The BFK (Bam, Ferrovial, Kier joint venture) Tunnel Boring Machine (TBM) Ada has finished building her last ring, reaching her final destination underneath the heart of London and marking the completion of the Crossrail C300 Western Running Tunnels. When completed Crossrail will run a total of 118 km’s from Maidenhead and Heathrow Airport in the west, through new twin-bore 21 km tunnels under central London to Sheffield and Abbey Wood in the east. The project will increase London’s rail-based transport network capacity by 10%, supporting regeneration across the capital and cutting journey times across the city. The arrival of Ada at Farringdon means BFK have completed a total of 13 kilometers of newly excavated tunnel and more than 9,300 concrete rings have been placed underneath some of the most expensive real estate in the world “Ada has completed one of the most challenging drives across the whole Crossrail project. This could not have been achieved without the exceptional dedication and skill of the BFK and Crossrail team”, assured Luis Amorim, Ferrovial Agroman BFK Board Member. Ada has had a much more challenging and eventful drive than her sister Phyllis, who finished in October 2013. Very early in her journey, Ada passed directly beneath the abutment of the Victorian era Lord Hill’s bridge with only 4 metres of overburden cover. This was achieved with no effect on the bridge or the utilities that it carried, she passed even closer to London Underground’s old cast iron lined museum tunnel, with negligible induced settlement.