By rosebell
As the first fully completed physical element of the CPK railway program,the launch chamber in Retkinia, where the TBM is due to commence excavation of the CPK tunnel, has been completed.
With over 180m long , 18–23m deep and 436 linear metres of diaphragm walls up to 43.5m deep, some 84,376m3 of soil was dug to build the Retkinia chamber.
The scheduled date for starting tunnel boring is late 2026, and high-speed trains are expected to run on the Y-line route by 2032.
Completing 150cm-thick diaphragm walls at the Fabryczna receiving chamber site was done by contractor Budimex, whereas the chamber measures 22x30m and is being excavated to 26m. Currently, a jet grouting wall separates the high-speed rail tunnel from an adjacent PKP PLK commuter tunnel and undergoing works include an anti-filtration barrier and a plug-in block of jet grouting columns. Concrete frames and temporary steel supports will secure excavation for the base slab.
With the aim of securing it during excavation of the chamber, which will partially pass underneath the structure, the historic Łódź Cultural Centre has undergone foundation reinforcement since 2024.
In order to stabilising the soil and transfer loads to deeper strata, main works included installing almost 1,400 micropiles and jet grouting columns, while steel bracing is currently being installed in the northern wing and dismantled interior spaces are being reconstructed.
Once the Fabryczna chamber and the LDK reinforcement are complete, a turnout chamber will be built.
As Poland’s longest and widest single-bore railway tunnel, the CPK tunnel is 4.6km long and 14m in diameter and is due to be designed for two-way train traffic travelling at speeds up to 160km/h.
Tunnel depth will vary from 23m at Retkinia to 34m near kilometre 3.2. Five underground evacuation chambers, technical walkways, and full fire safety systems are planned.
Geotechnical reinforcement such as diaphragm walls, jet grouting, and load-transfer elements is being implemented throughout to minimise settlement and safeguard nearby buildings.
The date of concluding the contract for tunnel excavation, and building assessments along the route are ongoing between CPK and contractor Porr was previous month.
Being planned to be inaugurated in 2032, the Łódź section of Line 85 (Warsaw West – Łódź Niciarniana) is currently the most advanced segment of Poland’s planned high-speed rail network. Linking Warsaw, the future CPK airport, Łódź, Wrocław, and Poznań, the full 480km Y-line is set for completion by 2035.
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