The plan to expand the Istanbul Metro system in Turkey from 145km to more than 480km is a step closer following delivery of another four new Terratec 6.56m diameter EPBMs. Ordered in July 2017 by the Gulermak, Nurol & Makyol JV for the Ümraniye-Ataşehir-Göztepe Metro Line and following recent factory acceptance tests, the new machines are now on site and ready to start work.

There are now seven Terratec machines building the five new metro lines for the Istanbul Metropolitan Municipality with completion expected in 2019.

Members of the JV were keen to employ a further four Terratec machines on this latest project after being impressed by the performance of those already in use on the Metro Line.

“Terratec is pleased to provide yet more machines to the metro projects in Istanbul,” said Bruce Matheson, Terratec Sales & Marketing Director. “We are confident they will perform as well as previous machines and look forward to continued good production rates.”

Five new metro lines are currently under construction in Istanbul, Turkey and when completed in 2019, these new lines will increase the city’s current 145km metro network to more than 480km. Construction of the underground sections of these metro lines is fueling a high demand in Istanbul for metro TBMs.

Fig 1. New metro lines currently under construction in Istanbul

Adding to a current three machines working in the city on the metro expansion, Terratec has secured an order to supply four new 6.56m diameter EPBMs for the Ümraniye-Ataşehir-Göztepe Metro Line. The order is placed by Turkish tunnelling joint venture of Gulermak, Nurol & Makyol. The order will see a total of seven Terratec EPBMs working simultaneously on the Istanbul Metro by the middle of 2018.

The order follows strong performance of a Terratec EPBM delivered two years ago to the Gulermak, Kolin & Kalyon JV for the Mahmutbey-Mecidiyekoy Metro Line and progress of two 6.56m diameter EPBMs purchased last year by the Şenbay Madencilik-Kolin-Kalyon JV for the Dudullu-Bostancı Metro Line project (Fig 1).

The new TBMs will be used by the Gulermak, Nurol & Makyol JV on the €600 million Ümraniye-Ataşehir-Göztepe Metro contract awarded in April. The 13km-long line and its 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 30m. The TBMs are currently in production and will begin factory testing in the final weeks of 2017.

Istanbul continues investment in metro construction

The Terratec machines in Istanbul have versatile mixed-face cutterheads with an opening ratio of about 35%. The configuration has proven to work effectively in the mixed geology of Istanbul, which includes low-strength sandstones, siltstones, limestones and shales. The machines also feature VFD electric cutterhead drive, cutterheads that can be fitted with either soft ground cutting tools or 17in disc cutters, high torque screw conveyors and active articulation systems.

“We are expecting great things from the TBM,” said Ufuk Yapıcı, Project Manager for the Gülermak-Nurol-Makyol JV. “We have confidence that Terratec will deliver. We view the company as a solution provider for the project in addition to an equipment supplier.”

In recent years, the Terratec order book has grown as the company has established a network of loyal customers. “Terratec is becoming a first choice for more contractors,” said Bruce Matheson, Head of TBM Sales for Terratec. “Earlier this year, we opened a new large-diameter TBM facility in Guangzhou, China, that will deliver more than 12 new machines in the second half of 2017 and into 2018, including the four new EPBMs for Istanbul.”