September 25, 2016, 10.44 am local time in Doha, Hamad International Airport: with precision the seven meter tunnel boring machine “Msheireb” pierces the final target wall of the “Red Line South”. It is the last of 76 breakthroughs in the gigantic project Doha Metro. The TBM breaking through marks the finale of one of the most ambitious tunnel structures in the world. Cleverly master-planned by client Qatar Rail, it took just 26 months to provide the capital of Qatar with three city-wide metro lines with 111 km of ultra-modern tunnel systems. According to Qatar Rail the overall completion of the project “Doha Metro, phase 1” stood at 50 % by the end of September 2016.
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 als well as Herrenknecht Chairman of the Board of Management Dr.-Ing. E.h. Martin Herrenknecht, celebrated a unique technical construction and engineering achievement. 111 km of newly bored and built tunnels under the capital of Qatar in just over two years outshine everything previously achieved in urban metro tunnelling worldwide.
Tunnelled into the Guinness Book of Records
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. 470 497 individual lining segments were mechanically assembled into 70 071 high quality tunnel rings. At peak times 20 TBMs tunnelled their way forward simultaneously and 2.5 km per week of metro tunnels grew under Doha. This 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 tunnelling was therefore one of the core requirements during construction.
Altogether 76 TBM-Breakthroughs
During 2016 Qatar Rail celebrated completion of tunnelling on Doha Metro’s Red, Green and Gold Lines:
Completion of tunnelling on the northern section of the Red Line was achieved in March by TBM “Lebretha” which achieved the final breakthrough on this part of the line between Legtaifiya Station and Qatar University (QU).
Following this, the excavation Doha Metro's Green Line was completed in April this year with the breakthrough of TBM “Al Messila” at Education City station.
Qatar Rail also saw the completion of tunnelling on Doha Metro's Gold Line with the final breakthrough on May 19, 2016 at Msheireb station.
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 – and once again tuned for speed.
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." All the participating companies handled the gigantic project with pioneering boldness and the highest degree of team spirit and operational professionalism. The Herrenknecht full-service competence center set up near Doha specifically for the project provided additional support. Competent and proactive contacts were available here for all matters relating to tunnelling technology, assembly and disassembly, provision of specialist personnel, tunnelling support, spare and wear parts management as well as the maintenance and refurbishment of the used cutting tools.
72 additional Stations and another Metro Line planned
The newly emerging metro system in Doha is only the beginning of the mobilization of public transport in Qatar. “Qatar’s vision is to connect every corner of the country by public transport,” explains Demmler. “The Doha Metro project represents the supporting backbone of an integrated public transport system,” says Qatar's Minister of Transport, H.E. Jassim Saif Ahmed al Sulaiti, in describing the substantial significance of the metro network, the first three lines of which are scheduled to be opened by 2020. By 2026 an extensive expansion by 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.
In 26 months, four international construction joint ventures have built a 111 km metro tunnel system in Doha on three lines:
Red Line North
ISG joint venture (Salini Impreglio S.p.A.; SK Engineering & Constructing Co Ltd; Galfar Al Misnad Engineering & Constructing W.L.L)
Red Line South
Qatari Diar Vinci Construction JV (QDVS); GS Engineering & Construction Corp.; Al-Darwish Enginering W.L.L
Porr Bau GmbH; Saudi Binladin Group Company Ltd; Hamad Bin Khalid Contracting Co. W.L.L.
ALYSJ 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)