Multiple fault zones, variable face conditions and squeezing ground requiring extensive bypass tunnelling were just a few of the challenges that needed to be met in order to successfully complete Turkey’s Kargı Kızılırmak Hydroelectric Project.

A Robbins 10 m diameter double shield tunnel boring machine (TBM) achieved breakthrough for the project on 5 July 2014 after an impressive run through some of the most difficult conditions ever encountered by a Robbins field team.

The machine type, selected in collaboration by the owner, consultants, Robbins and the contractor Gülermak of Turkey, excavat...