Below the streets of Kassel, a city as well known for world-class engineering as it is for contemporary art, two sections of historic egg-profile sewer were rehabilitated in March 2026. Insituform supplied a CIPP felt liner across 127 metres of complex underground network – restoring full structural integrity without breaking the surface.
CIPP Felt Liner for Kassel’s Egg-Profile Sewers
The rehabilitation covered two sewer sections, each with its own geometric demands. The first, at 84 metres, featured a 666 x 1000mm egg profile with an equivalent circular diameter of approximately DN 830. The second, at 43 metres, had a 260 x 520mm profile corresponding to approximately DN 440.
Egg-profile sewers are a common feature of older city centres. Historic networks rarely follow simple alignments – changes in direction, varying cross-sections, and localised deformation are the norm. The Insituform CIPP felt liner system is well-suited to precisely these conditions. Its flexibility allows it to follow non-linear pipe runs and conform to complex geometries, while still achieving a tight, structural fit against the host pipe.
The outcome is a fully renewed sewer rehabilitation lining that preserves the existing alignment of the historic network, with no open-cut construction, no unnecessary disruption, and significantly extended service life.
Project Outcome
The installation was carried out together with the experienced team at Swietelsky-Faber Kanalsanierung GmbH. To support the process, the Insituform conveyor belt system was used throughout, ensuring controlled liner handling and precise positioning during inversion. The project was completed in five days.
For the infrastructure owner and the city of Kassel, the trenchless approach kept disruption to traffic, residents, and local businesses to a minimum. Beneath the surface, the network – and the communities depending on it – continues to perform.
Pipeline Details and Project Summary
Client: Swietelsky-Faber Kanalsanierung GmbH
Location: Kassel, Germany
Scope: Supply CIPP Felt Liners for pipe rehabilitation
Length: 84m and 43m
Diameter: DN 830 and DN 440
Liner Type: CIPP Felt Liner
Duration: Five days
