GERMANY: Tunneling is on track to complete the final high-speed train link between Stuttgart and Ulm
by Nigel Griffiths
Every two hours the ground shudders as another explosion resonates in one of the tunnels being excavated through the Alb Plateau to take Germany’s high-speed ICE – Inter City Express – right into the center of the ancient city of Ulm.
Behind the project is Deutsche Bahn, Germany’s national railway and a global symbol for quality, efficiency, speed and punctuality.
Work on the twin-bore Albabstieg tunnels began in spring 2014 and a tight tunneling schedule has been set to carve a way through 4km of limestone rock and emerge in front
of Ulm main station – in the shadow of the great Ulm cathedral – by December 2017. Helping to achieve this daunting task is a fleet of Volvo machines.
The tunnel is the final link between Stuttgart and Ulm central station for the ICE, the fastest of the Deutsche Bahn trains. It connects all the major German cities, such as Frankfurt, Hamburg, Stuttgart, Munich, Cologne and Berlin. The next stop will be Ulm. Though the ICE can travel at 330km/h, there is a speed limit of 250km/h on the Ulm line.
Sitting on the River Danube, Ulm is one of the economic hubs of the state of Baden-Württemberg. Founded in AD 850, it is also a city rich in history and tradition. At more than 160m tall, its world famous cathedral, the Ulm Münster, boasts the tallest steeple in the world. The city is also the birthplace of Albert Einstein.
Building the tunnel is the responsibility of the construction consortium, ARGE Tunnel Albabstieg. The project involves excavating two single-track rail tunnels from the town of Dornstadt to Ulm. Each bore is more than 9m in diameter and 5.9km in length, with a 40-50cm thick inner shell.
In November 2013, Volvo CE dealer Robert Aebi GmbH was awarded a contract to supply nine Volvo L150 wheel loaders – four series G and five series H – and a further 10 Volvo A30 articulated dump trucks, eight series F and two series G.
ARGE project manager Mathias Abele says that the seamless operation of the extraction process is critical for achieving the project timetable. They needed machines, he explains, that could provide the reliability, service and back-up required for such an intensive tunneling schedule.
“As far as ARGE and Deutsche Bahn are concerned, every link in the extraction chain has to be solid and unbreakable,” explains Manfred Prinz, sales manager at the Robert Aebi GmbH dealership. ‘‘The contribution of our machines will be to keep this extraction carousel going day in, day out, for two-and-a-half years.’’
Eric Lüpfert, mechanical engineer at ARGE, says his experience of working with Volvo machines on
previous projects was positive enough to give him the confidence that this line of machines and the new versions could provide the service and reliability required for the project. The construction company had also decided it wanted to purchase outright, rather than rent – it was important for ARGE to deal with one reliable supplier, rather than many.
The wheel loaders and dump trucks have been specially configured for tunnel work, including custom tires, air filters, automatic engine cut-out systems, automatic fire extinguishers, optical and acoustic reversing warning devices, LED lighting, protective headlamp guards and reinforced heavy-duty cabin roofs.
The twin tunnels to Ulm are each being bored at a rate of 15m per day. This schedule will run day and night, 24-hours a day, seven days a week until December 2017. Critical to the plan are the wheel loaders and dumper trucks that have to work continuously to remove the excavated limestone rubble, as the high-intensity mining operation proceeds.
The work schedule is unrelenting. Each explosion releases thousands of tonnes of limestone rubble which is shifted by the Volvo wheel loaders on to Volvo dump trucks for transporting to designated recycling sites. The rubble is sorted on-site and sold for use in cement production – Deutsche Bahn takes its environmental responsibility seriously.
For the fleet of Volvo dump trucks, this work schedule represents an estimated 370 round trips every 24 hours. Over the life of the project, the Volvo machines will shift an estimated 3 million tonnes of rubble.
As tunneling progresses, the demands will increase. The final stages of the project will see the Volvo dump trucks making an 8km round trip to the ‘business end’ of the tunnel, returning up a 1% incline with their 30-tonne loads. This will certainly test the performance of the Volvo carousel, although both ARGE and Volvo CE are confident of the machines living up to expectations.
Manfred Prinz emphasizes the lengths his company has gone to in meeting the need for reliability and availability. In addition to the fleet of machines purchased for the tunnel project, the dealer has placed an L150 wheel loader and an A30 dump truck on-site, available as standby machines for the contractor.
“Nothing is left to chance,” Prinz stresses. “The 24/7 tunneling schedule cannot be allowed to stop.” While day-to-day maintenance is undertaken on-site by ARGE, specialists at the Robert Aebi GmbH dealership are just 20km away for technical support and ready to intervene whenever necessary.
“In addition to supplying them with high-performance machines, we are capable of providing the level of back-up and support they require for this time-critical project,” says Prinz.