Mt Albert Tunnel, Wellington 2014
This contract was a repair job on a 150mm diameter ductile lined pipe line that had failed. The pipe was a sludge line from the treatment plant to landfill that was buried under the floor of the Mt Albert gravity sewer tunnel.
The tunnel is 1.8km long and only had access to each end through 7m deep manholes. The peak flows through the tunnel were up to 900L per second. This needed to be bypass pumped via temporary pipes laid on the floor of the tunnel. Ventilation need to be set up as were breathing lines, air and communication lines. All workers in the tunnel had to wear breathing apparatus.
The floor of the tunnel had to be broken out, the concrete removed from the tunnel, the pipe replaced and the concrete re-poured.
This project won the inaugural NZ Contractors’ Federation Wellington/Wairarapa Branch Health and Safety award.