Qatar Railways Company (Qatar Rail) has announced the successful re-launch of its Tunnel Boring Machine (TBM) at the Corniche station at the Doha Metro’s Red Line, following a three-month period of intense and coordinated rehabilitation efforts.
The repair process, split into cleaning, rewiring and re-installation phases, covered the replacement of damaged equipment and approximately 80% of the machinery was changed. The repair moved at considerable speed, meaning that the initial timeline for the completion of both the Red Line and Doha Metro were unaffected.
The TBM re-launch followed a flooding incident that affected its works at the Corniche station during tunneling operations in mid-February. Assisted by the concerned service providers, Qatar Rail and the assigned contractor immediately contained the damage incurred on the TBM by discharging water through pumping.
Because of rigorous health and safety standards and procedures, and carefully devised incident management processes, Qatar Rail confirmed that there were no injuries and no environmental impact. Tunneling works, initially five months ahead of schedule at the Corniche station, are still respecting the assigned timetable after spending only three months on rehabilitation works.
CEO of Qatar Rail, Engineer Saad Ahmed Al Muhannadi, said:
We had put in place strict risk mitigation and emergency control strategies and processes before we initiated the tunneling works for the Doha Metro. We are very aware that such a complex tunneling project is prone to incidents of this sort and our planning processes identify what are the most likely risks and plan for them. We are proud of the team who handled the incident management at Corniche station. This was teamwork and technical expertise at its best. Thanks to the prompt reaction, rehabilitation process took only 3 months while comparable events usually need from six months to one year and a half to reach recovery. Tunneling Incidents are complex, however we were able to prove efficiency and swiftness in dealing with it.’
Al Muhannadi noted that the incident has demonstrated the strength and effectiveness of the company’s incident management team.
Qatar Rail confirmed that it has now completed 30km of tunnels. This represents strong progress from when it last reported on tunneling progress in April when just under 20km had been achieved. When complete, the Doha Metro will have 113km of tunnels.
Red Line Project Manager at Qatar Rail, Gerhard Cordes, further explained the technical aspect of the incident. He said:
The TBM that was boring the tunnel encountered a gate closure failure and flooding in the tunnel. We reacted immediately to the incident by discharging water through pumping, with planning for recovery and mitigation. Dewatering wells were installed and surface dewatering commenced in early March. An intense repair period for the TBM followed, involving general cleaning as well as tunnel preparation for removal, refurbishment, re-installation inside the TBM and electrical and mechanic cabling. It is a lengthy process that we have productively managed to complete in a remarkably short timeframe and efficient manner.’
Qatar Rail already received the 21 TBMs assigned for the project, after being imported from Herrenknecht, the German world market leader in mechanised tunnelling technology. All Qatar Rail TBMs are currently operational, with expectations to successfully accomplish the tunneling phase by the second quarter of 2017.