The death of a worker who became trapped when an excavation wall collapsed on him on a new-homes building site has led to Argyll-based building company Carrig Construction being prosecuted by the Health and Safety Executive (HSE) and fined £75,000. We examine the incident and see how IOSH members can help their organisations be better prepared when dealing with excavations.
THE INCIDENT
On 25 November 2019, 44-year-old Derek Caddie was working on a building site at Belhaven Terrace West Lane, Glasgow, where new houses were being built. Together with a colleague, Derek had entered an excavation to repair damaged and leaking pipework.
While the two men were in the excavation, part of the excavation wall collapsed. Although Derek’s colleague was left uninjured, Derek was trapped in soil from the neck down. After being rescued by the emergency services, Derek died from his injuries in hospital three days later.
Carrig Construction Services Limited had been appointed as a contractor on the site and Derek was working under the company’s control at the time of the incident.
THE INVESTIGATION
An investigation by the HSE found the collapse was caused by a lack of support to the vertical walls of the excavation. Carrig Construction Services, a company that specialises in groundworks and drainage works, failed to identify the risks from working in the excavation and did not ensure there were practicable steps in place to make certain workers were protected while inside the excavation.
On top of this, none of the workers under the control of Carrig had any formal training on working within excavations and were unaware of the risks involved.
THE PROSECUTION
On 28 August 2024 at Glasgow Sheriff Court, Carrig Construction Services Ltd pleaded guilty to breaching sections 2(1) and 3(1) of the Health and Safety at Work Act. The company was fined £75,000.
Graeme McMinn, principal inspector at the HSE, said: ‘This was a tragic and wholly avoidable accident, caused by the failure of Carrig Construction Services Limited to put in place measures to control the risk of the sides of the excavation collapsing.’
LESSONS FOR IOSH MEMBERS
How can you ensure your staff are safe when working in excavations? In terms of ensuring excavations maintain structural integrity, the HSE says duty holders need to focus on two key factors:
Temporary support
- Before digging any trench pit, tunnel, or other excavations, decide what temporary support will be required and plan the precautions to be taken.
- Make sure the equipment and precautions needed (trench sheets, props, baulks, etc) are available on site before work starts.
Battering the excavation sides
- Battering the excavation sides to a safe angle of repose may also make the excavation safer.
- In granular soils, the angle of slope should be less than the natural angle of repose of the material being excavated.
- In wet ground, a considerably flatter slope will be required.