Dutch offshore transmission system operator (TSO) TenneT has opened an application period for a €3 million tender for surveys of cables installed in the Dutch sector of the North Sea.
Work will start in 2025 and will be performed on the export cables at the Borssele and the Hollandse Kust offshore wind farm zones and the Cobra and NorNed interconnectors.
TenneT has divided the three operations and maintenance (O&M) survey areas into separate lots but applicants can submit proposals for multiple lots. The deadline for requests to participate in the tender is 9 December 2024.
The scope of work includes multibeam echosounder (MBES), side-scan sonar (SSS) and airborne surveys or surveys using other solutions to cover landing/tidal areas following set technical specifications. The contracts also include establishing the bathymetry and topography of the seabed and its features to identify the obstructions in the corridor and identify any possible cable exposures or freespans.
In the Borssele zone, the work will be undertaken on the export cables running from the Borssele Alpha and Beta platforms and the interlink of Borssele Beta.
In the Hollandse Kust offshore wind area, TenneT plans to survey export cables at Hollandse Kust Zuid Alpha, Hollandse Kust Zuid Beta, Hollandse Kust Noord, Hollandse Kust West Alpha and Hollandse Kust West Beta.
Surveys are also planned to be carried out on the interlinks between Hollandse Kust Zuid Alpha and Beta, and Hollandse Kust West Alpha and Beta.
Exact routes and quantities will be published in the second phase, the invitation to tender (ITT).