Peasenhall Substation Refurbishment

Falco were contracted by UK Power Networks Services to design and undertake the civils work required to facilitate the replacement of two transformers in the Suffolk village of Peasenhall.

Mobilisation involved installing CDM-compliant welfare facilities. As this was existing arable land the existing topsoil was removed (stored for later use) and replaced with type 1 and a temporary works design was installed including full hoarding to the site.
To maintain operational resilience, the transformers were replaced sequentially to minimise the period that there would be reliance on a single transformer while maintaining supply to the surrounding areas.

Once the site was established we commenced installing the earthing system while UK Power Networks Services arranged the isolation and disconnection of the existing transformer. Our experienced management team designed and installed a GRP palisade demarcation fence for the civils work associated with T1 and managed the movement of long objects in the live substation using a qualified Authorised Person (AP) to take the permit from the Senior Authorised Person (SAP).

During the excavation of T1 we uncovered 31 unchartered services. These cables were exposed by the site team using safe excavation techniques and no cable was damaged. We worked with UK Power Networks Services to re-design the works to accommodate the cables. Despite these challenges the bund was constructed in just three weeks and allowed us to install the first transformer ahead of programme.

We procured and managed the installation of a 6.5m high precast wall to seprate the existing switch-room from the new transformer. This was facilitated with the planned isolation of existing 11Kva overhead cables, obtaining a crane permit and serving a road opening notice via liaison with Suffolk Highways.

The significant challenges of conducting major works near live apparatus were managed on site through the enforcement of robust procedures and controls set out in UK Power Networks Distribution Services’ Network Safety Rules (DSRs). The primary controls centred around the continual presence of an electrically competent AP working to safety arrangements set in place by the designated SAP to ensure compliance with the DSRs and a competent, experienced workforce.
All our personnel were vetted for suitability before commencement with task-specific competencies validated during the thorough site induction. All prospective supply chain partners were also subject to a stringent pre-qualification review which included an in-depth analysis of their safety history and accident statistics.

Falco’s management team on this project are accredited ISO 9001 quality management systems auditors. They prepared a project-specific Inspection and Test Plan which was submitted to UK Power Networks Services for approval and maintained throughout the course of the works.

All high-risk activities were carefully managed via task-specific Risk Assessment and Method Statement documents (RAMS) that were thoroughly evaluated prior to approval and kept under review as work progressed.

Uncharted buried cables were an ever-present hazard and all excavations were carefully controlled so that damage was prevented throughout the works. High risk lifting operations were an essential part of the scope and Falco’s CITB-accredited lifting team of Appointed Persons, Lifting Supervisors and Slinger Signallers ensured that all lifts were executed in accordance with the applicable plans.

Risks associated with temporary works were carefully managed in line with our temporary works procedures which are directly aligned to BS 5975-1. Falco Site Manager, Michael Sheridan described the focus of health & safety: “From the outset we focused on managing our risks. Site segregation was established from the start with clear separation between pedestrians and traffic/plant. Uncharted electricity cables were a constant hazard, but by rigidly applying the DSRs we avoided harm. The spirit of collaboration was nurtured throughout and innovative ideas to solve problems were listened to and acted upon. External auditing was conducted regularly by Lloyds Register for NERS compliance on behalf of the UKPN’s Senior Leadership team. These combined with in-house site inspections conducted by Falco Directors and Senior Managers provided a wealth of constructive feedback for us to work with.”