AKTOR has started Varvara, the second tunnel boring machine (TBM) that drills the pair of the twin tunnel Ormenis on the mountain nearby Racoș, on the thread of the future Brasov-Simeria railway line, part of the Rhine-Danube Corridor, Brasov-Sighisoara section, subsection 2: Apața-Cața. Varvara (named after St. Varvara, the protector of miners) thus joins Eleni, the first TBM, which began drilling on March 5, 2024.
The project is co-financed by the European Union, and the contract was signed by the National Railway Company (CFR SA) with the consortium of AKTOR SA – Alstom Transport SA – Arcada Company.
The two TBMs will drill the Ormeniș twin tunnels in the mountain, with a length of 6.9 km each, between Racoș and Ormeniș, the southern segment of the railway section that will pierce the hills in the area.
Meanwhile, as of last week, Eleni has dug 102 meters (equivalent to 68 prefabricate concrete rings) inside the mountain. The pace of the boring speed up after complex tests and calibrations necessary to set such a big machine in the right direction and tilt. AKTOR’s team will apply the same procedures of approaching the drilling with Varvara as they did with the first TBM, Eleni: firstly, there is a testing phase, and then gradually, the boring gains speed.
There is also the aspect related to the soil composition, through which Eleni is digging, which Varvara will also have to cope with. According to Sotirios Koropoulis, the Project Director for the Apața-Cața section, Lot 2 construction site, the current lithology the AKTOR team is mining can be classified as clay. The composition of the soil also dictates the approach for drilling.
“This project is an engineering masterpiece for the railway between Brasov and Sighisoara. We drill the longest railway tunnels in Romania through the mountain between Apața and Racoș. The singularity of the technical challenges due to the soil variable structure makes this project a premiere for Romania. It also highlights AKTOR’s capability to implement complex and challenging construction projects and our strong support for the country’s growth,” stated Alexandros Exarchou, CEO of Intrakat Group.
As a technical detail, the team manning Eleni has fixed so far 68 concrete prefabricate rings. The factory producing the rings in Zarnesti has secured at this moment an impressive stock of 875 for this first pair of tunnels.
A second pair of tunnels, called Homorod, with a length of 5.1 km each, will be drilled between Racoș and Homorod, and their start is scheduled for this summer. TBMs 3 and 4 have been delivered 100% and are in the assembly process in different stages. According to the execution plan, they are scheduled to start in July and, respectively, August, and will drill for approximately 15 months, Homorod being a shorter tunnel than Ormeniș.
The tunnels will be connected by galleries: 13 connecting galleries, with a total length of 601 linear meters for the Ormeniș tunnel, respectively 10 connecting galleries, with a total length of 417 linear meters for the Homorod tunnel.
The Ormeniș/Homorod underpasses will each consist of two railway tunnels with one railway line each. The distance between the two bored tunnels will be variable and is planned to be between 30m near the entrance areas and 70m near the high overburden area.
The four tunnels will have an inner diameter of 8.6 meters (an outer diameter of 9.4 meters, due to the concrete lining). They will be drilled with four TBMs, built by the HERREKNECHT company. The first two TBMs, Eleni and Varvara, have a remarkable length: Eleni is approximately 105 meters long, and Varvara is approximately 84 meters long.
A TBM can drill large-scale tunnels with an average of 10-15 meters per day, six days per week, and one day of maintenance.
Besides the Brasov-Sighisoara section, subsection 2: Apața-Cața, AKTOR is working around the clock to complete the A0 South Bucharest Lot 3 section, whose deadline is early September.
AKTOR Construction is a member of the Intrakat Group, an industry leader in Greece’s construction, infrastructure, concessions/public-private partnerships (PPP), renewable energy sources (RES), energy storage, real estate development, environmental projects, and digital technologies sectors, with a significant presence in Southeast Europe, listed on the Athens Stock Exchange since 2001.
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