The main construction contractors excavated the last metres of the service pipes of the Lokev (T1) and Beka (T2) tunnels on the Second track route, marking the final breakthrough and excavation of 37.4km of tunnels.
Despite the challenges of the karst terrain, fires in the karst two years ago, and Turkish workers leaving when their country suffered a massive earthquake last year, 2TDK says excavation was completed in record time. Works started in September 2021, with the excavation of the Mlinarji and Škofije tunnels. 2TDK says in three years, more kilometres of tunnels have been excavated than have been built in 30 years on the entire Slovenian motorway network.
“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,” said 2TDK director Marko Brezigar.
The karst terrain was a particular unknown, with the Beka tunnel breakthrough taking place in a karst cave.
The 430m of difference in altitude between Divača on the karst plateau and Koper, at sea level, were the main reasons for 75% of the Second track running in seven tunnels. In addition to the 20.5km of rail tunnels, there is also nearly 17km of service and rescue tunnels. The service tubes, which run parallel to the three longest tunnels, Lokev, Beka and Škofije, are built 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.
