The Hydrographic Society Benelux (HSB) organised a workshop in conjunction with the Offshore Energy 2018 exhibition at RAI in Amsterdam, The Netherlands on the 24 October 2018. Four speakers took to the stage discussing the theme ‘Maintenance aspects of windfarm infrastructure’ related to the Offshore Energy 2018 exhibition and conference.
Rob Lambij, who worked at the Ministry of Waterworks, Directorate of the North sea and co-founder of the Foundation “wet” archaeological projects (SNAP), started off the day with a talk entitled ‘Fishery and bottom related obstacles on the North Sea’.
An estimated 10,000 objects (e.g. shipwrecks, ammunition, lost cargo, ships anchors, oil and gas pipelines, and electricity and telecom cables) are lying on the bottom of the Netherlands Continental Shelf. Offshore pipelines with a diameter <16 inches, and telecom and electricity cables have to be laid at a government-prescribed depth below the seabed.
Uncovered cables and pipelines
Caused by the mobility of the North sea bottom, the cables and pipelines frequently become uncovered. Particularly “free lying” cables can be damaged by fishing gear causing a possible cable break or rupture. These “free lying” cables were discussed with particular interest due to the high number of damages. He mentioned a recent case where a fisherman damaged a telecom cable. The cable owner launched a lawsuit against the fisherman with a claim in excess of US$650K. In the final verdict (Feb 2018), the court rejected the claims of the cable owner stating the owner must ensure the cable has a depth of 0.6 metres in the seabed with the groundcover maintained.
The next speaker, Reinier Nagtegaal (CEO - ECE Offshore), showed in his presentation ‘The process of a cable repair project’, that with the increased amount of offshore wind farms, cable repairs have significantly increased over the last few years. And as cable faults generally come unexpected, the time pressure for these projects is extremely high while the available means are limited. In his presentation he gave the audience an insight into the process of a cable repair project - starting at fault detection and ending at the installation of the repair joint and new cable at the fault location by interesting slides an videos.
The contribution of software in the construction of offshore windfarms
The 3rd speaker, Bart van Mierlo (CEO - Periplus Group), spoke on the contribution of software in the construction and maintenance of offshore windfarms as these require an enormous amount of hydrographic and geophysical data to be collected. Different stakeholders might have different objectives and are individually responsible for the collection of new data or at least the interpretation of existing data. A centrally organised data repository would save both time and money - but this does not exist. By providing access to this data, all parties would benefit while working with the same information. A web-based application will provide up-to-date information of the windfarm area.
The last speaker was Mike Lycke (Survey Offshore Manager – Jan De Nul Group) who spoke in his presentation on ‘Scour protection: maintenance and more’ and the various aspects of an offshore contractor working on the maintenance of windfarms illustrated by photos and videos.
A well-attended networking drink concluded the interesting workshop.