MineARC Systems has won an order from Herrenknecht to supply custom-engineered Emergency Refuge Chambers for 11 of the 15 TBMs the German manufacturer is currently producing for Phase 1 of the Doha metro project, in Qatar. The chambers will provide immediate safe-haven for workers requiring shelter in the event of a fire, a fall of ground, or similar emergency.
Each of the 11 MineARC Refuge Chambers can shelter up to 20 people for a minimum of 30hrs and features a number of important life support systems, including; primary and secondary oxygen supplies and a carbon monoxide/carbon dioxide scrubbing system to regenerate the air.
Each refuge chamber also features an automatic overpressure system. Special sensors constantly monitor the relative pressure both inside and outside the refuge chamber, and relay this information to the chamber’s internal air systems. Based on the readings, a precise amount of air is periodically released into the refuge chamber, ensuring positive internal air pressure of at least 200 pascals above outside air pressure, at all times.
All of these vital safety features ensure the chambers meet the latest industry safety legislation pertaining to refuge chambers. This includes the current British Standards and the 2014 ITA Guidelines for the Provision of Refuge Chambers in Tunnels under Construction.
Phase 1 of the Doha metro project is due for completion in 2018, and consists of four newly constructed sections: The 11km twin-running underground section of Red Line North, the 16km twin-running underground section of Green Line, the recently awarded 13.8km twin-running underground section of Red Line South, and the 13km twin-running tunnel of the Gold Line, the contract for which is expected to be awarded later this year.
Future scope for the metro project includes the 17.5km underground section of the semicircular Blue Line that will link Airport City and West Bay Central and the extension of the Green Line, which are both yet to get under way.
For more information on tunnelling in Doha see: previous stories by www.tunnellingjournal.com