One of the machines will be a 7.6m diameter factory-rebuilt unit, and the other two will be new 7.2m diameter machines. The TBMs will be fitted with Robbins 19 inch cutters, which have been proving successful on the Little Calumet Leg tunnel in south suburban Chicago.
Impregilo won the US$530M contract to construct the Kárahnjúkar dam and underground works from Iceland's power company, Landsvirkjun, earlier this year. The project includes a 39.8km long 7.6m diameter headrace tunnel and 13.5km of diversion tunnels.
The first TBM machine is due to be delivered later this year and the others in early 2004.
