Tunnels have been built for centuries and for many reasons, and in Britain there is a proud heritage of tunnelling. The world’s first sub-aqueous tunnel was built under the River Thames by Marc and Isambard Kingdom Brunel in 1843. Today, this tunnel is still in operation, being used by trains on London Overground’s East London Line.
There are many methods of tunnel construction, each requiring specialist skills and equipment. These include techniques such as bored tunnels using Tunnel Boring Machines (TBMs), sprayed concrete lined tunnels, tunnels constructed by blasting with explosives, and tunnels constructed by pipejacking, piperamming, or thrustboring. This large variety means the tunnelling world and the skills it needs are constantly varied and challenging.
Tunnel construction in the UK has been increasing over the last few years, with a range of major projects currently underway and in the pipeline, and there has never been a better time to embark on a career in tunnelling.
There are many reasons why tunnels or other underground excavations are required, and many methods for their construction. What they all have in common is the need to provide a conduit or space under or through an obstacle, be it a mass transit system under a busy city centre, a high-speed rail line underneath a mountain range or sea, a road link underneath a river, an oil, gas or elctricity pipeline, or a water supply or sewer tunnel for a city. The method employed for the construction of a tunnel depends on the length and size, but most importantly on the ground and groundwater conditions through which the tunnel is built.
The International Tunnelling Association (ITA) website provides a great deal of useful information on the need for, and construction, of tunnels.