TBM manufacturer Terratec finishes 2015 on a double high note: first breakthrough for the Istanbul Metro in Turkey and successful completion of factory acceptance tests for two new microtunnelling systems at its facilities in Thailand for that country’s MRTA Green Line North Project.
On 4 December a Terratec S42 EPBM completed the first of two 2,900m running tunnels between Yenimahalle Station and Veysel Karani for the contractor joint venture of Gulermak, Kolin and Kalyon.
“The S42 EPBM has performed without fault in the mixed ground conditions that are typical for this area in Istanbul, from full face rock to full face soil and everything in between,” said Sinan Acun, the Chief Tunnel Engineer for the contractor JV. The drive was completed in seven months, with a best daily advance of 23 rings (34.5m), and a best monthly advance of 532m.
The ground has varied from true mixed ground, to soft ground, with up to 4 bar EPB face pressure being applied. The machine will now be pulled 200m through the station cavern before being removed via a 60m deep shaft and transported back to the launch shaft at Yenimahalle Station ahead of the parallel drive.
A generous schedule set by the owner sees the contractor JV set a target of TBM tunnelling completion by February 2017. If, as is expected, the drive is completed earlier, the S42 machine may be reassigned to assist other machines on the project to complete their lots.
Just 11 days after its success in Istanbul, Terratec completed factory handover of two microtunnelling systems, at its Thai manufacturing plant, for the country’s MRTA Green Line North Project in the capital, Bangkok.
The MTBMs will install standard concrete pipes measuring 1,500mm and 1,800mm i.d. x 3000mm length, using the pipe jacking method. The contractor, the Italian-Thai Development Public Company Limited, will use the machines to complete the power cable tunnels associated with the new Sky Train System.
Scope of supply includes the shields, the main jacking station, intermediate jacking stations, the slurry transport system, a digital guidance system and a control room on the surface.
The system is designed by Terratec at its Engineering Centre in Australia, with production and assembly completed at the company’s new plant in Thailand. Key components were sourced mainly from Australia and Japan.
Both MTBMs are expected to encounter a typical Bangkok soil composed of clay, stiff clay and very stiff clay. Since the machines may encounter wooden piles from ancient houses and structures, the cutterhead design integrates a cone crusher system. Other state-of-the art features include the collaborative Enzan-Terratec laser guidance system – specially developed for small tunnelling machines – the VFD drive for the cutterhead, and the data recorder and remote access for the complete tunnelling system.
In the last three years Terratec has sold 21 microtunnelling systems in the 300mm–2,000mm diameter range. With factory acceptance of these latest small diameter machines, and other orders in production, the company consolidates its presence in the international market as a leading supplier of MTBMs, in addition to supply of larger diameter machines for transit projects.