Hitchin Grade Separation involved the design and construction of a 2.5km elevated railway extension, including an 800km viaduct, which carries trains between London and Cambridge over the East Coast Main Line (ECML). HOCHTIEF delivered the scheme under a Pure Alliance contract, integrating contractor and client teams to drive innovation, manage risk and save time and costs.

Key features:

  • 2.5km grade separated railway extension
  • 800km, 29 span viaduct
  • 1.2km embankment – 100,000m3earthworks
  • 500linm of tie ins
  • Rail systems

The biggest challenge on the project was lifting the 60m central steel beams for the viaduct over the ECML within one possession. After meticulous planning and risk mitigation involving the whole alliance team, we performed the lifting operation flawlessly in less than a third of the allocated possession time.

Several innovations enabled us to save time and money. We standardised the pier and pile cap design to simplify construction, and we developed a mitigating methodology for the piling that eliminated the need to remove 30,000m3of contaminated ground, saving 6 weeks. We also reduced the need to import embankment materials by using a local borrow pit, saving 30,000 vehicle movements and £250k. 

Hitchin Grade Separation won several awards including Considerate Constructors – Performance Beyond Compliance, RoSPA Silver Award, CEEQUAL ‘Excellent’, ‘Best Collaboration’ at the Network Rail Partnership Awards 2013, and ICE East of England Merit Awards in 2014 for Physical Achievement and for Team Achievement.

The new flyover opened six months ahead of schedule, within budget and with zero defects.