On April 26, 2021, Kouwenberg Infra received the award decision for the project "replacing DN1000 Hoekselijn pressure sewer line" in the Municipality of Vlaardingen. The project in Vlaardingen involved replacing a DN1000 pressure sewer. The pipeline, which drains wastewater from the pumping station, crosses the Hoekse Lijn railroad near the James Wattweg and the van Boendaleweg.
Using the Closed Front Technique (GFT), a 1499 mm GRP casing pipe was drilled parallel to the current route under the Hoekse Lijn railroad line with a length of 30 meters. In this casing pipe the new DN1000 steel sewer pressure pipeline was placed. The discharge pipe was then connected south of the railroad to the existing DN1000 steel section and on the north side to the existing DN1000 concrete sewer discharge pipe.
Such GFT drilling is daily business for Kouwenberg Infra and our company also has years of experience in the field of railroad crossings. Mostly in the role of subcontractor, but for this project we were the main contractor. In addition to the drilling, we were responsible for the total pipework of the pressure pipe with the associated complete preparation. For the pipe work, which is not normally part of our portfolio, we hired the expertise of a specialist company.
The challenge of this project consisted of breaking the existing pipeline and connecting the new one to be laid. This involved a strict time limit due to the decommissioning of the pumping station and the closing of the valves at Vlaardingenvaart. Within a maximum time frame of 120 hours, all work had to be completed, including a "Tie In" on both sides, i.e. the connection of the new pipeline to the existing one. This time frame was carefully chosen by the responsible party for the Sewerage Works, the Municipality of Vlaardingen and the Municipality of Maassluis. Weather conditions and the water-rich peat soil played an important role in this.
It was a challenging project in which we were able to manage the necessary risks well and respond to quite a few changes. Thanks to the good and pleasant cooperation with our client, the Municipality of Vlaardingen, we were able to conclude this project successfully and are already looking forward to our next challenge.