Explosive Detonation Clears Rock for Rocchetta Tunnel Construction

It was 12:26 p.m. yesterday when a loud bang shattered the silence of the lake. The explosion was caused by one and a half tons of explosive used to break off the rock ledge that was precariously hanging over Gardesana, just above the stretch of road dividing the first and second galleries. This made it effectively impossible to start work on the new tunnel, which will span 12,000 meters through the heart of Rocchetta.

Few, very brief moments later—and as dozens of seagulls took flight in alarm—the large boulder, about 1,600 cubic meters in volume, crumbled and fell into the lake waters. To detach it from the rest of the mountain, technicians had worked all morning, placing dynamite into seven holes about six meters each, drilled at the base of the boulder.

The explosion and demolition techniques

Then, at 12:26, the blast. Or rather, it would be better to say the multiple blasts, since although the human ear perceived only one explosion, the charges (equipped with micro-delay detonators) detonated sequentially (within milliseconds) to ‘guide’ the landslide in the manner considered optimal by the technicians.

In a few days, therefore, the construction site for the tunnel will be opened.