The Northern Line Extension

Overview

The Northern Line Extension extended the London Underground network to Battersea, including the construction of two new stations. Booth Industries was appointed by London Underground/Ferrovial Laing O’Rourke to design, manufacture, and install 328 specialist steel hinged doors—ranging from tunnel and cross-passage doors to station access and security solutions.

Our proven track record on complex rail projects, including Crossrail, made us the clear choice to deliver high-performance, fully-assured doors that met the stringent requirements of a live underground rail system.

Project Complexities

Delivering the scheme meant creating and certifying 96 unique door types with varied performance criteria, including:

• Fire resistance
• Acoustic performance
• Security rating
• Thermal insulation
• Pressure relief and blast resistance

All were manufactured in either mild or stainless steel.

Technical complexity was compounded by the onset of the Covid-19 pandemic, requiring immediate adaptation to new working methods without compromising programme delivery or safety.

Our Response

• Rapid mobilisation of remote engineering capability to maintain design momentum.
• Modified factory layouts and procedures to enable safe production under social distancing.
• Stockpiling completed doorsets ready for installation when site access resumed.
• Following an initial halt to construction at the beginning of the pandemic, our teams adapted working methods to allow site installation to continue and programme slippage to be mitigated.
• Close coordination with Warrington Fire and UL to test or assess all bespoke variations.

Outcome

Despite unprecedented challenges, we completed the final installation in May 2021—delivering every door on time, to specification, and with full certification. Our collaborative approach, adaptability, and cross-departmental expertise ensured the project’s success under exceptional circumstances.