QATAR Railways Company (Qatar Rail), the company overseeing the construction of Qatar’s integrated railways network, has received four more tunnel boring machines (TBMs) for Phase One of the Doha Metro.

The four TBMs – Al Mayeda, Al Khor, Lehwaila and Al Wakra – manufactured by Germany’s Herrenknecht, will join five other existing TBMs – namely Lebretha, Al Bidda, Doha, Al Zubarah and Mushaireb – to be used on the Red Line North and South Underground projects.

Al Mayeda and Al Khor along with Lebretha and Al Bidda, which are already on site to be assembled, are proposed to bore the required rail tunnels for the Red Line North project. The design-and-build (D&B) contract for this project will be undertaken by a joint venture (JV) led by Italy’s Salini Impregilo and comprising South Korea’s S K Engineering and Construction Company, and Qatar’s Galfar Al Misnad Engineering and Contracting.

Lehwaila and Al Wakra along with Doha, Mushaireb and Al Zubara will be launched into service for the Red Line South Underground project. The D&B for this project will be undertaken by a JV led by the French-Qatari company QDVC and comprising South Korea’s G S Engineering and Construction and Qatar’s Al Darwish Engineering.

Each TBM will travel a distance of 7 to 9 km and will take approximately two years to complete their respective journeys. The TBM average speed will be between 12 to 21 miles a day, depending on ground conditions. Daily excavation quantity will be more than 600 cu m, with an estimated predicted total excavation quantity of over 5 million cu m.

The TBMs ... arrive in Doha.

Each of the TBMs for the Doha Metro measures 7.05 m in diameter and 120 m in length and hence are dismantled into smaller sections to ensure easier and successful transportation from the Doha Port to the respective construction sites. It will take a few months to reassemble all four TBMs into complete machines.

The TBMs will ensure there is minimal disruption to the bustle of Doha city, and can tunnel below the city streets. They are also suitable for longer lengths of uninterrupted tunnelling, as is required for the Doha Metro project.

The scope of work for Red Line North Underground comprises the design and construction of a 13.4-km twin-bored tunnel, including seven underground stations, between the proposed Msheireb Underground Station and Doha Golf Course via Doha West Bay. The tunnels will be built at an average depth of approximately 20 m below ground.

Red Line South Underground extends from Msheireb in the north to Hamad International Airport in the south. It includes seven underground stations and the design and construction of approximately 14 km of twin-bored tunnel to be built at an average depth of 25 m below ground.

Qatar Rail is awaiting the delivery of a further 12 TBMs in Qatar over the coming months, to be utilised between the Green Line and Gold Line underground projects.

The Green Line, to be implemented by a JV led by Austria’s Porr Bau and comprising Saudi Arabia’s Saudi Binladin Group and Qatar’s Hamad bin Khaled Contracting, will receive six TBMs.

The Gold Line project, which recently awarded a D&B contract to a JV led by Greece’s Aktor and comprising India’s Larsen and Toubro, Turkey’s Yapi Merkezi Insat ve Sanayi Anonim Sirketi and Sezai Turkes Feyzi Akkaya Marine Construction and Qatar’s Al Jaber Engineering, will receive six TBMs as well.