{{Use British English, date=April 2020 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 The Historical Railways Estate (HRE) is a group of over 3,200 structures—predominantly bridges, but also including tunnels, embankments, and other works—associated with former railways in the United Kingdom. The structures are owned by the Depa ...

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 & chainage, for emergency 'phone contact to Network Rail whether or not, the bridge carries track. 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 C ...

running from

Charing Cross Charing Cross ( ) is a junction in Westminster, London, England, where six routes meet. Clockwise from north these are: the east side of Trafalgar Square leading to St Martin's Place and then Charing Cross Road; the Strand leading to the City; ...

via

Tonbridge Tonbridge ( ) 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 Malling, it had an estimated population ...

Dover Priory The Priory of St. Mary the Virgin and 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 the Augustinian r ...

, and ''VTB'' is the

Brighton Main Line The Brighton Main Line (also known as the South Central Main Line) is a major railway line in the United Kingdom that links Brighton, on the south coast of England, with central London. In London the line has two branches, out of and station ...

from

Victoria Victoria most commonly refers to: * Victoria (Australia), a state of the Commonwealth of Australia * Victoria, British Columbia, provincial capital of British Columbia, Canada * Victoria (mythology), Roman goddess of Victory * Victoria, Seychelle ...

Brighton Brighton () is a seaside resort and one of the two main areas of the City of Brighton and Hove in the county of East Sussex, England. It is located south of London. Archaeological evidence of settlement in the area dates back to the Bronze A ...

. 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 Line ...

(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''. Bridge miles and chains

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 Earsdon Junction to Morpeth North Junction (''hence the ELR of EJM''). The bridge shown in the associated photograph is located at 112M 63ch on ELR ''MLN''; this ELR has subsequently been superseded by ELR ''MLN1'', Paddington - Bristol - Penzance (Paddington - Change of Mileage - Plymouth Station West). As at 2020, there were a total of 1,595 ELRs on Network Rail infrastructure.

External links

An authoritative public domain reference to ELRs is available on Phil Deaves
Engineers' Line References page
Rail infrastructure in the United Kingdom