Emu Wraps Up London Array Survey
Emu were commissioned to undertake a number of pre-construction surveys of the wind farm site and export cable route, to be sited in the outer Thames Estuary some 20km from the Kent and Essex coasts.
For the final engineering survey Emu used their high resolution UXO/debris detection system, developed in 2009, which has since collected over 35,000 km of data. The Emu system offers developers maximum freedom with cable routeing and turbine siting using high precision data, which provides accurate location of dangers. Of benefit to London Array, the system enables large areas to be surveyed in relatively short periods.
During their London Array wind farm geophysical survey, Emu Limited discovered a wreck on the seabed in the approaches to Foulger’s Gat channel in the Thames estuary.
The wreck, which was previously undiscovered despite having been passed over in previous years by other surveys, is 45m long and lies in 4.5m of water. The hatch coamings and thwarts of the ship are preserved and can be clearly seen on the side-scan and swath sonar imagery gathered by Emu Limited. The wreck’s identity and the circumstances surrounding its loss are not yet known.
Emu’s RV Discovery located the wreck, which lies just east of part of the planned export cable route. As a result a new Archaeological Avoidance Zone has been put in place. The cable will be re-routed to further west to avoid this zone and will require additional surveys of the new route. The anchor patterns for the installation vessels may also require some amendment.
Four vessels were employed during the survey, the Emu vessels Emu Surveyor, RV Discovery and Ceejay and the chartered Nab Cat II.
The client representatives have reported that they were impressed with the enthusiasm and professional approach of Emu’s staff and have been very satisfied with the outcome.
