The Brenner base tunnel

If you’d been passing through Verona on 23 March 1859, you might have noticed an unusual crowd of people outside Ponte Vescovo station.

Elegantly dressed women with veils and umbrellas and mustachioed men in tophats descended from carriages, while strutting gendarmes with rifles and feathered caps checked tickets at the station entrance. Inside, a whistle and a blast of steam heralded the departure of a train, about to head northbound along the Adige valley towards Trento.

For many of those elaborately coiffed men and women, it was just another chance to see and be seen during the height of the Austrian empire, and the train was a fast, convenient alternative to the horsedrawn carriage. But looking back from our vantage point 159 years later, the inauguration of the Brenner railway marked the first page of a history that is still very much in progress.

The line was extended from Trento to Bolzano a couple of months later. In August 1867, after the Veneto became a part of Italy, it was continued still further, to Innsbruck.

This has been a major route from central Europe to the Mediterranean for a very long time, but until now it has been underused, mostly for reasons imposed by nature.

It reaches gradients of up to 26 percent in places, sometimes limiting the speed of freight trains to fifty kilometres an hour and loads to 450 tonnes. It also requires the use of a second locomotive to pull the train and to help with braking on downhill stretches.

These restrictions pose a safety risk, and create a bottleneck that is no longer compatible with modern transport systems – especially since the Brenner is the central part of TEN 1, the trans-European rail network linking Berlin to Palermo.

The Brenner base tunnel (BBT), begun in 2007, is intended to solve this problem by providing an underground alternative to the old route. It will be the world’s longest rail tunnel, totalling 63.5 kilometres and comprising two one-way train tunnels, a full-length safety tube, and three emergency exits.

The tunnel will reduce the journey by 20 kilometres and gradients to 4 percent, cut journey times from 80 minutes to 25, and increase freight and passenger traffic.

So far, the Italian and Austrian contractors have completed thirty of the 230 kilometres of tunnels and infrastructure. Dieci Pegasus telehandlers are being used at the four construction sites, two in Italy and two in Austria, which is not surprising given that the tunnel is top of the EU’s list of thirty priority projects and is required to use advanced technology and materials.

We’ve written previously about the use of Pegasus on excavation sites, but it’s worth repeating the reasons for its popularity in the industry: its long arm, exceptional lifting capacity, mobility, and ability to rotate.

These features make it among the best of its kind when it comes to fitting out tunnels and installing conduits for power, lighting, communication, and the forced ventilation that is essential in such a low tunnel.

The Pegasus has also discovered a new vocation deep in the Brenner: that of shotfirer. Seventy percent of the tunnels’ length is dug using advanced boring machines, but the remaining 30 percent is excavated using the tried and tested method of controlled explosions. The drill head has a pattern of blasting holes into which the explosives are placed, and these are electrically detonated at intervals calculated in tenths of a second, penetrating the rock to create a hole with centimetre precision.

The Pegasus is used for the delicate operation of packing the holes spread across the eight-metre diameter of the drilling head, with operators using the drum to connect each blast hole to the hundreds of metres of electrical cable that transmit the detonation signal to each stick of explosive.

After the explosion, the excavator sucks out the broken rock and the drilling process begins again, taking the tunnel another a few metres into the granite.

The project is scheduled for completion in 2025, and will come into operation a year later.

So you’ll probably hear more about Dieci models that are still on the drawing board but may well be put to use in the Brenner base tunnel.