Deadly trench collapses like this one in the U.S. and the one in this article are entirely preventable
Photo provided by David Dow
On 21 March 2018, two men went to work on a housing development in Delacombe, a suburb of Ballarat in Victoria. Charlie Howkins was 34. Jack Brownlee was 21. They were laying pipes in a trench when the walls collapsed and engulfed them both. Charlie died at the scene. Jack died in hospital the following day.
The trench had no battering, no benching, no shoring, and no trench shields. In 2021, the Ballarat County Court convicted the company, Pipecon Pty Ltd, and imposed a fine of $550,000.
Two families lost someone they loved. A company lost its reputation and a significant sum of money. And the industry lost two workers whose deaths were, in the words of the court, entirely preventable.
This article is about the legal obligations that exist in Australia to prevent exactly this kind of tragedy — and why, despite those obligations being clear, well-documented, and actively enforced, things can still go wrong.
The 1.5 Metre Rule
Australia operates under a harmonised Work Health and Safety (WHS) framework adopted across most states and territories, with Victoria maintaining its own OHS legislation but substantively identical requirements. The critical threshold every civil contractor must know is 1.5 metres. Any trench deeper than 1.5 metres is classified as high-risk construction work under the WHS Regulations — a defined legal category that triggers mandatory obligations regardless of soil type, job size, or prior experience without incident.
At 1.5 metres, two things must happen without exception. A Safe Work Method Statement (SWMS) must be prepared, communicated, signed, and followed. And a protective system must be in place before any worker enters the trench. The choice of system depends on site conditions, but the requirement to have one is absolute.
1.5 metres is not a guideline. It is the legal line. Cross it without a protective system and you are in breach — before anything has gone wrong.
The 1.5 metre rule is a minimum threshold, not a safety guarantee. Loose, sandy, waterlogged, or previously disturbed ground can collapse at far shallower depths. The Regulations require a risk assessment for all excavation work regardless of depth. The 1.5 metre mark simply removes any discretion — at and beyond it, protection is mandatory.
Shoring, Battering, and Benching — Knowing the Difference
Shoring physically supports the trench walls using hydraulic shores, timber systems, or prefabricated steel trench boxes. A trench box does not prevent collapse — it provides engulfment protection within which workers operate. Workers must remain inside the box at all times. Stepping outside it to reach a pipe or fitting removes all protection.
Battering means sloping the trench walls back at an angle sufficient to prevent collapse. Australian practice caps battering at 45 degrees from horizontal without geotechnical certification — steeper angles require a written engineer’s assessment. Battering is space-intensive and best suited to open ground where conditions permit.
Benching excavates the trench in horizontal steps rather than a continuous slope, reducing load on the trench face. It is an alternative where full battering is impractical and can be combined with shoring in deeper excavations. In all cases, the selection of method must be documented, and for complex ground conditions or proximity to roads and structures, a geotechnical engineer must assess and certify the design.
A trench box does not stop the walls from collapsing. It protects the workers inside it. Step outside and that protection is gone.
The Court Record
The Ballarat case is not an anomaly. In June 2022 in New South Wales, a 19-year-old plumbing apprentice was clearing a trench with a shovel when a section collapsed on him. His employer, Mills and Watson Plumbing, was convicted in October 2025 and fined $225,000. The Director was fined a further $22,500.
In South Australia in July 2022, a worker measuring depth in a 1.6-metre trench had his leg crushed when the walls gave way. The contracting company was sentenced in October 2024. The magistrate noted that the collapse was entirely preventable had the 14-metre trench been benched, battered, or shored as required. Fine: $75,000.
In Queensland in 2021, two workers were directed into a 2.5-metre trench to repair a water pipe with no risk assessment and no shoring in place. The earthmoving company was fined $60,000 in the Goondiwindi Magistrates Court in 2023.
Every one of these cases shares the same thread: the risk was known, the law was clear, the protective measures were available, and a decision was made — consciously or through negligence — not to implement them.
Industrial Manslaughter: The Raised Stakes
The most significant legal development for Australian civil contractors in recent years is the national rollout of industrial manslaughter legislation. Queensland led in 2017. Every other Australian jurisdiction followed, with New South Wales and Tasmania completing the sweep in 2024. A company director found to have been reckless or grossly negligent in circumstances that caused a worker’s death now faces the possibility of imprisonment, with maximum penalties in some jurisdictions reaching 25 years. Fines for body corporates reach $18 million. Critically, in several states including Victoria, NSW, and Western Australia, insurance cannot be used to cover WHS penalties — the fine comes directly out of the business.
Before You Dig — and Before You Dig Further
Before any trenching begins, a Before You Dig Australia (BYDA) enquiry must be lodged at byda.com.au to identify registered underground assets. This should be a legal obligation, not a courtesy.
BYDA plans show approximate locations only — physical locating using calibrated equipment must follow before mechanical plant breaks ground. A BYDA response is the beginning of due diligence, not the end of it.
What Good Practice Looks Like
For Australian civil contractors who want to keep their workers safe and stay on the right side of the law, the compliance chain for trenching work is not complicated:
Lodge the BYDA enquiry
Physically locate underground services
Prepare the SWMS before the machine arrives on site, not after the trench is already open
Assess soil conditions before any worker enters the excavation
Install the appropriate protective system — shoring, battering, or benching
Inspect the trench at the start of each shift and after any event that could affect stability
Document everything
None of this is technically difficult. The protection equipment is readily available for hire. The standards are well-documented, freely available and written in plain English in Safe Work Australia’s Code of Practice: Excavation Work.
The knowledge exists in the industry. What causes incidents is not a lack of knowledge — it is a decision, made under time pressure or cost pressure or simple familiarity, to skip a step.
Charlie Howkins and Jack Brownlee were laying pipes in Ballarat on a Wednesday morning. The job must have seemed routine. The wall came down.
No schedule justifies that outcome. No budget does either.
Jeff Moore is the Director and Compliance Manager of Locating Unlimited Pty Ltd (RTO 45518), a registered training organisation based in Queensland, Australia, specialising in utility location, vacuum excavation, and ground disturbance safety training. He is also the founder of the Locators Association of Australia and publisher of The Dangers Below e-magazine.