Road - A406 Fore Street

A406 Fore Street Tunnel Maintenance

Following an assessment of its assets in July 2014, Transport for London identified the need for immediate repair works to the 361m A406 Fore Street tunnel under Phase 1 of its Structures and Tunnels Investment Portfolio (STIP). VVB Engineering worked closely with civils Principal Contractor BAM Nuttall to develop the programme.

A406 Fore Street Tunnel M&E Maintenance

The key activities undertaken on this programme involved the immediate installation of temporary systems, which included; temporary mains power distribution, temporary lighting with transformers and photometers, emergency telephone points (x14), a temporary firemain, AQM, CCTV, temporary VMS, SOS signage and wayfinders. Once the temporary systems were complete all existing and failed infrastructure was stripped and removed from the tunnel. Maintenance of temporary systems persisted throughout the civils structural works, whilst the issue of water ingress was addressed. Weekly inspections of temporary M&E systems were conducted and planned maintenance schedules maintained throughout the project whilst the new permanent M&E systems were being installed by our installation teams.

As part of the planned works our QA and HSE Managers prepared project documentation to map the quality controls and safe systems of work. Night closures offered the safest approach for completing the works. Each morning during the hand-back of the tunnel the site was cleared to accommodate normal operation of the tunnel. The QA manager and the HSE advisor assigned to the project completed weekly inspections of quality and health and safety aspects to ensure that operatives and the working environment were in compliance with the procedures that had been established. Any comments or observations made or non-conformances were logged and followed up to ensure that relevant parties were made aware of the concern/issue and, where appropriate, corrective measures were undertaken to remedy and or prevent any repeat occurrence.

Advanced Project Thinking (APT) was used on the programme to assess and monitor progress, a look ahead programme was adopted to schedule preventative maintenance works efficiently around the permanent works to ensure best use of night closures. The project was awarded on an accelerated programme to ensure that the tunnel was operating safely.

A collaborative approach was adopted for the project with regular discussion being held with the client, principal contractor and each of the stakeholders. Discussion were also held with the emergency services to establish emergency plans for the tunnel during the construction works.

“VVB’s degree of professionalism, collaborative approach, organisation and competence has allowed the project to achieve the success that is being widely recognised within TfL’s STIP Framework…”
“…I would like to thank VVB for their hard work and helpful attitude that has led to a successful project and good morale among the team.”

— Project Manager, Principal Contractor BAM Nuttall