PYMBLE AND ARTARMON TUNNELS
Design and construction of two pipe jacked tunnels: one through shale at Pymble 97m long and 1650mm in diameter a 33 kV cable circuit; and the other through sandstone at Artarmon 111m long and 1650 in diameter to carry a 132 kV cable circuit. The tunnels were bored beneath rail corridors, a major freeway and a watercourse.
Restricted work area limited space for storage of pipe sections pending their jacking into place, requiring careful procurement and delivery scheduling, taking into account lead times for off-site manufacture. Mid-way through drilling of the Artarmon tunnel, the client called for a change to the depth of one section of the tunnel, requiring a sharp curve to be bored and lined.