The San’ah TBM arrives at the 5C1 on King Abdel-Aziz Road.

The Riyadh Metro project marked yet another milestone with the San’ah tunnel boring machine (TBM) having arrived at its second station – the 5C1 on King Abdel-Aziz Road – early last month.

The machine completed approximately 3.1 km out of its designated 4.9 km of tunnelling on Line Five (Green line), according to Arriyadh Development Authority (ADA), which is spearheading the project, and FAST Consortium, which is building lines Four, Five and Six. This distance translates into three stations.

Ahmed Al Drees, project manager for Package Three, comments: “Collaboration is key, and we believe that the ADA and FAST have a strong partnership and are achieving timely results and performance in building the world’s largest public transit system. This breakthrough (with the TBM) is an excellent example.”

He says the arrival of the machine to its second station marks a major milestone as the consortium is ahead of the tunnelling excavation schedule.

San’ah will continue to drill the northern section of Line Five until it reaches the Riyadh Airbase Roundabout. There it will meet our second tunnel which is being excavated by Dafrah TBM – the first TBM to start drilling on the Riyadh Metro project – thus completing the Line Five tunnel, which is 12.9 km long,” says Al Drees.

FAST consortium first broke ground on the metro project when it started tunnelling work in April last year.

FAST Consortium is one of three consortiums contracted by ADA to design and build the Riyadh Metro project. It is led by Spanish construction group FCC and includes partners Korean Samsung C&T, French company Alstom, Strukton of The Netherlands, Freyssinet Saudi Arabia, Atkins of the UK, Typsa of Spain and Setec of France. FAST is responsible to deliver the Yellow, Green, and Purple lines (lines Four, Five and Six) of the project, totalling 64 km.

The other two consortiums include BACS, which is building lines One and Two; and ArRiyadh New Mobility (ANM) undertaking Line Three.

Riyadh is one of the world’s fastest-growing cities, with a population expected to increase 50 per cent by 2035 to 7.5 million. The $22-billion Riyadh Metro is part of a 25-year strategic plan prepared by ADA to cater for this growth. When complete, the 176-km, six-line driverless network will serve 400,000 passengers. It is expected to be one of the largest metros in the world.

Last November, Alstom announced it had started production of trainsets for the Riyadh Metro in its Katowice plant in Poland as part of the contract. The Katowice plant will manufacture all 69 of the Metropolis trainsets. The first three Metropolis trainsets will be delivered to ADA in 2017.

“A full-size mock-up of the Riyadh Metropolis trainset manufactured by Alstom will soon be unveiled to the city’s inhabitants by ADA,” a spokesman for Alstom says.

In July 2015, the leader of ANM consortium, Salini Impregilo, started tunnelling works on its section of the Riyadh Metro. The giant TBM named Jazlah is working on the Orange Line, which is the longest line at 41.2 km.

Jazlah, 10 m in diameter and weighing 700 tonnes, started boring on the 5.8-km tunnel in the downtown of Riyadh and will pass through the Riyadh main train station.

The route is mostly elevated along the western part of Al Madinah Al Munawwarah Road, underground in bored and mined tunnels in the central section of the line, and generally at-grade along Prince Saad Ibn Abdulrahman Road in the east.

The line features 22 stations including the two iconic stations named Qasr Al Hokm and Western designed by Snohetta and Omrania respectively. The line also includes also six ‘Park&Ride’ facilities that will contribute in the future to the integration between transportation systems.

In the same month, Bechtel, which leads the BACS consortium, began tunnelling on Line One. The consortium, which includes Saudi company Almabani General Contractors, Middle East-based Consolidated Contractors Company, and Germany’s Siemens, has a $10-billion contract for the design, construction, train cars, signalling, electrification and integration of lines One and Two.

The work includes 39 stations, two of which are key interchange stations: Olaya Station, situated in the centre of Riyadh at the intersection of lines One and Two, and King Abdullah Financial District Station, located slightly to the north on Line One.

Its first tunnel boring machine, Mneefah, named after the horse of Saudi Arabia’s founder king, will steadily ramp up to its planned average tunnelling rate of about 325 ft per week and is scheduled to complete its journey this year. In total, seven tunnel boring machines will be deployed by the Bechtel-led team to dig and construct more than 35 km of tunnels beneath the capital city.