Masters of rehabilitation: IMPREGLiners set new benchmark in the Netherlands

Two IMPREGLiners, together weighing nearly 80t, were successfully installed in the Netherlands under exceptionally challenging conditions, marking a significant milestone in trenchless sewer rehabilitation. This ambitious project demonstrated the ideal application of light-curing pipe liners in a high-stakes environment.

A highly demanding construction project

The rehabilitation involved two DN 1500 sewers that had suffered severe structural damage from hydrogen sulphide (H2S). Positioned beneath a heavily trafficked roadway in the city of Leiden, the work had to be performed exclusively at night to minimise disruption.

The planning phase was intensively supported by IMPREG GmbH’s expert team, Francis Clauss, Oliver Vorlop, and Roland Hahn who collaborated closely with longstanding partner Kumpen NV Renovatietechnieken, led onsite by Willem Bollen, and with the City of Leiden. Together, they developed and executed a meticulous site strategy tailored to the complex environment.

Overcoming installation challenges

Trenchless rehabilitation using UV-curing technology proved to be the most efficient and costeffective solution. IMPREGLiners are manufactured to specification and delivered installation-ready, ensuring streamlined deployment.

The first DN 1500 liner, 265m long, with a wall thickness of 15.5mm and weighing 35.5t, presented a major logistical challenge. Using a conveyor belt, installation aid, and a 20t Bagela winch, the team installed the liner directly from a heavyduty transporter.

The second liner, weighing 36.5 tons, was pulled through the previously rehabilitated section over a 500m stretch, an even greater challenge. Glide foil was employed to protect the already-installed liner and ease the insertion process. The two liners were connected using a precision-engineered AMEX sleeve.

A masterful accomplishment

“The successful completion of this complex project within the specified timeframe is the result of our long-standing, trusted partnership with IMPREG, the exceptional quality of their liners, and the expertise of our on-site team,” said Gert-Jan Merkx, Managing Director at Kumpen NV Renovatietechnieken.

Alain Adloff, Sales Europe at IMPREG GmbH, who was present on-site, added: “This project showcases true teamwork and outstanding performance from everyone involved. Our production teams had never manufactured liners of this weight.