India’s longest transportation tunnel made through bigh achievement for railways in USBRL project

New Delhi  : General Manager, Northern Railway Ashutosh Gangal informed that Northern Railway has achieved a major milestone in USBRL project on February 15 this year by executing break-through of Tunnel T49 between Sumber and Arpinchala Station on ongoing Katra-Banihal Section. The line and level of the tunnel is precisely achieved in break-through. T49 is a tunnel of length 12.758 Km long and it is going to be longest tunnel of Indian Railway surpassing Peer Panjal Tunnel of 11.2 Km length constructed by USBRL on Banihal-Qazigund section. The south portal (SP) of Tunnel T-49 is located in picturesque Sumber Village at a distance of 45 km from District H.Q. Ramban of (Jammu & Kashmir) at an altitude of 1400 meters, while the North Portal (NP) of the tunnel is located near Arpinchala village Tehsil Khari, District Ramban, in Mahu-Mangat Valley at an altitude of 1600 meters approx.
T-49 tunnel is having two tubes, i.e. one is main tunnel and other being escape tunnel. The tunnel has been constructed by NATM (i.e. New Austrian Tunneling Method), which is a modern technique of drill and blast method. The Cross section profile of the tunnel is modified horse shoe shaped. This tunnel length is very long. In order to facilitate construction, three adits namely Urnihal Adit, Hingni Adit and Kundan Adit have also been constructed. The tunnel has a ruling gradient 1 in 80 and designed speed of 100 Kmph. As per International standards, the Escape Tunnel being constructed parallel to the Main Tunnel is connected by cross passages at an interval of 375m to facilitate rescue and restoration work.
The work of construction was entrusted by NR to M/s IRCON International Ltd. which has assigned works in two packages to M/s HCC and M/s AFCONS. M/s. HCC is executing the work of 5.1 Km length from South Portal and M/s AFCONS is executing the length of 7.658 Km from North Portal. Several Challenges were encountered in the course of construction such as shear zone, perched aquifer, and highly jointed rock mass, rock problems of squeezing and high ingress of water. The team of experienced engineers of Northern Railway, M/s IRCON and the executing agencies M/s HCC & M/s AFCONS successfully negotiated all challenges and made possible to achieve this major breakthrough.
During construction activities of the tunnel local population was employed by agencies for various works, in the region which has changed the overall socio economic landscape. Break-through has been achieved on February 15 this, in the presence of A.K. Khandelwal CAO/USBRL along with NR team, IRCON Officers, Officers of M/s. HCC and M/s. AFCONS.