Document ID: chunk:federal_register_of_legislation:F2016L00416:reg:4:p11
Version: federal_register_of_legislation:F2016L00416
Segment Type: reg
Provision Reference: reg 4 (pt 11/21)
Character Range: 59112–62132

excavated using various techniques.

Shaft sinking involves excavating a shaft from the top, with access and spoil removal from the top. Other construction methods include raise-boring, which is a method of constructing a shaft (or raise) where underground access has already been established. Raised bored shafts can be from the surface or from one horizon to another underground. The method can be remotely executed, not requiring people to enter the shaft.
Access to shaft openings should be controlled by using a secure cover that is lockable and accessible only by a designated persons. An alternative means is to use a suitable guard rail
and toe-board with gate for access and supporting the sides by steel frames or sets of timber.
In special cases support can also be provided by installing precast concrete or steel liners.

Shafts can have special features so design and construction advice should be obtained from a competent person (for example an engineer) before excavation and installation. In some cases, special ventilation facilities may be required.

Common hazards and risks involved in shaft construction include:
    * shaft dimensions limiting work space, possibly including confined space work
    * the potential for ground instability for lifting and removing spoil
    * falls and falling objects including fine material and water from the shaft wall
    * hoisting equipment (e.g. winch, ropes and hooks)
    * hoisting and winching people, materials, spoil and plant
    * water inflow/inrush and dewatering
    * airborne contaminants and ventilation
    * confined space
    * manual tasks
    * hazardous materials
    * fire or explosion
    * inadequate communication systems
    * mobile plant
    * noise, and
    * emergency exits.
Control measures include:
    * stabilising the ground at the head of the shaft and removal of spoil
    * continuously lining or supporting the shaft
    * providing appropriate fall protection for example temporary work platforms
    * providing and maintaining appropriate hoisting equipment
    * installing dewatering systems
    * installing mechanical ventilation to control airborne contaminants and air temperature/humidity
    * isolating access to moving parts of plant and equipment
    * guiding the working platforms and material
    * avoiding overfilling material kibbles and cleaning kibbles before lifting
    * closing shaft doors before tipping, and
    * cleaning the spillage off doors, stage and any steelwork.
Further guidance on confined spaces is available in the Code of Practice: Confined spaces.

   6          PREVENTING GROUND COLLAPSE

Ground collapse is one of the primary risks to be controlled in excavation work. Ground collapse can occur quickly and without warning, giving a worker virtually no time to escape, especially
if the collapse is extensive. A buried worker is likely to die from suffocation before help arrives
(for example either the head is buried, or the chest is so restricted by the weight of