We worked for Southern Gas Networks (SGN) on the gas works site in the Berkshire Market Town of Newbury.

This project involved the decommissioning (desludging and dewatering) and demolition of Gasholder No. 5 an above ground multi lift spiral gasholder and the demolition of the associated gas plant and ancillary buildings; infilling of the voids and general clearance of site furniture to leave an overall clear and level site.

Gas holder decommissioning is normally considered difficult due to the significant health hazards and the associated environmental impacts. The works in this particular project were further complicated because the site was sandwiched between the busy B3421 main road at the northern boundary and a railway line at the southern boundary with offices to the east and western boundaries.

The vessel, which measured approximately 35 metres in diameter was constructed of steel that varied in thickness at each of the inner layers, and due to its size and the thickness of the metal,  the vessel was cut up mechanically using hydraulic shears with no section of the works being ‘hot cut’.

We were appointed as the CDM Advisor for the project. First, we began by reviewing the Principal Contractor’s Construction Phase Plan (CPP) and the Risk Assessment and Method Statement (RAMS) for the project before issuing the authorisation to commence the construction activities. 

Throughout the project’s period, we carried out audits that were planned to coincide with the specific phases of the project. Such audits included the CDM compliance audit, a specific environmental audit to ensure the sludge and waste 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.