The second track between Divača and Koper will be operational in March 2026

As Matej Oset, CEO of 2TDK, explains, the promises that were made still stand: “The line will be operational in March 2026, as was announced to the public this past April. We have encountered major challenges on the project: we have invested a great deal of expertise, time, and energy into appropriately and safely addressing karst phenomena. We have also paid special attention to stopping the rock slide in Glinščica, but we remain committed to the goal of having the line operational in March of next year, with all work scheduled for completion in September 2026. In this regard, I would like to emphasize that, even though the Second Track project is a multi-year endeavor, we remain committed to ensuring that the project does not exceed its budget. Let me remind you that at the beginning of the summer, 2TDK successfully secured an additional 156 million euros in non-repayable European funds, and that European institutions, which are also closely monitoring the project, present it as an example of best practice.”

More than 90 karst features were encountered during construction. Five of these features in the tunnels required the construction of more complex bypass structures. One karst feature, which we discovered on the surface section of the route upon completion of the excavation work, will also require an appropriate bypass. The longest underground bridge measured over 40 meters in length, and all underground bridges were constructed more than 100 meters below ground in 6-kilometer-long tunnels. Seven additional karst phenomena requiring bridges longer than 15 meters were encountered along the second-track route. Solutions for bridges up to 15 meters were included in the project documentation, while all spans longer than 15 meters required special solutions and months of work by experts in surveying, construction, and engineering, as no one could have anticipated them before work began, despite all the research that had been conducted.

This summer, a karst sinkhole was discovered along the surface section of the route. To cross this sinkhole, a bridge approximately 35 meters long will need to be built. Since this is a geologically complex karst feature, additional geological surveys and detailed design documentation (PZI) must be prepared before the bridge structure can be constructed.

However, the greatest challenge likely remains the rock slide in the Glinščica Valley, where initial measures to stabilize the terrain have already been implemented. Following the installation of the piles, the rock on the right side of the T1 tunnel will be secured with deep geotechnical anchors up to 35 meters long, and six shafts will also be constructed, each 30 meters deep and 6 meters in diameter. Due to the landslide-prone terrain in the Glinščica Valley, additional geological and geomechanical investigations were required, and project documentation had to be prepared for the construction of the shafts. Given the nature of the terrain, the construction of the shafts in the Glinščica Valley will be highly demanding and represents a major construction challenge.

Matej Oset also points out: “Despite numerous challenges that we could not have foreseen and that came to light during construction, we are proud that the project is proceeding as planned. By March of next year, the track will be ready and the track systems will be completed, so that testing can then begin.”