A consortium led by global engineering, project management and construction company Bechtel has begun tunnelling on Line One of the Riyadh Metro in Saudi Arabia, thus marking an important milestone in the construction of this landmark project.

The consortium - BACS as it is known, which also includes Saudi-based Almabani General Contractors, regional company Consolidated Contractors Company, and Germany's Siemens - is responsible for the $10-billion contract for the design, construction, train cars, signalling, electrification and integration of Lines One and Two - two of the most challenging lines on the Riyadh Metro project.

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.

Riyadh Metro is set to be the country's first underground rail system and on completion it will be one of the largest in the world.

"The metro, set to be the cornerstone of Riyadh's new public transport network, will revolutionise how people move around the city," said Amjad Bangash, Bechtel's director on the project. "Sending our team's first tunnel boring machine (TBM) on its underground voyage is a significant step for all," he stated.

Bangash said the tunnelling work beneath the streets of the Saudi capital will prove challenging. "Getting early agreement on the alignment in the heart of the city was crucial to advance the detailed design work needed to start tunnelling. We appreciate the efforts that our client, Arriyadh Development Authority (ADA), and many other stakeholders undertook in helping us achieve this," he added.

The 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 100 m per week and is expected to complete its journey by mid-2016, said Bechtel in its statement.

In total, seven TBMs will be deployed by the Bechtel-led team to dig and construct more than 35 km of tunnels beneath the capital city, it stated.

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 metro network is part of a 25-year strategic plan prepared by the High Commission for the Development of Arriyadh to cater to this growth.

Saudi Arabia awarded contracts worth $22.5 billion last year to three foreign-led consortium for the design and construction of the metro system, which is hoped to ease traffic congestion in the capital. 

When complete, the 176-km, six-line driverless network will serve 400,000 passengers.

A global leader in the rail industry, Bechtel has successfully delivered some of the largest and most complex rail projects in the world, including the Channel Tunnel, High Speed 1, the San Francisco Bart system and the Athens Metro.

The company is currently providing project management services on Crossrail in London, UK, which is Europe's largest civil engineering project, and where 42 km of tunnelling has just been completed on schedule, said the company in its statement.

It is also working on the Rio de Janeiro Metro in Brazil and the Toronto-York Spadina subway extension in Canada, it added.-TradeArabia News Service