- The Gotthard Base Tunnel is the longest and deepest
rail tunnel in the world, 57 kilometers through the Alps. Literally, through.
It's called a "base tunnel" because it's at the base of the mountain. At its deepest point, there are more than
two kilometers of rock above. It's so far down into the ground
that the earth in there is hot. Without ventilation, the air temperature
will be more than 40°. Around the turn of the century, there were two devastating fires
in road tunnels under those mountains, and the authorities here in Switzerland want to make sure that nothing like that
can ever happen again. How they do that is fascinating. So here's what's going to happen. We're going to see the control center
that watches over the tunnel, and also visit one of
the intervention centers, with the firefighters
and first responders that'll step in if the
worst were to happen. And then I want to show you
what I reckon is the most important bit of safety equipment. It isn't anywhere near the tunnel, and most people will
probably never notice it. But before that, we start
at the control center, just over there. - In the Gotthard Base Tunnel, there are six freight trains and two passenger trains,
per hour, per direction. This means that at the same
time, there are several trains inside the tunnel, in
both of the two tubes. The Gotthard Base Tunnel is
divided into three thirds. If there is a disturbance
in one of these thirds, the train can be diverted
at one of the two changement points, into the other tube,
to bypass the disturbed section. There are different sections
to control the traffic. The signal box controls the track. The movement authority is
given by the signal box, and by the traffic controller. If there is a disturbance on one
of the systems in the tunnel, then we have different
possibilities. First of all, we get noticed by an alarm
that there is a problem. They first of all try to
fix the problem remotely. If this is not successful, they can send people on
site to try to fix it. - This tunnel is actually a bit of a
tourist attraction in itself. You can get driven in,
down the service tunnel, on a guided tour, and end up at this
reinforced, windproof, visitor's window with 8cm-thick glass,
and watch the trains go by at anything up to 230km/h. That was terrifying! - If a train has a technical
problem, first of all the train driver tries to
reboot the train system. If it's not successful,
we have the firefighting train, which goes into the tunnel
to tow out the broken train. In case of an incident in
the tunnel, let's say a fire, we have two intervention
centers, North and South. "Intervention center" means
firefighting stations. They get an alarm, and
within five minutes, usually both of the firefighting trains go into the tunnel
from north and from south at the same time to fight the fire. They have the obligation to
be on any point in the tunnel within 45 minutes. Firefighting train is a convoy
of firefighting trucks on rail. They bring water in, foam liquid.
They bring special equipment, tools, to handle any possible
situation inside the tunnel. At the two emergency stops, there is a possibility
to refill their water. If people have to be
evacuated in the tunnel, they do not walk out of the tunnel
because it's much too far. The train brings them to one
of two evacuation stations, where the passengers can go
into the evacuation tube. This evacuation tube is under pressure,
so fresh air is streaming in. They are safe because
they have enough oxygen, and smoke cannot enter. Then they go to the
next evacuation section, where the evacuation train
is waiting for them. We have to be able to
evacuate the entire tunnel within 90 minutes. - As I went round today,
one of the team said that if there ever is an
evacuation or a fire in the tunnel, several other things
had to go wrong first. Yes, you can never protect against every possible weird
circumstance, but you can try. Which brings me here, to what's basically the
middle of nowhere in Switzerland, about 15km away from the
south entrance to the tunnel, and to this gantry over the tracks. 15km sounds like a lot, but at the
speed Swiss trains can travel, that could be about four or five minutes. And while it doesn't look like much, this gantry scans every train, at speed,
before it even gets near the tunnel. There are sensors on the
track around here too, and if the train has anything unbalanced, any hot spots that look out of place, anything poking out,
then it's not going into the tunnel. - We have laser systems which measure
the profile of a train. Maybe the load of a train has moved, and doesn't respect any more
the necessary profile to enter a tunnel. We have heat detection,
where we can detect overheated axles or
overheated brakes. All these controls, they happen
at usual commercial speed of the trains, in different
points, all over Switzerland, and we get about 200 alarms per day
from these measuring stations. If we do not confirm an
alarm within 30 seconds, the train is stopped automatically. It's not an emergency stop, it's...
but it's quite... you feel it! If a train seems to be wrong, it gets to a side track
where it has to wait. If the inspection says,
this train is okay, then it can continue its journey, if not, the owner of the train
has to resolve the problem before the train can continue its journey. - Yes, there are lots of systems in place
for if "the worst happens", but prevention is better than cure, and for me, this gantry
is the most important bit of safety equipment here, because the best solution
is to stop problems before they even start.
We have the same thing here, except instead of a lovely mass transit system, we have potholed roads and rusting bridges.
Wait, it's 40C under the mountains? Why aren't we living under mountains?