The west flyover at Stockley airport junction, London, UK Available to Purchase

The west flyover at Stockley airport junction forms part of the ‘On network works’ of the Crossrail project. The structure is a two-span weathering steel truss 117·8 m long, curved in plan, carrying one new line from Heathrow airport to London. It passes at a highly skewed angle over five railway tracks, including the Great Western main and relief lines. The structure was launched into position at Easter 2014 and was opened to regular services at the end of December 2014. The west flyover includes the longest single span constructed on the Great Western railway since Brunel's Saltash Bridge in 1859. The trusses are formed from fabricated closed box sections. The structure was assembled on a strengthened earthworks approach ramp using extensive site welding. The launch philosophy was based on a requirement to install the superstructure while maintaining unrestricted live railway operations beneath. The launch system included roller bogies on the approach ramp with jackable, sliding stainless steel–polytetrafluorethylene (PTFE) supports at the abutments and central pier. To facilitate construction of the central pier crosshead within a restricted island site between the up main and down relief lines, a permanent, bespoke, precast concrete formwork shell was developed.