Project Name: Milking Lane

Scheme background: SGN & WCB Utilities — Supporting Biggin Hill Airport's Runway Resurfacing
Overview - When Biggin Hill Airport planned its critical runway resurfacing, ensuring the integrity of nearby utilities became a top priority. SGN, working alongside WCB Utilities, stepped up to deliver essential gas infrastructure upgrades ahead of the resurfacing, all while keeping the airport running smoothly.

Located in the London Borough of Bromley, this project showcased strong collaboration, adaptability, and problem-solving under tight deadlines and operational constraints.

The Challenge - In August 2024, SGN identified a leak on the existing gas main located close to the runway. Recognising the urgency, Tony Embling reached out to SGN on 18th September 2024 to explore whether the aging main could be replaced in advance of the runway works. Biggin Hill Airport wanted to avoid any future disruption from gas infrastructure after the runway had been newly resurfaced — the window of opportunity was limited.

SGN quickly mobilised a project team and partnered with WCB Utilities to develop and deliver a solution, ensuring the gas network was upgraded before the runway works commenced.

The Solution - SGN and WCB Utilities designed a solution combining both live and dead gas main insertions to replace the aging asset while minimising operational risk.

Key works completed:

• 597.5 metres of 90mm PE pipe installation
• 260 metres of 75mm PE pipe installation
• Abandonment of 857.5 metres of old 4” cast iron gas main
• Renewal of all gas services using vacuum excavation (vac ex) for safe and efficient access

All excavations were temporarily backfilled and reinstated by SGN, allowing the airport's resurfacing contractor to seamlessly carry out their works.

Collaboration in Action
The project relied on close coordination between SGN, WCB Utilities, Biggin Hill Airport, and other key stakeholders. Beyond scheduled conference calls, extra meetings were arranged to resolve challenges quickly and keep the project moving at pace. Critical discussions focused on roles, responsibilities, and maintaining momentum despite a complex operational environment.

To further support the airport’s operations, SGN and WCB worked flexibly, including carrying out night works where necessary to avoid disrupting airport activities. Thanks to this proactive approach, the airport remained open and fully operational throughout.

Outcome
Start Date: 2nd January 2024
Completion Date: 14th March 2025
Total length of upgraded main: 857.5 metres
Airport operations: Maintained without interruption

This successful scheme is a strong example of effective collaboration under time-sensitive conditions, achieving infrastructure resilience while supporting one of London’s key regional airports.

Stakeholders Involved

• Greater London Authority (GLA)
• SGN
• WCB Utilities
• Biggin Hill Airport
• Bromley Council
• Local Businesses

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