page_title: Glossary of United Kingdom railway terms
section_title: S
hierarchical_section_title: Glossary of United Kingdom railway terms / S
context_page_description: This page contains a list of jargon used to varying degrees by railfans, trainspotters, and railway employees in the United Kingdom, including nicknames for various locomotives and multiple units. Although not exhaustive, many of the entries in this list appear from time to time in specialist, rail-related publications. There may be significant regional variation in usage.
context_section_description: Shed
  A Canadian-built Class 66 diesel-electric locomotive (from the roof shape and also the corrugated bodysides)
  Shunter
  A small locomotive used for assembling trains and moving railroad cars around
  A person involved in such work
  Signal passed at danger (SPAD)
  An incident when a train passes a stop signal without authority
  Signal-post telephone (SPT)
  A direct no-dial telephone link to the relevant signal box, positioned on or near a signal
  Silver bullet
  China Clay slurry wagons
  Six foot
  The space between a pair of adjacent lines, nominally six feet wide. See also four-foot and ten-foot.
  Skipper
  Class 142 DMUs
  Slack
  A temporary speed restriction to protect, for example, sections of track in poor condition and awaiting repair. Also applies to the timing tolerance included in timetable schedules to allow for such restrictions.
  Slack action
  Looseness in a train caused by mating clearances in couplers
  Slam-door train
  Any diesel or electric multiple unit with manually opening hinged doors (mostly the British rail classes 423 and 421), so called after the noise made by passengers slamming the doors
  Sleeper
  Bars of wood or concrete placed beneath and perpendicular to track to support the rails
  Slim Jim
  Narrow-bodied version of the British Rail Class 33 diesel-electric locomotive (identified as sub-class 33/2)—built for the confined loading gauge on the Hastings line. See also Crompton).
  Slip coach
  A passenger coach that is disconnected from a train without the train having to stop. While the train continued on its route, the slip coach would be guided and stopped by a guard on board using the coach's own brake mechanism. This practice was almost entirely limited to the United Kingdom and was discontinued in the 1960s.
  Spinner
  A Midland Railway 115 Class steam locomotive, due to their large driving wheels
  Splut
  Another nickname for the British Rail Class 25, referring to their habit of spluttering when their engines cut out and failed, which they often did. See also Rat.
  Station pilot
  A shunting engine based at a major passenger station and used for passenger-train shunting duties
  Stop and examine
  A now-defunct British Railways rule which required a train crew to stop the train and examine the cause of an unexpected noise, vibration, etc. Section TW of the Network Rail rulebook covers the requirements when working a modern train.
  Subway
  A tunnel passing underneath the railway tracks to allow passengers to cross from one platform to another
  Super 60
  A rebuilt class 60, upgraded by DBS. Mainly seen in an overall red livery, with half-yellow fronts, but a couple can be seen in the original Sector livery.
  Superelevation
  The banking of railroad track on curves. Specifically, the practice on high speed lines (where the cant needs to be higher) of gently introducing the elevation of the outer rail before the bend starts, in order to avoid sudden lurches. Synonymous with cant.
caption: The roof shape on Class 66 diesel locos resembles that of a garden shed.
exif: {"Image Make": "Panasonic", "Image Model": "DMC-FZ20", "Image Orientation": "Horizontal (normal)", "Image XResolution": "72", "Image YResolution": "72", "Image ResolutionUnit": "Pixels/Inch", "Image Software": "Ver1.0", "Image DateTime": "2005:02:23 17:03:21", "Image YCbCrPositioning": "Co-sited", "Image ExifOffset": "418", "Image PrintIM": "[80, 114, 105, 110, 116, 73, 77, 0, 48, 50, 53, 48, 0, 0, 14, 0, 1, 0, 22, 0, ... ]", "Thumbnail Compression": "JPEG (old-style)", "Thumbnail Orientation": "Horizontal (normal)", "Thumbnail XResolution": "72", "Thumbnail YResolution": "72", "Thumbnail ResolutionUnit": "Pixels/Inch", "Thumbnail JPEGInterchangeFormat": "6804", "Thumbnail JPEGInterchangeFormatLength": "6837", "Thumbnail YCbCrPositioning": "Co-sited", "EXIF ExposureTime": "1/6", "EXIF FNumber": "8", "EXIF ExposureProgram": "Aperture Priority", "EXIF ISOSpeedRatings": "100", "EXIF ExifVersion": "0220", "EXIF DateTimeOriginal": "2005:02:23 17:03:21", "EXIF DateTimeDigitized": "2005:02:23 17:03:21", "EXIF ComponentsConfiguration": "YCbCr", "EXIF CompressedBitsPerPixel": "4", "EXIF ExposureBiasValue": "-133/100", "EXIF MaxApertureValue": "3", "EXIF MeteringMode": "Pattern", "EXIF LightSource": "Unknown", "EXIF Flash": "Flash did not fire, compulsory flash mode", "EXIF FocalLength": "111/10", "EXIF FlashPixVersion": "0100", "EXIF ColorSpace": "sRGB", "EXIF ExifImageWidth": "1280", "EXIF ExifImageLength": "960", "Interoperability InteroperabilityIndex": "R98", "Interoperability InteroperabilityVersion": "[48, 49, 48, 48]", "EXIF InteroperabilityOffset": "6652", "EXIF SensingMethod": "One-chip color area", "EXIF FileSource": "Digital Camera", "EXIF SceneType": "Directly Photographed", "EXIF CustomRendered": "Normal", "EXIF ExposureMode": "Auto Exposure", "EXIF WhiteBalance": "Auto", "EXIF DigitalZoomRatio": "0", "EXIF FocalLengthIn35mmFilm": "67", "EXIF SceneCaptureType": "Standard", "EXIF GainControl": "None", "EXIF Contrast": "Normal", "EXIF Saturation": "Normal", "EXIF Sharpness": "Normal"}