The Riyadh Metro work is expected to start in two months as the tunnel boring machine (TBM) parts from Germany have arrived , a report said.

The assembling of TBM will take two months, the Arab News report said quoting a source.

A manhole of about 30 m deep with a diameter of 10 m or more has already been dug at the King Abdulaziz Road. From the bottom of the manhole, work on the tunnel will be started. As far as I know, this is the biggest metro project in the world, a source said.