OHS Code Explanation Guide

Published Date: July 01, 2009
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Part 32 Excavating and Tunnelling

Section 462 Drilled or bored underground shaft

Subsections 462(1) and 462(2)

Large-sized mechanical drilling or boring devices are sometimes used to excavate underground shafts. Before a worker is required to enter the shaft, the employer must ensure that protective structures have been installed. Such structures can be an installed casing or a temporary protective structure certified by a professional engineer. The professional engineer must certify that the installed protective structure is of sufficient strength to resist shifting of the surrounding materials.

To prevent materials at the surface from falling into the shaft and onto workers, the casing or temporary protective structure must be designed and constructed to extend at least 300 millimetres (12 inches) above surface level.

Subsection 462(3) and 462(4)

During the removal of excavated material, a worker in the belled area of an underground shaft can be exposed to falling material unless it is possible to stand clear. If the worker is unable to stand clear of falling material, then the worker must return to the surface ahead of (precede) each load going to the surface.

If it is not possible to precede each load to the surface, then the worker must accompany the load to the surface using equipment designed to do so, following written safe work procedures prepared by the employer. Section 8 of the OHS Regulation requires the procedures to be in writing and available to workers.