Adventures? Not in the Gotthard Base Tunnel

In the past, reaching the other side of the Alps has been an adventure. Today the journey through the Gotthard Base Tunnel is safe and comfortable – thanks to the Siemens solutions for tunnel safety and fire protection.
Tunnel construction

Fast and secure through the Alps

Most every child has dreamed of being a superhero: strong, fast, and invincible. But if you travel through the Gotthard Base Tunnel in the future, do not expect any great adventures. At 57 km long the tunnel is the longest railway tunnel in the world and the paradigm of modern tunnel technology. Between Erstfeld and Bodio, Switzerland, the Gotthard Base Tunnel crosses a gigantic mountain range, approximately 500 meters above sea level. Thereby the ingenious safety system from Siemens ensures fast and very safe travel. 

The story of the tunnel

Up to 2,400 workers spent more than a decade building the two tunnel tubes. There was a massive celebration on October 15th, 2010, when the main tunnel excavation was completed. It took another five years before the tunnel was equipped with railway and safety technology. By October 2015 testing and trial operations began, with a view to opening the Gotthard Base Tunnel at the end of November 2016, the culmination of 17 years of planning and construction. Soon up to 50 passenger trains – such as Intercity and Eurocity services – will run through one of the two single-track main tunnels daily at a maximum speed of 250 km/h. Additionally it has a capacity of up to 260 freight trains. The main tunnels, connected by transverse tunnels every 325 meters, are equipped with additional safety and ventilation shafts. Siemens makes sure that even the most anxious passengers will be able to enjoy a very relaxing journey through the Gotthard Base Tunnel, thanks to the latest in safety, monitoring and building technology. In addition, the Ceneri Base Tunnel has also been in operation since September 2020, making the journey from Zurich to Lugano around 45 minutes faster for travelers.

Animated Map
Safety requires a system

At the heartbeat of tunnel technology

As far as safety is concerned, even little superheroes can sit back and relax just like regular passengers. Siemens railway and tunnel control technology and fire protection system are fully integrated in the tunnel infrastructure, ensuring safe passage through the record-breaking long tunnel. The technology monitors all movements, so that every passenger will arrive safely and on time at their destination.

The tunnel control system

A team monitors all technical facilities from the tunnel control center south (TCC). 3,200 km of power and 2,600 km of data cables form the "main arteries" of a safety infrastructure that is unrivaled worldwide: Over 70,000 data points and more than 200,000 sensors register every variation. The tunnel is dotted with control electronics and monitoring devices all connected to the TCC via fiber optic cables. There is a redundant tunnel control center at the north portal – providing a maximum level of safety. Lighting, fire and smoke alarms, power supply, fire extinguishing, hazardous materials recognition, ventilation, emergency call systems: An Automated Incident Detection (AID) employing video and radar systems, operates in the Gotthard Base Tunnel.

Quicker response with early warning systems

Siemens developed and successfully tested its early warning systems based on the latest innovations in detection technologies, as a part of the framework of a collaborative project (SKRIBT) funded by the german Federal Ministry of Education and Research. Combining video feeds with thermal imaging: This means that all events are identified as soon as possible, even before the train enters the tunnel. The system does not miss anything – including the monitoring train components susceptible to fire, like wheels, brakes, axles and the engine, obstacles on the tracks, smoke or even lost cargo. A special image processing program for surveillance cameras transforms the video feed of a passing train into a segmented two-dimensional picture. Subsequently, using newly developed algorithms, a 3D model is created from the picture. In the tunnel, smart zones and virtual barriers are in place that help to trigger an alarm automatically if any faults are detected. The ventilation system then automatically switches to the predefined safety mode. An important aspect of this system are the internationally standardized open interfaces, enabling simplified data exchange with subsystems from third party manufacturers.

Fire protection in the tunnel

The longest railway tunnel in the world has two 600 meter multi-function monitoring stations. Because smoke is a particular hazard in the tunnel, the system is equipped with numerous sensors, monitoring devices and regulators connected to the two control centers via fiber optic cables. Should a fire break out, despite the safety measures in place, the cutting edge video and smoke detection system locates the fire as quickly as possible. It also provides valuable information about smoke characteristics and detects any other changes in the tunnel. The video surveillance system detects smoke within 10 to 20 seconds. The Siemens FibroLaser heat detection system supports the smoke detectors and video cameras, which may be enveloped by smoke in the event of fire, by precisely indicating the location, propagation direction and size of the fire.

Maximum protection with FibroLaser

The FibroLaser system, with over 2,000 kilometers of installed cables and over 1,200 monitors, is the most successful linear early warning system in operation on the market. The 100 % maintenance-free sensor technology, completely immune to dirt, dust, moisture, corrosive atmospheres, electromagnetic fields and radioactive radiation, offers the highest possible standard of protection. Fire detection in the tunnel is carried out with three monitoring systems and is in direct control of the ventilation flaps in the event of an imminent evacuation. Data is assessed and recorded by the control system in a matter of milliseconds; wherein the event history is also tracked so that triggering parameters can be optimized. Sensor leads monitor the wall and floor of the tunnel for any warning signs. A reinforced housing protects them against water and mechanical stress. In addition, thermal imaging cameras and smoke detectors constantly check the temperature and the air for smoke particles. To protect them against the harsh tunnel conditions, they are housed in cages - specially designed for the Gotthard Base Tunnel.

Tunnel control system

Monitors and controls all tunnel's electrical systems

Approx. 70,000 input/output messages and commands

Fully redundant tunnel control system

Railway control system

Controls rail operations

Fire Protection System

28 smoke detectors

controlling the air inside the tunnel

15km FibroLaser cable

along the tunnel detecting high temperature and fire

56 thermal imaging

cameras constantly checking the temperature

2 multifunctional stations for incidents
Ventilation system

exhausts smoke and inflates fresh air


to access other tube every 325m

Safety door

will be opened automatically in case of emergency

Main tunnel control system

Monitors and controls all tunnel's electrical systems

Approx. 70,000 input/output messages and commands

Fully redundant tunnel control system

Emergency response system

Supporting tool to accomplish incidents,
i.e. accident or fire

Railway control system

Control rail operations

Please rotate your device.

Facts & figures

Masterpiece of engineering

A total of more than 4 million man-hours were spent on the Gotthard Base Tunnel. Siemens integrated tunnel technology regulates energy distribution, lighting, ventilation, emergency call systems as well as smoke and fire detection – with more than 70,000 data points, 280 tunnel radio amplifiers, 250 transformers and 10,000 lights.

0 km

of data cables detect every movement in the tunnel.

0 km

electrical cables control the entire infrastructure.


sensors in a sophisticated safety system place maximum demands on logistics and data processing.

Not just machines

People behind the scene

However important the role of technology, it is people that must have the precise know-how. Learn more about the people behind the scenes, ensuring that passengers in the longest railway tunnel in the world enjoy the ride.