The London 2012 Summer Olympic and Paralympic Games was Britain's largest peacetime logistical exercise and a major challenge for Transport for London (TfL). London's road network had suffered decades of under-investment preceding TfL’s ownership, and the highest priority structures had to be in a state of good repair before the Games began.
With over 1,800 structures including 475 bridges and footbridges, 676 retaining walls and 281 subways, and 12 major road tunnels, TfL demonstrated how cities can plan, build and operate a transport network able to support the most challenging logistical exercise. TfL determined the interventions and investment needed to ensure infrastructure and assets are fit for the future. This led to TfL’s Structures and Tunnels Investment Portfolio (STIP).
STIP objectives and scope
The Structures and Tunnels Investment Portfolio (STIP) is part of TfL’s Road Modernisation Plan which will see £4bn invested in surface transport infrastructure to make journeys safer and more reliable and to improve the environment for all users of the network. Ramboll and Parsons Brinckerhoff were appointed in a joint venture at an early stage to begin design work on all eight projects in the portfolio.
The objective of the STIP is to replace, strengthen and refurbish key bridges, tunnels and other structures on the Transport for London Road Network (TLRN) to ensure network safety and reliability, while considering the needs of other transport modes. The STIP schedule began by delivering three discrete packages of work within an Early Contractor Involvement (ECI) Framework to improve the following structures:
- Work Package 1 (WP1) consists of Upper Holloway Railway Bridge and Highbury Corner Bridge on the A1, the A127 Ardleigh Green Railway Bridge and the A406 Power Road Railway Bridge
- Work Package 2 (WP2) consists of the A406 Fore Street Tunnel, Chiswick Bridge on the A316 and the reconstruction of the Woodlands retaining wall on the A406 near Golders Green
- Work Package 3 (WP3) consists of the second phase of improvement works on the Hammersmith Flyover, following the successful Phase 1 -strengthening works during Spring 2012
TfL appointed Ramboll and Parsons Brinckerhoff in a joint venture to begin design work across the portfolio, which will cost around £250m to deliver. The three tier 1 contractors appointed later by Tfl were Hochtief (WP1), BAMNuttall (WP2), and Costain (WP3).