Natsproektstroy Companies Complete Installation of Track Slabs at the Sablino – Tosno Testing Site
Natsproektstroy companies completed the installation of track slabs at the Sablino – Tosno testing site, where field trials of the slab track for the High-Speed Railway will be conducted. Over a section of more than 1 km, 263 concrete structures have been laid: 207 NGP 4.0 track slabs and 56 turnout slabs.
22 July 2026
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The work was completed in several stages. Concrete foundation slabs were placed on the reinforced soil layer. Turnout slabs were installed manually, while the main section was laid using an automated concrete paving system. The process requires high precision: elevation deviations must be within 5 mm. Three-position jacks placed track slabs above the foundation. Weight of each slab is approximately 7 tonnes, they are installed with a 55-tonne crawler crane and a 70-tonne mobile crane.
The most challenging part is slab alignment — they must be positioned with high precision down to 1 mm. For this purpose, a robotic total station is used, which determines position while accounting for temperature and time of day. The device uses proprietary software developed by Natsproektstroy: in real time, the system compares the slab's actual coordinates against the design at four reference points and provides adjustment recommendations.
Once the slabs were aligned and secured, the construction team installed formwork and poured a layer of self-compacting concrete between the slabs and the foundation through the slab openings. The mix is non-shrink and fills every void without any vibration.
Next, Russian Railways personnel will lay thermally hardened rails on the slabs and commission the railway automation systems. After that, the testing site will be used to validate how the rolling stock interacts with the subgrade and the slab track system when exposed to loads from Sapsan high-speed trains.
The most challenging part is slab alignment — they must be positioned with high precision down to 1 mm. For this purpose, a robotic total station is used, which determines position while accounting for temperature and time of day. The device uses proprietary software developed by Natsproektstroy: in real time, the system compares the slab's actual coordinates against the design at four reference points and provides adjustment recommendations.
Once the slabs were aligned and secured, the construction team installed formwork and poured a layer of self-compacting concrete between the slabs and the foundation through the slab openings. The mix is non-shrink and fills every void without any vibration.
Next, Russian Railways personnel will lay thermally hardened rails on the slabs and commission the railway automation systems. After that, the testing site will be used to validate how the rolling stock interacts with the subgrade and the slab track system when exposed to loads from Sapsan high-speed trains.
