1. Introduction

1.1. Background

  1. Ossian Offshore Wind Farm Limited (Ossian OWFL) (hereafter ‘the Applicant’) is a joint venture between SSE Renewables (SSER), Copenhagen Infrastructure Partners (CIP) and Marubeni Corporation (Marubeni). The Applicant is developing Ossian, an offshore wind farm project within the E1 Plan Option (PO) Area awarded by Crown Estate Scotland (CES) as part of the ScotWind Leasing Round.
  2. Ossian includes both the offshore and onshore infrastructure required to generate and transmit electricity from the offshore infrastructure to an onshore grid connection point. The Applicant is seeking consent to develop the offshore components of Ossian Array (hereafter referred to as ‘the Array’).
  3. In March 2024, as part of the Holistic Network Design Follow Up Exercise (HNDFUE), the National Grid Electricity System Operator (ESO) published their Transitional Centralised Strategic Network Plan (TCSNP) in the ‘Beyond 30’ report (National Grid, 2024). Within this publication, it was confirmed that Ossian will be offered two grid connections in Lincolnshire, one at Weston Marsh and one at the Lincolnshire Connection Node. Separate consent applications will be submitted for the Proposed offshore export cable corridor(s) and the Proposed onshore transmission infrastructure (including Proposed onshore export cable corridor(s) and the Proposed onshore convertor station(s); landward of Mean Low Water Springs (MLWS)) once the grid connection location has been identified. The Proposed offshore export cable corridor(s) and Proposed onshore transmission infrastructure will be considered within the Cumulative Effects Assessment (CEA) of the Array Environmental Impact Assessment (EIA) Report (as appropriate) to comply with the EIA Regulations.
  4. RPS has been commissioned to prepare an Archaeological Monitoring and Mitigation: Outline Written Scheme of Investigation (WSI) and Protocol for Archaeological Discoveries (PAD) (hereafter referred to as the outline WSI and PAD) for the Array. This outline WSI and PAD detail the principles to be implemented to ensure the protection of marine archaeological receptors through all three phases of the Array (construction, operation and maintenance, and decommissioning). The measures within this outline WSI and PAD encompass the range of development options under consideration for the Array to allow post-consent flexibility in the final design.
  5. The outline WSI and PAD will be monitored and updated throughout the lifetime of the development to ensure that the outline WSI and PAD are appropriate for all activities associated with the Array. The outline WSI and PAD will continue to be developed in consultation with Historic Environment Scotland (HES) and will be submitted to Marine Directorate - Licensing and Operations Team (MD-LOT; as the licensing authority) for approval, prior to construction.
  6. The combined outline WSI and PAD and the Marine Archaeology Technical Report are standalone documents. The Marine Archaeology Technical Report (volume 3, appendix 19.1) is provided with the Array application as an ‘accompanying document’ to ensure that the archaeological baseline that corresponds to the WSI is available to consultees.

Figure 1.1:
Array Location and Marine Archaeology Study Area

Figure 1.1: Array Location and Marine Archaeology Study Area


1.2. Project Description

  1. The offshore elements of the Array of relevance to this outline WSI and PAD relate to:
  • site preparation activities;
  • wind turbine generators;
  • floating foundations and associated moorings and anchoring systems;
  • Offshore Substation Platforms (OSPs);
  • fixed bottom foundations for the OSPs;
  • inter-array cables connecting the turbines to the OSPs;
  • interconnector cables connecting the OSPs to each other; and
  • scour protection and cable protection.
  1. The Array will be located approximately 80 km south-east of Aberdeen, Scotland, with an area approximately 858 km2 ( Figure 1.1   Open ▸ ). A maximum of 265 wind turbines supported on floating foundations (including associated mooring and anchoring systems) will be installed within the Array. Up to three large OSPs and up to 12 smaller OSPs and associated fixed bottom foundations will be installed within the Array. Subsea dynamic/static inter-array cables will connect wind turbines to each other and to the OSPs. Interconnector cables will connect the OSPs to each other.

1.3. Aims and Objectives

  1. The aim of this outline WSI and PAD is to present the archaeological mitigation measures to be undertaken by the Applicant prior to and throughout the construction, operation and maintenance, and decommissioning phases of the Array. The outline WSI and PAD is informed by pre-application consultation with HES (reported in volume 2, chapter 19) and the baseline review of known and potential archaeology within the marine archaeology study area ( Figure 1.1   Open ▸ ) outlined in volume 3, appendix 19.1.
  2. The objectives of the outline WSI and PAD are as follows:
  • to fulfil the requirements of the Archaeological Curator (AC) in respect of archaeological monitoring and mitigation of works associated with the Array;
  • to establish the exact position and extent of any Archaeological Exclusion Zones (AEZs) and Temporary Archaeological Exclusion Zones (TAEZs);
  • to ensure consultation with archaeologists on all elements of the Array’s design that have the potential to impact archaeological sites and materials;
  • to ensure that any further geophysical and geotechnical investigations associated with the Array are subject to archaeological input, review, recording and sampling where required;
  • to ensure archaeological involvement in any proposed remotely operated vehicles (ROVs) obstruction surveys conducted within the Array;
  • to propose measures for the mitigation of archaeological remains encountered during further geophysical survey and/or geotechnical sampling or investigations, or during construction work associated with the Array; and
  • to establish the reporting and archiving requirements for the archaeological works undertaken during all phases of the Array and post-construction monitoring.
  1. The best practice guidance for Archaeological Written Schemes of Investigation for Offshore Wind Farm Projects (The Crown Estate, 2021) indicates that a WSI should “set out the importance of research frameworks in setting objectives that are delivered through realisation of the work”. The Marine Archaeology Technical Report, and this outline WSI and PAD, were developed in line with the research objectives identified by the Scottish Archaeological Research Framework (ScARF) (ScARF, 2012). Regional research frameworks for the maritime regions of eastern Scotland, namely the Perth and Kinross Archaeology Research Framework (PKARF) (Perth and Kinross Heritage Trust, 2022). Other regional or practice specific frameworks may be deemed relevant, depending on specific packages of work undertaken.
  2. Archaeological work and reporting under the WSI shall tie those outcomes into the relevant research frameworks to ensure the knowledge dissemination to those areas where there is a demonstrable need for further understanding. The identified objectives derived from relevant research frameworks will be used to guide the advice from the Retained Archaeologist (RA) to the Applicant.
  3. Connections between the relevant research frameworks, site-specific investigation aims and objectives, and specific work packages will be identified within the Method Statements (MS) supplied before the onset of any archaeological work. The connection with the specific work package to be undertaken, and the relevant research framework, aims and objectives, will be identified within the MSs which will proceed archaeological work. The MS will also explain how the work package will be tied to the identified research frameworks during Online Access to the Index of Archaeological Investigations (OASIS) reporting.