Elevated underground lines
None of the planned U2/U5 routes will be elevated, largely because the urban area above is far too dense. It was possible to have parts of the U1, U2 and…
Advancing with the tunnel boring machine
The tunnel boring machine is around 120 metres long, seven metres high and is also affectionately known as the ‘mole’, it bores slowly through the soil, carrying all the necessary…
Exploratory drilling
The ground must be surveyed and the subsoil explored so as to determine how the underground line should run and which construction techniques are required. This includes conducting exploratory drilling…