The tunnel is just over 4 km longer than the Seikan rail tunnel in Japan, which at 53.9 km had previously been the longest rail tunnel in the world.
Completion of the Gotthard Base Tunnel will cut the travel time between Zurich and Milan in Italy by 60 minutes to two-and-a-half hours and provide an easier and more economic route for heavy freight trains.
The tunnel -- which is in fact composed of two single-track tunnels -- cost $10.6 billion (£6.6 billion).
Since the first preparations for the tunnel were laid in 1996, over 2,500 workers have taken part in its building according to AlpTransit Gotthard, the company constructing the tunnel. It is due to be operational by the end of 2017.
Link | Photo: EPA