Tunnelling on the first stage of the $1.5 billion Perth-Mandurah rail link has been completed.It comes at the end of a week when the project was drawn into focus over claims totalling $191 million lodged by Leighton against the State Government. When the project is complete next year, trains will travel along the 470-metre long tunnel between the new Esplanade and William Street stations.Leighton Contractors managing director Peter McMorrow hailed the tunnel completion a landmark event in the delivery of the city rail project. In coming weeks, tunnelling will continue under Wellington Street, the Perth rail yard, and the Horseshoe Bridge before eventually concluding in Northbridge.