Reliability of the Kouvola–Luumäki railway improves

The Kouvola–Luumäki rail connection is a nationally important route for passenger and freight traffic. To enhance the reliability of this busy line, the superstructure is being renewed, and Sweco was responsible for the construction design of the northern track.

Renewing the Kouvola–Luumäki railway superstructure

The Kouvola–Luumäki double-track superstructure is being renewed in two phases to increase the route’s capacity and reliability. The Finnish Transport Infrastructure Agency selected Sweco from its framework partners for the construction design of the northern track.

“Initially, the assignment was relatively small, but at the client’s request it expanded into a larger package during the design phase. Sweco managed to take this on and deliver within the same schedule,” says Eliisa Haavanlammi, an expert at Welado who oversaw the design.

In addition to renewing the superstructure, the project improved track drainage, replaced the most deteriorated culverts, and designed frost protection for the track.

Haavanlammi has worked with Sweco’s rail designers before and found it easy to trust that they would deliver on their promises.

“The project was supported by highly experienced professionals, such as Project Manager Jukka Hackman. He has extensive knowledge across technical fields, which allows him to seamlessly integrate different design disciplines into a complete solution.”

Local knowledge from Sweco experts familiar with the region was also an advantage. “It helped, for example, in resolving utility relocation issues within the construction design area,” Haavanlammi notes. “Additionally, design solutions were adapted for locations where land acquisition agreements with landowners could not be reached.”

Construction design from geotechnics to safety systems

Sweco’s rail designers worked through the details of replacing the superstructure—from track ballast and rails to service roads and new ditches. Track geometry was also adjusted in some sections.

“Fortunately, the long switches were left untouched, though there was plenty to adjust with the electrified line,” says Antti Nyberg, Team Manager at Sweco. The project also included safety system design, risk management, and field surveys. Species inventories were carried out even before the contract began: “We mapped invasive species as well as endangered plants and sensitive habitats along the track embankments.”

Since the Kouvola–Luumäki line has had frost issues, Sweco’s geotechnical experts investigated the situation and improved frost protection with new insulation panels. Although the track runs along the Salpausselkä ridge, soft soil areas were also found and reinforced with counter embankments. In addition, the condition of dozens of culverts under the track was checked during site visits.

“Some culverts were renewed by drilling steel pipes through the embankment, because Kouvola–Luumäki is not a quiet forest line where traffic breaks are easy to arrange,” explains Tuomo Passi, Sweco’s Director of Geotechnical Design. Trains run frequently at speeds up to 200 km/h. “Excavations for the northern track upgrade had to account for the fact that traffic on the southern track continued almost throughout the works—just five meters away.”

Extending the life of the historic Kouvola–Luumäki line

During design, archive images were digitized to ensure information is available for future generations. “The northern track was one of the first rail connections from Helsinki to St. Petersburg in the late 1800s, and now the historic line’s lifecycle continues,” Passi notes.

Future-oriented solutions were also integrated through circular economy practices. Rails, good-condition wooden sleepers, and switches are being reused. “In this project, we were even able to recycle old track ballast for forest roads owned by local landowners,” Nyberg adds. During superstructure renewal, ballast was swept aside to a depth of about 50 centimeters.