Challenge

Maintenance surveys carried out by Tube Lines identified serious power supply problems at eight 'Section 12' London Underground stations, classified as high-risk due to their size, passenger numbers, and strict safety standards. Voltage drop and phase imbalance were increasing the likelihood of under- or overvoltage conditions, putting essential safety systems at risk and threatening the smooth operation of these busy stations.

In addition to the technical challenges, the project had to navigate strict London Underground working regulations, limited physical space for equipment installation, and restricted access windows, often outside of operational hours. These constraints demanded precise planning, compact solutions, and a high level of coordination to ensure safety and compliance throughout the project.

Solution

Claude Lyons was awarded the contract by Tube Lines, “based on the experience of the company, given the complexity involved”. The project presented unique challenges - tight access routes, strict weight limits, and limited working hours within the Underground environment. Our team designed modular stabiliser units that could be dismantled, transported through restricted access points, and reassembled safely on-site.

Every step of the solution was engineered to meet rigorous safety standards. The approvals process required adherence to LUL standards, with detailed documentation, design submissions, and extensive testing - both in-house and through certified facilities. Furthermore, to ensure full compliance, our staff completed essential training courses including Entry Permit, Fire Engineering, Equipment Room/Quaff 54, Asbestos Awareness, and Trackside Access.

Key Specifications

• Claude Lyons' design allowed for disassembly and transportation of units into section 12 Underground Stations via restricted access routes.

• The units were designed to be assembled in confined locations and within the limitations of engineering working hours in an underground environment.

• Approval processes involved conforming to LUL Standards and rigorous testing to ensure compliance and safety.

Result

Following installation and commissioning, power at eight London Underground stations - including Goodge Street, Tufnell Park, Swiss Cottage, Turnpike Lane, Archway, St John’s Wood, Kennington, and Hounslow West - was successfully stabilised and brought back within London Underground’s strict operational standards. This eliminated the risks associated with voltage irregularities, helping prevent equipment failures and potential station closures.

Claude Lyons’ innovative stabilisation solutions not only resolved Tube Lines’ power supply challenges but also reinforced the company’s commitment to safety and reliability. By overcoming complex engineering constraints and meeting rigorous compliance standards, Claude Lyons helped ensure uninterrupted station operations and safeguarded critical infrastructure. This project highlights our dedication to quality and sets a benchmark for dependable engineering in the transport sector.