Company Fined After Preventable Storage Tank Rupture With Life Changing Injuries

Brief Summary

A company operating a marine supply base was fined £350,000 after a storage tank holding calcium chloride solution catastrophically ruptured without warning. HSE concluded the structural failure was wholly foreseeable and preventable, following evidence of long standing corrosion that had been identified years earlier without effective remedial action or consistent inspection.

What Was The Incident?

On 21 June 2023, a worker conducting surveys of storage tanks at an offshore supply base was on site when Tank 7, a bolted steel tank containing about 480,776 litres of calcium chloride solution weighing around 700 tonnes, catastrophically ruptured. The failure occurred around halfway up the tank where plate splitting was found along a bolted seam. The released fluid immersed the worker to chest height and displaced nearby equipment including a cherry picker and a pickup vehicle. The worker sustained multiple severe traumatic injuries and extensive chemical burns.

What Was The Outcome?

The employer pleaded guilty to breaches of the Health and Safety at Work Act etc. 1974 relating to workplace health and safety duties and failure to comply with relevant requirements. The company was fined £350,000. Following the incident, it removed all bolted tanks from its sites and closed the Peterhead operation, relocating to its Aberdeen premises.

Key Points To Consider

Treat identified corrosion as a critical defect. Where corrosion is found, including on seams and bolted connections, you must act promptly with effective remedial measures rather than relying on future inspections.

Follow inspection and maintenance requirements consistently. HSE found no evidence that the inspection regime required by the manufacturer was consistently followed, even after an earlier inspection identified extensive corrosion and corrosion at bolted connections.

Verify tank integrity against the actual degradation you have. External degradation and loss of protective coating can accelerate corrosion to the point where remaining steel thickness can no longer withstand the forces from the stored fluid.

Control foreseeable conditions such as filling to capacity. The tank was filled to capacity shortly before failure, and HSE concluded the collapse was foreseeable and preventable, emphasising the need to assess risk under operating conditions.

Escalate and respond when evidence of inspection gaps emerges. If you cannot demonstrate that inspections were carried out as required, you should assume the equipment condition is not assured and take immediate steps to reduce risk and secure compliance.

HSE Prosecution Link