Leask Marine Case Study -The Dounreay Subsea Link Project

The Dounreay Subsea Link Project

Leask Marine was appointed by OCU Group to support the installation of the Orkney to Caithness 220kV subsea electricity link at Dounreay. As part of the Horizontal Directional Drilling (HDD) punch-out works, almost three metres of sediment covering the offshore duct exit had to be removed before installation could proceed.

To overcome this challenge, Leask Marine deployed the Raptor Scout, a remotely operated tracked intervention vehicle fitted with a precision suction dredging system. Operating entirely from a multicat support vessel, the system used live HD video, forward-looking sonar and real-time controls to excavate sediment accurately while protecting the drilled duct and complying with Dounreay’s strict radiation mitigation requirements.

Through careful project management, remote excavation and continuous monitoring, Leask Marine successfully cleared the duct exit without requiring divers to enter the excavation area. The works were completed safely and efficiently, with a post-clearance survey confirming the required excavation had been achieved.