TBM manufacturer Herrenknecht has been awarded the fourth and final section of Phase One of the Doha Metro Project, an integral part of the Qatar Rail Development Program.
In addition to the German manufacturer’s supply of 15 tunnel boring machines (TBMs) for the first three sections of Phase One, they have now been awarded the final section, dubbed the Gold Line, consisting of an additional six TBMs. Of the 21 machines that Herrenknecht are preparing to supply, 17 will be fitted with a MineARC Tunnelling Refuge Chamber, providing an immediate safe-retreat for workers in the event of a fire or other emergency.
Qatar, which frequently suffers from traffic congestion, will receive the new Metro system to lead up to the Gulf nation’s 2018 FIFA World Cup. The four-line network will cover the Greater Doha area and include connections to town centres and vital commercial and residential areas throughout the city.
TBM excavation is imperative to the Doha Metro Project, requiring minimal interference to people’s day-to-day lives and living in the area. A large proportion of the development will be completed underground with just one entry point, highlighting the importance of refuge chambers onboard the boring machines, providing a secondary means of egress in an emergency.
Each tunnelling refuge chamber can shelter up to 20 people for a minimum of 30 hrs and features several important life support systems including; primary and secondary oxygen supplies plus a carbon monoxide and carbon dioxide scrubbing system.
An automatic overpressure system always maintains positive internal pressure, periodically releasing calculated amounts of air into the internal chamber.
TunnelSAFE Chambers have been developed and refined to meet the latest industry legislations on tunnel refuge chambers, including the current European Standard (EN 16191:2014) Safety Requirements for Tunnelling Machinery, the British Standard (BS 6164:2011) Code of Practice for Health and Safety in Tunnelling in the Construction Industry, and the ITA’s Guidelines for the Provision of Refuge Chambers in Tunnels Under Construction.