Written by Dr. Ales Pustovrh – Bogatin, EECFA Slovenia
The largest Slovenian civil engineering project in recent history – the construction of the second railway connecting Port Koper with the core international railway network in Slovenia – officially started in March 2019. Still, many questions remain to its successful completion.

The past
Port Koper, which is the only deep-sea port in Slovenia, recorded an impressive growth in the last decade; it transported more than 24 million tons of goods, including almost 1 million containers (TEU) and more than 750.000 cars. Since 2009, it has increased the quantity of its throughput by more than 10 million tons. The throughput continues to grow fast.
However, its growth is encountering limitations from the infrastructure that was designed for much smaller traffic volumes. 59% of the goods has been transported from the port using rail, essentially reaching the capacity of the existing railway connecting the port with the international railway junction at Divaca.
Before recent and ongoing modernization, the existing railway had a capacity of 72 train compositions per day, allowing for the annual transportation of 9.2 million tons of cargo. When the modernization is completed, the capacity of the existing railway will increase to 14 million tons. Yet, with projections of Port Koper reaching 35 million tons of throughput by 2030, this essentially means that all additional cargo will have to be transported on road. This ultimately results in doubling the current road cargo transportation by 2030 and tripling it by 2040.
More about Slovenian civil engineering can be found in the EECFA Slovenia Construction Forecast Report. Sample report on eecfa.com
A simple solution would be to expand railway capacity by constructing the second railway next to the existing one, but unfortunately, this is not possible as the existing railway was constructed in 1967 as an industrial railway owned by the port. Due to its history and very difficult terrain with very steep gradients, it does not fulfil technical EU standards for the core TEN-T railway network. Thus, the construction of the second railway actually requires the construction of the whole new railway with two tracks to enable longer train compositions and faster speed.
Since 1996, and in the period of 10 consecutive Slovenian governments, 17 different technical plans have been prepared for the construction of the new railway.
The present
The final plan obtained a building permit in 2016 and will allow for the construction of 27.1 km of new railway. Together with the existing railway, the capacity of the new railway will be 231 train compositions per day, making the transportation of 43.4 million tons of cargo possible. Its steepest gradient will be 17%, while the existing railway has the steepest gradient of 26%. In order to achieve this key technical characteristic, 37.4 km of tunnels (including service tunnels) and 1.1 km of viaducts will need to be constructed. This plan is still being adjusted to construct a full two-track railway as the existing building permit only allows a single-track railway with service tunnels.
This will further increase the price of the project. Estimated construction value of works Continue reading The past, present and future of Port Koper