Subsea field work for the €400M (£353M) Greenlink Interconnector has started.
Marine survey firm MMT has started the offshore and nearshore surveying along the proposed route of the Greenlink Interconnector between the UK and Ireland.
The 500MW 200km high voltage direct current (HVDC) link is being developed by Greenlink Interconnector and will include 205km of underground and submarine cable. It includes of a converter station at each end, connected by two electricity cables and a fibre optic cable. The cables will run underground and under the sea from the Great Island substation in County Wexford to Freshwater West beach in Wales, before continuing to run underground to the Pembroke substation.
Expected to take approximately 40 days, MMT’s geophysical marine survey work will comprise of intertidal topographic survey, geophysical and hydrographic nearshore and offshore data acquisition, geotechnical investigations with vibrocoring and piston coring and cone penetration testing (PCPT), environmental sampling and imagery, infrastructure crossing survey with ROV, UXO survey, and geotechnical boreholes to inform horizontal directional drilling.
These operations shall provide measurements of the bathymetry and seabed features and the shallow geological conditions along the route. This will be supplemented by localised unexploded ordnance (UXO) surveys, environmental sampling and imagery as well as surveys of infrastructure crossings using an ROV.
The findings will form all appropriate data for the confirmation of a preferred route for the High Voltage Direct Current (HVDC) cable system, as well as contribute to the cable burial risk assessment and provide information for the planning applications.
Greenlink project director Simon Ludlam said: “We are delighted to have appointed the expertise of MMT to undertake the marine survey work for Greenlink. This will collect vital data for the project development and planning applications, helping us determine the best route between Pembrokeshire and Co. Wexford from an environmental, health and safety and economic point of view. The launch of the surveying work today is a significant step in the development of this important electricity infrastructure project.”
MMT were awarded the contract for the Greenlink Marine Survey (GMS) by Greenlink Interconnector in August, and back in June WSP was appointed to help procure contractors for 205km of underground cables
The privately-financed €400 (£353M) project is being developed by Greenlink Interconnector Limited, a subsidiary of Element Power, and construction is scheduled to start in 2020.