When most people think about tunnels it’s common to visualise road or train tunnels, but in truth, tunnels are defined across many shapes and sizes.
In New Zealand, tunnels under construction are grouped by one common feature – they are all covered by the Health and Safety in Employment Act 1992 (as amended in December 2013) and the Health and Safety in Employment (Mining Operations and Quarrying Operations) Regulations 2013, regulations that redefined what counts as a tunnel for the New Zealand mining and tunnelling industries.
Following the 2012 report from the Royal Commission on the Pike River Coal Mine Tragedy, where 29 miners and contractors died on 19 November 2010, recommendations were made and, as a result, the New Zealand Government pledged to reduce all workplace deaths and serious injuries by 25 per cent by 2020.
In December 2013 changes were introduced to mining regulations in New Zealand and some codes of practice were provided to assist mining operators in safely managing their operations. More codes are currently being developed.
A key area of interest for those in the industry is what defines a tunnel’s eligibility. Put simply, a tunnelling operation is considered a mining operation if it extracts material underground in any direction, be it horizontal, vertical or any angle in between. The exclusion order defines what isn’t a tunnel.
The updated definition of a tunnelling operation, as outlined in Section 19O of the HSE Act, is as follows:
Meaning of tunnelling operation:
- Means an operation involving extraction of fill with the purpose of creating a tunnel or shaft or enlarging or extending any tunnel or shaft; and
- Includes the place where an operation described in paragraph (a) is carried out; but
- Excludes any tunnelling operation of a kind declared under section 19P not to be a tunnelling operation.
(Section 19O: inserted, on 16 December 2013, by section 11 of the Health and Safety in Employment Amendment Act 2013 (2013 No 95).)
The new definition, as stipulated by the updated regulations, is far broader than one may think.
For instance, if the contractor is extracting the fill for the purposes of creating a tunnel or shaft, including operations involved in microtunnelling, then this is still considered a tunnelling operation and the new mining regulations may apply.
It is prescribed in Section 19O of the Health and Safety in Employment Act, and further defined in an Order in Council titled Health and Safety in Employment (Tunnelling Operations”ÓExcluded Operations) Order 2013.
Essentially, this Order excludes certain operations from the definition of a tunnelling operation if they meet all of the following criteria;
- No more than two mine workers work underground during the operation at any one time
- Explosives are not used underground
- The operation relates to a tunnel or shaft that is, or is intended to be, no more than 15 m long
- The concentration of methane is not likely to be more than 0.25 per cent of the general body of air in any working area in the operation.
This means for example, that any tunnel works (including microtunnelling) exceeding 15 m in length, where more than two workers will be underground during construction, is a tunnel as defined by the new regulations. As defined, the exclusion order means that even if no workers are working underground and the tunnel is over 15 m long, it is still covered by the new regulations.
For members of the industry, these new regulations will have very little impact on costs. Project timings will need to allow for the two month notification period required prior to commencement.
At some future date the Order in Council may be reviewed to determine if it is adequate, but until that review occurs, the definition of a tunnel stands as it is currently written.
WorkSafe New Zealand understands that the new definition of a tunnel may include operations not normally associated within the tunnelling industry, for example directional drilling.
WorkSafe’s High Hazard Unit (HHU) Mining Team is at the frontline of enforcing the tunnelling regulations. Their focus is on the health and safety performance in the extractive industries such as mining (underground, open-cast, coal and metalliferous) and tunnelling.
The team’s top priority is to premeditate process safety risks and there is a significant emphasis on inspecting the management systems structures and shaping workplace practices.
The focus of the HHU is to work with operators to prevent catastrophic events and inspectors are focusing on compliance and enforcement activity in operations that place people underground in tunnels over 15 metres in length.
The HHU may also intervene in situations where hazards like methane and explosives exist.
WorkSafe’s key focus is on ensuring people come home from work to their families and loved ones safely.
WorkSafe will act immediately and decisively, closing sites if necessary, where the organisation sees inadequate hazard control and poor risk management.