Bombardier plans to assemble the trains at its SahagĂșn plant in Mexico, and expects to test the first trains at its Kingston facility in Canada.

Bombardier is a member of the Arriyadh New Mobility Group consortium led by Ansaldo STS, which was awarded a $US 5.2bn contract to build and equip the Orange Line earlier this year.

The Orange Line is due to be completed by 2019.