KM Bentonites have been used extensively in tunnels where the ground conditions dictate the use of a Slurry Tunnel Boring Machine (TBM). The role of the bentonite is to lubricate the boring machine bits, to seal the sides of the tunnel as the TBM moves forward as well as to carry away the cuttings from the working face. The bentonite is cleaned in a slurry plant and continuously recycled.
KM Bentonites were used for the slurries in the case of the Docklands Light Railway tunnels from Greenwich to Island Gardens ( ref: Nishimatsu JV ) and for the Channel Tunnel Rail Link tunnels under the Thames ( KM2 and KM-HY were the grades specified)..
Our recently developed KM Ultrabore bentonite played an essential role in the 2011-12 linking of the Isle of Wight to the mainland with twin 3.8km tunnels by LMR drilling, who drilled the 2 tunnels accurately and on time. The project subsequently won the Capital Project Management Award for Scottish Gas.