Are you digging a trench or a death trap?

Not using appropriate controls can be fatal.

WorkSafe is warning employers and workers to take trenching safety seriously. Between 2017 and 2019, four fatalities occurred in trenching incidents at Victorian construction worksites. This highlights
the significant need to address unsafe trenching practice in the construction industry.

Hear from Brian Chamberlin, Construction Industry Education Officer, on what should be considered before commencing trenching works on construction sites.

To reduce the risk of incidents occurring during trenching work, employers and self-employed persons need to be adequately prepared, have the right controls in place, and adhere to OHS rules and regulations.

Before the trenching work begins:

Employers and self-employed workers should create a documented safe system of work identifying the hazards and risks. They should:

  • Fill out a Worksafe Excavation Notification and email it to WorkSafe for trenches 1.5 meters or more if applicable.
  • Develop a safe work method statement (SWMS) prior to work commencing
  1. For all trenches where the depth exceeds 1.5 metres.
  2. Where powered mobile plant is involved

Preparation for trenching work is of utmost importance. To ensure that trenching work is adequately prepared, employers must:

  • Regardless of the depth have an emergency procedure in place if there is a risk of a worker becoming engulfed
  • Determine appropriate engulfment control measures
  • Ensure site can be secured

During the trenching work:

Regardless of the depth of a trench, engulfment control measures must be in place where workers are at risk of potential engulfment. Examples of such controls are:

  • Benching or battering the walls to prevent collapse
  • Shoring systems to support the sides
  • Trench shields

Appropriate supervision by a competent person, experienced in trenching works should be provided focusing on factors such as:

  • Workers remaining within engulfment control measures, including where protection is being progressively installed
  • Materials, spoil and plants are kept away from the trench edge
  • The trench and work area is secure and will prevent unauthorised access
  • Any changes to the work or soil conditions.

Fall prevention tips:

Falls into trenches can also lead to serious or fatal injuries. Not only do you need to protect workers entering and exiting trenches, but also anyone working nearby from falling into trenches. Fall protection controls may include, but are not limited to:

  • Extending trench shield at least 900mm above the trench
  • Fitting trench shield systems with attachable guardrail system. Where possible, be fitted before installing the trench shields
  • Appropriate fall protection in place during access/egress
  • Exclusion zones of at least 2 meters where possible, around excavation works
  • Securing the work area to prevent unauthorised access.

Listen to causes of engulfment for top tips on how to avoid these situations and other incidents involved in trenching.
Listen to more construction top tip videos from inspector Brian Chamberlin on reducing the risk of incidents while carrying out excavation works.

More information
Visit for further information on safe trenching works.

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