Second HS2 tunnel reaches Greenford, completing Western Northolt tunnel

A second 5-mile railway tunnel has been completed underneath west London after one of HS2’s tunnel boring machines arrived at a shaft at Greenford.
The 8.4 mile long dual Northolt Tunnel is being dug by four tunnel boring machines (TBMs). Two of the TBMs are heading from Ruislip and have dug five mile tunnels each, and the two TBMs heading from Old Oak Common are digging 3.4 mile tunnels. They all meet next to Greenford station in west London.
London tunnels (c) HS2
Due to high water press