Delivering a 132kV grid site at Biggleswade East

Situation

UK Power Networks (UKPN) commissioned M Group as Principal Contractor and Principal Designer to establish a 132kV grid site at Biggleswade East.

Challenge

We were tasked to install 132kV outdoor AIS switchgear, including concrete foundations, cable sealing ends, surge arrestors, disconnectors, circuit breakers, and associated electrical components.

The project also required us to install two 132/33kV 90MVA grid transformers, complete with concrete bases, bund walls, acoustic barriers and auxiliary earthing systems. The construction of elevated control rooms and switch rooms involved installing steel structures, roofing, cladding, mechanical and electrical services, and various switchgear panels.

There was also a requirement for 33/ 11kV 40MVA primary transformers, distribution substations, busbars, and extensive cabling for 33kV and 11kV systems.

The project included roadway construction as per design, with associated drainage, and all primary and secondary electrical equipment.
Our key responsibilities included maintaining and managing the CDM area, procuring necessary materials, and constructing essential infrastructure including palisade fencing, access gates, roads, parking spaces, footpaths, compound lighting and drainage systems.

Upon completion, the project also entailed the demolition of a barn and the reinstatement of grass in welfare and site establishment areas, ensuring a comprehensive and well-managed execution of all tasks.

Solution

As Principal Designer, we were responsible for design management, associated design and work breakdown structure. To facilitate this, we adopted a design package approach and our Lead Design Manager, Steve Sadler managed its overall coordination and production. The design package comprised:

• Basis of design document
• Design Management document
• Design interface list
• Design Deliverables list.

Design Intent Document

We submitted a Design Intent Document (DID) for comment from our design partners four weeks prior to the start of our Detailed Design activities. The DID included:

• A technical commentary, understanding and interpretation of the project design requirements as set out in the Works Information, ie the design criteria including any areas where assumptions had been made
• Details of our proposed design criteria including reference documentation
• Details of the proposed Quality Assurance arrangements for the design and related survey activities, clearly demonstrating how we integrated third party design information, results of any type or site tests and/ or inspections, temporary works, design risk assessments and environmental requirements
• A schedule and programme reference of the design, materials specifications/ testing and related survey deliverables.

As Principal Contractor, we were responsible for the construction management, associated design and work breakdown structure.

We took a structured approach to project delivery, using a stage gate process. This defined the documentation required to inform executive decision making throughout the projects, ensuring sufficient knowledge and understanding was available before committing to the next stage. This approach allowed us to protect our client in the event of project changes and any potential cost increases, as we made extensive documentation from each stage available.

Stakeholder engagement

We developed a detailed stakeholder engagement plan that identified all construction interfaces and third parties that had an interest in the project. An interface meeting took place at the beginning of the project to support the production of an Interface Management Plan (IMP) and Interface Matrix which clearly defined the various interfaces and how we would manage these relationships on the project.

Regular meetings and reviews

As part of our coordination activities, we held regular meetings to review the design as follows:

Weekly – construction meetings to manage the interfaces and discussions between multiple disciplines.

Fortnightly – work reviews to manage interfaces between the design, equipment procurement and construction teams.

Monthly – project-wide reviews (in accordance with SR188) and engagement with the assurance team and site team.

Our Project Manager led project reviews and risk mitigation meetings and assigned a wayleave warden to ensure that all aspects of Wayleaves and Consents attributable to us were managed and delivered on-time and within project budget. Our warden had a good knowledge of land rights and wayleave procedures and developed a communications plan to ensure landowners were kept informed of all aspects of the works ahead of time. All staff deployed on site undertook an induction that informed them of all the access boundaries and the requirements of the landowner, either personal or in relation to the running of their business.

We agreed access routes that ensured minimal inconvenience for landowners and shared our programme with them for their awareness.