17 December 2024

Arch drilling under the Dintelhaven successfully completed

Another special section of the Porthos route has been completed. On behalf of main contractor Denys, Van Vulpen carried out horizontal directional drilling (HDD, Horizontal Directional Drilling) under the Dintelhaven. Senior project manager Yke Norg of Porthos explains the process of withdrawing the pipeline in the video.

A special feature is that this is a so-called arch drilling. Unlike a conventional HDD bore, the pipes here are pre-bent and each segment is pre-welded together and prepared. Withdrawing the pipeline is an impressive continuous process: each segment is welded, examined, coated and then retracted on site. The process repeats until the entire string is retracted.

This type of drilling is chosen when there is insufficient explanation strip for a full pipe strand or, as in this case, when the watercourse to be crossed is relatively short. At the HDD under the Dintelhaven, the pipe was withdrawn with an exit angle of 17 degrees – quite a curvature!