Borkum 2

Utility ROV Services were contracted by Seaway Offshore Cables GmbH to provide an offshore support vessel with provision for mattress installation capabilities at the Trianel Windpark Borkum II Offshore Windfarm. A total of 128 mattresses and 5 ‘basalt bags’ were to be installed to provide stabilisation to the inter-array cables adjacent to the WTG monopiles.

Operations were conducted from the DP2 vessel, EDT Jane, which was chartered for the duration of the project by Utility ROV Services. The onboard WROV was used to conduct pre-installation debris, freespan and touchdown point surveys.

The mattresses were placed in stacked pairs using the Mattress Installation Frame (MIF), one metre from the cable touch down point to stabilise the cables at their catenary. The UTROV® and MIF controlled the mattress heading and monitored the touchdown ensuring accurate placement within tolerance. When in position, the UTROV® operated the MIF hydraulic release latches releasing the slings and therefore the mattresses.