The footage shows the 1,000 tonne Phyllis tunnel boring machine being launched at the Royal Oak Portal as it passes under Hampden Street footbridge which was jacked up to allow the 7.1 metre diameter machine underneath.
The 6.4km Western Tunnel drive is being carried out by the BFK consortium of BAM Nuttall, Ferrovial Agroman and Kier Construction.
To see the project in action click here