WITH the inauguration of the Gotthard Base Tunnel on June 1, Switzerland celebrated one of its greatest engineering achievements and the completion of the country's largest-ever construction project. Seventeen years after blasting began on the first access shaft for the world's longest main line railway tunnel, AlpTransit and its contractors have successfully overcome one of the greatest obstacles to transalpine rail operations, bringing northern and southern Europe closer together.

However, the story doesn't end with the popping of champagne corks on June 1, and another six months of intensive preparation lie ahead to ensure a seamless transfer of traffic to the new infrastructure when commercial operations begin on December 11.

Gott SBBControl of the tunnel passes from AlpTransit to Swiss Federal Railways (SBB) on June 1, but preparations for this transition have been underway since 2011, when SBB and AlpTransit set up the Gotthard North-South Corridor Project Organisation (Pons) to ensure the tunnel meets the railway's operational requirements when it opens.

Pons developed timetable concepts for the tunnel, managed upgrading of the access lines, including the rollout of ETCS Level 2, and is responsible for training around 3900 staff. It also acts as the interface between SBB and AlpTransit with the aim of achieving a seamless handover between the two companies. "We have developed our plans hand-in-hand with AlpTransit using the same processes and tools and we are one common commissioning organisation," explains Mr Peter Jedelhauser, SBB's Pons manager. "The only change on June 1 is that the manager and deputy manager swap roles, with SBB leading."

The Swiss Federal Office of Transport (BAV) granted authorisation to begin testing in the tunnel at the end of September 2015 and trial operation began on October 1, with the first ETCS Level 2 test run taking place a few days later. SBB's radio test train was used to validate the performance of the tunnel's radio network and GSM-R and testing of the rail-wheel interface and interaction between pantograph and catenary contact wire was also carried out at this stage.

High-speed trials started at the beginning of November using German Rail's ICE-S test train and the first high-speed trial was carried out on November 8 at the maximum permitted speed of 275km/h.

In addition to normal operations, simulations of degraded operations have been conducted. Four separate full-scale rescue exercises took place earlier this year, culminating with the successful evacuation of 800 people from an ICN train on March 19 following the activation of an onboard fire alarm. This exercise involved SBB's fire and rescue trains as well as local emergency services.

On February 8 a series of test runs took place with a 1500m-long freight train to establish whether a freight train of this length could operate in the tunnel under ETCS Level 2 should the need arise. The test run was made by a 2216-tonne unloaded train with 76 flat, telescopic, and container wagons, with traction provided by three 8MW SBB Re 620 locomotives, which were positioned at the front, centre, and rear of the formation. Another milestone was reached at the end of April when the completion of GSM-R acceptance-measurement runs were completed.

SBB is managing all test runs and providing locomotives, rolling stock and train crew for the programme. By mid-May 2730 test trains had covered more than 100,000km.
Intensive trials

Following the handover on June 1, SBB will begin its own intensive programme of trials to ensure infrastructure and staff are ready for the start of commercial operations in December. During the trial phase activities are divided into driver training and staff familiarisation; maintenance operations; degraded operations; incident simulation; and trial operation with commercial services. By December 11, SBB will have operated up to 5000 test trains, most of them freight trains, through the tunnel. A number of special trains will carry passengers through the tunnel during this phase and from September, some commercial passenger trains will be diverted from the mountain route to run through the tunnel as SBB moves towards its goal of authorisation for full operation, which will be granted by the Swiss Federal Office of Transport (BAV).

Maintenance activities occupy around 10% of time slots during the commissioning phase. Under normal operating conditions scheduled maintenance will not be carried out during commercial operations, which means all work in the tunnel will be done at night. "Maintenance is one of the biggest challenges we face because we only have two access points, the northern and southern portals," Jedelhauser says. "You can develop processes on paper for how you will carry out maintenance activities and you can train your staff, but to fine-tune your processes you have to be able to work in the tunnel in real-life conditions."

Early completion of any remaining finishing and guarantee work by contractors will be key for the maintenance training schedule. "We cannot train when the equipment we are working on hasn't been handed over," Jedelhauser says. "We can't do this work in a laboratory, we have to get used to the conditions that are unique to the Gotthard Base Tunnel. We can train in the Lötschberg Base Tunnel but this has road access so maintenance processes are different."

In total, 3900 staff including 1000 drivers will have received training in the tunnel by the time trials conclude.

From December 52 passenger trains and up to 210 freight trains will pass through the tunnel each day with up to four daytime freight paths (five at night) and two passenger paths per hour in each direction. In order to fully exploit this capacity, the maximum speed will be at least 100km/h for freight trains and up to 200km/h for passenger trains.

Milan in three hours

The opening of the tunnel will cut the Zürich - Milan journey time from 4h 3min to 3h 30min. Further improvements are anticipated in 2020, when the opening of the Ceneri Base Tunnel will cut Zürich - Milan journey times to just three hours and significantly improve rail links between southern Swiss towns such as Chiasso, Lugano, and Bellinzona. With reduced journey times and the introduction of a new fleet of Stadler EC250 trains, which will enter service from 2019, SBB forecasts that passenger numbers on the Gotthard corridor will double by 2025.

The benefits for freight traffic on this key international corridor will be even more profound, with the tunnel unlocking significant operating efficiencies for freight operators. The opening of the tunnel will reduce the transit time between the German frontier at Basle and Bellinzona to just 3h 45min, which means it will be possible for one driver to make a return trip between these two hubs in a single shift. With the tunnel bypassing the severe gradients of the original mountain route, only one locomotive will be required to haul a 1600-tonne train to Bellinzona or Luino.

However, the full impact of the Gotthard Base Tunnel on freight traffic will only become apparent in 2020 with the opening of the 15.4km Ceneri Base Tunnel, which will further reduce transit times, and the completion of an SFr 940m project to upgrade the Gotthard route to accommodate lorry semitrailers with a corner height of 4m.

The existing mountain route via Göschenen and Airolo will be retained when the Gotthard Base Tunnel opens and will continue to be used by an hourly regional passenger service as well as local freight workings. The line will also act as a diversionary route for passenger trains if the tunnel is closed, although freight trains would need to be diverted via the Lötschberg route.

While considerable work remains for SBB before the start of commercial operations, Jedelhauser says June 1 will be an occasion for Switzerland and the people who made the Gotthard Base Tunnel a reality to celebrate. "You should never start the party before the sun sets and we still have a lot of work to do, but I'm very happy to reach this milestone," he concludes. "The tunnel is an achievement of team spirit and the commitment made by everyone involved in the project to a common cause. Ultimately human beings decide whether you succeed or fail and the Gotthard Base Tunnel is a human achievement as well as a technical one."