The channel tunnel is the only direct link between England and our Gallic neighbours. It’s the second longest rail tunnel in the world – 31.35 miles, to be precise. 24 of those miles are under the sea. During building, eight-million cubic metres of soil were removed at a rate of 2400 tonnes per hour (that’s enough to fill about 3500 Olympic-sized swimming pools!). An interesting fact, or is it just bore-ing?
Have you ever wondered why tunnels don’t collapse? And do they leak?
You might like to …
• carry out some research into tunnels; find out how they are built, what forces act on them, what they are made of, etc. A good starting point is:
• investigate how easy it is to bore through various different materials
• investigate different ways of finishing tunnels; find out how they are made waterproof
• find out how tunnels are ventilated; design a ventilation system for a tunnel.