• Employer: National Railway Infrastructure Company
• Contractor: Infrastructurno Stroitelstvo – Geostroy Consortium
• Project implementation period: 2019 - 2020 

In February 2020, Infrastructurno Stroitelstvo – Geostroy Consortium commenced construction works under the project Rehabilitation of the Railway Track, the Artificial Facilities, the Facilities and Devices of the Power Supply System from the Railway Infrastructure in Koprivshtitsa – Stryama Interstation Section from km 100+525 to km 106+337. The total length of the section is 5.8 km.

Koprivshtitsa – Stryama interstation section was built as a one-way railway line on the 3rd Railway Line Iliyantsi-Stolnik-Karlovo-Tulovo-Dabovo-Zimnitsa. Almost the entire section runs through Koznitsa Tunnel which is now the longest railway tunnel in Bulgaria.

The contract scope includes design and complete renewal of the railway track in the section. The project works also include strengthening of the railway subgrade, construction of drainage facilities, repair of the tunnel structure and catenary, installation of a tunnel lighting system, as well as a video surveillance system at the two tunnel entrances. Furthermore, works related to the installation of safety equipment and telecommunication facilities were carried out.

The construction works are to be completed during the second half of 2020.