With the “Special train” to Sweden: A slab track system is being created in the Malmö city tunnel

A slab track is being laid in the tunnel section with two individual 6km tunnels. The sleepers are embedded in concrete and can absorb the vibration caused by high-speed trains in a better way due to having an extremely flexible insert. Maximum precision is required when the tracks are installed. The sleeper shoes that have been freshly embedded in the concrete must not be subjected to vibration. Even the slightest variations in the alignment of the tracks can result in the railway no longer complying with the original designs for high-speed travel.

The order for constructing the slab track in the Malmö city tunnel was placed with Rhomberg Bahntechnik. The objective was to find a solution for installing the concrete track bed over a distance of two times six kilometers without a major amount of vibration. The plan was to do the concreting at a speed of 15-20m/h. Together with the Concrete Project Division department at the main Putzmeister plant in Aichtal, all of the parties involved collaborated to produce a solution for supplying a tunnel concreting train based on the patented installation solutions of Rhomberg Bahntechnik.

The concreting train consists of various railway wagons on which all of the necessary components for carrying out a continuous and smooth procedure are mounted (including the necessary cleaning and maintenance work). All systems are protected by an emergency power unit. The Putzmeister stationary concrete pump is on the third wagon, plus a small conveyor belt for feeding the concrete pump. The concrete is transported from the pump to the concrete paver up to 400m away via a steel delivery line that is installed on special wagons. The maximum permitted concrete pressure of the delivery line is 130bar. Since the slab track in the Malmö city tunnel also has a long curve with a radius of 760m, the line has been adapted accordingly. Non-critical load transmission was a challenge during dimensioning. Particular attention was also paid to having an environmentally friendly disposal and cleaning concept that meets the strict regulations in Sweden.