Rain may hamper Pernem tunnel restoration work

Heavy rains in Goa for the past few days have hampered the restoration work of the tunnel at Pernem along the Konkan Railway (KR) route. A 5m stretch of the lined wall inside the tunnel caved in the early hours of Thursday, paralysing train traffic along the Konkan Railway route. A number of trains on the route have been cancelled or diverted through the South Western Railway (SWR) line.

Baban Ghatge, deputy general manager, public relations, Konkan Railway Corporation (KRC) said that the track is likely to become operational by August 20 though heavy rains could delay completion of the work. Senior KRC officials are supervising the repair and restoration operations inside the tunnel.

“As the working area inside the tunnel is small, only a certain number of labourers can be deployed for the work. However, adequate number of men and machines are engaged for the task,” Ghatge said. Sources said that as multiple cracks have developed in the lined wall, water gushes out through these cracks during heavy rain which hampers repair work.

The railway board has cancelled Thiruvantapuram – Lokmanya Tilak (T) – Thiruvantapuram Special Express and New Delhi – Thiruvanatapuram Central – New Delhi Rajdhani Express upto August 20.

Madgaon – Nizamuddin – Madgaon Goa Express will originate from Hubbali instead of Madgaon upto August 23 and for the return journey, it will terminate at Hubbali instead of Madgaon, states a press note by KR.

Similarly, the Ernakulam – Nizamuddin – Ernakulam superfast special Express is diverted via Madgaon – Londa – Miraj – Pune – Panvel –Kalyan, while the Nizamuddin – Ernakulam – Nizamuddin Duranto special Express is diverted via Pune – Wadi – Guntakal – Renigunta – Melpakkam – Jolarpettai.

The 1.56 km-long Pernem tunnel was built largely in soft soil strata. The collapsed portion lies 300 m from the Mangalore end of the tunnel. Sources said that while the tunnel already had a 50 kmph permanent speed restriction, a 20 kmph restriction was imposed at the spot of the collapse since last year. Works on this tunnel commenced in mid-1992 and was completed on January 10, 1998.

Sources said that engineers faced a daunting task during the tunnelling work at Pernem as the substrata of the soil altered between soft schist rock, slanting rock, hard laterite and soft clay, with constant water seepage. There were problems of mudflow, collapses, cavity formation and squeezing of supports. Techniques such as fore-poling, insertion of perforated pipes for draining out water, and grouting were employed for the tunnelling work in Pernem.