European Rail Traffic Management System in Great Britain


The European Rail Traffic Management System is an initiative backed by the European Union to enhance cross-border interoperability and the procurement of signalling equipment by creating a single Europe-wide standard for train control and command systems.
Its main components are European Train Control System and GSM-R communications system. ETCS is a standard for track-train radio communications using balises and associated in-cab train control while GSM-R is the GSM mobile communications standard for railway operations. ERTMS can operate at different levels depending on specific local requirements. Under ERTMS speeds are displayed in the driver's cab in km/h and at Level 2, lineside speed indicators are optional.

History

In 2007 the British Government published its response to a European Union directive requiring the use of ERTMS on High Speed and Conventional Trans-European Railway Network routes. The response proposed a roll-out plan of ERTMS equipment on existing lines that would be completed by 2044 though the actual timing of the programme will depend on changing circumstances – new trains will be ordered with ERTMS equipment on board and ERTMS would be installed during any electrification programs.
In 2009, the Rail Safety and Standards Board confirmed that km/h would be used on ERTMS lines in the United Kingdom.
With the ongoing introduction of ERTMS, it is foreseen that the metrication of British rail transport will be completed over the next few decades.
The Uff/Cullen inquiry following the Southall and Ladbroke Grove rail crashes identified a need for in-cab signalling on high-speed trains and recommended that ERTMS should be installed onto all of Britain's high-speed lines by the year 2010. However, this timescale was not viable because of the time required to develop the technology.

Features and current implementation

A standard feature of the speedometers used by ERTMS/ETCS systems is the use of the metric system.
At a Railway Conference in 2002, it was argued that a changeover to using metric units for speed in advance of the introduction of ERTMS was unlikely to be financially viable unless the decision is taken to adopt Level 2 ERTMS without lineside signalling. There would however still be a need to handle dual both mph and km/h.
A 2010 voluntary standards document published by the Rail Safety and Standards Board addressed this issue when it recommended that the speedometer of a ETCS system be designed so that it switches automatically between mph and km/h depending on the route being traversed. The speedometer would display "mph" when the speedometer was displaying "miles per hour", otherwise would display nothing. Its graduations would be chosen such that the angle of the needle would not change when the system switched from one scale to the other. The conversion between metric and imperial units would be a function of the speedometer, not of any other on-board equipment. In 2012 a technical specification matching this proposal was published.
The Cambrian Line, a low volume rail link between Shrewsbury in the east and Aberystwyth and Pwllheli in the west, was chosen as Britain's first ERTMS line. This line was chosen as its signalling system had reached the end of its useful life, and because it is a low capacity line almost separate from the national network, making it an ideal site on which to gain ERTMS experience. All speeds in the Cambrian Line Rule book are in km/h." ERTMS will be rolled out on the Great Western Route as part of the electrification and resignalling work which is expected to reach Oxford and Newbury by 2016 and Cardiff by 2017.

Future use

Other early mainline conversions to the ERTMS standards are expected to include of the East Coast Main Line from London to Doncaster and of the Midland Main Line from London to Leicester while the specification for the proposed High Speed 2 link from London to Manchester, Leeds and beyond assumes a minimum of Level 2 ERTMS control and signalling for the "day one service". The Crossrail project in London will also implement ERTMS technology.
In February 2016, Network Rail announced that it was considering a trial of ERTMS on the Wherry Lines from Norwich to Lowestoft and Great Yarmouth in the East Anglia. This will be followed by a national roll-out, which will be carried out in stages with each of the twelve Rail Operating Centres being upgraded at a different time.