Worksafe has recently prosecuted two Wellington men after poorly planned excavation work caused a power pole to fall onto a road. Although no one was hurt, the incident could easily have injured or killed someone.
In a media release dated 9 Oct 2020, Worksafe alleged that excavation work was done within the 4 meter minimum approach distance for power lines and that neither man adequately communicated their actions to one another. They were each prosecuted under sections 36(2), 48(1) and 2(b) of the Health and Safety at Work Act 2015, namely as a Person Controlling a Business or Undertaking (PCBU) they each had a duty to ensure, so far as is reasonably practicable, that the health and safety of other persons is not put at risk from work carried out as part of the conduct of the business or undertaking namely project management work, and failed to comply with that duty, leading to the incident.
Excavation work can be challenging, especially when the terrain is sloping. The Hire Industry Association of New Zealand has produced an equipment safety data sheet for safe excavation, based extensively on the Worksafe NZ Excavation Good Practice Guideline and industry input.
There are a couple of factors worth mentioning with regards to the Worksafe prosecution: Minimum Approach Distances and the concept of a ‘Zone of Influence’.
The minimum approach distances vary according to the service or utility. For cables, gas transmission lines or high press pipelines its 2 meters. For overhead power lines its 4 meters, poles 5 meters and transmission towers 12 meters. You’d be an absolute mug (and breaking the law) if you got closer than these MAD’s.
A Zone of Influence means an area, usually upslope from a geologically hazardous area, where changes in land use (such as excavation) and hydrology can affect the stability of the geologically hazardous area. It all sounds terrible complicated so its best to think of the area sloping away at 45 degree. Working within this zone of influence, such as at the edge of an excavator can lead to a collapse. Just don’t. Okay?
Check out the ESDS at https://www.upperhutthire.co.nz/wp-content/uploads/2019/04/190416-ESDS-Excavators.pdf or have a look at the Worksafe info. It’s all provided on our Health & Safety page or you can have a look at the support information for our excavators at https://www.upperhutthire.co.nz/product-category/excavators/
And if in doubt, ask an expert before you start digging. It could save you or someone else a nasty injury or worse.