Tunnel boring machines (TBMs) prefer to chew rocks, not mud. Besides, they can't support the wet ground, so the tunnel walls are collapsing! TBMs work much better in rock tunnels. Try this ...
The tunnel boring machine named Florence had been making slow ... "[On Monday] the contractor commenced work using high-pressure water jets to remove the rock impinging on TBM Florence's shield.
A 1,600-tonne tunnel boring machine has made it halfway through its journey to build the 3.5 mile (5.6km) Bromford Tunnel between Water Orton and Washwood Heath. Working about 40m (131ft ...