Channel Tunnel

The Channel Tunnel opened in May 1994 after six years of construction and is the longest undersea tunnel in the world. It actually consists of three tunnels running parallel to each other; the two outer tunnels are used for trains and the smaller central service tunnel is used for ventilation and access. The two larger tunnels are 7.6m wide and are high enough to take a double-decker bus. They curve gently up and down or left and right so that they can run through the chalk strata. On average, the tunnels are 45m below the sea bed. The Channel Tunnel has cut travel times between the UK and mainland Europe dramatically. Before the tunnel, it took around 6-7 hours by rail and ferry from London to Paris. Trains can now do the same journey in 2.5 hours.