British Rail Telecommunications

British Rail Telecommunications was created in 1992 by British Rail (BR). It was the largest private telecoms network in Britain, consisting of 17,000 route kilometres of fibre optic and copper cable which connected every major city and town in the country and provided links to continental Europe through the Channel Tunnel.

Britain's railways have made use of telecommunications in their operations since the late 1830s, having commissioned the first commercial electric telegraph line in the world. Furthermore, several of the first switched voice networks were installed by British railway companies. Under BR, the use and capability of telecommunications expanded greatly; early moves included the adoption of teleprinters, leading to the creation of the National Teleprinter Network (NTN) in the late 1970s. In the late 1960s and early 1970s, under the National Telecoms Plan (NTP), a nationwide co-axial cable based 4 MHz system was installed, which provided transmission bearer services for both voice and real-time data networks. This network was an essential component for the increasing use of real-time centralised control and information systems, such as the TOPS computer system used by BR for managing railway locomotives and rolling stock across its network. BR also operated its own national trunked radio network, providing dedicated train-to-shore mobile communications; this was eventually replaced by the GSM-R radio system in the early 21st century.

In 1992, as a part of the wider reorganisation in advance of the privatisation of British Rail, BR Telecommunications Limited (BRT) was created as a separate entity. In 1995, BRT was acquired by Racal Electronics to create Racal-BRT. This entity merged with Racal Network Services (RNS) in 1997, rebranding as Racal Telecom. Following further restructuring and acquisitions, much of what had been BRT was merged into Thales Telecommunications Services (TTS) in April 2002. In the 2000s, the national railway infrastructure owner Network Rail decided to replace the transmission systems that had been sold off with a new nationwide fibre network, known as the Fixed Telecommunications Network (FTN), in conjunction with the rollout of GSM-R.