69aee89cfbd254d5b6bea2013a46a5da English series Scira Offshore Energy Ltd COWRIE uploader 0044 (0) 203 204 3200 N/A One Kingdom Street London W2 6BD United Kingdom info@scira.co.uk www.scira.co.uk pointOfContact 2009-07-02 MEDIN Discovery Metadata Standard Version 2.3.5 021 OGP 2008, Metoc, Sherigham Shoal Offshore Wind Farm, Cable Landfall Erosion Study 2008-01-01 publication 2008-06-02 creation 3573 http://data.offshorewind.co.uk/ StatoilHydro is planning to install two export cables to connect its Sheringham Shoal Offshore Wind Farm to the UK National Grid. The landfall will be at Weybourne on the North Norfolk coast. This desk study was commissioned to identify the optimum burial depth of the cables at the landfall by investigating the surface geology. Design requirements are: 1) The overburden must never reduce below 1.5 m, which is the safety margin deemed to prevent the cables being exposed; and 2) Subject to requirement 1, the overburden should be kept to a minimum to permit effective dissipation of heat from the cable. The target of the present study is thus to determine the minimum burial depth that will preserve both the above conditions throughout the lifetime of the scheme, taking account of future erosion and climate change deliberations. The storm beach at the landfall is actively mobile and is migrating alongshore in a westward direction; it is also retreating landward due to coastal erosion with an average landward erosion rate of around 1 m per year. Additionally, there is a risk that beach material may be temporarily denuded at times of severe storm surge such as those of 1953 and 1997; events of this severity would be likely to expose the cables if simply buried in the beach material. Therefore, it is strongly advisable to bury the cables in the rock underlying the beach rather than in the beach material itself. Due to the complex geology at this location, it is not possible to prescribe a burial depth profile that will guarantee to satisfy both of the above design requirements. The precise nature of the underlying rock is uncertain; there are several candidate formations ranging from firm chalk to loose glacial material. The Project has provided some geotechnical survey data at locations offshore of the landfall. However, in order to answer the above questions, more geotechnical and geophysical data will be needed at the landfall itself (e.g. subsurface radar and deep boreholes). Also, a site visit is recommended to improve understanding of the beach profile and to help to identify the underlying geology. This desktop study has been based on literature in the public domain; survey charts provided by StatoilHydro; and experience of similar projects in the region. There is potential to progress this work further with follow-up studies as more survey data become available. Scira Offshore Energy Ltd COWRIE uploader 0044 (0) 203 204 3200 N/A One Kingdom Street London W2 6BD United Kingdom info@scira.co.uk www.scira.co.uk custodian Scira Offshore Energy Ltd COWRIE uploader 0044 (0) 203 204 3200 N/A One Kingdom Street London W2 6BD United Kingdom info@scira.co.uk www.scira.co.uk originator notPlanned PDF Cable Landfall The Crown Estate Renewable Energy Development Areas 2012-05-15 revision 1 Pre-Construction monitoring The Crown Estate Renewable Energy Development Phases 2012-05-15 revision 1 Wave height estimates SeaDataNet Parameter Discovery Vocabulary 2018-09-07 revision 109 Coastal geomorphology SeaDataNet Parameter Discovery Vocabulary 2018-09-07 revision 109 Sediment grain size parameters SeaDataNet Parameter Discovery Vocabulary 2018-09-07 revision 109 Marine Environmental Data and Information Network Marine Environmental Data and Information Network no conditions apply eng geoscientificInformation 1.07422162145914 1.22448867986637 53.0961222170913 53.1743332557592 2008-06-02 2008-06-02 Presentation type: digital representation of a primarily textual item (can contain illustrations also) Origin: METOC http://www.marinedataexchange.co.uk/search?q=#fq=fq%3DProject%253Amde1r2ss005 download https://www.marinedataexchange.co.uk/details/1969/summary A link to the web service or dataset. https://www.marinedataexchange.co.uk A link to the general host site. dataset This desktop study has been based on literature in the public domain; survey charts provided by StatoilHydro; and experience of similar projects in the region. There is potential to progress this work further with follow-up studies as more survey data become available.