We worked for Southern Gas Networks (SGN) on the gasworks site in the famous, historic town of Reading, Berkshire

This project involved the decommissioning (desludging and dewatering) and demolition of Gasholder No.4 which was a column-guided gasholder. The works included the dismantling of the gasholder and associated plant, along with a water tower and other additional structures occupying the site.

The site-specific constraints were significant as the triangular-shaped site was demarcated at the north of the site by the main rail line into London, which was approximately 15 metres from the fence line and ran over the River Kennet, which is a tributary of the River Thames. The river flowed north and met the rail track at the east of the site and was approximately 4m from the fence line at the closest point.

A housing estate bound to the site to the west was the only route to move the vehicles and plant.

The vessel was constructed of steel and measured approximately 50 metres in diameter; the structure was cut up mechanically using hydraulic shears with some sections of the works being ‘hot cut’ once the vessel was opened up and the tank was no longer enclosed.

Site overview video:

We were appointed as the CDM Advisor for the project. Our roles included checking the Principal Contractor’s Construction Phase Plan (CPP) and reviewing the Risk Assessment and Method Statement (RAMS) for the project before issuing the Authorisation to Commence Construction Activities.

Throughout the works we carried out audits which were planned to coincide with the specific phases of the project that started with the CDM compliance audit, continuing with a specific environmental audit to ensure the sludge and wastes were removed in line with the Environmental Agency’s requirements, and a process-specific demolition audit.

• Review and comment on the Construction Phase Plan and issue a report.
• Review and comment on the Risk Assessments and Method Statement and issue a report.
• Carry out the pre-start CDM site audit and issue a report.
• Carry out the environmental site audit and issue a report.
• Carry out the demolition process site audit and issue a report.