Rail features are defined as features related to travel by railway or tramway. The exception to this is railway tunnels, which are currently in the Structures theme. OS MasterMap Topography Layer contains information relating to permanent railways that form the network between two points, for example, from railway station to railway station, or from an industrial building to a private quarry.
Standard-gauge railways are shown to scale by a pair of rails and represent tracks 1.435m apart. Railways narrower than 1.435m are deemed to be narrow gauge and are shown by a single line representing the central alignment. Tramways, metros, and light-rapid-transit systems are treated as railways.
Underground portions of the Metropolitan and District lines in London that are close to surface level are shown; where a deep-level tube railway comes to the surface and continues as a normal railway, it is shown as a standard-gauge railway. In other cities, only the sections of underground railways that are open to the sky are currently shown.
Physical features shown in the Rail theme include:
Level Crossings
Lighting Towers
Loading Gauges
Turntables
Mile or Kilometre Posts and Stones
Sand Drags
Signal Posts, Bridges, and Gantries
Switches and Slips
Retarders
Bridges and Viaducts
Mail Pick-ups
Rails
Permanent Ways
Station Buildings and Platforms
Some physical features are not shown in the Rail theme:
Telephones associated with Level Crossings
Conductor Rails and Overhead wires for electrified trains
Detail beneath the roofs of Railway Stations
Water Troughs
Repetitive Features, such as signal lights within marshalling yards
Some non-physical features are shown in the Rail theme: these are text descriptions of railway and associated railway features.