’s preferred organization. Sometimes determined by the distance a steam locomotive was able to travel before requiring service and/or a change of crew. The central location of a division was referred to as a division point. A division point would provide offices for the various necessary supervisory positions to administer the division.
donkey – obsolete slang for an engine employed on yard switching duties.
double-header – a train pulled by two engines.
double a hill (to) – take a train over a hill in two parts.
double track – continuous parallel tracks between two established points, affording simultaneous train movements in the opposite or same direction.
doubling track – a siding or spur at the top of a gradient where cars could be set off temporarily.
drop, (to - or make a) – switching a car onto another track where the car is already uncoupled while the engine and car are in motion. Also referred to as “switching on the fly” or as "a running switch." A very dangerous practice, now banned on most railways.
elevator – grain storage tower with ability to load grain direct into railway cars.
embankment – a raised mound of earth shaped to support a railway track, usually in preference to building a trestle or bridge; or sometimes created when a trestle is filled in.
engine – a unit propelled by any form of energy, or a combination of such units operated from a single control, used in train or yard service.
engine house – a rectangular building for stabling locomotives; consisting of one or more tracks, connected by switches outside the engine house. Most smaller engine houses can only be entered from one end. See also roundhouse.
engines, class of – a series of locomotives manufactured to the same specifications, not necessarily by the same builder. Sub-classes of a series of locomotives were created when changes or modifications were made to the original design, either when being built new or when being modified during a rebuild.
engineman – a railway employee in charge of and responsible for the operation of an engine. (In the 19th century, also “engine driver”.) Commonly referred to as an “engineer”, or less elegantly as a “hogger”, (derived from an early slang name for an engine as a “hog”).
engineer – a person employed or retained by the railway who is trained in engineering applications (e.g. civil, mechanical, signal engineering). See also engineman.
express – merchandise moved on passenger trains.
express car – car for the purpose of carrying merchandise on passenger trains, sometimes also perishable goods for faster transportation than by freight train.
flag stop – a station building, small shelter or platform, where intending passengers may board a train upon waving a flag or operating a semaphore signal on its approach, or where they may request the conductor to drop them off. .
flanger – used in territories where there is a lot of snow. In appearance like a caboose, but equipped with retractable blades that are lowered to clean out the snow between the rails. The blades have to be lifted on approaching a road crossing or a switch.
footplate – of a steam locomotive, the metal floor that extends from the front to the rear of the cab.
freight – all manner of merchandise carried by the railway in freight cars of various kinds, including box, stock, gondola, flat and tank cars. (Early pioneer railway freight rolling stock usually consisted of box and flat cars.)
freight shed – an attachment to a station or a separate building where freight is stored. Accessed by a team track, siding or spur.
gandydancer – US slang for a railway section hand.
gauge – the distance between the inside edges of two rails forming a track.
- “Standard" gauge is a worldwide gauge of 4' 8 (and 1/2)".
- In 1851, the Province of Canada required the “Provincial” (or “broad”) gauge of 5' 6" for any railway eligible for and desirous of applying for government financial assistance under the 1849 Railway Guarantee Act. This requirement fell into disuse by the early 1870s, whereupon conversions to the “standard gauge” took place during that decade.
- “Narrow gauge” refers to any gauge of less than 4' 8 1/2".(It should however be noted that the Great Western Railway, in their Provincial gauge days, referred to the standard gauge as the “narrow gauge”.)
George – obsolete nickname for a sleeping car porter
grade or gradient – slope, rate of ascent or descent. “At grade” – at the same level, i.e., a road crossing “at grade” would constitute a grade or level crossing.
gradient “ruling" or “controlling” – the severest gradient on any given route.
grade crossing – where a road crosses a track.
grade separation – another term for a trestle or bridge crossing another railway line or highway. From the perspective of the owning railway, a railway bridge over another railway may be appropriately referred to as an “overpass”, whereas the other railway would view it as an “underpass”. In the case of a highway, one over the railway would be viewed as an “overpass”, and one under the railway as an “underpass”.
guard rail – a rail placed on the inside of a running rail at a curve, bridge or switch/crossing to discourage a wheel from jumping the rail or taking the wrong direction. Note: On narrow gauge lines, it is customary to place the guard rails on the outside of the running rails at bridges and trestles.
halt – UK term for a flag stop (qv), or a wayside platform.
handbomber – slang for a manually-fired steam locomotive.
hand brake – used during switching operations to slow or stop cars. Also, used to hold cars that are spotted on a yard track, or a string of cars set off in a siding.
helper engine – an engine assisting a train engine (qv) on account of total tonnage to be moved, and/or gradients.
hog – slang for a(n) older locomotive, hence name hogger for a locomotive engineer.
hole, to take the/be in the/go into the – slang for a train to go into a siding to yield to a superior train in the opposite or same direction
hoop – a device in outline like a carpet beater, but with a hollow oval or sometimes triangle, used by the agent or telegrapher “to hoop up” a new order to a train en route. The crew would catch the hoop by thrusting an arm through the open loop, detaching the order and throwing the hoop back on the ground.
hostler – a railway employee responsible for moving engines in and around the roundhouse, readying incoming engines for the next day by topping them up with coal and water and then dumping their fires.
“hot box” – slang for a wheel journal bearing that has lost its lubrication and is running dry. If the car concerned is not detached from the train, likely to cause a derailment when it seizes up.
jigger – a small, four-wheeled, platform car easily set on or taken off the track; used by a section gang to inspect their section of track. Usually hand-pumped, but sometimes motorized.
job – any running trade (qv) work assignment, whether on train, helper engine, transfer movement, yard, and whether regularly-assigned or "spare" (qv spare board).
Johnson Bar – control lever on a steam locomotive, used to control the timing of the admission of steam into the locomotive's pistons. By controlling this timing, the amount of power delivered to the wheels is regulated, as is the direction that the wheels rotate, giving the lever the alternate name of the reversing lever.
Jordan spreader – see spreader
junction – a place where one line or more diverges to another place.
ladder (ladder tracks) – a series of parallel sidings at a yard, all from the same lead track. The ladder sidings may have entry switches at both ends, or be single-ended, i.e., with bumper stops at the other.
lead track – a track connecting a yard or facility with a main line or running track.
line switches, (to) – to set one or a succession of switches to permit a train to travel over a designated route.
live load – the force exerted by a train on a structure such as a bridge or turntable.
loading – see live load.
locomotive tender – a car permanently assigned to a steam locomotive to carry its fuel - coal/oil and water.
loop – see siding.
lower quadrant – the position of a semaphore signal arm that clears to below horizontal.
mail – formerly "Royal" mail, carried by the railways under contract with the Canadian Post Office. It was carried in sealed canvas bags, on passenger and mixed trains, all across Canada. “Closed” mail was mail ready-sorted by destination post offices on trains not having an RPO car, where the bags would be handled, but not opened, by the train baggage man. See also RPO (Railway Post Office).
mail catcher – a vertical pole and hook-type device mounted at the edge of a platform, enabling a passing RPO car to pick up a mail bag without requiring the train to stop.
marker – large lamp, with three green and one red lens used to indicate the end of a train.
navvy – short for navigator - originally canal builders (hence the term), but later sought work on railways as builders of roadbeds, involving grading, embankments and tunnels.
operator – an employee of the railway engaged full-time (usually at major stations and junctions) in the transmission of messages and train orders by the Morse telegraph or by telephone. (At smaller stations, the station agent received and sent messages himself.)
order board(s) – originally a variety of disk or semaphore designs to indicate whether a train needed to stop to obtain a train order (qv). Both the GTR and the CPR had rotatable oval disk designs, coloured red on one side and green on the other, visible above the roof overhang and operated by means of a lever and rod from the telegrapher’s bay at an agency station. If the train was required to stop to pick up a train order, the red aspect would be displayed to the oncoming train. If not, the aspect would show green. The CPR later switched to lower-quadrant semaphores. These were in turn replaced generally by a pair of upper-quadrant semaphore arms (one for each direction) visible above the roof line, again worked by levers from the telegrapher’s bay. If a train was required to stop for orders, the arm would be extended in the horizontal (red) position. An order board in the half-way (yellow light) position indicated a non-restricting order, i.e., one that could be picked up with a hoop.
overpass – a bridge or similar structure where a railway passes over another, or over a road - from the perspective of the railway that is passing over. From the perspective of the railway or road that passes under, its path is an underpass..
permanent way – a generic term for a track laid into position with proper ballasting for regular operation of trains. "Permanent" derives from affirmation as to its finished state, as opposed its "temporary" state while still under construction, likely not yet ballasted.
pilot engine – the leading engine in a double or triple header (qv) train.
platelayer – UK term for a section hand (qv).
platform – a paved walkway beside a track to accommodate arriving or departing passengers.
porter – railway employee to attend to passengers' baggage and to assist with the loading/unloading of express and baggage cars, also sleepingcar porter, an attendant on sleepingcars.
pusher engine – an engine assigned to the rear of a train to assist with moving the train, usually in mountainous terrain.
pushpole – a long pole carried by a yard engine that would allow it to move a car on an adjacent track.
rail – a length of iron (earlier) or steel (latterly) designed and rolled as a rail to support a railway wheel. Produced in standard lengths and to a defined weight as in lbs per yard. Latterly welded together to form long sections, known as “ribbon rail”. In transverse profile, a rail consists of the railhead (top), web (middle) and railfoot (bottom). In North America, the railfoot was originally spiked direct to the tie. Eventually a tie plate came into use, an iron or steel plate that came between the railfoot and the tie to afford greater strength and stability. Fastening methods as between the railfoot, tie plate and tie have many variations using spikes, bolts, screws and clamps. A rail would be connected to the next rail by means of nuts and bolts with a joint bar, also known as a splice bar, or in the UK, as a fishplate.
railhead - the furthest point reached by a railway, at which road transport of goods begins. Also the top segment of a rail when viewed in profile. See rail.
railroad – US usage - a railway. Note that some early Canadian railways, such as the Ontario Simcoe & Huron Union Railroad, followed US usage.
railroader – US usage - a railway employee.
rail stop – see stop block.
railway – track or set of tracks of iron or steel rails for passage of trains of carriages or cars drawn by locomotive engine and conveying passengers and goods/freight. UK and Canadian usage.
railwayman – UK and Canadian usage - a railway employee
RPO (Railway Post Office) – Railway Post Office mail was carried in a special car or compartment. The outward appearance of an RPO car was very similar to that of a regular baggage car. It was specially equipped for sorting mail, and the mail clerks (employees of the Post Office) sorted the mail en route. Mail thus sorted would bear a distinctive RPO cancellation mark.
redcap – nickname for a porter.
reefer – slang for a refrigerator car for the movement of highly perishable goods.
right-of-way – the track and its roadbed. Legally, the land occupied by a railway, shown in a land deed as having a centre line, with a defined amount of land on either side. The standard allowance for a single track was 66 ft, or one “chain”.
road – a term dependent on its context. It may refer to an entire railway company, or specifically to the track and the right-of-way.
roadbed – the earth and gravel that supports the track. After a track is removed, what is left is the roadbed.
rollingstock – any passenger, mail, baggage or freight car or caboose. The term does not include engines or auxiliary (wrecking crew) equipment. (It should however be noted that in the late 19th century, it was usual for references to “rolling stock” to include engines.)
roundhouse – a building for servicing and repairing locomotives, strictly speaking of a semi-circular design; with a turntable at its mouth, for the purpose of assigning a locomotive to a particular roundhouse track. Often used interchangeably, although not accurately, with the term engine house (qv).
Rule G – prohibition against working while intoxicated, will result in suspension and/or dismissal.
ruling gradient – see gradient.
running rail – a rail upon which a wheel runs (as opposed to a guard rail).
running switch – see drop.
running trades – the employees who operate the trains - conductors, engineers, firemen, conductors, train/brakemen.
section – technically, formerly a stretch of track about seven miles long, that was inspected daily by a section gang (consisting of one or two section men or hands, in charge of a section foreman. They would use a jigger (qv) to ride up and down their assigned section. They would store their tools and jigger in a section hut. The foreman was at one time provided with accommodation by the railway, known as a section man’s house or dwelling. Also used as a general term to describe a stretch of line.
section foreman – in charge of a section gang, or working with a section hand.
section gang - hand - duties – daily track inspection, gauging (checking the correct distance between the rails), weeding, tie replacing (25-50 per day as required), repairing bridges and fences, straightening posts after frosts, painting signboards, putting in new cattle guards, putting in snow fences, loading water barrels for bridges, snow shoveling, unloading iron and pilings for track and bridge repair.
seniority – length of service in one of the running trades - not to be confused with seniority in the company's employment. Set up: to be promoted - set back: to be demoted - to be bumped: to be displaced by someone with more seniority - to be cut off: laid off.
set off, (to) – see cut off (to).
shoo-fly – see diversion.
shove, (to) – to switch cars into a siding or spur track.
siding – a track adjacent to the main track, for passing trains, usually with a switch at either end, sometimes referred to as a loop. Also in (marshalling) yards to accommodate freight trains. See also team track. Note: In a yard, a siding may have a switch at one end only.
signal cabin – a building placed at a complex track layout, usually at a large city, for the purpose of controlling the trackwork and signals, originally by means of rodding, but latterly electrically.
single track – a single track between two established points, affording train movements in the opposite direction by means of sidings (also known as loops) placed at stations and/or other locations to allow an inferior train to yield to a superior train (qv trains, superiority of)
spare board – a list of junior men who are available to handle non-scheduled jobs, and to cover off sickness, holidays and so forth.
special work – an unusual or non-standard track formation that has to be made specially for that location.
spectacle – the coloured lenses portion of a semaphore signal.
spreader (Jordan) – a specially-designed railway vehicle whose various ploughs, wings and blades allow them to remove snow, build banks, clean and dig ditches, evenly distribute gravel, as well as trim embankments of brush along the side of the track. The Swiss army knife of trackside maintenance.
spur – a track for “spotting” (setting off) cars at a plant, etc. Also a remainder of a portion of a main line after partial abandonment, e.g., the (name) Spur.
station – a place designated in the timetable by name. A station is usually a building with an agent (qv) in charge, that handles passenger and freight traffic, but it could also be just a sign board by the side of the track, that may coincide with the former location of a station building or flag stop shelter or platform.
stop block – a pile of ties, a “half moon”-shaped metal block clamped to a rail, or a large metal frame bolted to both rails with a transverse wooden or metal bar at the same height as the coupler. A track with a stop block is a spur, a doubling track or a yard track.
string of cars – see cut of cars.
subdivision – a lesser operating section within a division (qv). Typically, a division would consist of numerous subdivisions, in the GTR known as districts.
sun kink – a track knocked out of alignment by heat beyond the rail’s allowance to expand.
switch – As a noun: (in the UK, points). Also known as a turn-out; a track configuration that allows a train to pass from one track to another. The earlier design was a stub switch whereby a bending pair of rails were lined up with the “stubs” of the diverging tracks. (To throw a switch is still sometimes referred to as “bending the rail”.) The stub switches were replaced in the 1890s by point (in the UK, blade) switches, where one of the two moving points would line up with the desired track. A “facing” point switch is where one approaches the diverging tracks, a “trailing” point switch where one approaches from one of the diverging tracks. As a verb: to move cars around (in the UK, “shunt”). Terminology for the components of a switch varies according to country, but generally the outside rails are the stock rails. The moving rails of a switch are the blade, switch or point rails. The rails to which those connect are the wing, closure or connecting rails. The V-shaped component of the switch where the inside rails join is the frog. The short sections of rail that are placed on the inside of the stock rails opposite the frog are guard or check rails. The space between the check rail and the stock rail is the flangeway, the flange of a wheel being the raised wheel edge that keeps the wheel on the rail. A switchrod is one or more rods that hold together the blade, switch or point rails near their contact point with the stock rails. The operating rod is the rod that connects the switch assembly to the switch stand. The switch stand is supported by two headblock ties, and is the frame that consists of the lever "to throw the switch", together with a disk to indicate to the train crew the direction of the switch's alignment.
switch on the fly – see drop.
switcher – a locomotive employed exclusively in a yard to switch cars - sometimes referred to as a "yard goat". If a steam locomotive, it would have only driving wheels.
tank engine – a steam locomotive design without a tender (qv locomotive tender), where its coal is carried behind the footplate in a bunker and the water across (saddle) or alongside (panniers) the boiler.
team track – often used interchangeably with “siding”, but strictly speaking the track parallel to the main line at a station, usually nearest to the station with a combination freight shed, at which freight is delivered or picked up by the teams (of horses) or, latterly, by trucks.
telegraph – communication by wire of train orders and other railway business between a dispatcher and agent or telegraph operator, by means of a telegraph key/sounder and Morse railway code.
tender – see locomotive tender
terminal – a large installation, consisting of a passenger station, freight sheds, yards and locomotive and car servicing facilities.
throw a switch, (to) – to set a switch to allow a train to pass from one track to another (slang – to bend the rail).
tie – a wooden or concrete beam designed to hold two rails to the assigned gauge. (In the UK, “sleeper”.)
timetable – the authority for the movement of regular trains (i.e., those shown in the timetable, as opposed to “extra” trains, which are not), according to the rules. The timetable contains classified schedules with special instructions related to the movement of trains and includes other important information. The “schedule” is that part of the timetable which prescribes class, direction, number and movement of a regular train (see also trains, class of). Also referred to as an “employee timetable”, to distinguish it from a “public timetable” that is displayed or given to the public.
tower, interlocking – a building equipped with levers to operate signals at a crossing (qv) between separate lines of the same railway, or by different railways.
track – two rails fastened to wooden or concrete ties to form a track.
train – any engine with or without a consist, authorized by timetable or dispatcher, to move from point A to point B.
train engine – the engine assigned to a train from departure to destination. (As opposed to a helper or pusher engine (qv).
trainman – see brakeman.
train order – a written instruction or permission from a dispatcher to a train crew. For many years, there were two kinds of orders, the "31" order that had to be signed for, and the "19" order that could be delivered without taking a signature. The conductor could usually sign for a "31" order and deliver it to his engineman, so that he would not have to leave his engine and go to the office, which was inconvenient and time-consuming. The “non-restricting” "19" order was handed up to the train without a stop. A train order, as it was written on tissue paper, was often referred to as a “flimsy”.
trains, class of – in the pioneer period (1850 to 1880), trains were usually “express”, “mail”, “accommodation” or “freight”. During the later period and subsequently, trains came to be numbered as “first class” through to “fourth class”. Normally main line passenger trains would be “first class”. Some branch line passenger trains were “second class”. Mixed trains (i.e., trains composed of both freight and passenger cars and doing both freight and passenger work) would normally be second or third class. Freight trains were normally third or fourth class, or designated as “extra”.
train sections – in the event of heavy traffic, a train may be divided into "sections". As far as the timetable is concerned it is still one train, but is run in two or more sections.
trains, superiority of – a train is superior to another by right, class or direction. Right is conferred by a train order. Class or direction is defined by timetable. Right is superior to class or direction. On single track, direction is superior as between trains of the same class. Trains of the first class are superior to those of the second class, and so on. On single track, east- or southbound trains are superior to west- or northbound trains of the same class. (The timetable specifies the direction for the purpose of the determination of superiority.) Extra trains are inferior to regular trains.
transfer table – a track mounted on a moveable platform supported by rails in a transverse pit, that can transfer an engine to any one of a number of parallel tracks leading into a wide engine house with a large number of tracks. The transfer table can be fed by a single lead track.
trestle – a structure consisting of short, more or less equi-distant spans, built with local timber to carry a railway across a valley. Because of decay, fire, or instability for heavier trains, these were eventually filled in with earth (as an embankment) or replaced by bridges. (See also the Trestles, Bridges and Culverts Glossary below.)
triple-header – a train pulled by three engines.
turntable – a track mounted on a deck with a centre pivot in a circular pit; for turning or assigning a locomotive to a “stall” at the end of its run. The earlier ones were hand-operated (frequently referred to as “armstrong” tables). Others at smaller locations were equipped with a small compressed air engine at one end and powered by air from the locomotive. See also wye.
type – steam locomotives in particular are defined as to “type” by their wheel arrangement, which is also usually described by a name.
Common locomotive types are:
0-6-0 – six-wheel switcher (often referred to as a “yard” or “pony” engine)
4-4-0 – American
2-6-0 – Mogul
2-6-2 – Prairie
2-6-4 – Adriatic
4-6-0 – Ten-wheeler
4-6-2 – Pacific
4-6-4 – Hudson
4-6-4T – Baltic (T denotes tank engine)
0-8-0 – eight-wheel-switcher
2-8-0 – Consolidation
2-8-2 – Mikado
4-8-2 – Mountain
2-8-4 – Berkshire
4-8-4 – Northern
0-10-0 – ten-wheel switcher
2-10-0 – Decapod
2-10-2 – Santa Fe
2-10-4 – Selkirk or Texas
- The combination of numbers is known as the “Whyte” classification system. The first (0, 2 or 4) refers to the number of wheels on the pilot (leading) truck. The second (4, 6 or 8) refers to the number of driving wheels (drivers). The third (0, 2 or 4) refers to the number of wheels on the truck under the cab.
underpass – see overpass.
upper quadrant – the position of a semaphore signal arm that clears to above horizontal.
varnish – slang for a passenger train.
velocipede – an early hand-operated three-wheel inspection vehicle used by a section gang.
viaduct – a longer bridge structure supported by stone piers or steel towers. (See also the Trestles, Bridges and Culverts Glossary below.)
water station – a Grand Trunk Railway generic term for any place where a steam locomotive could take on water. This could be direct from a water tank or water tower, or from any kind of stand (usually located at the end of a station platform). Later, better known as a “water plug” or “stand pipe”.
water tank or tower – a tall circular or square frame or stone foundation that supports a (usually) round tank beside a track, from which the tender of an engine can be refilled with water. On the CPR some water tanks were totally encased in a wooden frame to prevent freezing.
way freight – merchandise handled at a freight shed and by way freight crews. Also, trains designated to handle and move way (freight) cars and do switching en route.
wayside – en route, along the right-of-way.
weight load – see live load.
Whyte classification system – see type
wye – a triangular track formation used instead of a turntable for turning a locomotive or cars. A wye requires more land but less maintenance, and has the added advantage of not having the same limitations of weight load or length as a turntable. Depending on the distance between the three switches, a wye could be used for turning a whole train. Preferred to a turntable also because it does not require to be dug out after snow storms.
yard – a system of tracks for the making up of trains, storing of cars and other purposes. A larger yard would be under the jurisdiction of an assistant superintendent, a trainmaster or a yard master. A yard at a smaller station, would likely be under the jurisdiction of the (station) agent (qv).
yard goat – slang for an engine employed on yard switching duties.
yard limits – that portion of main line trackage within limits defined by yard limit signs. Yard limits need not be near a yard, although they may be included. The signs exist to restrict the speed of trains entering any congested area, such as a busy junction. Yard limits do not restrict first and second class trains.
TRESTLES, BRIDGES AND CULVERTS
Excerpted from Hamilton’s Other Railway by Charles Cooper. Originally provided by Art Clowes.
Abutment – any kind of retaining wall at either end of a trestle or bridge which holds the abutting earth in place and provides an end-support. A “timber wall”, for instance, was a series of stout horizontal planks placed on top of each other to form a vertical wall to hold back the earth. These were held in position on the inside by the fill, and on the outside by a bent that also provided an end-support to the trestle or bridge deck. More modern materials commonly used for abutments are masonry, brick and concrete. Abutments usually also have wing walls to hold back the fill on either side of the approach as well. An essential feature of abutments constructed with any of the more modern materials is an indentation, known as a bridge seat or “shelf”, which receives the floor system of the bridge.
Batter – the outer piles of a trestle bent usually have an outward “batter” or slope, which provides stability to the horizontal load and counteracts sway from passing trains.
Bent – each complete set of vertical trestle supports. In the case of a timber pile trestle, a bent is simply the line of piles (usually four to six, but sometimes more) that have been driven into the ground.
Bracing – strengthening of a structure using the principle of triangular support. Bracing not only adds overall strength (especially to help withstand the secondary forces of the structure itself), but also, in the case of braced sets of piles or frame bents, counteracts the side-sway created by the passage of trains. (See also Cross brace and Longitudinal brace.)
Bridge – a structure consisting of plate girder, I beam or truss spans, intermediately supported, if needed, by piers at longer intervals than those of the closely-spaced pile, frame or steel bents of a trestle.
Bridge – deck-type – where the deck (floor system) is at the top of the structure. This design requires sufficient clearance over the water, railway or road below, and is described as a “deck plate girder” or a “deck truss” bridge.
Bridge – half-through-type – where the deck (floor system) is located somewhere between the top and the bottom of the structure. Referred to as a “half-through plate girder” bridge.
Bridge – plate girder – see Plate Girders.
Bridge – through-type – where the floor system is at the bottom of the structure. Referred to as a “through plate girder” or “through truss” bridge.
Bridge seat – an indentation or “shelf” in the abutment, designed to receive the deck (floor system) of the bridge.
Bridge ties – ties laid across the width of a bridge that are fastened to the stringers below with hook bolts, and support the rails on top.
Bridge – truss – truss bridges are commonly built of iron or steel (or of wood in the early days). They consist of two sets of chords, top and bottom, with a series of posts and braces as part of the truss form. See also Truss and Pony truss.
Cap – a heavy timber at the top of each frame bent or set of piles. The cap is spiked to its supporting structure, and in turn supports the stringers in the floor system.
Chord(s) – the top and bottom horizontal members of a truss. In any track-carrying structure, the top of a load-carrying member is said to be “in compression”, while the bottom is said to be “in tension”.
Cross brace (also X-brace) – a diagonally-crossed pair of timber or steel lengths, that brace or hold together:
• a set of piles or a frame bent; or
• longitudinally, two bents, usually on alternate spans; or
• rows of longitudinal bracing.
Culvert – a constructed opening under a railway track to allow water to flow from one side to the other, either for drainage or for unimpeded flow of a smaller water course.
Culvert – box – many early small culverts were simple box culverts. These could be built of either wood or stone. Either way, they were usually only two heavy timbers or two layers of stone high. The stone would usually be laid dry. If small and near enough to the track, they would be left open (without a top). Deeper ones would be covered, either with stone or a layer of timber, and then with fill. Some larger open top culverts would have stringers across the opening to carry the track. Since wood has a limited life, such culverts eventually needed to be replaced, usually with stone.
Culvert – stone arch – these vary considerably in size (with the larger ones resembling one-arch bridges), but all have earth fill between the arch and the railway track. Most of the better ones have a floor in the form of a very shallow “U” to keep the water to the middle, but large ones with considerable water flow may have flat floors. The inside walls are vertical to the water line. The angle of the wing walls to the culvert mouth varies, depending on the local situation. For culverts in a more open valley, the wing walls would probably run almost parallel with the track, much like the portal of a tunnel, but they could be at almost any angle to the embankment (with 45° being very common), depending on stream conditions, water flow, and what was considered the best way of retaining the embankment. Above the water line, the stone was cut to provide a semi-circle roof with a key stone at the top. As to the stones themselves, a cut narrow flat edge around the face of the stone indicates more care, and generally a better quality job, than those having a full rough face. A uniform mortar thickness also usually attests to a more experienced craftsman (a mason or an apprentice). Some contractors included enhancements, such as a carved (marble) keystone with the date of construction, sometimes with any or all of the contractor’s, engineer’s and stonemason’s names.
Deck (system) – the horizontal component of the trestle or bridge, designed to support the track. In the case of a trestle, the deck system consists of the caps, stringers and the bridge ties. In the case of a bridge, the deck consists of the floor beams, stringers and the bridge ties. (Today, many bridges use solid U-shaped plates over the stringers that permit the deck to be ballasted.)
Floor beams – are the equivalent on a bridge of caps on a trestle. Made of steel, they extend across the structure between the girders or trusses, and carry the weight loads from the floor system to the main girders; or, depending on their positioning, to the piers. It is rare, however, for bridge stringers to be supported on top of the floor beams. The stringers typically extend from floor beam to floor beam, and have clip angles on each side of the web at both ends. These are rivetted, bolted or welded to the web of the floor beam, in order to keep the floor system as shallow as possible.
Floor system – see Deck (system).
Frame bent – a pre-assembled bent, i.e., a set of vertical, square-cut, framed, ready-cross-braced timbers, is placed on top of the prepared piles. Frame bents provide a vertical structure to carry live loads from the caps to the piles.
Grade separation – another term for a trestle or bridge crossing another railway line or highway. From the perspective of the owning railway, a railway bridge over another railway may be appropriately referred to as an “overpass”, whereas the other railway would view it as an “underpass”. In the case of a highway, one over the railway would be viewed as an “overpass”, and one under the railway as an “underpass”.
Guard rails – rails placed on the inside of the running rails on a trestle or bridge. In the event of a derailment on the structure, the guard rails would deter the wheels from running off the deck. Guard rails are of interest to the railway historian because it was a common practice to use older, lighter (worn) rails for this purpose.
Headwall – a wall (parallel with the track) often found above the ends of older culverts to hold back (retain) the earth embankment, thus preventing it from sliding into the waterway. In the case of larger culverts, the headwall was combined with wing walls to provide this retention. Because of cheaper materials, e.g., corrugated metal pipes, and today’s mechanized earth moving, newer culverts tend to be longer, and require little or nothing in the way of headwalls.
Live load – the force exerted by a train on a structure such as a bridge or turntable.
Longitudinal brace – a timber that runs longitudinally (horizontally) between bents for the full length of the structure, to help maintain the piles or bents in a vertical position. These braces are normally spaced at 8 ft to 10 ft intervals between the top and bottom of the structure. There are always braces at the battered piles, and usually a number of inside braces as well.
Overpass – see Grade separation.
Pier – an intermediate bridge support formerly built of masonry or, if readily available, brick. (The material used would almost invariably match that used for the abutments.) An earlier, cheaper form of construction (because of the ability to use unskilled labour), was a timber box filled with stone or rip-rap. Another early form of pier was two pile bents spaced closely together and cross-braced, so as to constitute one solid support. Today, concrete is the choice for building piers and abutments.
Pile – a round timber pole (a tree with the bark and limbs removed) driven vertically into the ground to support a structure. For trestles, piles are driven usually four, five or six in a row to form a single support, called a bent. It should be noted that most bridges have piles driven under their piers and abutments. Generally, all piles, whether used as bents or as footings, would be driven with the small end down, to help develop friction with the soil. From around the beginning of the 20th century, piles have been creosoted to help them last longer, especially where they are exposed to wet/dry cycles.
Pile driver – a very old application. The first ones used, at the start of the railway building era, were “drop hammers”. These were usually a block of iron on a pair of vertical guides. Horse-power was used to lift the iron block, which would then be allowed to fall free, driving a timber pile into the soft soil. The horse-power could be one to four horses. The slowness of this process often gave less than desirable results.
- As the design of the stationary steam engine improved, while the drop hammer principle was still employed, the horses were replaced. Steam power was quite well established by 1875-80. With steam-powered pile drivers, end-bearing piles (resting on bed-rock) became more common (as opposed to the earlier “friction” piles, which relied for their support on the soil around them). Today, most pile drivers are diesel-powered, consisting of a self-contained double-acting single cylinder. The cylinder can rest right on the pile as it is being driven, thus obtaining fast penetration.
Plate girders – steel mills typically roll standard shapes, i.e., various weights of rails, standard size plates, L angles and I beams. Steel mills have a maximum size of roller for forming rolled sections, and if a deeper or longer beam is required, it has to be built. Girders larger than rolled I beams are made up of plates and L angles. For many years these were riveted, but today most girders just use plates that are welded. From the early 1960s onwards, repairs to large existing structures have usually had their rivets replaced with high-tensile bolts.
- Plate girder bridges have the girders built up from various-sized plates. Typically, a plate girder frame consists of vertical web plates and horizontal top and bottom plates, called “flange plates”. The flange plates work on the same principle as the chords of a truss. They are connected in the middle by the vertical web plates. The whole girder is held together with L angles, rivets and, today, smaller welded plates or stiffeners. Girders get considerable extra support from these L angle or stiffener plates that are fastened and extend between the top and bottom flanges along the web. In addition to stiffening the structure to prevent buckling, these L angles and stiffeners also provide support for internal bracing.
- As noted, the deck (floor system) of a bridge, because of its design and location, provides one layer of horizontal bracing between the two outside girders, or trusses.
Pony truss – where, because of site conditions (e.g., lack of clearance) a truss is built with extra strength but less height, it is known as a “pony truss”. Where the deck is at the top of the structure, it is known as a “deck pony truss”. Where the deck is located at the bottom, it is usually known simply as a “pony truss”. Pony trusses are often used for spans shorter than those requiring a full through truss, therefore their depth (the distance from the top to the bottom chord) does not need to be as great as that of a through truss.
Refusal – the point at which a driven pile strikes rock.
Released girders – girders “released” from a bridge at the time of its reconstruction and re-used elsewhere, usually for a smaller structure on a railway line with less or lighter traffic. (Many of them also were re-used for highway structures.)
Shelf – see Bridge seat.
Span – the distance between the series of supports (bents) on a trestle, or piers on a bridge. Since a bridge span is usually much longer than a trestle span, the materials needed to support the live loads on bridges need to be considerably stronger than those for trestles. This entails more substantial piers, girders or trusses, as well as heavier abutments.
Stiffeners – see Plate girders.
Stringers – the longitudinal component of the deck (system) of a trestle or bridge. In the case of a trestle, originally heavy squared timbers, later replaced by plate girders or I beams. In the case of a bridge, plate girders and I beams. Stringers carry the live load from the rails and bridge ties and spread it to the piles, girders or trusses and then downward to the foundation. See also Deck (system) and Floor beams.
Trestle – a structure consisting of short, roughly equidistant spans. In the early days, timber trestles were light, often built with local timber, and the piles were generally carried up to the deck level (a timber pile or pile trestle). As with all structures, trestles evolved in their design and the materials used. Soon, better and treated piles were used. In the period of the trestles’ reconstruction, the piles were often cut off near the ground level, and frame bents were used between the ground and the deck structure where the distance in-between warranted this (thus, a timber frame bent, or frame bent trestle). The frame bent trestle design was also used where the piles had to be driven very deep, and the timbers were not long enough to reach the deck height; and also in the case of higher trestles that necessitated two or more layers of bents, giving the structure the appearance of a multi-storied building. Because of decay and fire, many trestles were replaced with culverts, bridges or fill. In more recent times, steel piles and floor systems came into common use.
Truss – any assembled support frame constructed from timber, iron or steel that provides sufficient support for a span longer than that afforded by a girder. Trusses do not have solid webs, but are made up of a series of posts and braces. There are two basic truss styles, the King Post (for shorter spans) and the Queen Post.
- Advanced truss designs are, for example, Howe, Bollman, Whipple, Lattice (or Town), Warren, Pratt, Baltimore, and so forth). They all work on the same basic Queen Post truss principle, with top and bottom horizontal members, called “chords”, and various patterns of “posts” and diagonal bracing, from which the various designs are determined. The most common advanced design of the earlier era was a Howe truss. For lesser bridge works, 50 ft span Queen Post trusses were often used.
Underpass – see Grade separation.
Viaduct – in Canadian railroading, viaducts are generally structures supported by steel towers. These towers consist of two bent-like structures linked by bracing to each other to form a separate self-supporting structure. However, this term is also commonly used to describe a long bridge with piers, or a steel frame trestle that is usually, but not necessarily, of great height. There are also many examples of arched viaducts built of masonry or brick. Some structures are a classic viaduct, but others may be better classified as bridges, although also referred to as viaducts.
Wall – timber trestles generally have a wooden wall at each end, called a back wall or dump wall. The term “wood wall” or “timber wall” describes a vertical wall that holds back the earth and provides support for the deck, performing the same function as a bridge abutment.
Web – the steel plate that defines the height of a girder, and provides support for the stiffeners, etc. See also Plate girders.
Weight load – see Live load.
Wing walls – walls at any angle around the bridge abutment or culvert to support or hold back the earth fill of the embankment. See also Headwall.