An Engineer's Line Reference (ELR) is a three alpha, or four alpha-numeric, code used to uniquely identify a railway line on the main-line railway of Britain owned, or maintained, by Network Rail but official railway records retain the ELR codes for lifted branch lines and any structures such as bridge abutments, tunnels, viaducts, retaining walls etc., still maintained by the former British Railways Properties Board. Highways England's Historical Railways Estate group succeeded that organisation and further changes recently came about with the National Highways Organisation. Such structures are identified on records by the locational branch mileage and chainage and is repeated on the actual structure and therefore essential for reporting to site for works projects and maintenance, and most important, for any mishaps. In particular, bridge strikes are still prevalent by high-sided vehicles and Network Rail fix a metal plate to bridge abutments giving the bridge name, mileage and chainage, for emergency 'phone contact to Network Rail whether or not the bridge carries track. Bridge miles and chains

An ELR is formed of a minimum of three upper-case letters identifying the line, normally using acronyms or abbreviations of the names of the primary locations (junctions or principal railway stations) they connect. For example, ''XTD'' is the

South Eastern Main Line The South Eastern Main Line is a major long-distance railway route in South East England, UK, one of the three main routes crossing the county of Kent, going via Sevenoaks, Tonbridge, Ashford and Folkestone to Dover. The other routes are the ...

running from

Charing Cross Charing Cross ( ) is a junction in Westminster, London, England, where six routes meet. Since the early 19th century, Charing Cross has been the notional "centre of London" and became the point from which distances from London are measured. ...

via

Tonbridge Tonbridge ( ) (historic spelling ''Tunbridge'') is a market town in Kent, England, on the River Medway, north of Royal Tunbridge Wells, south west of Maidstone and south east of London. In the administrative borough of Tonbridge and Mall ...

Dover Priory The Priory of St. Mary the Virgin and Martin of Tours, St. Martin of the New Work, or Newark, commonly called Dover Priory, was a priory at Dover in southeast England. It was variously independent in rule, then occupied by canons regular of t ...

. To ensure uniqueness, and convey local geographic (rather than railway principal junction or station) naming convention, an ELR may be formed of commonly-referred nomenclature, e.g. ''NKL'' is the railway line between North Kent East Junction and Dartford Junction, but is more frequently referred to as the

North Kent Line The North Kent Line is a railway line which branches off the South East Main Line at St Johns junction west of Lewisham station in Greater London and runs to Rochester Bridge Junction near Strood, Medway where it links to the Chatham Main ...

(hence, the ELR). A mandatory requirement of an ELR is that the mileage within it must be unique. Where a section of track is made up of several pre-existing routes, or where a mileage changes or reversal is present, the ELR is suffixed with a single digit (1 to 9). For example, the ''East Coast Main Line'' route from London King's Cross station to Edinburgh Waverley station is formed of ELRs ''ECM1'' (King's Cross to Shaftholme Junction) through to ''ECM9'' (Edinburgh Waverley station) with intermediate ELRs of ''ECM2'', ''ECM3'', ''ECM4'', ''ECM5'', ''ECM6'', ''ECM7'' and ''ECM8''. Similarly, the

Brighton Main Line The Brighton Main Line is a railway line in southern England linking London to Brighton. It starts at two termini in the capital, and , and the branches from each meet at , from where the route continues southwards via to the coast. The line ...

from

London Victoria Victoria station, also known as London Victoria, is a London station group, central London railway terminus and connected London Underground station in Victoria, London, Victoria, in the City of Westminster, managed by Network Rail. Named afte ...

Brighton Brighton ( ) is a seaside resort in the city status in the United Kingdom, city of Brighton and Hove, East Sussex, England, south of London. Archaeological evidence of settlement in the area dates back to the Bronze Age Britain, Bronze Age, R ...

is formed of ELRs VTB1, VTB2 and VTB3. As the mileage within an ELR cannot be duplicated, any main-line railway location on Network Rail owned, or maintained, infrastructure can therefore be uniquely identified by a combination of ELR and mileage. For example, ''EJM 13M 16ch'' refers to Plessey Road level crossing on the former Earsdon Junction to Morpeth North Junction route (''hence the ELR of EJM''). The bridge shown in the associated photograph is located at 112 miles 63 chains on ELR ''MLN''; this ELR has subsequently been superseded by ELR ''MLN1'', Paddington - Bristol - Penzance (Paddington - Change of Mileage - Plymouth Station West). As at 2023, there were a total of 1,590 Engineer's Line References listed within the Network Rail infrastructure geospatial model.

References

{{Reflist

External links

Engineer's Line References page from Railway Codes

Engineer's Line References from the Signalling Record Society

Engineer's Line References index page from GeoFurlong
Rail infrastructure in the United Kingdom