Open main menu
Home
Random
Recent changes
Special pages
Community portal
Preferences
About Wikipedia
Disclaimers
Incubator escapee wiki
Search
User menu
Talk
Dark mode
Contributions
Create account
Log in
Editing
TOPS
(section)
Warning:
You are not logged in. Your IP address will be publicly visible if you make any edits. If you
log in
or
create an account
, your edits will be attributed to your username, along with other benefits.
Anti-spam check. Do
not
fill this in!
===TOPS numbering under British Rail=== {{Details|British Rail locomotive and multiple unit numbering and classification#1973 numbering and classification - TOPS|British carriage and wagon numbering and classification}} [[File:British Rail Class 31-4 dataplate.jpg|thumb|''Brush Type 2'' locomotives became [[British Rail Class 31|Class 31]] under TOPS. This is the data panel from a Class 31/4; the 31/4 subclass being used for locomotives with [[Electric Train Heating]].]] Sequentiality was all that was required but, given the need to renumber, it was decided to adopt a logical system for classification, and the five- or six-digit TOPS number was divided into two parts. No class of locomotive or [[multiple unit]] numbered over 1,000 examples, so the last three digits were used for the individual number between 001 and 999 in that class, although [[British Rail Class 43 (HST)| Class 43]] goes down to 000, that being the number of the only remaining [[British Rail Class 41 (HST)|HST prototype]] power car. The first two or three digits were used to denote the class of locomotive or multiple unit. The numbers were often written in two space separated groups, such as "47 401" to highlight that division, but the TOPS system actually stored and displayed them without the space: "47401". Sub-classifications were indicated in the TOPS system with a slash and a subclass number, e.g. "47/4". It was convention, though not enforced within the TOPS system, that subclass numbers were boundaries in the locomotive numbering system, such that class "47/4" started with number "47 401". If there were more than 99 numbers in a subclass, the number series extended to the next value of the third digit; thus, since there were more than 200 locomotives in class "47/4", subclasses "47/5" and "47/6" did not exist, and the next valid subclass by convention was "47/7" starting with "47 701". However, in some cases, the sequences do not match, e.g. [[British Rail Class 158|158/'''0''']] numbers start at 158 '''7'''01. Locomotives are assigned classes 01β98: diesel locomotives 01β79 (originally 01β69), AC electric locomotives 80β96, departmental locos (those not in revenue-earning use) 97, and steam locomotives 98. DC [[electric locomotive]]s were originally allocated classes 70β79 but this was modified in 2011 (see [[British Rail locomotive and multiple unit numbering and classification]]); the sole relic of this is [[British Rail Class 73|Class 73]] which continues unrenumbered, probably because it can be considered equally a diesel locomotive as it is a DC electric. One oddity was the inclusion of British Rail's shipping fleet in the system as Class 99. [[Diesel multiple unit]]s (DMUs) with mechanical or hydraulic transmission are classified 100β199, with electric transmission 200β299. [[Electric multiple unit]]s (EMUs) are given the subsequent classes; 300β399 are overhead AC units (including AC/DC dual-voltage units), while Southern Region DC [[third rail]] EMUs are 400β499, other DC EMUs 500β599. More recently, new electric multiple units and [[Electro-diesel multiple unit|bi-mode multiple units]] have been given the 700 series and new [[High-speed rail|high-speed]] units have been given the 800 series. Selected numbers in the 900 series have been used for departmental multiple units, mostly converted from former passenger units. [[Coach (rail)|Coaching stock]] and individual multiple unit cars are allocated five-digit numbers; since the early 1980s, it has been forbidden for them to have the same numbers as locomotives, but before then duplication was possible because they carried a prefix letter, which was considered part of the number. More recent EMU deliveries have six-figure coach numbers.
Edit summary
(Briefly describe your changes)
By publishing changes, you agree to the
Terms of Use
, and you irrevocably agree to release your contribution under the
CC BY-SA 4.0 License
and the
GFDL
. You agree that a hyperlink or URL is sufficient attribution under the Creative Commons license.
Cancel
Editing help
(opens in new window)