Installation of a 2t iMPREGLiner in a small lake

Challenging DN 800 liner installation

Installation of a 2t iMPREGLiner in a small lake

Mönsheim/Pforzheim – In the community of Mönsheim near Pforzheim, unusual circumstances for installing a DN 800 pipe liner from iMPREG GmbH arose for the construction team from Rossaro Kanaltechnik GmbH u. Co. KG. In terms of logistics and technology, the requirements were far from being an everyday challenge.

Good planning and preparation of the construction site were fundamental for the rehabilitation measure using an iMPREGLiner GL16. This was the responsibility of the office of Kirn Ingenieure in Pforzheim. A number of days in advance, it was already necessary to drain and treat the water of the lake (Blautopf). A pedestal was set up in order that the GL16 DN 800 liner, WD 11.0 mm, length 35 m, weight 2t, could be inserted at the same height as that of the pipe being rehabilitated. So that the team from Rossaro Kanaltechnik GmbH u. Co. KG could safely enter the lake, scaffolding from the bridge into the lake also had to be set up.

Acute danger of collapse

Utmost haste was required for this rehabilitation measure. The conduit and sole outflow of the “Blautopf” lake was severely damaged and deformed, and was therefore on the verge of collapsing. If this scenario has arisen, there would no longer have been an outflow for the water, and the adjacent houses would have been submerged.

Challenge for end shaft

On the installation day, a large truck crane was in use early in the morning. This had to convey the large, 2t crate with the iMPREGLiner and packer from the bridge over the lake to the bed of the lake. Temperatures were close to freezing. Only after the truck crane had driven away was it possible to get started and bring the UV system into position. One challenge was the end manhole. This was inaccessible for a cable winch, because the manhole could be reached only via an accessible garage roof. In the inaccessible end shaft, which is approx. 6 m deep, for inserting the liner a bend of approx. 20° was built in to a manhole another 13m away.

Trenchless and time-saving

The trenchless sewer rehabilitation process was the first choice. The process made time-saving installation possible, and excavation works and diversion of traffic were avoided. The iMPREGLiner was impregnated and tailor-made in the factory, and arrived at the construction site in Mönsheim punctually and fully ready to install. The gliding foil provided ensured that the liner was inserted without damage. During this process, curing by means of a UV light chain was recorded and video-monitored by camera. The good handling properties of the iMPREGLiner simplified the work for the application technologists.

Experience and good preparation are guarantees of success.

All participants indicated that they were very satisfied after the rehabilitation measure. “Thanks to the experience and incredible cooperation within the team, and the optimum preparation of the construction site, the installation went swiftly and without problems”, project manager Sven Coumont said in praise of all participants. The experience and support provided by iMPREG GmbH through its application technologist also contributed to the conclusion of the rehabilitation within one working day.