iMPREGLiner in the dunes of Katwijk in the Netherlands

Facts & figures

laid in the dunes and discharges into the sea
Location: Katwijk, Holland
Length: 250 m
DN: 1200
WT: 13 mm

Sea – what iMPREGLiner can do!

Heavyweight liners of up to 26 tons installed successfully. In the dunes of Katwijk in the Netherlands, 3 pipes with lengths exceeding 600 metres required rehabilitation because of leaks. Water under enormous pressure from sea and sand had severely attacked the existing sewers and made rehabilitation necessary. This major project represented a new challenge for technology and Logistics. Good teamwork between the companies involved, NV Kumpen and iMPREG GmbH, was therefore a prerequisite. This was the only way in which the major project could be completed successfully and without problems.

Challenge for manufacturer, user, and technology

The maximum installation length (250 m) of the liners presented new challenges for the production team and for the iMPREG equipment in Ammerbuch. In order to build the appropriate transport crates, even the company’s own joinery workshop adapted its working arrangements to such large liners. The full staff resources worked day and night shifts. For the longest DN 1200 WD (wall thickness) 13 mm iMPREGLiner, with a length of 250 m, the tailor-made crate weighed in 26 t! This in turn meant a significant task for Logistics, especially the transport from the production hall. Two heavy lift trucks were used, one of which was an autonomously guided lift truck.
The maximum utilisation and capacity of the UV system almost disrupted the schedule of the construction project in Holland. The sandy ground characteristics also resulted in aggravating conditions. For example, because of the high liner weights, unloading the HGV by crane directly adjacent to the construction site was not possible. The first option available was 10 km away from the actual construction site. Many years’ experience by the implementing construction company, combined with the specialist expertise of the application technology team was decisive for this successful rehabilitation

Five large Impreg liners

Two DN 1000 WD (wall thickness) 12 mm liners, each with a length of 230 m, plus three DN 1200 WD (wall thickness) 13 mm liners with lengths of 250 m or 100 m, tailor-made and ready to install, were supplied and installed for the “Dunea” construction project. However, the circumstances of the installation were anything but normal. “I’ve never installed a liner in this way”, stated application technologist Matthias Sündermann. Because there was no blind manhole, the iMPREGLiners were successfully connected to each other within the pipe. “That was a first in the history of trenchless rehabilitation”, recollected Francis Clauss from iMPREG.

„We have great confidence in the iMPREGLiner, and this time too we are very happy and satisfied about our choice of liner.“

Gert-Jan Merkx, Geschäftsleiter von Kumpen NV und Kristof Maesen Technischer Leiter

Out of consideration for nature and environment

Because the existing pipework is laid in the dunes and discharges into the sea, environmental and water conservation were decisive aspects in the construction of the liner. Styrene was therefore deliberately avoided. That excluded in advance the problem of residual styrene

Rising to the challenges

Quality, experience, and teamwork were the trump cards – that is how the construction project could be described overall. The very good collaboration between the client, engineering office, Kumpen NV, and the liner manufacturer, iMPREG GmbH, was fundamental to the success of the superb project. The quality and excellent handling properties of the iMPREGLiner also speak for themselves in this regard. Gert-Jan Merkx, managing director of Kumpen NV, and Kristof Maesen, Technical Manager, confirm this: “We have great confidence in the iMPREGLiner, and this time too we are very happy and satisfied about our choice of liner.”
Particular thanks are due to all the Kumpen workers involved for their commitment, without which this outstanding performance would not have been achieved.