Modernization of the Sofia-Burgas Railway Line: Progress on the Key Tunnel

Sofia, Bulgaria — A glimmer of hope for the future of Bulgarian railways appeared today, after Deputy Prime Minister and Minister of Transport and Communications Grozdan Karadzhov inspected construction work on the key railway line from Kostenets to Septemvri. The reason for his optimism is the progress in the modernization of the route, which is part of the ambitious project to upgrade the line from Sofia to Burgas.

During the inspection, Minister Karadzhov was present at the symbolic demolition of the final centimeters of the stone wall that separated the two breakthroughs of the longest tunnel in this section. With a length of nearly 2.5 km, the structure was excavated simultaneously from both sides, which accelerated the process.

An element of key infrastructure

Although relatively small, the section is of extreme importance for the country's overall transport scheme. According to the minister, this is only one of ten sections that are currently being repaired, with the aim of a complete modernization of the railway connection between the capital and the Black Sea coast.

Karadzhov admitted that the large-scale repairs create temporary difficulties for passengers, resulting in reduced speeds and train delays. However, he expressed hope that all ten projects will be finalized by 2029.

Large-scale construction achievements

The minister explained that in the Kostenets-Septemvri section, the excavated tunnel with a length of almost 2.5 km is the longest of a total of three. He added that the same construction company is also working on the longest tunnel in all of Bulgaria, located between Sofia and Plovdiv. This structure consists of two 6.5 km tubes, with a total length of 13 km.

Karadzhov noted that when he took office, the project was enormously behind schedule, as work was practically frozen throughout 2024. However, the possibility of regular and rhythmic payments to the contractors has activated their serious work, which has made it possible to catch up with the backlog.

"We currently have very serious reasons to believe that this route will be completed by 2029"

The minister also described the future parameters of the project, pointing out that after the tunnel, construction work will continue with a massive viaduct, almost half a kilometer long and nearly 40 meters high, followed by another tunnel. These structures will allow trains to move on relatively straight lines with small turns, reaching a speed of up to 160 km/h along the entire route from the Serbian border to Burgas.

Faster, more comfortable, more eco-friendly

After the completion of the project, the journey from Sofia to Burgas is expected to take just over three hours at a maximum speed of 160 km/h and an average of 140 km/h. This is a significant reduction compared to the current travel time, which is 5 hours and 30 minutes with the express train.

The minister emphasized that the main goal of the reform is for railways to become the backbone of Bulgarian transport. For this to happen, they must offer two main advantages - a competitive price and a competitive time.

Karadzhov also highlighted the advantages of traveling by train over car.

"We can certainly offer much greater comfort than traveling by car, because on the train you can get up, visit the restaurant car, walk around, get together with several families - things that are not possible in a car. In addition, you won't pollute the air"

The modernization is expected to completely change train travel in the country, making it faster, more convenient, and more environmentally friendly.