TERRATEC announced the on-time delivery of four new 6.56-m diameter earth pressure balance tunnel boring machines (EPBMs) for the ongoing expansion of Istanbul’s Metro system in Turkey, following a number of recent factory acceptance tests. These EPBMs bring the current number of TERRATEC machines working simultaneously in the city up to a total of seven.
The robust TERRATEC TBMs have versatile mixed-face dome-style cutterheads with an opening ratio of about 35% that has proven to work extremely effectively in Istanbul’s mixed geology – which includes low-strength sandstones, siltstones, limestones and shales – as well as other state-of-the-art features such as VFD electric cutterhead drives, tungsten carbide soft ground cutting tools that are interchangeable with 17-in. roller disc cutters, high torque screw conveyors and active articulation systems.
The new TBMs will be used by the Gulermak, Nurol & Makyol JV on the Ümraniye-Ataşehir-Göztepe Metro contract, which was awarded in April 2017. The 13-km long line, along with 11 new stations and NATM-built connections, will form a second north-to-south rail corridor under the densely populated Anatolian side of the city and will be located entirely underground at an average depth of about 30 m.
The Ümraniye-Ataşehir-Göztepe project is one of five new metro lines currently being built by the Istanbul Metropolitan Municipality (IMM). Members of the JV were so impressed with the performance of the TERRATEC machine used on the Mecidiyeköy-Mahmutbey Metro, which is being built by the Gulermak, Kolin & Kalyon JV – and the progress of two other 6.56-m diameter EPBMs that were delivered last year to the Şenbay Madencilik-Kolin-Kalyon JV for the Dudullu-Bostancı Metro Line – that they were keen to employ a further four TERRATEC machines on this latest project.
“Terratec is excited to be providing yet more machines to the metro projects in Istanbul,” says TERRATEC Sales & Marketing Director, Bruce Matheson. “We are confident they will perform as well as previous machines have in the city and we look forward to breaking more records for on-time delivery, quick assembly and excellent production rates.”
Due for completion in 2019, the new lines will increase the city’s current 145 km Metro network to more than 480 km.