Slurry TBM (Benton' Air®) Developed and patented by NFM Technologies, the Benton' Air® tunnel-boring machine (Slurry TBM) is used for tunnel-boring in highly permeable unstable terrain, or under civilian structures sensitive to ground disturbances.
The use of TBM (tunnel boring machine) gradually increases in worldwide tunneling projects. TBM machine are often applied to more difficult and complex geological conditions in urban area, and many problems and difficulties have been reported due to these geological conditions.
Tunnels and underground excavations - Future trends in underground construction: Unexpectedly rapid increases in urbanization throughout the world, especially since World War II, have brought many problems, including congestion, air pollution, loss of scarce surface area for vehicular ways, and major traffic disruption during their construction.
A single shield hard rock tunnel boring machine is set to bore in hard rock, high water inflows and high water pressure in New York State. The TBM will bore a tunnel to replace a damaged portion of the Delaware Aqueduct that supplies half the raw water to New York City.
The first successful tunnelling shield was developed by Sir Marc Isambard Brunel to excavate the Thames Tunnel in 1825. However, this was only the invention of the shield concept and did not involve the construction of a complete tunnel boring machine, the digging still having to be accomplished by the then standard excavation methods.