The launch chamber in Retkinia, where the TBM will begin excavation of the CPK tunnel, has been completed. It is the first fully completed physical element of the CPK railway programme.
Some 84,376m3 of soil was excavated to build the Retkinia chamber. It is over 180m long and 18–23m deep, with 436 linear metres of diaphragm walls up to 43.5m deep.
Tunnel boring is set to begin by late 2026, and high-speed trains are expected to run on the “Y-line” route by 2032.
At the Fabryczna receiving chamber site contractor Budimex has completed 150cm-thick diaphragm walls. The chamber measures 22x30m and is being excavated to 26m. A jet grouting wall now separates the high-speed rail tunnel from an adjacent PKP PLK commuter tunnel. Current 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.
Since 2024, the historic Łódź Cultural Centre has undergone foundation reinforcement to secure it during excavation of the chamber, which will partially pass underneath the structure.
Main works included installing approximately 1,400 micropiles and jet grouting columns to stabilise the soil and transfer loads to deeper strata. Steel bracing is currently being installed in the northern wing, while dismantled interior spaces are being reconstructed.
Once the Fabryczna chamber and the LDK reinforcement are complete, a turnout chamber will be built.
At 4.6km long and 14m in diameter, the CPK tunnel will be Poland’s longest and widest single-bore railway tunnel. It will 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.
To minimise settlement and safeguard nearby buildings, geotechnical reinforcement – including diaphragm walls, jet grouting, and load-transfer elements – is being implemented throughout.
Last month, CPK and contractor Porr signed the contract for tunnel excavation, and building assessments along the route are ongoing.
The Łódź section of Line 85 (Warsaw West – Łódź Niciarniana) is currently the most advanced segment of Poland’s planned high-speed rail network. It is scheduled to open in 2032. The full 480km “Y-line” – connecting Warsaw, the future CPK airport, Łódź, Wrocław, and Poznań – is set for completion by 2035.
