In the Gotthard you can surf with 4G

The Oerliker Eraneos Group planned the telecommunications and control technology in the Gotthard tunnel. The long implementation phase was a major challenge.

The prominent politicians from all over Europe drove through the Gotthard at the opening on 1 June. Images of German Chancellor Angela Merkel, French President François Hollande and Italian Prime Minister Matteo Renzi were eagerly sent from the 57-kilometer-long tunnel into the wide world. At the same time, Swiss television broadcast live images into the country's living rooms. Anyone sitting on the train could watch the live broadcast directly on their smartphone.

Roger Emmenegger was also on the train. He is Head of Public Transport at the ICT consultancy Eraneos Group. And he did not miss the opportunity to put the mobile network in the tunnel through its paces. "Everything worked and there were no interruptions," says Emmenegger proudly. For the Gotthard Base Tunnel, the Oerlikon-based company was significantly involved in the project planning of parts of the railway technology. "We planned the tunnel control technology, the data network, the telephony and the radio," says Emmenegger. The biggest challenge was the long implementation phase of 13 years. "We have been involved in the project since 2003".

Now it is almost complete, and the Gotthard Base Tunnel is being put through its paces with test drives. Emmenegger: "We still have some adjustments to make, but they're only minor." While the railway control system is responsible for operating and automating the interlockings, the tunnel control system remotely controls systems such as ventilation, low-voltage distribution, doors and lighting. "Monitoring is carried out from the operations control centre in Pollegio near the south portal," explains Emmenegger. A functioning railway system also requires a reliable mobile communications network. "A special system is needed to ensure that the radio signal in the tunnel does not break off". The signal is therefore distributed in the tunnel with a so-called leakage cable.

A cable with "holes

Emmenegger: "You can imagine the cable as an irrigation hose." The cable has "holes" where the radio waves enter and exit. "Since there are no railway signals in the tunnel, the train drivers receive the information directly via radio into the driver's cab," explains Emmenegger. The tunnel radio is thus used on the one hand for train protection and on the other for the safety radio network (Polycom) of the rescue organisations. In addition, the mobile communications of Swisscom, Sunrise and Salt are also disseminated via this network. "The tunnel is equipped for 4G," says Emmenegger. This was a particular sticking point, said the 53-year-old electrical engineer. "3G technology was the latest technology in the planning phase. We therefore had to expand the system to 4G."

For the Eraneos Group, a long project is now slowly coming to an end. "In the last year and a half, I've been driving through the tunnel on my electric bike at least once a week and checked the work," says Emmenegger. But it was worth it. "Working on such a construction of the century is something unique. But the NEAT is not yet letting go of the engineer. "The Eraneos also planned the telecommunications and control technology in the Ceneri Base Tunnel," says Emmenegger. This will not open until the end of 2020.

From: Pascal Wiederkehr, Quarterly newspaper "Zürich Nord", 15.06.2016