World's Largest TBM Ready to Cross the Yangtze in ShanghaiAt the end of April 2006, Herrenknecht handed over the first tunnelling machine with a diameter of 15.43 m to the Chinese client Shanghai Changjiang Tunnel & Bridge Construction Co. Ltd. Together with the Chinese partner Shanghai Tunnel Engineering Co. (STEC), the mixshield was assembled at the STEC location in Shanghai Wuhaogou (Pudong) in only four months. At the beginning of September 2006, this giant machine will begin its underground journey beneath the Yangtze River towards the river island of Changxing (or Changjing). A second machine, for the production of a second parallel three-lane road tunnel of the Changjiang under-river tunnel project, is currently being assembled at STEC. Visit www.herrenknecht.com The first Herrenknecht mixshield (machine S-317) was assembled within schedule and is currently the world's largest TBM, with a diameter of 15.43 m. This gigantic TBM will construct one of two 7.2 km, three-lane road tunnels, at depths of up to 65 m beneath the Yangtze River in Shanghai Pudong. These two tunnels are to be opened to traffic in April 2010 when Shanghai hosts the World Expo. The megalopolis of Shanghai has been growing at an extremely rapid pace for more than a decade and is always seeking more space to expand. This search extends beyond the natural limits of the Yangtze River delta. More than 20 million people currently live in the Greater Shanghai area and 500 new vehicles are registered every day. The new tunnels will connect the Changxing river island, with a population of approximately 600,000, to the road traffic network. A bridge construction will also provide a traffic link between Changxing island and the large island of Chongming opposite. Investments in the two tunnel projects and the bridge amount to approx. USD1.5 billion. Herrenknecht was awarded this important contract for the construction of the two mixshields (slurry tunnelling shields) 13 months ago, in spring 2005. Not only is this the first direct Chinese order for Herrenknecht's most advanced tunnelling technology but also the first time worldwide that two machines with a excavation diameter of this size have been built. During tunnelling, the machines will face water pressures of up to 6.5 bar, which can only be mastered safely using mixshield technology. To allow skilled personnel to change tools at the cutting wheel in these extreme conditions without compromising high safety standards, the six cutting wheel arms are accessible from within the shield under atmospheric pressure. This reduces to a minimum the need for diving operations to change cutting tools. Assembling these two machines at the premises of Herrenknecht's partner STEC in Shanghai Pudong, some 6 km from the planned construction site, was a logistical and organisational masterpiece. This Herrenknecht tunnelling shield, with a total length of 125 m and a total weight of 2,300 tonnes, has been specially designed and developed for this project over the past 13 months. The main hydraulic and electromechanical components (thrust cylinders, main drive, etc.), the process and control technology and the cutting wheels of the two TBMs were produced by Herrenknecht engineers and specialist workers at Herrenknecht headquarters in Schwanau, Germany. The heaviest components arrived from Germany at Shanghai at New Year 2005/2006. The main drive (3,500 kW cutterhead power), weighing a total of 170 tonnes, had to be offloaded with a special floating crane. Now, after acceptance by the customer, the machine is being dismantled at STEC as quickly as possible, under the supervision of Herrenknecht, to prepare it for action at the tunnel construction site. The TBM will commence tunnelling for the first time on 8th September, 2006 in the launch shaft at a depth of 26 m. The infrastructure construction is being assisted by engineers from Bouygues of France. The second tunnel, with a distance between centrelines of 23 m, will be driven with machine S-318 which is scheduled to begin tunnelling beneath the Yangtze on 8th December, 2006. The two machines will install a total of 7,500 lining segmental rings. Each ring is made up of 11 segments, each weighing up to 16 tonnes. By the time the two tunnels have been completed, 2.7 million cubic metres of earth will have been excavated. A total of 1,500 people will be employed on this large construction site in the next few years. The first mixshield is expected to arrive at the target shaft on the river island of Changxing at the end of 2008. This mega project in China is of enormous strategic importance to Herrenknecht. It will send an important signal in Asia as a reference project in large-scale mechanised tunnel construction. Click cn/51. Read E-News Weekly 37/2004 & 15/2002. 23/06. Official workshop acceptance ceremony, with from left to right: Zhang Minqing, director of STEC machinery plant, Mr. Kuehorn, director for traffic tunnelling of Herrenknecht Asia, Yu Xuanping, vice general manager of STEC, Jiang Yunsu, tunnel project director of commanding post of Shanghai Changjiang Tunnel & Bridge Construction Development Co. Ltd., Dai Xiaojian, general manager of commanding post of Shanghai Changjiang Tunnel & Bridge Construction Development Co. Ltd., Huang Rong, director of Shanghai Municipal Construction and Management Office and Zhou Wenbo, general manager of STEC.