Trenchless installation of 13 kilometres of Hallingplast JAPI
In the middle of the idyllic farming area of Tosebygda in Østfold, one of the largest trenchless projects of the year in Norway is currently being carried out. The first pilot drilling started in May 2024 and by the beginning of November about 85 per cent of the project was completed. Staff and equipment are still in full swing carrying out the work.
About six kilometres south-east of Oslo, Indre Østfold Municipality is building a new water treatment plant. The drinking water pipeline between Tosebygda and Mørkved, a distance of 4.6 kilometres, is an important part of the pipeline network for the new sewage treatment plant. In addition to this pipeline, preparations are also being made for future expansion of pressure sewage pipes in the area. In total, three pipelines made of PE pipes are being installed with a total length of just over 13 kilometres.
Demanding soil conditions
When the project started, there was an expectation of a smooth operation in simple soil conditions, a hope based on a positive geotechnical report. However, the work has been tougher than expected.
“The soil masses are extremely varied,” says supervisor Ludwig Ljungdahl. “Everything from soils so soft that it has been difficult to control the pilot drilling, to soils so hard that they have been difficult to dig into – all in the same stretch. This work clearly shows why one should always expect the unexpected in a project. It also shows how important it is to have skilled people to do the work.”
Hallingplast JAPI for trenchless installation
The project uses Hallingplast JAPI, a pressure pipe made of PE with an extra-high-strength PP jacket that protects the media pipe during installation using trenchless methods. Hallingplast JAPI is being supplied for this project in dimensions of Ø 90, 110, 180 and 560 mm. More than 13 kilometres of pressure pipes in different dimensions must be welded, drilled and routed in place by guided drilling.
The main contractor is very pleased with the work that has been completed so far. “For us, it is a bit unusual to carry out a project with such a large proportion of guided drilling,” says project manager Jon Øivind Opsahl at Eivind Engseth Entreprenør AS.
