The annual increase in the tonnage of the freight traffic sets new tasks for the subdivisions responsible for the railway track maintenance.

The increasing axial loads, mass and the length of the freight trains and the use of high-speed trains on the railways nowadays call for a mandatory inspection of the tracks under load to detect the areas with high dimensional instability.

The effective instrument for such inspection is a dedicated self-propelled track geometry laboratory developed by TVEMA engineers. The laboratory is built on the basis of the VL-11M main-line electric freight locomotive.

The laboratory measures all track irregularities under the axial load 23 tonnes, taking into account the elastic displacement of the rails. The differences in the readings from the various inspection devices at the same track sections characterise the irregularity of elastic displacement of the rails and provide detection of the track

sections with variable stiffness, backlash, and other defects. The Company specialists specially adapted all measurement systems for installation  on the electric locomotive. One of the locomotive sections was converted into a space for the workshop compartment, auxiliary and amenity rooms. Two monitoring and measurement systems were installed on the locomotive. The SVOD-2 system for high-speed visual inspection which detects the defects of the permanent way, and SOKOL-2 high-speed system of track geometry assessment which monitors and analyses the track parameters, inter alia:

• track gauge;

• level;

• alignments;

• sag;

• rail wear;

• rail cant;

• track plane and profile.

When used together, both systems based on the differences in the geometry parameters of the track under load and without load provide detection of the sections where the actual condition of the track structural elements and the roadbed does not ensure the stability of the track geometry.

All captured data is processed by URRAN and CASCADE automated systems.

The information acquired by the self-propelled track geometry laboratory based on VL11m locomotive is meant to facilitate the improvement of the track maintenance system and optimize the planning of comprehensive repair works.