4064 x 2704 px | 34,4 x 22,9 cm | 13,5 x 9 inches | 300dpi
Date de la prise de vue:
4 avril 2003
Lieu:
London, UK.
Informations supplémentaires:
Cette image peut avoir des imperfections car il s’agit d’une image historique ou de reportage.
A tunnel is a man-made horizontal passageway located underground and hollowed out through soil or rock. It must be more than 0.16km (0.1mile) in length to be called a tunnel (less and it’s a subway or underpass). Constructing a tunnel is one of the most difficult and complex challenges faced by civil engineers and many completed tunnels are rightly considered to be technological masterpieces. In ancient times, the most active tunnellers were the Romans who created an extensive network of tunnels to carry water from mountain springs to cities and villages. They carved underground chambers and built elegant arch structures, not only to carry fresh water into the city but also to carry wastewater out. In modern times, using the latest tunnel construction technology, engineers regularly bore through mountains, under rivers, under seas and beneath huge cities. Longer and bigger diameter tunnels at much greater depth; bored through more demanding geology will undoubtedly be the challenge of the future. Life above ground, particularly in urban conurbations, has become increasingly congested and tunnels will provide some of the last available space for road, rail and metro transportation, water, wastewater and sewage, power and hydropower stations and cables and communication lines.
