Interlockings are the core of railway signalling, but their life expectancy varies considerably. Mechanical interlockings typically have a life of 80 years, compared with 40 years for relay-based interlockings, and just 15-20 years for electronic ones, so the life is halving with each step change in technology, with the result that electronic systems are becoming obsolete before older legacy equipment.

Continuous development of signalling technology since the mid-19th century has left railways with a "technology zoo" of equipment and a huge diversity of interfaces, which makes the installation of new systems such as ERTMS difficult and costly.

Just to spice things up a bit, it looks like the signalling supply industry is about to go through a period of consolidation with Hitachi about to take over Ansaldo STS, Bombardier Transportation seeking an outside investor which could trigger a takeover, and the Alstom-GE deal being finalised. In the telecoms market, Nokia will take over Alcatel-Lucent next year. Signalling companies find it difficult to allocate sufficient funds to research and development, which could also spur consolidation. Having fewer suppliers poses the risk of vendor locking and higher prices.

Europe's Eulynx initiative, launched in 2014, is designed to address these issues by standardising signalling interfaces which Eulynx describes as crucial to streamlining planning, engineering, construction, testing, commissioning and approval. The objective is for equipment to be able to communicate in a standard language using a standard protocol within a standardised network. This should enable suppliers to compete effectively as products will be standardised, while the promoters hope this will cut costs, accelerate installation and commissioning, and result in more equipment being replaced.

"This will be a game changer in railway signalling," Mr Frans Heijnen, Eulynx's project manager, told IRJ. "It will change the way signalling is provided and maintained. For the first time railways will have a formalised model for signalling interfaces."

Eulynx was set up by 10 predominantly northern European infrastructure managers from Britain, France, Belgium, Netherlands, Luxembourg, Germany, Norway, Sweden, and Finland plus Slovenia in the south. Heijnen is keen for more partners to join Eulynx to extend its geographic reach.

Eulynx is already making progress. Norway's Jernbaneverket will use available Eulynx specifications this year for tendering its national rollout of ERTMS. In November, DB Networks will demonstrate communication between interlockings from different manufacturers, and plans the first applications next year.

Turning to the telecoms sector, Mr Chiel Spaans, from the European Railway Agency (ERA), asked provocatively whether the industry can manage the evolution of railway radio communications. Suppliers have given an assurance that they will support GSM-R until 2030, although the rapid development of technology could make this irrelevant. In any event, this means GSM-R has already reached the mid-point of its lifecycle. Given that the implementation of a new radio system throughout Europe could take 10 years and time is needed to develop standards, the European Commission has tasked ERA to lead a project to develop a successor to GSM-R with a view to starting its deployment in 2022. Up to the end of next year, ERA will be studying such factors as the requirements, network ownership and control, migration, traffic levels to establish spectrum requirements which are already scarce, technology trends, and the feasibility of using satellites for ETCS and voice communications. The specifications for architecture and technologies will need to be ready by 2018, followed by validation and testing between 2019 and 2022.

As Spaans points out, the key will be to develop a stable architecture without inhibiting innovation, with predictable costs and low depreciation, while catering for future but as yet unknown functionality.

The new system will have to coexist with GSM-R during the 10-year migration period. Railways will want to see lower costs through the greater use of standard technologies and products while still catering for specific railway requirements.

On top of these considerable challenges, 5G is expected to be launched in time for the 2020 Olympic Games, and some railways are already trying alternatives to GSM-R.

The traditionally staid world of railway signalling and train control is clearly facing a period of huge change which will need to be managed carefully. This might help to attract a new breed of engineers which the industry desperately needs both to plug a serious manpower shortage and provide the brainpower to meet the new challenges.