Red Electrica Eyes Mainland-Mallorca Seabed Survey

Spanish grid operator Red Electrica has launched a tender call for the provision geophysical, UXO and geotechnical services to be performed along a corridor of approximately 345 kilometers between Spanish mainland and Mallorca Island, in the Mediterranean Sea.

The purposes of the geophysical and geotechnical investigations are the determination of the detailed seabed conditions and stratigraphy with detailed characterization of the materials in the surface and subsurface soil layers in order to inform the installation of submarine cables.

Mallorca is already linked to the Spanish mainland via COMETA (aCOnexión MEditerránea Transporte Alta tensión) subsea interconnector, developed by Red Electrica, also known as the Majorca–Valencia interconnector and the Romulus project).

The geophysical investigation shall include both surface and subsurface survey (sub-bottom profiling)  in water depths ranging between 0 and approximately 1,600 meters .

The purpose of the UXO survey is to ensure an As Low As Reasonably Practicable (ALARP) UXO risk at each anticipated geotechnical location to be investigated during the subsequent geotechnical survey. The execution and the scope of the UXO survey will be subjected to the results of the ‘UXO risk assessment and mitigation strategy’ study.

The geotechnical investigation will consist in CPTs, vibro cores, piston cores, rock cores and similar. It includes the collections of quality samples of soil and rock to be tested onshore and offshore for the determination of physical and mechanical properties, to support the interpretation of the geophysical data.

The deadline for the submission of applications is March 02, 2020.