Uploaded April 2024 | Updated September 2026, 3 weeks ago
Before the first passenger could travel through the Gotthard Base Tunnel, the engineers needed to excavate over 20 million tonnes of rock. For this herculean task the tunnel boring machine, also known as a “mole”, needed a serious technology upgrade. 4 football fields long with a cutter head spanning 10 metres, this specialised metal monster can munch its way through 40 metres of rock a day. On a good day it rips 6,000 tonnes of rock out of the mountain, then amazingly puts the rock straight back in. A quarter of the material carved from the mountain is recycled and turned into concrete, shotcrete is sprayed onto the tunnel walls to keep the tunnel open, or spread on the floor to prepare the bed for the train tracks.
The tunnel boring machine is a gigantic rock-eating factory, the ultimate tunnelling tool, even when it comes up against some of the toughest rocks on the planet!
Clip from the “Big Bigger Biggest” documentary series exploring the engineering breakthroughs that have enabled us to develop some of the largest structures in existence.
Watch the complete documentary here – youtu.be/QkBpgWLoylo
Subscribe to Element 18 – bit.ly/337R2uO
Before the first passenger could travel through the Gotthard Base Tunnel, the engineers needed to excavate over 20 million tonnes of rock. For this herculean task the tunnel boring machine, also known as a “mole”, needed a serious technology upgrade. 4 football fields long with a cutter head spanning 10 metres, this specialised metal monster can munch its way through 40 metres of rock a day. On a good day it rips 6,000 tonnes of rock out of the mountain, then amazingly puts the rock straight back in. A quarter of the material carved from the mountain is recycled and turned into concrete, shotcrete is sprayed onto the tunnel walls to keep the tunnel open, or spread on the floor to prepare the bed for the train tracks.
The tunnel boring machine is a gigantic rock-eating factory, the ultimate tunnelling tool, even when it comes up against some of the toughest rocks on the planet!
Clip from the “Big Bigger Biggest” documentary series exploring the engineering breakthroughs that have enabled us to develop some of the largest structures in existence.
Watch the complete documentary here – youtu.be/QkBpgWLoylo
Subscribe to Element 18 – bit.ly/337R2uO
