Adhesion (grip) – binding together of surfaces of physical bodies or solid or liquid particles (for example, a “smooth” railway wheel moving on a “smooth” rail requires adequate pressure applied on the rail to eliminate slipping, so-called adhesive weight).
Atmospheric steam engine – a type of a steam engine in which the pressure of steam produced by heating up water is similar to atmospheric pressure.
Block signalling – a railway traffic safety device used to control the movement of trains on the route allowing a safe distance to be maintained between trains – the route is divided into
a series of blocks to increase its capacity. Block signalling can be single direction or bi-directional. Depending on the technical solution adopted, block signalling can be semi-automatic or automatic.
Semi-automatic block signalling – this type of block signalling requires an external confirmation from a train dispatcher that the whole train has left the block (based on the observation of train end signals) before the block is released. Generally, the semaphore automatically conveys the “stop” signal (red light) and this signal is changed to the order of a train dispatcher.
Automatic block signalling – also known as Track Circuit Block, used for heavy train traffic, which requires a short distance between blocks. The railway route between stations is divided into blocks the length of which depends on the number and speed of trains. Automatic block signalling automatically releases signals allowing trains to enter. In basic block status (no obstruction), the signal automatically gives the proceed message (green light).
Cylinder – an element of a mechanical structure forming part of, e.g., a motor, a pump, a brake, with a piston moving inside.
Echelon – military transport unit, e.g. a set of railway wagons carrying supplies.
Inverter – a device changing direct current from its own supply system into alternating current with controlled output frequency. Inverters also enable control of output voltage.
Electromagnetic track brake – a brake used in railborne vehicles to shorten the braking path in an emergency situation. A track brake makes use of electromagnetic force produced between the braking shoe and the rail. When current is applied to the brake coil, the shoe is immediately pulled against the rail head and afterwards the vehicle brakes sharply, regardless of the weather.
Automatic brake – a brake that is actuated automatically when the wagons are disconnected.
Fire-tube boiler – a boiler in which so-called smoke tubes are used next to furnace tubes in order to increase the heatable surface. Smoke tubes had smaller diameter and carried hot flue gas from the furnace of the boiler.
High-speed railway – railway lines and rolling stock adapted to reaching speeds exceeding 124 mph (200 km/h).
Magnetic levitation railway – railway in which tracks are replaced by a system of electromagnets
Axle set wheel – the fundamental element of an axle set generating the rolling motion. There are two main types of rail wheels: ring and monoblock wheels.
Wheels with undercut flanges – they are used in some railborne vehicles in order to facilitate the negotiation of small curves.
Commutator – an element of an electric motor or electrical generator used for reversing the direction of current in the motor winding.
Traction (train) locomotive – a locomotive used to haul trains (freight, passenger or wagon transfer trains) between stations, characterised by relatively high power and maximum speed, in differentiation from a shunting locomotive the operating range of which is limited to one station only.
Shunting locomotive (shunter) – a locomotive designed for shunting work, usually not capable of developing high speeds. A shunter normally has a single driver booth because it often changes its travelling direction.
Box tilt mechanism (tilting body) – a mechanism enabling the vehicle body to tilt on curves, enabling considerable acceleration. It contributes to a reduction in the impact of centrifugal acceleration on the passenger.
Gear drive – a type of drive making use of an additional rack-rail located between the rails, on which the driving wheel or the braking gear moves. Rack-and-pinion (or cog) railways can be used on significantly sloping territory, on part of or a whole route.
Rolling resistance – resisting force occurring when a railborne vehicle and preventing the rolling movement – connected with friction force.
External and internal frame – a frame of a rail vehicle. Depending on its location – an internal frame is located on the inside of the wheel, and external frame – on the outside.
Crank axle – a crankshaft composed of two arms and a pivot whose axis is parallel to the axle of the shaft; the crank is used to convert reciprocating motion into rotary motion.
Pantograph – a device for collecting power from an overhead traction network and supplying it to the vehicle.
Steam turbine locomotive – a steam locomotive making use of a steam turbine and electrical transmission to utilise energy from coal combustion for heating water in the boiler and then generate electric energy (in a turbine-generator arrangement) conveyed to electric traction motors.
Steam locomotive with a flywheel – a type of locomotive with a steam engine equipped with a flywheel which made it possible to maintain mechanical energy for a brief moment.
Line shafts – wire elements connecting mechanical and driving devices (point machines, switch locks, etc.) with the signal box.
Smoke tube – the smaller fire tube inside the boiler drum of
a steam locomotive. Hot flue gas passes through this tube from the furnace to the funnel and heats water in the boiler.
Track tamper – a type of track maintenance machine for ballast compacting.
Sleeper – cross beams laid under rails to maintain uniform gauge of tracks, transfer the pressure of rails onto the ballast and ensure lengthwise and lateral track shift resistance. With regard to materials used, sleepers can be divided into: concrete, wooden, steel and composite ones.
Traction substation – a power device supplying properly converted electric energy from a power network to a traction network.
Mercury-arc rectifier (ignitron) – a rectifier converting alternating current into direct current, designed like a gas-filled tube; current is converted by electrical discharge of mercury vapours. Their drawback was the emission of small amounts of toxic mercury vapours.
Electrical transmission – a transmission converting the torque of an internal combustion engine into electrical energy generated by an electric generator; the resultant energy is then transmitted to electric traction motors.
Hydraulic torque converter – a type of a two-stage transmission converting the torque of an internal combustion motor into kinetic energy of a fluid, e.g. oil in a pump. Afterwards, the fluid's kinetic energy is converted into mechanical energy in a turbine and transmitted onto the vehicle's axles.
Box – a part of the vehicle's body above the frame, whose function is to accommodate, protect and secure the transported cargo or passengers.
Electrical energy recovery – recovering electrical energy due to the fact that during braking an electric motor works as an electric generator, converting mechanical energy of a vehicle into electrical energy.
Leaf spring – a springing element of a vehicle's suspension built from flat steel bars known as leaves.
Normal, broad, narrow gauge – the spacing of rails within a track, for example 1,435 mm (4 ft 8 1/2 in) is a standard gauge in most railway administrations over the world and it is referred to as normal gauge. If the spacing of rails exceeds 1,435 mm, the track is referred to as broad gauge (1,520 mm, i.e. 4 ft 11 5/6 in – Russia, 1,668 mm, i.e. 5 ft 5 2/3 in – Spain and Portugal), and smaller spacing is called narrow-gauge (1,067 mm, i.e. 3 ft 6 in – Japan).
Fire-tube – the larger fire tube in a fire-tube steam boiler, on one side flushed by hot flue gas from the boiler and surrounded by water on the other side. It contains steam superheater elements.
Commutator motor – an electric motor in which the rotor is moved by the flowing current and magnetic field generated by the stator, where rotor winding is linked to
a commutator on which carbon brushes slide supplying current.
Traction motor – a motor used for driving axle sets (wheel sets).
Three-phase asynchronous or synchronous motor – an alternating current motor, supplied by three-phase current, in which:
• the rotor speed is equivalent to the speed of rotation of the
magnetic field generated by the stator (synchronous motor),
• the rotor rotates with a slip in relation to the rotating magnetic
field (asynchronous motor).
Compression-ignition engine (diesel engine) – an internal combustion piston oil engine different from a low compression spark-ignition This type of engine is characterised. Characterised by considerably higher maximum pressure of the working medium (fuel and air).
Compensated traction network – a traction network in which the catenary line and the contact wire are fastened to supporting structures by means of tensioning devices. All wires and catenary lines in such a network are subject to tension compensation in contrast to a semi-compensated network where only the contact wire is compensated.
Chain coupling – a device for coupling rail vehicles, similar to screw couplings, in which the screw is replaced by a number of chain links.
Screw coupling – a device for coupling rail vehicles.
Shunting station – a goods station used for coupling or uncoupling freight wagons.
Stator – a stationary part of an electric motor opposite to the rotor (moving part).
Stoker – a device for automatic feeding of coal from the tender into the furnace, used in high-power steam locomotives, i.e. equipped with a large furnace which could not be fed manually due to its size.
Flat-bottomed rails (Vignoles rails) – rails currently in use. They are characterised by rounded heads and a symmetrical flat bottom.
Optical telegraph – a type of telegraph the operation of which is based on observation of visual signals; superseded by an electric telegraph in the mid-19th century.
Tender – a vehicle permanently joined with a steam locomotive used to transport fuel (coal, timber) and water.
Piston – an element of a motor, pump, or brake, taking over or exerting pressure on gas, fluid or another medium, transmitting or receiving energy to or from such a medium.
Ballast – a type of aggregate material used to build railroad surface.
Traction – a method of driving rail vehicles (electric, steam, diesel traction).
Third rail – a form of current supply, most often using an additional live rail alongside the railway track.
Gas turbine – a device used to generate extremely high power, normally composed of a compressor and turbine and a combustion chamber between them; kinetic energy of gases released during fuel combustion is used to generate turbine torque that is transmitted to the electric generator (or compressor) through the shaft.
Springing of traction motors – a method of flexible suspension of traction aiming to minimise the levels of vibration and shock.
Coupling rod drive – a system transmitting drive from the motor through coupling rods onto the vehicle's wheels.
Axle guard – an element of a rail bogie maintaining the axle box in a specific position.
Diamond bogie – a type of bogie used in wagons characterised by a simple and inexpensive structure with a single transverse beam.
Points lock – an element securing a rail turnout by locking it in the right position during the passage of a train.