The $4.3bn railway connects the Al-Jalamid phosphate mines in the northwest of Saudi Arabia and the bauxite mines in Al-Zabirah to the giant industrial complex of Ras al-Khair on the Gulf coast.
The project was conceived to fully integrate the kingdoms fertiliser and aluminium industries, connecting the downstream production facilities directly with their feedstock sources.
The railway began trial operations in May 2011, and has the capacity to transport 4 million tonnes a year of minerals to production facilities in Ras al-Khair.
The 1,390-kilometre minerals railway forms the main component of the larger 2,750km North-South Railway. The North-South railway also includes a passenger network, linking Riyadh, Qassim, Hail, Al-Jouf and Qurayyat.
Trial runs began in 2016 and full operations are due to begin this year. Passenger services will run at up to 200km an hour and will operate in areas where temperatures can fluctuate between -5 and 50 degrees Centigrade.
The alignment of the minerals railway required obtaining permission from land owners and right of way through traditional camel-grazing and migration areas. To win them over, the railway was constructed to include crossing tunnels for animals and herdsmen.