The investigation into this critical incident is ongoing – further lessons from this incident will be shared following completion of the full report.

The incident occurred at an aggregates wharf in May 2024. The concrete retaining wall was used for retaining wet silt. The incident occurred in the morning after some additional material had been added to the stockpile. An hour later the concrete retaining wall collapsed, the wall struck the edge protection around the area allowing silt to flow out of the stockpile area. No material left site or obstructed any walkways. The area was cordoned off to allow an investigation to take place.

The initial investigation has highlighted that structural defects with the wall had been identified in all previous structural assessments from 2019 as requiring replacement. These had not yet been completed. The image below was extracted from the last structural survey which had taken place in 2023.

The images below show the concrete wall structural collapse and damage to edge protection to silt bays May 2024

This incident highlighted the importance of checking structural surveys and the related processes associated with the management of surveys.

• Have you completed all required actions, including observations with recommended actions? 
• If issues are found, discuss with your regional engineer to ensure they are assessed by a competent person on a regular basis in line with your Structural Inspection Standard.
• Referring to Stockpiles, Excavations and Tips. Do your rules include the capacity for all the volume and type of material you intend to store on site?
• Ensure appointments and associated forms such as weekly/month inspections scheduled are completed;
• Discuss with your Geological Team member and update your system with any findings that you discover regarding stockpile designs.