Modus’ HAUV-2 wraps up Gwynt-y-Môr depth of burial survey

Modus Seabed Intervention has completed a high speed bathymetric and depth of burial survey of the inter array cable routes on the innogy operated Gwynt-y-Môr offshore wind farm.

The company utilised the Modus HAUV-2 (Hybrid Autonomous Underwater Vehicle) for the work.

The Gwynt-y-Môr offshore wind farm comprises 160 Siemens 3.6MW WTGs located approximately eight miles from the North Wales coast in Liverpool Bay in water depths ranging between 12 meters and 28 meters.

The WTG’s are connected by 161 inter array cables which total circa 147 kilometres in length.

To execute the O&M depth of burial survey scope, Modus mobilised its HAUV-2 system, equipped with optimal ranging Orion cable tracking system and dual head R2Sonic 2024 multibeam echosounder, on the chartered DP2 vessel ‘Noordhoek Pathfinder’.

Gwynt-y-Môr was the first complete offshore wind farm inter array survey performed by HAUV-2.

This work was critical for the maintenance and operation of the wind farm. Gwynt y Môr offshore wind farm generates enough renewable electricity to meet the equivalent needs of approximately 400,000 average UK homes.

Graham Thorpe, asset integrity engineer for Innogy Renewables UK said: At innogy we are always striving to enhance our operations at the Gwynt-y-Môr offshore wind farm. Being in the long-term O&M phase of the project, cost saving is a significant driver and we have a continued effort to deliver operational performance. Part of this is the ongoing inspection and maintenance of our assets through periodic surveys in order to ensure a continued reliable supply of Renewable Power to the UK. The HAUV’s performance capability was proven and the system delivered high speed data acquisition without compromising quality.”

Nigel Ward, chief cmmercial officer for Modus said; “The HAUV’s capability has now been proven across the energy sector since 2018. The ability to perform high speed depth of burial in high current areas has been an ongoing requirement of the offshore wind industry. With HAUV, we were able to significantly reduce overall survey time at this important offshore wind farm for the UK energy industry. As well as cost savings, use of this vehicle significantly decreases the carbon footprint of a survey of this nature. Going forward, the flexibility of payload enables this vehicle to combine various types of survey and inspection to improve efficiency and further reduce vessel days offshore, setting new standards for subsea operations. The next phase of development is to remove the need for a dedicated support vessel and to use the autonomous features of the HAUV to perform scopes from vessels or structures already in field, such as SOVs.”