TBM Liva last month completed her 12th breakthrough beneath the streets ofCopenhagen as the full face earth pressure balance tunnelling machine arrived at an underground station box for the Danish capital's new £550M metro system.
Named after local music hall stars, Liva and her twin Betty have now battled beneath city streets for more than two and a halfyears through difficult ground conditions varying from boulderriddled abrasive glacial sands to limestone containing broad bands ofhard flint.
Comet, the multinational contracting team - led by Britain's Carillion with geotechnical specialist Bachy Soletanche, France's SAE, Austria's Ilbau, Italy's Astaldi and NCC Rasmussen & Schiotz from Denmark - hopes to complete all 15km ofthe 5. 2m diameter tunnels by February.
Most ofthe halfdozen,60m long underground station boxes are nearing structural completion.
Their 25m deep secant piled walls were bored through central streets tight against 100-year-old housing. First phase ofthe 13km metro is planned to open in autumn 2002.