Posted on Sep 14, 2009 in Highlights
Excavation of Gautrain’s 15km tunnel is complete. This major milestone was achieved on Friday when construction teams detonated the final blast at Emergency Shaft 2, near The Wilds in Johannesburg.
This is also the spot where Gautrain’s customised Tunnel Boring Machine came to a halt at the end of January 2009 when it completed its three kilometre drive.
In order to excavate the 15,5km tunnel between Park Station and Marlboro Portal in the most efficient manner, tunnelling progressed from several access shafts and tunnel portals simultaneously. As construction reached its peak, teams have been working on 10 tunnel fronts, 24 hours for seven days a week. While emergency access shafts are being built for rescue purposes, they have also served as points from which to excavate the tunnel.
In Mushroom Farm Park, Sandton, a temporary shaft was used to provide access for tunnel construction in both northern and southern directions simultaneously. As tunnelling is completed, backfilling of the shaft is currently in progress as well as the dismantling and removal of site establishment facilities.
The single-track rail tunnel between Park Station and Sandton Station feature seven emergency shafts. These shafts will provide emergency services personnel access to the tunnels below. At the bottom of certain of these shafts will be safe havens where passengers can gather in case of an emergency.
The largest section of Gautrain’s 15km tunnel was excavated through conventional drilling and blasting which is commonly used inside South Africa’s mining environment.