Supply Of Detail Design And Construction Supervision Of 4 No. Single Line Bg Tunnels ( Approx. Total Length 1200 Rm ) Between Km 28.300 To Km 35.100 Excluding About 50M To 100M ( Approx. ) Cutting As Required On Each Face Of All Tunnel For Opening Of Face In Connection With Construction Of New Bg Rail Line From Koderma To Tilaiya Under Jurisdiction Of Dy. Ce / C / Dhn.