Shani Wallis, TunnelTalk
- At an open day on Friday (16 Nov), Seli presented the first of four EPBMs it will build and use to excavate the running tunnels of the new Cityringen metro project in Copenhagen, Denmark. The four, 5.78m diameter EPBMs will complete some 32km of twin tunnelling to link 17 underground stations and the depot of the circular metro line beneath the heart of the city's ancient and medieval centre.
- The first of the four machines, with its long trailing backup, was fully assembled at Seli's factory at Aprilia, about an hour south of Rome, with elements of the second TBM fabrication collecting in the adjacent bay. The cutterhead of the first machine was turned and its foam injection system activated for a test demonstration for the gathered audience of owner representatives from Copenhagen, Seli factory workers and staff, and representatives of machine design partner, Kawasaki of Japan. Through the licensing agreement, Kawasaki has designed and supplied the drive unit and screw conveyor components to fit with the Seli cutterhead, shield and backup design and fabrication.
- The machine will be dismantled and containerised for shipping to Copenhagen over the coming four weeks. All four machines, worth approximately €7 million each, are programmed to be built, shipped and launched during 2013.
Second EPBM ready 30 May 2013
Seli News Release
- Manufacture of the second Seli-Kawasaki EPBM for the Copenhagen Metro is completed. The second of four TBMs for the project was inaugurated at the Seli factory in Aprilia, Italy, on 10 May, 2013.
- The second Cityringen EPB machine will excavate the 8,900m north drive in two sections; Section 1 between the Norrebroparken shaft to Platanvej Station (3,800m), and Section 2 between the Norrebroparken shaft and the Oster Sogade shaft (5,100m). Excavation is scheduled to begin in September 2013, with Seli part of the construction JV (headed by Salini Construttori) that will build the 32km of twin tunnels and 17 underground stations.
- In making presentations on the day, Remo Grandori, President of the 60-year old family-established Seli company, said that working in collaboration with the Japanese engineers was a productive transnational experience. The Seli - Kawasaki license was signed three years ago in April 2010, and a fifth collaborative EPBM was built in China for Seli's Indian partner Coastal for its metro contract in Bangalore. There is another ordered for a project in Turkey, another to go to Ecuador and another possible order currently in competitive negotiations.
Test of the Seli-Kawasaki EPBM in action
- Grandori told TunnelTalk that the machines for Copenhagen are more robust than normal. "Each one has to complete longer than usual drives for metro projects. The machines will complete drives of up to 8km each working from a limit of three working shafts and either driving through the station zones or be dismantled, lifted and relaunched as necessary to meet a tight construction programme. The new Cityringen line is scheduled to be in service by 2018." Two machines will start at the Nørrebro Parken site, two more at the Ottobusses Vej site, with subsequent relocation of TBMs to the Østersogade site.
- The machines will work through complex geological conditions under a high watertable, ranging from sound Copenhagen limestone with bands of flint, to till and glacial deposits of sand, gravel, silt and clay. The cutterheads are dressed with both discs and scrapers and the machines are tested to 9 bar working pressures to operate under the anticipated 4.5 bar pressures of the alignment as it runs between 7m and 42m deep. The 5.78m diameter machines have a maximum cutterhead thrust of 42,000kN, a cutterhead speed of 0-5rev/min, a cutterhead drive power of 1,200kW and are fitted with a vacuum segment erector.
- Control of surface settlement and the protection of the historic urban fabric of the city centre is of the highest priority for the owner organisation Metroselskabet; the owner's design engineering JV of COWI, Arup, Systra; and CMT, the Italian Copenhagen Metro Team construction JV of Salini Construttori, Maire Tecnimont and Seli. "It is essential to maintain the ground water table," explained Søren Degn Eskesen, Tunnel Design Engineer with COWI. "The alignment also passes above the existing metro line at Kongens Nytorv and under the famous Marmor Kirken in historic Copenhagen. The TBMs will be required to operate in full EPB mode at all times. The double articulation of the shield is required to negotiate tight radii curves on the alignment."
Schematic of the EPBM design
- "The key," according to Grandori, "is effective conditioning of the material in the excavation chamber for controlled discharge through the screw conveyor and onto the transfer conveyor for haulage in muck trains of four, 20m3 skips." During a tour of the machine and its operating cabin, Leonardo Pia, Technical Director of Production for Seli at Aprilia, explained that there are 10 foam or polymer conditioning agent injection points, eight into the excavation chamber and on the cutterhead, and another two into the screw conveyor. "Discharge through the screw conveyor is further controlled by the in-line discharge gate of the shorter rather than the longer screw conveyor design with its external drive," said Pia. "In addition there are two belt weighers on the transfer conveyor, about five seconds travelling on the belt from the discharge gate, to provide rapid notification of any over excavation from the chamber."
- Safety elements include walkways along the backup to prevent anyone walking in the invert in the line of the trains, and a shuttle conveyor to fill the muck skips of a stationary train, eliminating train shunting during skip filling.
Interior of the articulated shield with conditioning injection system (left) and view along the trailing backup
- The segments of the 300mm thick bolted and gasketed precast concrete segmental lining is being produced by the JV at a casting yard in Germany from where they will be transported by sea to Copenhagen. The 4.9m i.d. of the running tunnels will accommodate the fully automatic, driverless trains of the Copenhagen Metro system.
- Unlike the more usual method of tunnel infrastructure procurement, Seli, as a contractor and a TBM manufacturer, and as a member of the CMT construction JV, will operate the TBMs it has built for the project. "This was a main point of the JV's prequalification proposal and its competitive bid against two other procurement finalists," explained Guy Taylor, Project Director for the Civil Works Management for Metroselskabet. "Seli is one of few firms in the world that undertakes both construction and TBM manufacture, they have designed and built these machines, in collaboration with Kawasaki, and now have to make them work. Cityringen was conceived for expansion of Copenhagen's Metro in the 1990s and after all these years inauguration of this machine is a major step for taking the project forward. We wish the JV well in operating the machines without accident or incident."
- During his presentation at the open day, Yugo Nakagami, Director of the collaboration for Kawasaki said, "we are confident we have built TBMs of high reliability, durability and maintainability to manage and complete the tunnels in Copenhagen safely and within the programme."
- Claudio Lautizi, the Director for JV lead partner Salini said that the TBM was built and ready on time and according to the contract. "The Seli team worked hard to meet the deadline and it is an important day today to inaugurate this first of the four project machines."
- Among the Seli management at the TBM inauguration day was Valerio Violo, Project Manager for Seli in Copenhagen, and Luca Giacomini, a Seli site manager who has moved from his previous post as Site Manager for the Seli TBM drive for the Kishanganga hydro scheme high in the Himalayas of Kashmir to take up the Site Manager's position for the EPB TBMs in Copenhagen.
- In closing the ceremony, Grandori told TunnelTalk that "the target of the cooperation with Kawasaki is to develop and manufacture a new line of EPB TBMs dedicated to the most challenging projects in the technologically advanced markets with a special focus on Europe and North America. We have the capacity to deliver seven machines from the factory here at Aprilia and another six or seven from the facility in China. Some 80% of the total TBM market annually is for EPB TBMs - that includes rock machines and slurry systems. As well as manufacturing for our own contracts we also build machines for other contractors. The TBM market will continue to grow especially when other developing countries of the world begin to drive demand."
- In the short term, the Seli team and works at Aprilia will be busy building the remaining three EPBMs for Copenhagen.
Four EPBMs selected for Cityringen drives - TunnelTalk, January 2011
Copenhagen metro contract award - TunnelTalk, December 2010
First five Seli-Kawasaki TBMs in production - TunnelTalk, June 2011
Seli and Coastal form subcontinent alliance - TunnelTalk, March 2011
New partner, new corporate structure for Seli - TunnelTalk, November 2012
Add your comment
- Thank you for taking the time to share your thoughts and comments. You share in the wider tunnelling community, so please keep your comments smart and civil. Don't attack other readers personally, and keep your language professional.