The work of slope (invert) of the main tunnel floor part of Siddhartha tunnel under Siddharth highway has been completed. According to Siddhababa Tunnel Project Office, 834 meters of structural coating (lining) work on the inner wall of the inner tunnel of the main tunnel has been completed.

Krishnaraj Adhikari, head of the Siddhababa Tunnel Project Office, said that 1,089 meters of invert work has been completed. Out of the 1,089 meters of the main tunnel, the invert work has been completed, and 8,34 meters of the 1,126 meters of lining have been completed. According to the project, only 292 meters of lining work is left. "Invert and lining" work is being done on Bypass 1, while "Invert" work has started on Bypass 3, according to the Siddhababa Tunnel Project Office. 

The project plan is to speed up the work of the main tunnel and send vehicles from inside to work on the road outside. "The project has speeded up the inner work of the main tunnel," said the chief project officer, "It is difficult to work because of the Bhirpakha outside and the river at the bottom." Therefore, the project is planning to bring vehicles through the main tunnel first.' 

Bypass one is 151 meters, bypass two is 161 meters and bypass three is 130 meters. Invert work of Bypass 1 has been done for 145 meters. 124 meters of lining work has been completed. Similarly, the chief officer of the project office said that 125 meters of invert work has already been completed for bypass three. Lining work has also been done for 30 meters. Invert and lining work of bypass two has not started.

The lowest part of the tunnel where water or sewage is arranged is called the invert. Drainage systems are especially important in tunnels. A pipe or conduit is placed inside the tunnel, called invert elevation. The lower part is also called invert level or invert elevation according to the technician. Linings in tunnels strengthen, prevent water leakage and make them safer in the long run. 

The overall physical progress of the tunnel under construction in Palpa's Tinau Rural Municipality-3 Dobhan Siddhababa area under Siddharth Highway has reached 56.03 percent, said the Project Chief Officer. Likewise, financial progress has also reached 50.24 percent.  Under the

project, the 2-lane main tunnel will be 1089 meters long. Its main tunnel will be 10.5 meters wide and 7 meters high. According to the Project Office, the total length of this tunnel including the lining will be 1,126 meters. Out of this, the lining work in the main tunnel to the north has been completed 388 meters to the north and 446 meters to the south. The project stated that 1,495 out of 2,300 south of slope protection, 495 out of 1,100 to the north, 481 out of 9,620 towards MR1 ​​Mountain side, 1,444 out of 7,440 towards MR2 Mountain site have been worked in the project. 

Even if the construction workers work on time, it is estimated that it will take another 6 months to complete the project. The tunnel will be electrified in the coming days. Security and communication equipment will be added. The chief officer of the project said that since the current road has to be demolished outside, the traffic should be conducted through the main tunnel.