Herrenknecht TBMs Bore Doha Metro

On Sept. 25, 2016, at the Hamad International Airport in Doha, a 7-m tunnel boring machine pierced the final target wall of the Red Line South of the Doha Metro. It is the last of 76 breakthroughs in the gigantic milestone project.

The TBM breakthrough marks the finale of one of the most ambitious tunnel structures in the world. Cleverly master-planned and highly professionally directed by client Qatar Rail, it took just 26 months to provide the capital of Qatar with three city-wide metro lines: 111 km of brand new, ultra-modern metro tunnel systems. Where before there was nothing, at peak times 2.5 km of tunnel per week were added underground – a record-setting pace.

“The world has never seen such performance. What Qatar Rail and our contractors in Doha have accomplished in just 26 months of construction time with the highest standards of performance, safety and quality is an absolutely Olympic achievement in modern infrastructure development,” says Dr.-Ing. E.h. Martin Herrenknecht, Chairman of the Board of Management of Herrenknecht AG, which provided the EPB shield used for the final breakthrough.

High-level political guests such as the Qatari Prime Minister and Minister of the Interior H.E. Sheikh Abdullah bin Nasser bin Khalifa al Thani, the Minister of Transport and Communication of Qatar H.E. Jassim Saif Ahmed al Sulaiti as well as the ambassadors of France, Korea and Japan in Qatar showed their admiration at an official completion ceremony. A total of around 200 guests, including the top management of Qatar Rail and leading representatives of the joint venture contractors, celebrated a unique technical construction and engineering achievement.

RELATED: Qatar Rail Announces Completion of Tunneling on Doha Metro

From August 2014 to September 2016, on three main lines (Red Line, Green Line, Gold Line) four international joint ventures consistently pushed forward a total of 21 TBMs designed and equipped by Herrenknecht specifically for the project. A total of 470,497 individual concrete segments were mechanically assembled into 70,071 high quality tunnel rings. At peak times 20 TBMs tunneled their way forward simultaneously, 2.5 kilometers per week of spotless metro tunnels grew under Doha. This Olympic quality parallel performance has gained the project a place in the Guinness Book of Records. In addition to the geology, consisting primarily of Simsima limestone, the demands on each TBM were complex – just from the dense urban development alone. The routes of the individual metro lines run under highly populated areas, for example near the impressive beach promenade Corniche, under the high-rise neighborhoods of Doha City and the tourist centers with their attractive hotel facilities. Settlement-free tunneling was therefore one of the core requirements during construction.

The construction joint ventures completed a total of 76 breakthroughs; more than 40 times the machines were quickly pushed forward in intermediate shafts ready for the next section. Herrenknecht supplied up to 125 service staff and specialists from 19 countries for support on the project.

In order to keep to the ambitious masterplan and the tight schedules, man and machine were in operation on the huge construction site around the clock, seven days a week. In addition to excellent planning, expertise and high material and machine quality, for Dr. Markus Demmler, Senior Director of the Qatar Integrated Railway Project, one prerequisite was vital for the success of the project: “Managing 21 TBMs working smoothly beneath a metropolis like Doha is only possible with 100 percent commitment from all partners involved.”

The new metro system in Doha is only the beginning of the mobilization of public transport in Qatar. Whether in the urban centers or in the countryside – everywhere people will be able to travel by public transport. “Qatar’s vision is to connect every corner of the country by public transport,” explains Demmler.

RELATED: Twin EPBs Complete Drainage Tunnels in Doha

The three new lines of the Doha Metro are scheduled to open by 2020. By 2026 an extensive expansion that includes 72 additional stations and another metro line is planned. The station Msheireb in the center of the metropolis already forms the accumulation point of the whole system. All lines meet here, 12 breakthroughs ended at this mammoth station alone.

The Red Line North involved 22.8 km of tunnels, the Red Line South 32.6 km, the Gold Line 23.3 km, and the Green Line 33.4 km. All lines were built as parallel twin tunnels.

Joint venture contracting teams for the metro included:

› for the Red Line North the ISG joint venture (Salini Impreglio S.p.A./ SK Engineering & Constructing Co Ltd/ Galfar Al Misnad Engineering & Constructing W.L.L0

› for the Red Line South the Qatari Diar Vinci Construction JV (QDVS)/ GS Engineering & Construction Corp./ Al-Darwish Enginering W.L.L

› for the Green Line Contractor PORR Bau GmbH/ Saudi Binladin Group Company Ltd/ Hamad Bin Khalid Contracting Co. W.L.L.

› for the Gold Line the joint venture Aktor S.A./ Larsen & Toubro Limited/ Yapi Merkezi Insaat VE Sanayi Anonim Sirketi/ Sezai Turkes Feyzi Akkaya Marine Construction/ Al Jaber Engineering LLC)

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TBM Specs

MACHINE DATA S-844-849 / S-860-868 / S-920-925

Machine type: 6 x EPB Shield

› Shield diameter: 7,050 mm

› Drive power: 1,440 kW

› Torque: 4,769 kNm

Machine type: 9 x EPB Shield

› Shield diameter: 7,050 mm

› Drive power: 1,280 kW

› Torque: 4,239 kNm

Machine type: 6 x EPB Shield

› Shield diameter: 7,110 mm

› Drive power: 1,440 kW

› Torque: 4,769 kNm