A worker is in a critical condition after suffering a head injury at the West Gate Tunnel project in Melbourne's Docklands.

The man in his 50s works as an engineer working for Wagstaff Piling, a subcontractor for John Holland and CPB Contractors, the joint venture appointed to build the $6.7 Billion West Gate Tunnel.  He was part of the piling works being done at the site in Footscray Road when he was hit in the head by a piling rig cable.  Ambulance Victoria rushed him to Royal Melbourne Hospital for treatment.

"WorkSafe and Victoria Police are on site and the contractor is co-operating with their investigations," said a Transurban spokesman.  "Safety is our priority and works have ceased on the site while the investigation is carried out."