A fatal trench collapse and a recent HSE prosecution are a reminder that excavation safety depends on decisions made before anyone enters the ground. Soil type, spoil placement, plant loading, nearby structures, temporary support and competent inspection all need to be considered before movement, cracking or collapse gives a visible warning.
A fatal trench collapse brought familiar failures back into focus
On 9 September 2026, HSE reported the sentencing of two companies and an individual following the death of 33-year-old Gheorghita Arsene, who was buried when the sides of a deep trench collapsed during pipework at Banstead in Surrey. HSE said the excavation had no support and excavated soil had been deposited immediately beside the edge.
Appledorn Developments Ltd was fined £500,000. Subcontractor T Vaughan Ltd was fined £650,000 plus £40,000 costs. A contracts manager received a 10-month suspended prison sentence and 150 hours of unpaid work after pleading guilty to an offence under section 7 of the Health and Safety at Work etc. Act 1974.
The value of the case is not in treating those penalties as a benchmark. It is in recognising the underlying issues: unsupported ground, surcharge at the edge and management failures that allowed people to work in a dangerous excavation.
The duty is to prevent collapse, not react to it
Regulation 22 of CDM 2015 requires suitable and sufficient steps to prevent danger from the collapse of an excavation and addresses the effect of materials and equipment placed near an excavation. The objective is prevention rather than waiting for obvious movement before taking action.
That does not mean every excavation needs the same support system. Depending on depth, ground conditions, loading and geometry, the solution might involve shoring, trench boxes, another designed support system or battering the sides to a suitable angle. The method needs to suit the actual conditions.
HSE’s excavation guidance warns that no ground should be relied upon to stand unsupported in all circumstances. It also notes that a cubic metre of soil can weigh more than 1.5 tonnes, which helps explain why even a localised collapse can be fatal.
Spoil and plant can change the ground loading
Excavated material is not harmless simply because it has been removed from the trench. Spoil placed close to the edge creates surcharge and can increase the likelihood of collapse. Excavators, dumpers, telehandlers and delivery vehicles can add further loading and vibration.
The safe stand-off distance should be determined from the excavation, ground conditions and equipment involved. It should not be an arbitrary site rule that is copied between projects without considering the real situation.
Nearby foundations, scaffold bases, services, retaining structures and temporary works also matter. Digging can remove support that another structure relies upon. A trench that looks straightforward in open ground may become a more significant engineering problem when it runs beside an existing building or loaded area.
Excavation support is often temporary works
HSE identifies excavation shoring as temporary works. That means it needs to be planned and managed as an engineered solution where the risk requires it, with suitable design and checking arrangements rather than improvised support selected after excavation has already progressed.
For more complex excavations, the temporary works process should define the design requirement, anticipated loads, sequence, interfaces and any limits on plant or material near the edge. The Temporary Works Coordinator needs enough information and authority to control the process, but the role title itself does not make an unsafe excavation safe.
Businesses needing a refresher on these principles can also use All Star Safety’s CITB Temporary Works General Awareness eLearning as an introduction to temporary works management.
Safe access and services still need attention
Collapse prevention is central, but it is only one part of excavation safety. Buried services should be identified and managed before digging starts, with work planned around the information available and safe digging practices used where services may be present.
People also need safe access and egress. Ladders, where used, need to be suitable, secured and positioned so people can get in and out without creating another hazard. Edge protection, water ingress, hazardous atmospheres and the possibility of materials falling into the excavation may also need control.
A trench box does not compensate for an insecure access ladder, a dumper operating too close to the edge or a failure to identify buried electricity or gas services.
Inspection is a live control measure
Regulation 24 of CDM 2015 sets inspection requirements for excavations where the relevant protective measures are needed. HSE explains that inspections should take place at the start of each working shift and after events that could affect stability, as well as following a fall of rock or earth.
The purpose is not another signature for the file. The competent person needs to recognise changes in the ground, supports, loading, water or surrounding activity and have enough authority to stop work until a defect or concern is resolved.
What should you do now?
- Confirm who is responsible for planning, supervision and inspection of each live excavation.
- Assess ground conditions and nearby structures before excavation starts.
- Decide the support, trench-box or battering arrangement before people enter.
- Control spoil, materials and plant loading near the edge.
- Locate buried services and use suitable digging methods.
- Provide secure access, egress and edge protection where required.
- Inspect at the legally required times and after anything that could affect stability.
Excavations should be treated as changing temporary conditions rather than holes that have already been “made safe”. All Star Safety’s consultancy service can support contractors reviewing excavation arrangements, temporary works interfaces and site controls.