Northern Railway has achieved a major milestone by breaking through tunnel T-14 (main tunnel) between Sawalkot and Sangaldan station in Katra-Banihal section under construction of Udhampur-Srinagar-Baramulla (USBRL) rail project. The line and level have been achieved precisely during break-through of tunnel T-14.
This has been done by Indu Paul Kaur, a female employee of Avantipora, Kashmir working as an engineer in IRCON. The total length of T-14 tunnel is 6.284 km. It has Reasi on one end and Ramban district on the other end. These tunnel portals are located in remote villages of Reasi and Ramban districts, where there was no road connectivity before the tunneling work started.
The South Portal (P-1) of Tunnel T-14 is located at an altitude of about 1070 meters at village Sawalkot in Arnas Tehsil, at a distance of 100 km from district headquarter Reasi (J&K). Whereas the northern portal (P-2) of the tunnel is located at village Ind, tehsil Gul, district Ramban at an altitude of about 1150 metres.
T-14 tunnel has two tubes i.e. main tunnel and second escape tunnel. The tunnel was constructed using the NATM (i.e. New Austrian Tunneling Method) method, which is an observational and sequential construction method. NATM is a suitable method for tunneling in different geological terrain and strata. The cross section of the tunnel is in the shape of a modified horseshoe.
To facilitate the construction of this long tunnel a 978 meter long access road has been made and the ruling gradient inside the tunnel is 1 in 80 and has a design speed capability of 100 kmph. The construction of escape tunnel is also going on parallel to the main tunnel as per international standards. It is connected by cross corridors at an interval of 375 meters to facilitate rescue, relief and restoration operations.
Northern Railway had entrusted the work of construction from South Portal (P-1) to M/s Konkan Railway Corporation Limited and from North Portal (P-2) to M/s IRCON International Limited.
The tunnel passes through complex geological conditions consisting of Muri Formation at the south end and dolomite at the north end and is separated from the Subathu Formation. The challenges faced during tunneling are shear zones, release of flammable gases (methane), aquifers and highly compacted rocks and ingress of high volumes of water.
The team of experienced engineers from Northern Railway’s RCL and IRCON has successfully overcome all the challenges and made this important break-through successful. During the construction activities of this tunnel, around 65 percent of the workers were local, which has also given a boost to local employment.
Out of the total 272 km of the Udhampur-Srinagar-Baramulla Rail Link (USBRL) project, 161 km has already been completed and rail operations have also started. Work on the remaining 111 km stretch between the Katra-Banihal section is in progress and passes through the hilly terrain of the lower Himalayas. It has many big bridges and long tunnels. Here also the work is going on at a fast pace.