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100 years – A signalling centenary

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Many of today’s big railway signalling companies can trace their origins back for decades, some almost to the time when railways first became commercial operations. Almost none still carry their original name because acquisitions, mergers and expansion into other disciplines have altered the structure of the companies.

The technology of signalling has advanced beyond even the wildest dreams of the early pioneers and this situation continues today with the fantastic opportunities presented by the computer age.

One company that has recently celebrated a hundred years in the signalling business is Bombardier, which has duly produced a book to record the history and achievements of its ancestry over this period.

Early milestones

The first public railway, between Stockton and Darlington in NE England, was in 1825 and it was quickly realised that a means of fixed signalling was needed with the rapid growth of rail transport. Traditional semaphore signals were well established by 1840 and 1843 saw the first telegraph in operation.

In Sweden, signalling was implemented by ‘local workshops’. The company Ericsson began business in 1876 and entered the signalling business by producing its first mechanical interlocking in 1888. Then, in 1915, SJ (the Swedish Railway company) asked Ericsson to form a railway technical department, which became Signalbolaget (The Signal Company).

This is the date from which Bombardier measures its centenary. The initial business was focussed on export orders, with LM Ericsson supplying an electrical interlocking for Russia. Going forward from that beginning in 1915, the companies that today make up the present Bombardier Rail Control Solutions were busily engaged in developing some notable engineering advances.

The Bombardier heritage

Bombardier is a Canadian company that started life in 1937 making snowmobiles. Perhaps better known for its involvement in the aircraft business, it made its first acquisition outside Canada in 1971 and so entered the rail sector.

Having won a contract in 1974 for supplying the mass transit system for the Montreal subway, and following various mergers and acquisitions, Bombardier has become a global player in railways, both in signalling and rolling stock provision. The ancestral history of the signalling element is both interesting and complex.

  • 1915-1988 – Ericsson was the dominant signalling supplier in Sweden
  • 1929 – Ericsson established a signalling business in Spain
  • 1935 – Dansk Signal Industri (Denmark) acquired by Ericsson
  • 1957 – ML Engineering established in the UK
  • 1970 – Ericsson Signalling in Italy is founded
  • 1989 – Ericsson Signal business transferred to EBSignal, subsequently becoming ABB Signal
  • 1989 – ML Engineering acquired by EB Signal
  • 1990 – EB Signal starts business in Portugal
  • 1991 – ABB Signal India is established
  • 1992 – ABB Signal established in both Finland andPoland
  • 1996 – IVV in Germany, a company established in 1980by academics to plan mass transit and main line railway projects, is acquired by ABB
  • 1996 – AEG Westinghouse (USA) integrated into ABB
  • 1996 – ABB Transportation and AEG Schienenfahrzeuge(part of Daimler Benz) merge to become Adtranz
  • 1999 – Daimler Benz becomes sole owner of Adtranz
  • 2001 – Bombardier acquires Adtranz and formsBombardier Rail Control Solutions
  • 2010 – JV with Elteza in Russia formed
  • 2014 – RSS Australia acquired
  • 2015 – Bombardier NUG Signalling Solutions Co formedas a JV in China
  • 2015 – Bombardier Rail Control Solutions celebrate itscentenary, employing 3,600 people world wide.
Stockholm-Roslagen Railway (SRJ) locomotive no.5 ‘Wallentuna’ with flat car loaded with overhead wire on Stockholm-Djursholm, the first line to be electrified in Sweden, 1895.


Driving the technology

Signalling is almost an obsolete term nowadays, the more appropriate title being Control and Communications. Companies in this discipline today cannot progress without having skills that span the full range of technologies required to control a modern railway. Bombardier and its ancestry can chalk up some notable firsts in recent years:

  • Centralised Train Control. Following a centralised relay-based train management system introduced in Sweden in the late 1960s, the first fully-electronic CTC system using computers was commissioned in 1971 at Stockholm Central. This covered 377km of route and 60 stations. From this, emerged the EBI Screen product that is commonplace today.
  • Electronic Interlockings. The world’s first computer- based interlocking was brought into service at Gothenburg in 1978. This stemmed from joint thinking by both SJ and Ericsson, requiring the development of a new logic language named STERNOL, named after Bengt Sterner and Dag Nordenfors, both from SJ but working closely with Ericsson. Recognising that safety was paramount, they adopted techniques used bythe American NASA organisation to gain acceptance of computers in the use of railway signalling. In 2009, Bengt received the European Railway Award in recognition of this pioneering work. The interlocking has been developed since that beginning and is now marketed as EBI Lock 950, it being used by many railways across the world.
  • Automatic Train Protection (ATP). The need for improved driving aids and particularly drivers failing to observe red signals was an increasing worry on most railways in the 1970s. Reacting to this, Ericsson in conjunction with SJ developed a balise-based system now known as EBI Cab, which has been deployed in both main line and metro applications.
  • ERTMS. No description of new signalling technology can be complete these days without some reference to the European Rail Traffic Management System. Bombardier along with the other major signalling companies has been collaboratively involved in the development, more accurately with the ETCS (European Train Control System) element. In 2001, Adtranz supplied the first ERTMS Level 2 system for commercial operation on the Olten-Lucerne line in Switzerland. Perhaps an even more notable achievement has been the introduction of ERTMS Level 3 on rural lines in Sweden. Known as Regional ERTMS, these lines may yet pave the way for deployment of Level 3 onto busier routes. Bombardier has branded its ERTMS product INTERFLO and has equipped 27,000km of route and 3,000 vehicles around the world.
  • Automatic People Movers. With its origins in the USA, and as a result of the Westinghouse/AEG acquisition, the Skybus automated rubber-wheeled electric vehicle has become commonplace for transit systems at major airports since 1966.
  • Automated Metro Systems. Having to deal with significant population growth in recent years, cities have invested in high-capacity metro systems and Bombardier has been at the forefront in developing CBTC (Communications Based Train Control) technology. Leading the way with the BART (Bay Area Rapid Transit) system in San Francisco back in 1972, this was followed by a radio-based moving block system at San Francisco airport in 2003. From these emerged the CITYFLO product now in service on Metro de Madrid and, latterly, in the Chinese cities of Shenzhen and Tianjin.

The UK dimension

ML Engineering, established in 1959 in Plymouth, won the contract for Stoke Powerbox as part of the original West Coast main line electrification. Fortunes varied thereafter, with the company being acquired by EB in 1989. The development of the TI 21 track circuit has been a huge success and thousands are deployed across the UK rail network. Now re-badged EBI Track 200, the design has been upgraded over the years, with the new generation EBI Track 400 deployed for Thameslink, and continues to be the first choice when jointless track circuits are needed.

Page 41_CTC Gothenburg_1978 [online]
World’s first computer-based interlocking, EBI Lock 750, for Centralised Traffic Control, Gothenburg Sweden, 1978.

CITYFLO mass transit systems have been supplied for the Glasgow, Manchester and Nottingham tram networks plus people movers at Gatwick and Heathrow T5 airports. A new level crossing design for rural locations – the EBI Gate 200 – is aimed at improving safety for pedestrians at these vulnerable sites. A recent success has been the award to supply EBI Cab 2000 equipment for the Crossrail trains, which will include EBI Drive equipment for driver advisory operational information. A further success has been the installation of depot signalling solutions.

Bombardier has experienced some disappointment with the intended deployment of the EBI Lock interlocking not being pursued in the UK so far, but remains positive that opportunities may arise in the future. but this has been partly due to the inflexibility of British signalling and operating rules and the expensive adaptation of the product needed to meet these.

The London Underground sub surface lines re-signalling contract which was mutually released by Bombardier and London Underground, caused a number of lessons to be learned despite the success of the CITYFLO solution in many other cities . All companies suffer setbacks from time to time but understanding the causes is all part of the advancement regime.

Both in the UK and globally, Bombardier can be very proud of its signalling ancestry despite its complex structure. Managers and engineers down the years have had the vision to see a progressive way forward that combined the winning of contracts with the development of new products and systems. It has established itself as a global supplier and with that comes the readiness to adapt to local conditions and requirements.

Long may it continue to be successful.

Clive Kessell
Clive Kessellhttp://therailengineer.com
SPECIALIST AREAS Signalling and telecommunications, traffic management, digital railway Clive Kessell joined British Rail as an Engineering Student in 1961 and graduated via a thin sandwich course in Electrical Engineering from City University, London. He has been involved in railway telecommunications and signalling for his whole working life. He made telecommunications his primary expertise and became responsible for the roll out of Cab Secure Radio and the National Radio Network during the 1970s. He became Telecommunications Engineer for the Southern Region in 1979 and for all of BR in 1984. Appointed Director, Engineering of BR Telecommunications in 1990, Clive moved to Racal in 1995 with privatisation and became Director, Engineering Services for Racal Fieldforce in 1999. He left mainstream employment in 2001 but still offers consultancy services to the rail industry through Centuria Comrail Ltd. Clive has also been heavily involved with various railway industry bodies. He was President of the Institution of Railway Signal Engineers (IRSE) in 1999/2000 and Chairman of the Railway Engineers Forum (REF) from 2003 to 2007. He continues as a member of the IRSE International Technical Committee and is also a Liveryman of the Worshipful Company of Information Technologists. A chartered engineer, Clive has presented many technical papers over the past 30 years and his wide experience has allowed him to write on a wide range of topics for Rail Engineer since 2007.


  1. I think that you will find that the earliest Signalling companies in the UK have been in existence for a lot longer than 100 years although as the article does state, different names now due to takeovers and mergers. Westinghouse Brake and Signal Company was an amalgamation of all of the old companies such as Saxby & Farmer, Evans O’Donnell, and McKenzie & Holland to name just a few. W B & S Co celebrated it’s centenary in 1981. The history of the company up to the present day can be found in a book published in 2006 (with a second edition published in 2014). I would have thought that a British author writing for a British publication such as The Railway Engineer would have given more time to a wholly owned signalling company rather than a non-British company! (The picture by the way is of an Electric Traction Control System rather than a signalling Control Centre)


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