The Nau Mile Nautanki!

BLURB
…the geology of the area cannot be altered, but better engineering techniques can be used

A COMBINATION OF FACTORS FROM BAD GEOLOGY TO POOR ENGINEERING HAVE CREATED THIS TROUBLESPOT

The sinking highway at 9 Mile on the Ranipool-Singtam axis has been a nuisance ever since it was carved out. NOW! speaks to a geologist to understand what makes this such a troublespot and how it could be reformed…

“Landslides are like human beings, they come in different shapes, sizes and personalities and the 9th Mile slide is like an irritating person who has overstayed his welcome,” says Geologist and former Director, Mines and Geology Department, Tsering Tashi, while talking to Sikkim NOW!
It has been around 55 years since this stretch of road under Tumlabong-Namli in East Sikkim on NH10 [formerly NH31A] was made motorable when Jawaharlal Nehru came on a visit to the then Kingdom of Sikkim. However, as early as 1914, former Maharaja of Sikkim, Sidkeong Tulku is known to have used this road too where he would drive his Baby Austin to Teesta. Since then, the slide at 9th Mile has irked government agencies and commuters alike. Everyone knows how big 15 August in Kalimpong used to be, and old-timers will attest that whenever families moved out from Gangtok [for Kalimpong] early on the morning of 15 August, they would send up a collective prayer hoping that the 9 Mile section was open. The alternate route via Pakyong was too long and the wait at 9 Mile too depressing. Well, those days are back for commuters.
According to Mr Tashi, bad geology and surface and ground water are the main causes for the landslide [sink rather] at 9th Mile while the reasons for the inability to arrest this problem are completely different. Characterized by highly fragmented fragile rocks, 9th Mile comes under a subsidence zone and is actually only part of a landslide. Other contributing factors are the water fed paddy fields above the slide and continuous vehicular movement on the stretch which causes vibration.
One solution to the problem, Mr Tashi opines, is draining the surface water away from the sink. Since this stretch has a sagging central section, he suggests the technique of “arching” where the road is aligned in the shape of an inverted bow which would automatically drain water [away from the sinking area]. This, he says, would prevent any major damage for at least 10 years. The other alternative is ‘piling’, used in construction, where huge steel rods are inserted deep into the ground to reinforce stability.
“The geology of the area cannot be altered, but better engineering techniques can be used to solve the problem. Sadly in Sikkim, no engineering or science is used to tackle the problem of landslides,” he says.
In 2006-07, when Brigadier RK Patyal was the Chief Engineer of Border Roads Organisation, a serious attempt had been made to realign this road. However, sudden and routine transfer of BRO chiefs did not allow for any substantial improvements or changes to be made or consistently attempted.
“The first proposal to undertake arching at 9th Mile was placed before the National Highways Authority of India under the Ministry of Surface Transport during Brigadier Patyal’s time. It was rejected and a second proposal was put up. This time, things looked positive and the Chief Engineer of the NHAI even visited Sikkim. However, shortly after, Brigadier Patyal was transferred back to the BRO headquarters and was replaced by Brigadier Rajeev Sawhney who was also soon replaced by SS Powai”, he shares. And, in all these transfer orders, the proposal appears to have been forgotten.
Critical of the regular practice when it comes to handling the problem of landslides, Mr. Tashi is of the view that the application of a thumb-rule for every case does not make sense. “Every disease has to be treated differently and the same goes for landslides. We cannot prescribe the same medicine for all kinds of diseases,” he underlines.
In a state where landslides have claimed numerous lives apart from causing economic losses and inconveniencing the public, it is imperative that sincere and well-thought out attempts are made to address a problem that is rooted in the geological structure of the region. Mr Tashi thinks science and technology have all the answers, if only we choose to look there.