ISS Kanal Services AG Installs “Record Liner” in Switzerland

In October 2012, ISS Kanal Services AG, a Swiss company specializing in trenchless sewer rehabilitation and maintenance, rehabilitated the main sewer of ARA Falkenmatt sewage treatment plant in Hendschiken, Switzerland.

During examinations of the municipal sewers, performed within the scope of the general wastewater management plan, cracks, signs of spalling and ingrowing roots were discovered in the main sewer in 2010. Thus, it was determined that rehabilitation measures were required. In addition to facilitating the sewage disposal for the municipality of Hendschiken, ARA Falkenmatt is also responsible for the municipalities of Ammerswil, Dintikon, Dottikon, Hägglingen and Villmergen.

The last section of the main sewer leading to the treatment plant had a total length of 722 m and ran through a drinking water and landscape protection area, which meant that particular caution needed to be exercised during rehabilitation operations. Another challenge to overcome was the difficult access to the construction site. Only two of the three access manholes could be reached via regular roads. A temporary site access road had to be built for the third manhole. A dewatering system with a capacity of 360 liters per second also had to be set up in order to facilitate the rehabilitation operations. Due to the fact that the volume of water was high anyway, the CIPP liners were not allowed to be installed during rainfall. These underlying circumstances presented special challenges with regard to construction site planning and logistics.

Therefore, the team around the site manager Fabian Murmann and the gang leader Philipp Meyer from ISS Kanal Services AG decided to rehabilitate the sewer, featuring a diameter of DN 1,100 mm, with only three long sections with respective lengths of 222, 239 and 252 m. In a further work step, a 9-m length of Alphaliner was installed in the end section, featuring a diameter of DN 1,230 mm, which opens up directly into the sewage treatment plant. The composite thickness of each of the CIPP liners measured 8.6 mm.

In order to simplify the project logistics, the almost 17-ton heavy Alphaliner was transported in overseas containers via trucks from the RELINEEUROPE production plant in Rohrbach directly to the manholes through which they were fed. Thus, neither transport crates nor a heavy-duty crane were needed to unload the liners. The liners were unloaded directly into the manholes and were then drawn in. This method of operation ensured that any encroachment of the landscape could be reduced to a minimum.

ISS Kanal Services AG has now worked with the light-curing CIPP liner system from Alphaliner for approximately two years. The Swiss company makes intense use of the Total Quality Management (TQM) provided by the manufacturer RELINEEUROPE in order to systematically improve its own installation results. Mario Saalow, RELINEEUROPE’s application engineer, accompanied the rehabilitation project. “Within just a short period of time, the learning curve of the crew members climbed quite impressively,” Saalow said.

ISS Kanal Services AG used the system provider’s most powerful 6×2000 Watt curing system at this site for the very first time. With this investment the company aims to establish itself on the market as a leading sewer service provider specializing in large profiles.

Throughout operations in Hendschiken, the curing system was able to prove its worth. Equipped with a cable length of 300 m, it was possible to cure each of the long sections in one go. The ISS Kanal Services AG construction crew needed no more than a single working day to complete any of the sections, including all preliminary and finishing operations. Even the longest section with a length of 252 m was laid and completely cured within only 18 working hours by a crew of just four staff members.

In addition to the high-performance curing system, the construction team also applied two systems that were newly developed by RELINEEUROPE in order to speed up and simplify operations.

A new and innovative folding system, which saves muscle power and time when installing large profiles, was used at the site for the first time. The wide and heavy CIPP liner was drawn out of the container and through this folding system by means of a conveyor belt. A special construction automatically folds the liner with the aid of rollers, thus, taking over the work that previously required the strength of six additional crew members. This innovation also ensures an easier joining of liner heads. The folding system was developed and put through trials at several test sites by RELINEEUROPE and, after the final test in Switzerland, now goes into serial production.

“The ISS Kanal Services team found the folding system to be such an ingenious device that they wanted to keep it,” explained Saalow, confirming the advantages of the construction.

Another premiere was also celebrated in Switzerland by a new, reusable airlock, with which a crew member can comfortably set up a chain of lights within the compressed air-inflated CIPP liner. The airlock is equipped with zips and is resilient and robust enough to prevent damage being caused to the inner foil.

“Our awarding authority was quite impressed by the quality and speed with which we executed this rehabilitation project,” said Roland Brühlmann, manager of ISS Kanalservices AG, who explained about the project at the site to a delegation of the municipalities. Hence, the project in Hendschiken provided the company yet another opportunity to prove its expertise in installing sophisticated large profiles.

This article was provided by RELINEEUROPE AG, Rohrbach, Germany.