Banihal: The main tunnel of T-49, the longest tunnel of Indian Railways, between Sumber and Arpinchala station of Katra-Banihal section of Udhampur- Srinagar-Baramulla Rail Link (USBRL) project has been connected with a perfect “line and level breakthrough” on Tuesday.
“Breakthrough was achieved today in the presence of A K Khandelwal CAO/USBRL along with NR team, IRCON officers and the officers of Messrs HCC and Messrs AFCONS,” officials informed.
Officials said that out of 272 km length of the USBRL project, 161 km project was already commissioned and operationalized.
“The work of an intervening stretch of 111 km between Katra-Banihal is under progress at a rapid pace. Katra-Banihal section is traversing through hilly terrain of lower Himalayas, in which geology is a major challenge. It has several major bridges and very long tunnels which are under construction at different stages,” they stated.
“Today a major milestone has been achieved by executing the break-through of tunnel T49 between Sumber and Arpinchala stations on the ongoing Katra-Banihal section. The line and level of the tunnel is precisely achieved in break-through. T-49 tunnel is 12.758 km long and it is going to be the longest tunnel of Indian Railway, surpassing Pir Panchal 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 the district headquarter Ramban at an altitude of 1200 meters, while the North Portal (NP) of the tunnel is located near Arpinchala village tehsil Khari of district Ramban in Mahu-Mangat valley at an altitude of 1600 meters approximately,” the officials informed.
According to them, T-49 tunnel has two tubes, i.e., one is the main tunnel and the other is the escape tunnel. The tunnel has been constructed by NATM (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 (entrance) namely Urnihal adit, Hingni adit and Kundan adit have also been constructed. The tunnel has a ruling gradient 1 in 80 and a 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 officials added.
The work of construction was entrusted by Northern Railway to Messrs IRCON International Limited which assigned works in two packages to Messrs HCC and Messrs AFCONS.
“Messrs HCC is executing the work of 5.1 km length from South Portal and Messrs 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, highly jointed rock mass, rock problems of squeezing and high ingress of water. The team of experienced engineers of Northern Railway, Messrs IRCON and the executing agency Messrs HCC, Messrs AFCONS successfully negotiated all challenges and made it possible to achieve this major breakthrough,” the officials said.
During construction activities of the tunnel, the local population was employed by agencies for various works in the region which has changed the overall socio economic landscape, they claimed.
Meanwhile, Hindustan Construction Company (HCC), in its official statement, said that it jointly achieved “day-lighting of the 13 km long India's longest and Asia's second-longest tunnel T49 on Dharam-Qazigund section of Udhampur-Srinagar-Baramulla new BG Railway line in Jammu & Kashmir.”
“The efforts were coordinated by the IRCON team led by Akhil Agrawal, Chief General Manager and the executing agency of HCC led by Sharanappa Yalal, Project Manager. The entire tunnel is waterproof with PVC membrane lining,” it said.