By rosebell
Breakthrough on all 10 tunnels of the Second track Divača-Koper railway line, was celebrated by Slovenian state development company 2TDK and contractors.
As an indication for the final breakthrough and excavation of 37.4km of tunnels, the main construction contractors bored the last metres of the service pipes of the Lokev (T1) and Beka (T2) tunnels on the Second track route.
Considering that there were challenges of the karst terrain, fires in the karst two years ago, and also departure of Turkish workers when their country suffered a massive earthquake last year, excavation was completed in record time as 2TDK states. The date of commencing works with the excavation of the Mlinarji and Škofije tunnels was September 2021. 2TDK says in three years, more kilometres of tunnels have been dug than have been built in 30 years on the entire Slovenian motorway network.
According to 2TDK director Marko Brezigar: “The excavation work is the most unpredictable part of the construction of the second track. Despite the tremendous efforts of geologists, geophysicists, engineers, karst scientists and other experts, we can never be 100% sure of what lies underground.”
With advance of the Beka tunnel in a karst cave, it was cleared that the karst terrain was a particular unknown.
Due to 430m of difference in altitude between Divača on the karst plateau and Koper, at sea level, 75% of the Second track was running in seven tunnels. In addition to the 20.5km of rail tunnels, there is also nearly 17km of service and rescue tunnels. Additionally, as the service tubes, which run parallel to the three longest tunnels, Lokev, Beka and Škofije, are constructed in the same cross-section as the main tunnel tubes, this will make 61% of the line ready for future double-tracking.
The Divača-Koper second railway line is Slovenia’s largest infrastructure project.
