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Hornsea Offshore Wind Farm Project One Environmental Statement Volume 5 – Offshore Annexes Annex 5.8.2 Offshore HVAC Reactive Compensation Substation Navigational Risk Assessment PINS Document Reference: 7.5.8.2 APFP Regulation 5(2)(a) July 2013
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Hornsea Offshore Wind Farm
Project One
Environmental Statement
Volume 5 – Offshore Annexes
Annex 5.8.2
Offshore HVAC Reactive Compensation Substation Navigational Risk Assessment
PINS Document Reference: 7.5.8.2
APFP Regulation 5(2)(a)
July 2013
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SMart Wind Limited
Hornsea Project One Offshore Wind Farm
Project One – Environmental Statement
Volume 5
Annex 5.8.2 – Offshore HVAC Reactive Compensation Substation Shipping and Navigation Risk Assessment
SMart Wind Limited
11th Floor
140 London Wall
London
EC2Y 5DN
Tel 02077 765500
Email [email protected]
Copyright © 2013
All pre-existing rights reserved.
Liability
This report has been prepared by Anatec Ltd, with all reasonable skill, care and diligence within the terms of their contracts with SMart Wind Ltd or their subcontractor to RPS placed under RPS’ contract with SMart Wind Ltd as the case maybe.
Anatec Disclaimer
This study has been carried out by Anatec Ltd on behalf of SMart Wind Ltd. The assessment represents Anatec’s best judgment based on the information available at the time of preparation. Any use which a third party makes of this report is the responsibility of such third party. Anatec accepts no responsibility for damages suffered as a result of decisions made or actions taken in reliance on information contained in this report.
Document release and authorisation record
PINS Document Reference 7.5.8.2
Report number UK04-050200-REP-0045
Date July 2013
Client name SMart Wind Limited
Client contact(s) Chris Jenner
Penny Pickett
Rachael Mills
Rosemary Tingle
Liam Leahy
Ditte Bilde
Sheelagh Guilmartin
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Table of Contents
Executive Summary ................................................................................................................... vi
1 Introduction .......................................................................................................................... 1
1.1 Background ........................................................................................................... 1
1.2 Navigational Risk Assessment .............................................................................. 1
2 Guidance and Legislation .................................................................................................... 2
2.1 Primary Guidance ................................................................................................. 2
2.2 Formal Safety Assessment Process ..................................................................... 2
2.3 Other Guidance .................................................................................................... 2
3 Consultation ......................................................................................................................... 3
3.1 Stakeholders Consulted as part of NRA Process ................................................. 3
4 Navigational Risk Assessment Methodology ....................................................................... 3
4.1 Flow Chart for NRA Methodology ......................................................................... 3
5 Cumulative effects Methodology .......................................................................................... 4
6 Data Sources ....................................................................................................................... 4
6.1 Data Sources Used ............................................................................................... 4
6.2 Lessons Learnt ..................................................................................................... 4
7 Marine Traffic Survey Methodology ..................................................................................... 6
7.1 Baseline Survey Methodology .............................................................................. 6
7.2 AIS Coverage ....................................................................................................... 6
7.3 Recreational Craft ................................................................................................. 6
7.4 Fishing .................................................................................................................. 6
7.5 Other Offshore Users ............................................................................................ 6
8 Offshore HVAC Reactive Compensation Substation ........................................................... 7
9 Location Selection ................................................................................................................ 7
10 Baseline Environment .......................................................................................................... 9
10.1 Navigational Features ........................................................................................... 9
11 Metocean Data................................................................................................................... 12
11.1 Introduction ......................................................................................................... 12
11.2 Wind.................................................................................................................... 12
11.3 Visibility ............................................................................................................... 12
11.4 Tide ..................................................................................................................... 12
12 Maritime Incidents .............................................................................................................. 13
12.1 Introduction ......................................................................................................... 13
12.2 Marine Accident Investigation Branch (MAIB) ..................................................... 13
12.3 Royal National Lifeboat Institution (RNLI) ............................................................ 13
13 AIS MArine Traffic Data Analysis ........................................................................................ 14
13.1 Introduction .......................................................................................................... 14
13.2 Survey Analysis ................................................................................................... 14
13.3 Vessel Density ..................................................................................................... 16
13.4 Main Routes and 90th Percentile Lanes .............................................................. 17
13.5 Commercial Traffic Impact Assessment .............................................................. 18
14 Commercial Fishing ............................................................................................................ 20
14.2 Fishing Vessel Impact Assessment ..................................................................... 20
15 Recreational Craft Transits ................................................................................................. 21
15.2 Recreational Craft Impact Assessment ................................................................ 21
16 Consultation ........................................................................................................................ 22
17 Vessel-To Structure Allision Risk Modelling........................................................................ 23
18 Fishing Vessel Collision ...................................................................................................... 24
19 Impacts on Communication and position fixing ................................................................... 24
19.1 Visual Navigation and Collision Avoidance .......................................................... 24
19.2 Electromagnetic Interference (EMF) on Navigational Equipment ........................ 24
19.3 Communications Equipment including VHF Use ................................................. 24
19.4 Radar ................................................................................................................... 24
20 Emergency Response ........................................................................................................ 25
21 Mitigation Measures ............................................................................................................ 28
21.2 Standard Industry Practices ................................................................................. 28
21.3 Additional Mitigation ............................................................................................. 28
22 Cumulative Effects .............................................................................................................. 29
23 Conclusion .......................................................................................................................... 29
24 Next Steps – Impact Assessment for EIA ........................................................................... 30
References ................................................................................................................................ 31
Appendix A – Ridley Thomas Data Validation Report ............................................................... 32
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Table of Figures
Figure 2.1 Formal safety assessment process. ...................................................................... 2
Figure 4.1 Overview of methodology for navigational assessment. ....................................... 3
Figure 8.1 Typical Offshore Substation Platform. ................................................................... 7
Figure 9.1 Heat sensitive map – potential development areas. .............................................. 8
Figure 10.1 Navigational features in the vicinity of the offshore HVAC reactive compensation substation location. ............................................................................................. 10
Figure 10.2 Navigational features – zoomed plot. .................................................................. 11
Figure 11.1 Annual wind direction distribution for the offshore HVAC reactive compensation substation area. ................................................................................................... 12
Figure 11.2 Annual wave height distribution for the offshore HVAC reactive compensation substation area. ................................................................................................... 12
Figure 12.1 MAIB incident locations within 10 NM of the offshore HVAC reactive compensation substation location. ...................................................................... 13
Figure 12.2 RNLI incidents by casualty type within 10 NM of the HVAC reactive compensation substation location. ............................................................................................. 14
Figure 13.1 AIS Data from Ridley Thomas used for Validation (7 Days). ............................... 15
Figure 13.2 AIS Data excluding Survey Vessel Tracks (28 days). ......................................... 15
Figure 13.3 Unique vessels per day during the survey period. ............................................... 15
Figure 13.4 Vessel types identified intersecting the proposed offshore HVAC reactive compensation substation site 10 NM buffer. ....................................................... 16
Figure 13.5 Cargo vessel tracks. ............................................................................................ 16
Figure 13.6 Tanker vessel tracks. .......................................................................................... 16
Figure 13.7 All vessels (excluding survey vessels) by course (28 days). ............................... 17
Figure 13.8 Ship density grid. ................................................................................................. 17
Figure 13.9 Main routes and areas of shallow waters. ........................................................... 18
Figure 13.10 90th Percentile lanes. ......................................................................................... 18
Figure 13.11 Amethyst development area detailed (28 Days). ................................................ 19
Figure 13.12 Vessels passing the Amethyst development area. ............................................. 19
Figure 13.13 Infield vessels within the Amethyst development area (ERRV and PSV). .......... 19
Figure 14.1 Fishing vessel tracks recorded during the survey period. ................................... 20
Figure 14.2 Density of fishing vessels from satellite data 2009. ............................................. 20
Figure 15.1 Recreational tracks recording during the survey period. ..................................... 21
Figure 15.2 RYA Recreational cruising routes. ...................................................................... 21
Figure 20.1 Lifeboat stations in location to the offshore HVAC reactive compensation substation. ........................................................................................................... 26
Table of Tables
Table 6.1 Survey data used for HVAC Reactive Compensation Substation NRA and validation. ...............................................................................................................5
Table 8.1 Estimated Dimensions of Offshore HVAC Reactive Compensation Substation. ....7
Table 9.1 Outputs from initial allision risk modelling. .............................................................7
Table 13.1 90th Percentile lane description. .......................................................................... 17
Table 16.1 Consultation feedback. ......................................................................................... 22
Table 17.1 Allision return period. ........................................................................................... 23
Table 18.1 Fishing vessel collisions – Base case with offshore HVAC reactive compensation substation. ............................................................................................................ 24
Table 20.1 Lifeboat Stations. ................................................................................................. 25
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Glossary
Term Definition
Allision The act of striking or collision of a moving vessel against a stationary object.
Automatic Identification System (AIS)
A system by which vessels automatically broadcast their identity, key statistics (e.g., length), brief navigation details (e.g., position, heading, destination and speed) and current status (e.g., survey). Most commercial vessels and EU fishing vessels over 15m are required to have AIS.
Collision The act or process of colliding (crashing) between two moving objects.
Marine Guidance Note
A system of guidance notes issued by the Maritime and Coastguard Agency which provide significant advice relating to the improvement of the safety of shipping and of life at sea, and to prevent or minimise pollution from shipping.
Marine Environmental High Risk Area (MEHRA)
Areas in UK coastal waters where ships' masters are advised of the need to exercise more caution than usual i.e. crossing areas of high environmental sensitivity where there is a risk of pollution from merchant shipping.
Not Under Command (NUC)
Under Part A of the International Regulations for Preventing Collisions at Sea (COLREGS), the term “vessel not under command” means a vessel which through some exceptional circumstance is unable to manoeuvre as required by these Rules and is therefore unable to keep out of the way of another vessel.
Offshore Renewable Energy Infrastructure (OREI)
Installations which are used, will be used or have been used for purposes connected with the production of energy and which permanently rest on, or are attached to, the seabed and are not connected with dry land by a permanent structure providing access at all times.
Radar An aerial detection system which uses radio waves to determine the range, altitude, direction, or speed of objects. Abbreviated from Radio Detection And Ranging.
Radar Early Warning
A system used primarily for the long-range detection of approaching objects in the air.
Safety Zone
A marine zone demarcated around an installation or works/construction area in which other vessels are prohibited from entering, except in special circumstances, in order to protect the safety of people working on, or in the immediate vicinity of the installation, to protect the installation itself against damage and to protect other mariners by reducing the risk of collision with the installation.
Term Definition
Traffic Separation Scheme
A traffic-management system ruled by the International Maritime Organization. The traffic-lanes (or clearways) indicate the general direction of the ships in that zone; ships navigating within a TSS all sail in the same direction or they cross the lane in an angle as close to 90 degrees as possible.
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Acronyms
Acronym Full term
AIS Automatic Identification System
ALB All weather Life Boat
CAA Civil Aviation Authority
CNIS Channel Navigation Information Service
CoS Chamber of Shipping
DCO Development Consent Order
DECC Department for Environment and Climate Change
EC European Commission
EMF Electromagnetic Field
ERCoP Emergency Response and Cooperation Plan
ERRV Emergency Response and Rescue Vessel
ES Environmental Statement
EU European Union
FSA Formal Safety Assessment
GIS Geographic Information System
GT Gross Tonnes
HSE Health and Safety Executive
HVAC High Voltage Alternating Current
HVDC High Voltage Direct Current
IALA International Association of Lighthouse Authorities
ILB Inshore Life Boat
IMO Internal Maritime Organisation
Km Kilometres
m Metres
MAIB Marine Accident Investigation Branch
MCA Maritime and Coastguard Agency
MGN Marine Guidance Note
MHWS Mean High Water Springs
MMO Marine Management Organisation
MOC Maritime Operation Centre
MoD Ministry of Defence
Acronym Full term
mph Miles per hour
MRCC Maritime Response Coordination Centre
NM Nautical Miles (1NM = 1,852metres)
NRA Navigational Risk Assessment
NUC Not Under Command
OREI Offshore Renewable Energy Installation
PEIR Preliminary Environmental Information Report
PEXA Practice and Exercise Area
PINS National Infrastructure Planning and The Planning Inspectorate
PSV Platform Standby Vessel
REZ Renewable Energy Zone
RNLI Royal National Lifeboat Institute
Ro-Ro Roll on Roll off Ferry
RYA Royal Yachting Association
SAR Search and Rescue
THLS Trinity House Light Services
TSS Traffic Separation Scheme
UK United Kingdom
UKCS United Kingdom Continental Shelf
VHF Very High Frequency
VMS Vessel Monitoring System
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EXECUTIVE SUMMARY
S.1. Using available baseline data sources this report analyses the potential development
area for a proposed offshore High Voltage Alternating Current (HVAC) reactive
compensation substation as part of Project One in line with standard methodologies
for assessing marine navigational risk.
S.2. This report includes an assessment of Automatic Identification System (AIS) marine
traffic survey data, existing navigational features, commercial fisheries and
recreational data in order to provide a baseline environmental picture. The AIS marine
traffic survey data was analysed to identify main routes and 90th percentiles.
S.3. The marine traffic survey identified eight main routes operating within a 10 Nautical
Mile (NM) buffer around the proposed HVAC reactive compensation substation
location with a variety of vessel types transiting between 1 and 13 times per day.
Levels of recreational activity were noted as low level in comparison to national levels
and fishing vessel activity was mainly located south west of the site.
S.4. Allision models were under taken to analyse the Vessel-to-Structure allision risk for the
proposed offshore HVAC reactive compensation substation location. The collision
return period ranged from 1 every 15,687 years for a drifting vessel to 1 every 186
years for allisions with powered vessel.
S.5. A data validation exercise was conducted using an additional 33 days of data obtained
from a geophysical survey of the cable route corridor (August to September 2012) to
validate against the traffic survey data already obtained. The validation are included as
Appendix A to this report. There is a good correlation between the NRA and the
validation exercise regarding both the main routes used and the number of vessels on
the main routes.
S.6. An additional route has been identified from the validation data to the north of the
proposed HVAC reactive compensation substation on which a Ro-Ro cargo service
operates between Killingholme and Gothenburg. It should be noted however, that this
route has since been terminated by the operator.
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1 INTRODUCTION
1.1 Background
1.1.1 SMart Wind has included options to connect Project One to the National Grid using
either High Voltage Alternating Current (HVAC) or High Voltage Direct Current
(HVDC) technology. The inclusion of both transmission technology options in the
Development Consent Order (DCO) consent submission to the Planning Inspectorate
(PINS) is required to meet full technical and economic flexibility to deliver against
government targets for offshore wind cost reduction.
1.1.2 Anatec was commissioned by SMart Wind Limited (SMW) to undertake a navigational
risk assessment (NRA) for the proposed offshore HVAC reactive compensation
substation which forms part of the offshore HVAC transmission works as part of
Project One.
1.1.3 It is important to note that the offshore HVAC reactive compensation substation
option is being considered in addition to the HVDC option, but only one transmission
option will be developed during the final design of the project following consent.
1.2 Navigational Risk Assessment
1.2.1 An Environmental Impact Assessment (EIA) is a process which identifies the
environmental effects, both negative of a proposed development and positive of a
proposed development in accordance with European Union (EU) Directives. A key
requirement of the EIA is the NRA. Following guidance set out in the Department for
Environment and Climate Change (DECC) Methodology (DECC, 2005) and MGN 371
(MCA, 2008), an NRA has been undertaken for the Project One offshore HVAC
reactive compensation substation and includes:
Overview of base case environment;
Marine Traffic Survey;
Implications of Offshore Renewable Energy Installations (OREIs);
Assessment of navigational risk pre and post wind farm development;
Formal Safety Assessment (FSA);
Implications on marine navigation and communication equipment;
Identification of mitigation measures;
Search and Rescue (SAR) planning; and
Through life safety management.
1.2.2 Assessments will be reviewed by phase:
Construction;
Operation and maintenance; and
Decommissioning.
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2 GUIDANCE AND LEGISLATION
2.1 Primary Guidance
2.1.1 The primary guidance documents used during the assessment are listed below:
Maritime and Coastguard Agency (MCA) Marine Guidance Notice 371 (MGN
371 Merchant + Fishing) Offshore Renewable Energy Installations (OREIs)
Guidance on UK Navigational Practice, Safety and Emergency Response
Issues (MCA 2008a);
Department of Energy and Climate Change (DECC 2005). in Association with
MCA Guidance on the Assessment of Offshore Wind Farms - Methodology for
Assessing Marine Navigational Safety Risks of Offshore Wind Farms (2005);
and
Guidelines for Formal Safety Assessment (FSA) – MSC/Circ. 1023 (IMO 2002).
2.1.2 MGN 371 highlights issues that shall be taken into consideration when assessing the
effect on navigational safety from offshore renewable energy developments,
proposed within United Kingdom internal waters, territorial sea or Renewable Energy
Zones (REZ).
2.1.3 The MCA require that their methodology is used as a template for preparing
navigation risk assessments. It is centred on risk management and requires a
submission that shows that sufficient controls are, or will be, in place for the assessed
risk (base case and future case) to be judged as broadly acceptable or tolerable.
2.2 Formal Safety Assessment Process
2.2.1 The International Maritime Organisation (IMO) Formal Safety Assessment process
(IMO 2002) approved by the IMO in 2002 under SC/Circ.1023/MEPC/Circ392 has
been applied within this study. This is a structured and systematic methodology
based on risk analysis and cost benefit analysis (if applicable). There are five basic
steps within this process:
1. Identification of hazards (a list of all relevant accident scenarios with potential
causes and outcomes);
2. Assessment of risks (evaluation of risk factors);
3. Risk control options (devising regulatory measures to control and reduce the
identified risks);
4. Cost benefit analysis (determining cost effectiveness of risk control measures);
and
5. Recommendations for decision-making (information about the hazards, their
associated risks and the cost effectiveness of alternative risk control measures).
2.2.2 Figure 2.1 is a flow diagram of the FSA methodology applied.
Figure 2.1 Formal safety assessment process.
2.3 Other Guidance
2.3.1 Other guidance used during the assessment is listed below:
MCA Marine Guidance Notice 372 (MGN 372 M+F) Offshore Renewable
Energy Installations (OREIs) Guidance to Mariners Operating in the Vicinity of
UK OREIs (MCA 2008b);
International Association of Marine Aids to Navigation and Lighthouse
Authorities’ (IALA) – 0139 The Marking of Man-Made Offshore Structures,
Edition 1 IALA (2008); and
Royal Yachting Association (RYA) – The RYA’s Position on Offshore Energy
Developments (RYA, 2012).
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3 CONSULTATION
3.1 Stakeholders Consulted as part of NRA Process
3.1.1 Key marine and navigational stakeholders have been consulted as part of the
offshore HVAC reactive compensation substation navigational risk assessment prior
to Phase 4 Consultation. The following stakeholders have been consulted:
Maritime and Coastguard Agency (MCA);
Trinity House Light Services (THLS); and
Chamber of Shipping (CoS);
3.1.2 Details of the consultation are included within the Environmental Statement Volume 2
Chapter 8: Shipping and Navigation, and in the Consultation Report. These reports
are to be presented at Phase 4 Consultation along with this NRA to ensure
consultation with all relevant stakeholders.
4 NAVIGATIONAL RISK ASSESSMENT METHODOLOGY
4.1 Flow Chart for NRA Methodology
4.1.1 Figure 4.1 shows an overview of the NRA methodology which was used in this study.
Figure 4.1 Overview of methodology for navigational assessment.
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5 CUMULATIVE EFFECTS METHODOLOGY
5.1.1 This NRA considers cumulative effects which includes considering the impacts
arising from all the current and planned UK offshore wind farms (and their associated
activities) within the southern North Sea within proximity to the offshore HVAC
reactive compensation substation.
5.1.2 It is noted that an offshore HVAC reactive compensation substation will also be
included as part of the Project Two design envelope and could be within close
proximity to the Project One offshore HVAC reactive compensation substation. At
this stage the effects of this cannot be assessed without further collision risk
modelling which will be undertaken as part of the Project Two NRA. However a
qualitative assessment has being done to determine cumulative impacts within the
impact assessment located in Volume 2 Chapter 8 Shipping and Navigation.
5.1.3 Other cumulative impacts including those related to existing or planned oil and gas
infrastructure have been considered within Section 22 of this NRA.
5.1.4 The following methods have been used to assess these cumulative effects identified
as part of the NRA baseline study:
Stakeholder consultation and expert opinion;
Lessons learned;
Desktop study;
Collision risk modelling; and
Regular operator feedback.
5.1.5 The methodology for screening projects is applied as per Section 22 to identify
projects to be included in the cumulative impact assessment within the ES and this
list of projects is used to verify the findings of the NRA. The routes which will be
impacted by the project will be used to set the spatial extent of the cumulative impact
assessment.
6 DATA SOURCES
6.1 Data Sources Used
6.1.1 The following data sources have been used to inform this assessment:
28 days of data recorded by AIS during July/August 2011 (14 days) and
February 2012 (14 days). It is noted that this data will not include vessel
movements under 200 gross tonnage (GT);
Optimal 7 days of a 20 days dataset recorded by AIS during August/September
cable route geophysical survey (see section 13.2.1 – 13.2.2).
UK Coastal Atlas of Recreational Boating, 2009 and 2010 Geographic
Information System (GIS) Shape Files (RYA, 2012);
Marine Management Organisation (MMO) Fishing Satellite Data (2009);
UK Coastal Atlas of Recreational Boating, 2009 and 2010 GIS Shape Files
(RYA, 2010);
UK Admiralty Charts 1187, 1190, 1503 and 1191; and
Oil and gas platforms (UK Deal).
6.1.2 A validation of the AIS data and main routes data used in this NRA has been
undertaken by comparing the data with data obtained from the Ridley Thomas survey
work undertaken between 11th August and 12th September 2012. The validation
report is presented as Appendix A to this NRA. The survey data used in this NRA and
in the validation report is identified in Table 6.1.
6.2 Lessons Learnt
6.2.1 There is considerable benefit in the sharing of lessons learned to developers within
the offshore industry. This NRA includes general consideration for lessons learned
and expert opinion from previous offshore wind farm developments and other sea
users including existing isolated structures used within the oil and gas sector.
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Table 6.1 Survey data used for HVAC Reactive Compensation Substation NRA and validation.
Survey Period Survey type Data type Data Capture Vessel Equipment Radar Personnel
NRA 07/02/12 – 28/03/12 Zonal Survey AIS 14 days Southern Star
Dive Support / Survey
Flagged Bahamas
JRC-JHS-182 Unknown Bridge Crew and FLO 24 hrs
NRA validation
11/08/12 – 12/09/12 Cable Route Geophys
AIS 33 days Ridley Thomas
Research / Survey Vessel
Cable Route Survey
Flagged Marshall Island
Samyung SI-30 n/a (AIS Only) Bridge Crew 24hrs
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7 MARINE TRAFFIC SURVEY METHODOLOGY
7.1 Baseline Survey Methodology
7.1.1 This section describes the survey methodology used when recording shipping survey
data for the offshore HVAC reactive compensation substation location. The data is
assessed within a 10 NM buffer of the offshore HVAC reactive compensation
substation to provide context.
7.1.2 Baseline shipping activity was assessed using AIS data. The period of data collection
encompassed seasonal fluctuations in shipping activity and also accounted for a
range of tidal conditions. This includes a combination of shore and vessel based
surveys to provide the best coverage of the offshore HVAC reactive compensation
substation location.
7.1.3 It is noted that data collection is on-going to allow main routes and 90th percentiles
assumptions to be continually validated. A continual analysis of data will be
undertaken as Zonal work progresses and where applicable any updates will feed
into Project level NRAs.
7.2 AIS Coverage
7.2.1 AIS is required on board all vessels of more than 300 gross tonnage (GRT) engaged
on international voyages, cargo vessels of more than 500 GRT not engaged on
international voyages, passenger vessels irrespective of size built on or after 1st July
2002, and fishing vessels over 45 m in length (at the time of surveying this changed
to 24 metres in May 2012 – SOLAS 78/79).
7.3 Recreational Craft
7.3.1 The RYA and the CA represent the interests of recreational users including yachting
and motor cruising. In 2005 the RYA, supported by THLS and the CA, compiled and
presented a comprehensive set of charts which defined the cruising routes, general
sailing and racing areas used by recreational craft around the UK coast. This
information was published as the United Kingdom (UK) Coastal Atlas of Recreational
Boating and has been subsequently updated (RYA, 2009). The latest addition of GIS
Shape files from 2010 showing cruising routes, sailing and racing areas has been
used in this assessment.
7.3.2 The RYA has also developed a detailed position statement (RYA, 2012) based on
analysed data for common recreational craft; this, along with consultation, were used
to inform the NRA.
7.4 Fishing
7.4.1 Fishing vessel satellite monitoring data were obtained from the MMO and presented
in density grids to validate the survey data presented in the baseline assessment.
Satellites record the positions of fishing vessels of 15 m length and over every
2 hours. Data from 2009 (all nationalities) have been analysed and are presented in a
density grid.
7.4.2 Fishing vessel data was also extracted from the AIS data sets.
7.5 Other Offshore Users
Oil and Gas Installations
7.5.1 Offshore oil and gas installation data were supplied by UK Deal and include fixed
platforms and wellheads. A desk top study was undertaken using these data to
identify any possible cumulative effects associated with offshore oil and gas
developments.
Marine Aggregates Area
7.5.2 Marine aggregates dredging data (licenced areas and active areas) were supplied by
The Crown Estate and passage plans. A desk based study was carried out using this
information to identify commercial aggregates dredging activity in the area.
Navigational Features
7.5.3 Other navigational features such as Ministry of Defence (MoD) Practice and Exercise
Areas (PEXAs) have been considered based on information from Admiralty charts.
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8 OFFSHORE HVAC REACTIVE COMPENSATION SUBSTATION
8.1.1 The following table (Table 8.1) defines the dimensions of the offshore HVAC reactive
compensation substation considered within this assessment; and forms a component
of the HVAC transmission system considered within the Project One design.
8.1.2 In order to limit the electrical losses inherent in using the HVAC transmission over
long distance it is necessary to use shunt reactors to provide reactive compensation
at some point close to midway along the transmission cables. The electrical reactors
will be housed in an offshore HVAC reactive compensation substation.
8.1.3 Other assumptions considered within this report:
The substation will be unmanned apart from periods of maintenance.
Table 8.1 Estimated Dimensions of Offshore HVAC Reactive Compensation Substation.
Number of Reactor Substations 1
Main Building Height from MHWS 50 m
Topside Width 45 m
Topside Length 40 m
Foundation Type Monopile, Jacket, Gravity base or Suction Caisson
Figure 8.1 Typical Offshore Substation Platform.
9 LOCATION SELECTION
9.1.1 In order to select the offshore HVAC reactive compensation substation location, an
initial study was undertaken by Anatec (2012), assessing a number of locations along
the export cable route to identify locations that were low risk to navigation.
9.1.2 Six locations with the shipping and navigation study area were assessed from a
vessel to structure allision, considered against baseline data and then ranked
according to these levels of navigational risk.
9.1.3 They were ranked in three categories and the results are displayed in Figure 9.1:
Category One - Potential for development following consultation and with
mitigations measures in place. Deviations for transiting vessels will be minimal
and likely to have no significant in-combination impacts associated with the
construction of the substation;
Category Two – Considered a consenting risk but possible with extensive
consultation and non-industry standard mitigations in place. Some level of
deviation from existing routes for commercial vessel will be required and in-
combination impacts will require further assessment including the potential for
increased displacement and congestion; and
Category Three – Development within this area is not recommended due to
impacts on receptors including significant impacts on main routes which are
defined by sandbanks and Traffic Separation Schemes (TSS), existing
navigational features associated with other offshore installations and significant
fishing activity posing a collision or snagging risk.
9.1.4 The following Table 9.1 shows the outputs of the vessel to structure allision risk
modelling. With locations A, B and D being the highest risk due to traffic routes and
dense fishing activity.
Table 9.1 Outputs from initial allision risk modelling.
Location Frequency Allision Return Period
A 2.2 x 10-2 1 every 45 years
B 2.8 x 10-2 1 every 35 years
C 6.3 x 10-3 1 every 159 years
D 4.6 x 10-2 1 every 22 years
E 9.5 x 10-3 1 every 105 years
F 7.1 x 10-3 1 every 140 years
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Figure 9.1 Heat sensitive map – potential development areas.
9.1.5 Conclusions of the assessment were:
Vessel-to-Structure collision risk modelling results range from 1 every 22 years
to 1 every 159 years, with locations in the western end of the potential
development area being notably higher risk due to density vessel activity;
The north / south main transit route has been defined by the sandbanks within
the area displacement of this route would have significant impacts for the
vessels using them including increased transit times and navigational safety.
This route also had the highest collision return period of 1 every 22 years;
Main routes running east and west from the Humber are defined by the
alignment required with the TSS lanes, there is also potential for increased
collision risk due to in-combination displacement and congestion within this
area. This route has a collision return period of 1 every 35 years;
Extensive fishing is undertaken in the Silver Pit to the south of the proposed
area. This area shall be avoided with consideration for a buffer to prevent
increased risk of gear snagging with the structure;
There are a number of existing navigational features associated with gas
extraction that shall be avoided and/or buffered including platforms, a relief well,
a pipeline and safety zones associated with the platforms;
Limited information is available on the development area in proximity to the
Amethyst field therefore the potential for construction within this area has been
assumed as possible. It is noted that this development area is avoided by
vessels therefore could provide a low risk area to develop the substation,
however further consultation would be required; and
Limited recreational data was available but assumed there is limited activity.
However the potential for congestion and displacement with commercial, fishing
and marine aggregate vessels shall be considered further in the western end of
the proposed development area.
9.1.6 Following assessment of these results including the collision risk modelling and
assessment of baseline data including geotechnical conditions a location to the east
of location E was selected which would reduce the allision risk return period by
moving the structure away from the dense north south shipping route (Figure 10.1).
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10 BASELINE ENVIRONMENT
10.1 Navigational Features
10.1.1 The following section identifies the navigational features within and in proximity of the
proposed offshore HVAC reactive compensation substation location. Figure 10.2
shows marine aggregate extraction areas, Figure 10.1 shows the Traffic Separation
Schemes at the Humber Estuary and a number of existing platforms, safety zones
and wells.
Oil and Gas Platforms including Development Fields
10.1.2 The closest wells to the south west and north east of the proposed location are
plugged and abandoned.
10.1.3 The closest platform, with a safety zone is Amethyst B1D situated 4.5 NM to the
south west and 4.16 NM west of the edge of the Amethyst Gas Field development
area.
10.1.4 The Amethyst Gas Field development area is to protect an area of high level offshore
activity including commercial diving, gas field development and two unmanned
satellite wellhead platforms.
10.1.5 Figure 10.2 shows the area surrounding the offshore HVAC reactive compensation
substation location in more detail.
Existing Aids to Navigation and Routeing Measures
10.1.6 There are no existing routeing measures in proximity to the proposed offshore HVAC
reactive compensation substation location.
10.1.7 There is a special mark buoy located to the north east of the proposed location which
is marking a plugged and abandoned well. There are no other aids to navigation in
proximity.
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Figure 10.1 Navigational features in the vicinity of the offshore HVAC reactive compensation substation location.
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Figure 10.2 Navigational features – zoomed plot.
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11 METOCEAN DATA
11.1 Introduction
11.1.1 This section presents nearby meteorological and oceanographic statistics and have
been used as input to the risk assessment.
11.2 Wind
11.2.1 The wind data for the area (EMU Ltd, MetOcean Dept, pers.comm. 2011), in terms of
average direction and speed, are presented in Figure 11.1 and Figure 11.2. It can be
seen that winds are predominantly from the south and west, and the occurrence of
excessive wave height is relatively low (It is noted that 0% of annual waves exceed 5
meters – severe level).
Figure 11.1 Annual wind direction distribution for the offshore HVAC reactive compensation substation area.
Figure 11.2 Annual wave height distribution for the offshore HVAC reactive compensation substation area.
11.3 Visibility
11.3.1 Historically, visibility has been shown to have a major influence on the risk of ship
collision. The annual average probability of bad visibility (defined as less than 1 km)
for the UK North Sea is approximately 0.03, i.e. an average of 3.0% of the year.
(UKHO, 2009).
11.4 Tide
11.4.1 Admiralty Chart 1190 (Tidal Diamond “M”) indicated that currents in the area set in a
generally NW to SE direction on the flood and SE to NW direction on the ebb, with a
peak spring tidal rate of 1.7 knots and peak neap rate of 0.5 knots.
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12 MARITIME INCIDENTS
12.1 Introduction
12.1.1 This section reviews maritime incidents that have occurred in the vicinity of the
proposed offshore HVAC reactive compensation substation between 2001 and 2010.
12.1.2 The analysis is intended to provide a general indication as to whether the area of the
proposed development is currently low or high risk in terms of maritime incidents. If it
was found to be a particularly high risk area for incidents, this may indicate that the
development could exacerbate the existing maritime safety risks in the area.
12.1.3 Data from the following has been analysed:
Marine Accident Investigation Branch (MAIB); and
Royal National Lifeboat Institution (RNLI).
12.1.4 It is noted that the same incident may be recorded by both sources.
12.2 Marine Accident Investigation Branch (MAIB)
12.2.1 All UK commercial vessels are required to report accidents to MAIB. Non-UK vessels
do not have to report unless they are in a UK port or are in 12 mile territorial waters
and carrying passengers to a UK port. There are no requirements for non-commercial
recreational craft to report accidents to MAIB.
12.2.2 The location of accidents, injuries and hazardous incidents reported to MAIB within
10 NM of the offshore HVAC reactive compensation substation for the last ten years
(January 2001 to December 2010) are presented in Figure 12.1 and are colour-coded
by type.
12.2.3 It shall be noted that the MAIB aim for 97% accuracy in reporting the locations of
incidents.
12.2.4 A total of 12 numbers of 12 unique incidents each involving one vessel were reported
within 10 NM, corresponding to an average of 1-2 incidences every year.
12.3 Royal National Lifeboat Institution (RNLI)
12.3.1 Data on RNLI lifeboat responses within 10 NM of the offshore HVAC reactive
compensation substation in the ten-year period between 2001 and 2010 have been
analysed. It is noted that due to the distance offshore of the proposed development,
the RNLI may not be called out to all incidents in proximity to the offshore HVAC
reactive compensation substation.
12.3.2 A total of 15 launches to 14 unique incidents were recorded by the RNLI (excluding
hoaxes and false alarms). Figure 12.2 presents the geographical location of incidents
colour-coded by casualty type.
12.3.3 The majority of the incidents recorded by RNLI were machinery failures on fishing
vessels and merchant vessels and were responded to by Humber ALB.
Figure 12.1 MAIB incident locations within 10 NM of the offshore HVAC reactive compensation substation location.
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Figure 12.2 RNLI incidents by casualty type within 10 NM of the HVAC reactive compensation substation location.
13 AIS MARINE TRAFFIC DATA ANALYSIS
13.1 Introduction
13.1.1 This section presents shipping data for the proposed offshore HVAC reactive
compensation substation recorded by AIS (28 days) during surveys between 20th
July 2011 and 7th August 2011, and between 16th February and 29th February 2012.
13.1.2 The majority of vessels were recorded on AIS. AIS is now fitted on all commercial
ships operating in UK waters over 200 GT engaged on international voyages, over
500 GT on domestic voyages, passenger vessels carrying 12 or more persons and
fishing vessels over 45 meters.
13.1.3 The proceeding figures show all tracks within 10 NM of the offshore HVAC reactive
compensation substation.
13.2 Survey Analysis
13.2.1 As part of the on-going data collection process for the Hornsea Zone additional data
was collected in August 2012 for the export cable route during a geophysical survey.
Seven days out of 20 days of recording of this data provided excellent coverage for
the proposed offshore HVAC reactive compensation substation location and was,
therefore used to validate routes.
13.2.2 The data was collected by the survey vessel Ridley Thomas between 11th August
2012 and 12th September 2012. The Ridley Thomas was undertaking a geophysical
survey of the cable route and the full data set was assessed to identify the days
which provided the best coverage for the location. Figure 13. 1 presents 7 days AIS
data from this survey between 12th August and 18th August 2012 used in this initial
validation. (A subsequent validation exercise of the AIS data was undertaken and is
included as Appendix A to this NRA.)
13.2.3 By comparing this data and the data below showing 28 days AIS from July 2011 to
February 2012, it can be seen that there are similar trends in vessel tracks and the
types of vessels transiting through the 10 NM buffer around the offshore HVAC
reactive compensation substation location.
13.2.4 A plot of the vessel tracks recorded during a 28 day survey period from July 2011 to
February 2012, colour coded by vessel type, is presented in Figure 13.2.
13.2.5 In total, there was an average of 40 unique vessels per day passing within 10 NM of
the proposed development site recorded on AIS. It shall be noted that counting
unique vessels means that support vessels on station at a platform or vessels bound
to and from a port in the same day are only counted once.
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13.2.6 Figure 13.3 presents the daily number of vessels passing through the proposed
development site and 10 NM buffer during the survey.
Figure 13.1 AIS Data from Ridley Thomas used for Validation (7 Days).
Figure 13.2 AIS Data excluding Survey Vessel Tracks (28 days).
0
10
20
30
40
50
60
Nu
mb
er
of
Ve
sse
ls
Date
Within 10nm Buffer
Figure 13.3 Unique vessels per day during the survey period.
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13.2.7 An analysis of the vessel types recorded within the proposed HVAC Reactive
Compensation Substation during the survey is presented in Figure 13.4.
13.2.8 The majority of tracks were cargo vessels (67%) and tankers (23%). The cargo
category includes some oil and gas vessels operating in the area who generally
broadcast their vessel types on AIS as cargo, tugs or other.
13.2.9 Figure 13.5 presents a plot of cargo vessels and a plot of tankers is presented in
Figure 13.6.
13.2.10 Figure 13.7 shows AIS tracks colour coded by course, this shows splits in the
direction of vessel traffic with clearly defined east / west bound routes.
13.3 Vessel Density
13.3.1 The AIS track data has been converted to a vessel density grid, based on a grid of
1 km x 1 km encompassing the proposed site and the 10 NM buffer, to assist in
identifying hot-spots of vessel activity.
13.3.2 The resultant grid for all vessels (excluding survey vessels) is presented in Figure
13.8. It shall be noted that this is shaded according to the relative density within the
area of the grid.
Figure 13.4 Vessel types identified intersecting the proposed offshore HVAC reactive compensation substation site 10 NM buffer.
Figure 13.5 Cargo vessel tracks.
Figure 13.6 Tanker vessel tracks.
<1% <1% 1% <1% 3%
<1%
67%
23%
5%
Fishing
Military
Dredger/Subsea
HSC
Tug
Passenger
Cargo
Tanker
Other Ship
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Figure 13.7 All vessels (excluding survey vessels) by course (28 days).
Figure 13.8 Ship density grid.
13.4 Main Routes and 90th Percentile Lanes
13.4.1 AIS data is assessed and vessels transiting at similar headings are identified as a
route. The shipping route width is then calculated using the 90th percentile rule from
the median line of the shipping route.
13.4.2 Figure 13.9 shows the main routes that have been identified from the collected AIS
data. The routes have also been considered against chartered features within the
southern North Sea that define the routes vessels take. The figure shows main routes
aligned with areas of deeper water between sand banks including the Outer Dowsing
Shoal and Triton Knoll. Route 3 shows vessels alternating course north of the
proposed development site to align with the Outer Dowsing channel between these
two banks. The route is transited, on average, by 12 to 13 vessels per day. It also
shows those routes running east/west bound to and from the Humber Traffic
Separation Scheme.
13.4.3 The proposed offshore HVAC reactive compensation substation is located to the east
of the main UK east coast traffic route (12-13 vessels per day) and to the north of the
Humber to Germany/Denmark route (4 vessels per day).
13.4.4 The 90th Percentile routes within 10 NM of the proposed HVAC reactive
compensation substation location are shown in Figure 13.10.
13.4.5 A brief description of the traffic on the main routes and 90th Percentiles is presented
in Table 13.1.
Table 13.1 90th Percentile lane description.
Route
Number Daily Numbers Description
1 4 vessels per day Humber (east approaches) to ports in Germany / Denmark. Route 5 is used predominantly by cargo vessels and includes DFDS roll-on roll-off (Ro-Ro) freight services from Immingham to Esbjerg and Cuxhaven.
2 3 vessels per day Humber ports (east approaches) to Germany. The vast majority of vessels on Route 13 are cargo vessels.
3 12 to 13 vessels per day
Main east coast traffic route. Route 2 consists of a variety of vessel types (49% tankers and 41% cargo) generally transiting between two UK ports of between NE UK ports and ports in The Netherlands and Belgium. It contains a Ro-Ro freight service from Rosyth to Zeebrugge. Route 2 passes to the east of the Amethyst development area and passes through the Outer Dowsing Channel.
4 1 vessel per day Route 4 is mainly used by Tankers travelling from Immingham to Rotterdam.
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Route
Number Daily Numbers Description
5 1 vessel per day Immingham to Cuxhaven, Germany. Route 4 is used by cargo vessels using the northeast approaches of the Humber Traffic Separation Scheme (TSS) ‘New Sand Hole’ and includes a DFDS Ro-Ro freight service.
6 2 vessels per day NE UK ports to ports in The Netherlands and Belgium. Route 6 is used generally by cargo vessels (86%) and includes a P&O Ro-Ro freight service between Teesport and Zeebrugge. Route 6 passes to the west of the Amethyst development area and passes through the Outer Dowsing Channel.
7 1 to 2 vessels per day
Route 12 is used by a variety of vessels including tankers (51%) and cargo vessels (43%), and routes via the Outer Dowsing Channel. Route 12 includes vessels using the northeast approaches of the Humber Traffic Separation Scheme (TSS) ‘New Sand Hole’.
8 1 vessel per day Route 10 is generally used by vessels associated with Tees, and is used by cargo vessels (40%) and tankers (46%).
Figure 13.9 Main routes and areas of shallow waters.
Figure 13.10 90th Percentile lanes.
13.4.6 Although not noted as main routes, the following figures show traffic within and in
proximity to the Amethyst Field Development Area. It can be seen that apart from the
Emergency Response and Rescue Vessels (ERRV) and Platform Standby Vessels
(PSV), passing traffic does avoid the area.
13.5 Commercial Traffic Impact Assessment
13.5.1 The offshore HVAC reactive compensation substation location is to the north and
east of two main routes identified in the area. A number of vessels do pass in close
proximity to the proposed location.
13.5.2 The isolated nature of the structure means that deviations would be negligible for
existing vessels to route a safe distance from the platform. However the isolated
nature could increase potential for allision risk if not adequately marked and lit in
accordance with THLS requirements.
13.5.3 A collision return period of 1 every 186 years is considered to be high for similar
structures within the North Sea which on average have a return period of 1,900. This
is due to the dense route operating in proximity to the location and the size of the
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structure. The offshore HVAC reactive compensation substation will need to be
mitigated to as low as reasonably practical (ALARP) against any potential allision risk
(Section 21.2).
Figure 13.11 Amethyst development area detailed (28 Days).
Figure 13.12 Vessels passing the Amethyst development area.
Figure 13.13 Infield vessels within the Amethyst development area (ERRV and PSV).
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14 COMMERCIAL FISHING
14.1.1 Regulations require AIS to be fitted on all fishing vessels over 45m in length, though
some smaller vessels are fitted with the equipment although it is not a requirement,
and so the AIS data presented in the previous section does not provide
comprehensive coverage of all fishing vessels. In addition to the AIS track data for
fishing vessels, this section presents the density of fishing vessels in the vicinity of
the proposed site, based on Marine Management Organisation (MMO) data.
14.1.2 Fishing vessel activity was recorded on AIS during the survey period and is
presented in the following figure.
Figure 14.1 Fishing vessel tracks recorded during the survey period.
14.1.3 Satellites record the positions of fishing vessels of 15 meters in length and over every
2 hours. The latest satellite data set analysed is from 2009 and the data includes both
UK and foreign vessels. The satellite positions have been converted to a density grid
and this is presented in Figure 14.2 (each cell in the gird used for the density plot is
1 km x 1 km).
Figure 14.2 Density of fishing vessels from satellite data 2009.
14.2 Fishing Vessel Impact Assessment
14.2.1 Marine traffic survey results and vessel monitoring system (VMS) density grids show
no fishing activity in the area and therefore are not expected to create any effects for
vessels engaged in fishing.
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15 RECREATIONAL CRAFT TRANSITS
15.1.1 This section reviews recreational vessel activity within the offshore HVAC reactive
compensation substation location based on information published by the Royal
Yachting Association (RYA), as well as AIS tracking of recreational vessels during the
maritime traffic surveys.
Survey Data
15.1.2 Figure 15.1 presents the recreational tracks recorded during the shipping survey.
Figure 15.1 Recreational tracks recording during the survey period.
15.1.3 There was one recreational vessel recorded intersecting the 10 NM buffer around the
offshore HVAC reactive compensation substation location during the shipping survey,
heading south east on 21st July 2011.
RYA Cruising Atlas Data
15.1.4 The following figure identifies recreational cruising routes as detailed within the RYA’s
UK Coastal Atlas of Recreational Boating. The 10 NM buffer around the proposed
site is intersected by three medium use routes. These cruising routes are indicative
only and are used to give a general indication of recreational transits routes. From
existing knowledge, it is anticipated that the majority of recreational activity will be
found at the western end of the 10 NM buffer due to the distance offshore. It is also
expected that recreational mariners in this area will have a level of experience in
avoiding offshore platforms such as the amethyst platforms and on board well
equipped vessels.
Figure 15.2 RYA Recreational cruising routes.
15.2 Recreational Craft Impact Assessment
15.2.1 Due to the distance offshore, limited recreational activity and the isolated structure of
the platform there are not anticipated to be any impacts on recreational craft
transiting in the area with standard mitigation, including lighting and marking, in place.
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16 CONSULTATION
16.1.1 Consultation for navigational issues has been carried out with stakeholders
throughout the appraisal process for the offshore HVAC reactive compensation
substation including the 2nd scoping opinion from PINS, Phase 3 consultation
responses to the Preliminary Environmental Information Report (PEIR) and Phase 4
consultation responses to the Draft Environmental Statement. This section
summarises the key points from consultations (Table 16.1).
Table 16.1 Consultation feedback.
Consultee Feedback
PINS
Response in PINS Second Scoping Opinion (IPC, 2012)
IPC stated in paragraph 3.50: The Applicant anticipates that potential project impacts on shipping and navigation will be similar for HVAC technology as for HVDC. However, additional impacts as detailed in paragraph 5.4.2 of the Addendum EIA scoping report will need to be assessed, including the collision risk for an isolated structure. Furthermore, the impacts of Electromagnetic Field (EMF) generated through the use of HVAC will need to be assessed.
MCA and THLS
Consultation Meeting June 2012
MCA confirmed the preference for locating the reactive station adjacent to the Amethyst platform although confirmed that options exist further to the east, also identified through heat mapping. It was mentioned by the MCA that although the reactive station would be a standalone structure it is off similar nature to existing oil and gas platforms in the North Sea and thus impacts are well known.
THLS commented that a location adjacent to the existing Amethyst platform would be most preferable from a navigational perspective.
MCA confirmed exclusion zones and aids to navigation would be required by the MCA and could be agreed in any marine license.
Chamber of Shipping
Consultation Meeting July 2012
CoS indicated that they agreed with the methodology applied and indicated that while MCA/TH would emphasize the safety aspects of the assessment, the CoS would consider any commercial impacts on its members.
Consultee Feedback
Maritime and Coastguard Agency
PEIR Response August 2012
New requirement for the offshore HVAC reactive compensation substation is not something that is welcomed placing additional remote structures outside the development area, however it is acknowledged that shall this technology be adopted then the approach needs to be included and assessed against the revised NRA.
MCA and THLS
Phase 4 Consultation Response and Consultation Meeting April 2013.
In the identification of a preferred location for the offshore HVAC Reactive Compensation Substation MCA and THLS agree with the methodology used as consulted upon in June 2012 and Phase 3 Consultation and the conclusions of the assessment as described in the Environmental Statement Volume 5 Technical Annex 5.8.2: Offshore HVAC Reactive Compensation Substation NRA and Section 8.7 of the Environmental Statement Volume 2 Chapter 8: Shipping and Navigation.
MCA remain uncomfortable with an isolated structure however understand the potential need for this and want to state that while it is not a significant issue, it is a new concept for a wind farm and it provides a separate source of risk form the wind farm array.
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17 VESSEL-TO STRUCTURE ALLISION RISK MODELLING
17.1.1 This section assesses the major hazards associated with the development of the
proposed offshore HVAC reactive compensation substation and includes major
hazards associated with:
Additional vessel to structure allision risk including powered and drifting (vessels
Not Under Command); and
Additional fishing vessel to structure risk.
Potential for Additional Vessel to OREI Collision Risk
17.1.2 The two main scenarios for passing ships colliding with OREIs structures such as the
substation are:
Powered collision where the vessel is under power but errant; and
Drifting Not Under Command (NUC) allision where a vessel on a passing route
experiences propulsion failure and drifts under the influence of the prevailing
conditions.
17.1.3 Based on the vessel routeing identified for the area and assumptions that effective
mitigation are in place, the frequency of an errant vessel under power deviating from
its route to the extent that it comes into proximity with the proposed offshore HVAC
reactive compensation substation is not considered to be a probable occurrence.
NUC Vessel Collision
17.1.4 The risk of a ship losing power and drifting into a structure was assessed using
Anatec’s COLLRISK model. This model is based on the premise that propulsion on a
vessel must fail before a vessel will drift. The model takes account of the type and
size of the vessel, number of engines and average time to repair in different
conditions but it does not consider human error.
17.1.5 The exposure times for a NUC scenario are based on the ship-hours spent in
proximity to the offshore HVAC reactive compensation substation (up to 10 NM from
perimeter). These have been estimated based on the traffic levels, speeds and
revised routeing pattern. The exposure is divided by vessel type and size to ensure
these factors, which based on analysis of historical accident data have been shown
to influence accident rates, are taken into account within the modelling.
17.1.6 Using this information the overall rate of mechanical failure within the area
surrounding the offshore HVAC reactive compensation substation was estimated.
The probability of a ship drifting towards a structure and the drift speed are
dependent on the prevailing wind, wave and tide conditions at the time of the
accident.
17.1.7 The following drift scenarios (worse case) was modelled:
Wind.
17.1.8 The probability of vessel recovery from drift is estimated based on the speed of drift
and hence the time available before reaching the structure. Vessels that do not
recover within this time are assumed to collide.
17.1.9 The following table identifies the allision return period for the offshore HVAC Reactive
Compensation Substation location.
Results
17.1.10 The following Table 17.1 presents the results of the allision risk modelling.
Table 17.1 Allision return period.
Frequency Allision Return Period
Powered 5.4 x 10-3 1 every 186 years
Drifting (NUC) 6.4 x 10-5 1 every 15,687 years
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18 FISHING VESSEL COLLISION
18.1.1 Anatec’s COLLRISK fishing vessel risk model has been calibrated using fishing
vessel activity data along with offshore installation operating experience in the UK (oil
and gas) and the experience of collisions between fishing vessels and United
Kingdom Continental Shelf (UKCS) offshore installations (published by the Health
and Safety Executive (HSE)).
18.1.2 The two main inputs to the model are the fishing vessel density for the area and the
structure details. The fishing vessel density in the area of the wind farm was based
on the number of sightings per patrol in the five-year period 2005-2009, as these
patrols attempt to identify all vessels in the area, unlike the VMS data which are
restricted to vessels of 15 m length and over.
18.1.3 Using the above site-specific data as input to the model, the annual fishing vessel
collision frequency with the offshore HVAC reactive compensation substation was
estimated (Table 18.1).
Table 18.1 Fishing vessel collisions – Base case with offshore HVAC reactive compensation substation.
Annual Collision
Frequency Allision Return
Period
Offshore HVAC reactive compensation substation location.
2.3 x 10-4 4,314 years
18.1.4 The worst case fishing vessel collision risk has been identified as 1 every 4,314
years. The estimated collision frequencies are low and reflect the maximum target
area assumed for the structure. It also assumes the fishing vessel density following
development will remain the same as current levels.
19 IMPACTS ON COMMUNICATION AND POSITION FIXING
19.1 Visual Navigation and Collision Avoidance
19.1.1 It is likely that the proposed offshore HVAC reactive compensation substation will
form a significant aid to navigation and will be highly visible to marine vessels.
Therefore it is not considered likely that the platform will degrade the ability of vessel
to navigate within the area.
19.2 Electromagnetic Interference (EMF) on Navigational Equipment
19.2.1 Due to its similarity to existing offshore structures, there are not expected to be any
impacts associated with EMF interference for vessels navigating in the vicinity.
19.2.2 EMF will be considered further within the Hornsea Project One wind farm area
(Subzone 1) Navigation Risk Assessment.
19.3 Communications Equipment including VHF Use
19.3.1 Due to the location and size of the offshore HVAC reactive compensation substation
structure and its similarity to existing offshore platforms there are not anticipated to
be any impacts on communication equipment in the vicinity of the platform.
19.4 Radar
19.4.1 Due to the location and size of the offshore HVAC reactive compensation substation
structure and its similarity to existing offshore platforms there are not anticipated to
be any impacts on marine based Radar in the vicinity of the platform.
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20 EMERGENCY RESPONSE
20.1.1 Although the offshore HVAC reactive compensation substation will be unmanned,
emergency response for construction, maintenance or decommissioning workers
shall be considered within emergency response planning.
Search and Rescue (SAR) Helicopters
20.1.2 The closest SAR helicopter base is located at Leconfield, operated by the RAF,
approximately 51.2 NM to the north west of the offshore HVAC reactive
compensation substation location. This base has Sea King helicopters with a
maximum endurance (the helicopters range at a specified speed and/or period of
time) of 6 hours and speed of 110 mph. This gives a radius of action of approximately
250 NM which easily covers the offshore HVAC reactive compensation substation
location. One helicopter is available at 15 minutes readiness between 0800 and 2200
hours. Between 2200 and 0800 hours, one helicopter is held at 45 minutes
readiness.
RNLI
20.1.3 The RNLI maintains a fleet of over 400 lifeboats of various types at 235 stations
round the coast of the UK and Northern Ireland.
20.1.4 At each of these stations, crew and Inshore Lifeboats (ILB) and All Weather Lifeboats
(ALB) are available on a 24-hour basis throughout the year. The following Table 20.1
provides a summary of the facilities at the stations closest to the offshore HVAC
reactive compensation substation and shown in Figure 20.1.
Table 20.1 Lifeboat Stations.
Station Lifeboats ALB Class ILB Class Distance to
Platform
Mablethorpe ILB (2) -- B Class & D Class 29.50 NM
Humber ALB Severn -- 29.62 NM
Withernsea ILB -- D Class 32.22 NM
Cleethorpes ILB -- D Class 34.45 NM
Skegness ALB/ILB Mersey D Class 35.62 NM
Wells ALB/ILB Mersey D Class 39.61 NM
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Figure 20.1 Lifeboat stations in location to the offshore HVAC reactive compensation substation.
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Coastguard
20.1.5 HM Coastguard, a division of the MCA, is responsible for requesting and tasking SAR
resources made available by other authorities and for co-ordinating the subsequent
SAR operations (unless they fall within military jurisdiction).
20.1.6 At the time of writing, HM Coastguard co-ordinates SAR through a network of 18
Maritime Rescue Co-ordination Centres (MRCC). A corps of over 3,100 volunteer
Auxiliary Coastguards around the UK coast form over 380 local Coastguard Rescue
Teams (CRT) involved in coastal rescue, searches and surveillance.
20.1.7 All of the MCA’s operations, including SAR, are divided into three geographical
regions. The East of England Region covers the east and south coasts of England
from the Scottish border down to the Dorset/Devon border, and therefore covers the
area around the offshore HVAC reactive compensation substation. The Wales and
West of England Region extends from Devon and Cornwall to cover the coast of
Wales, North West England and the Solway Firth. The Scotland and Northern Ireland
Region covers the remainder of the UK coastline including the Western Isles, Orkney
and Shetland.
20.1.8 Each region is divided into six districts with its own Maritime Rescue Co-ordination
Centre (MRCC), which co-ordinates the Search and Rescue response for maritime
and coastal emergencies within its district boundaries (East of England Region
includes an additional station, London Coastguard, for co-ordinating Search and
Rescue on the River Thames). The nearest rescue coordination centre to the
offshore HVAC reactive compensation substation is the Humber MRCC (located in
Bridlington).
20.1.9 The MCA published a consultation document (MCA, 2010) to modernise HM
Coastguard. The main part of the document proposes the reduction in the number of
Maritime Rescue Co-ordination stations around the UK coastline.
20.1.10 Revised plans were released by the UK Government mid-way through 2011 with a
second consultation period from 14th July 2011 to 6th October 2011. Under the
revised proposals the MCA intends to:
Establish a single 24 hour Maritime Operations Centre (MOC) based in the
Southampton/Portsmouth area with 96 operational coastguards. The MOC will
act as a national strategic centre to manage coastguard operations across the
entire UK network as well as co-ordinating incidents on a day to day basis. The
MOC will also generate a maritime picture using information from a variety of
sources;
Dover will be configured to act as a stand-by MOC for contingency purposes.
Dover would have 28 staff and would retain its responsibilities for the Channel
Navigation Information Service (CNIS); and
In addition to the MOC and Dover, there will be eight further centres, all of which
would be connected to the national network and the MOC. All would be open 24
hours a day with a total staffing of 23 in each. These would be based at the
following stations:
MRSC Aberdeen;
MRSC Shetland;
MRSC Stornoway;
MRSC Belfast;
MRSC Holyhead;
MRSC Milford Haven;
MRSC Falmouth; and
MRSC Humber.
20.1.11 The offshore HVAC reactive compensation substation currently lies within the East of
England region with the nearest rescue coordination centre being MRCC Humber.
MRCC Humber’s area of responsibility provides search and rescue coverage from
Haile Sand Fort to the Scottish/English Border.
20.1.12 The proposed changes to the UK MRCC structure will result in MRSC Humber
covering a much wider area; however it will continue to respond to any incidents in
the vicinity of the offshore HVAC reactive compensation substation location.
Salvage
20.1.13 Each MRCC holds comprehensive databases of harbour tugs available locally.
Procedures are also in place with Brokers and Lloyd’s Casualty Reporting Service to
quickly obtain information on towing vessels that may be able to respond to an
incident.
20.1.14 Emergency tug provision will generally be a contracted agreement between the
vessel owners and tug operators. Coastguard Agreement on Salvage and Towage
(CAST) will be invoked when owners are either unable or unwilling to engage in a
commercial tow contract. MCA will pursue costs through arbitrators on a cost
recovery basis.
20.1.15 Tug assistance may also be available from vessels supporting gas fields in the area.
20.1.16 As the offshore HVAC reactive compensation substation will be unmanned there are
not expected to be any impact on Emergency Response capabilities. During periods
of maintenance when the platform will be manned it is assumed a vessel will be on
station to assist and if required safety zones will be applied for to provide additional
mitigation.
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21 MITIGATION MEASURES
21.1.1 Mitigation and safety measures will be applied to the offshore HVAC reactive
compensation substation development appropriate to the level and type of risk that
has been determined during the EIA process. The specific measures to be employed
have been selected in consultation with the MCA Navigation Safety Branch and other
relevant statutory stakeholders where required.
21.2 Standard Industry Practices
Aids to Navigation
21.2.1 As with wind turbines and other offshore structures associated with Project One, the
offshore HVAC reactive compensation substation will be marked in accordance with
the requirements of THLS, the MCA and the Civil Aviation Authority (CAA). Lighting
and marking will include, as per guidance laid out in IALA 0-139;
Any structure shall be marked at night by one or more white lights so
constructed and fixed as to ensure that at least one light is visible upon
approaching the structure from any direction;
The lights shall be placed not less than 6 m and not more than 30 m above
Mean High Water Springs (MHWS) with a minimum effective intensity of 1400
candelas. The lights shall be operated in unison with a flashing character
according to Morse letter « U » (· · ¾ ) and with a maximum period of 15
seconds. The vertical distribution of the projected beam shall be such that the
light will be visible from the immediate vicinity of the structure to the maximum
luminous range of the light;
The horizontal and vertical extremities of the structure shall be adequately
marked in a manner determined by the Authority and in conformity with the
requirements of air navigation regulations;
The structure shall, where practicable, display identification panels with black
letters or numbers 1 m high on a yellow background visible in all directions.
These panels shall be easily visible in daylight as well as at night, either by the
use of illumination or retro reflecting material;
Each structure may carry one or more sound signals so constructed and fixed
as to be audible upon approaching the structure from any direction;
The sound signals shall be placed not less than 6 m and not more than 30 m
above MHWS with a range of at least 2 nautical miles. The character shall be
rhythmic blasts corresponding to Morse letter « U » (· · ¾ ) every 30 seconds;
and
The minimum duration of the short blast shall be 0.75 seconds. The sound
signals shall be operated when the meteorological visibility is two nautical miles
or less.
Construction, Decommissioning and Significant Maintenance Safety Zones
21.2.2 A 500 m safety zone around the platform will be established during
construction/decommissioning in order to minimise disruption to mariners and other
users of the sea, safety zones for the construction, major maintenance and eventual
decommissioning phases will be established on a ‘rolling’ basis, covering only those
areas of the total site in which such activities are actually taking place at a given time.
Promulgation of Information
21.2.3 Notice to Mariners, Radio Navigational Warning, NAVTEX and/or maritime safety
broadcasts will be promulgated in advance of any proposed works including
construction and decommissioning.
Guard Vessel
21.2.4 The use of guard vessels may be required during construction; operation and
significant maintenance to both protect the installation and workers.
Search and Emergency Response and Cooperation Plan (SAR ERCoP)
21.2.5 Operators of the offshore HVAC reactive compensation substation will formulate an
emergency response plan (ERCoP). The SAR ERCoP will be developed and put in
place for construction, operation, maintenance and decommissioning phases. The
SAR ERCoP will be completed following the MCA template however due to the
isolated nature of the structure in comparison to a wind farm some modifications may
be required which will be consulted on with the MCA.
Marine Pollution Contingency Planning
21.2.6 The wind farm operator will develop an Emergency Response Cooperation Plan
(ERCoP) with the relevant Maritime Rescue Coordination Centre from Construction
Phase onwards as well as cooperation with UK National Contingency Plan as per
MCA Requirements.
21.3 Additional Mitigation
21.3.1 Any additional mitigation such as additional Aids to Navigation, Buoyage or exclusion
zones will be discussed with the MCA and THLS as part of the on-going consent
process.
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22 CUMULATIVE EFFECTS
22.1.1 Cumulative effects have been considered for the offshore HVAC reactive
compensation substation location and the impacts on shipping and navigation arising
from offshore wind farms (and their associated activities) combined together with
impacts from other marine activities or users of the sea. Figure 10.1 shows the
offshore HVAC reactive compensation substation location in relation to the Hornsea
Zone and Project One boundary and the cable corridor.
22.1.2 Due to the isolated location and size of structure it is not expected to have any
significant cumulative impacts on vessel routeing in the area.
22.1.3 There are no other existing infrastructure, including gas platforms within close
proximity, to the proposed location that are likely to have cumulative impacts on
vessel routeing. There is the potential for future gas platform developments in the
licence block that the offshore HVAC reactive compensation substation is located
within, however none are currently planned.
22.1.4 Although awaiting its own separate NRA, there is the potential for a second offshore
HVAC reactive compensation substation to be located within proximity to the Project
One offshore HVAC reactive compensation substation as part of the design envelope
for Hornsea Project Two. Cumulative impacts could include;
Increased allision risk dependant on its location to vessel routes;
Deviations for vessels depending on the size of structure and location in
comparison to the Project One offshore HVAC reactive compensation
substation; and
Impacts on other sea users such as fishing vessels.
22.1.5 In terms of assessing cumulative impacts of Project One which consider the potential
second offshore HVAC reactive compensation substation within Hornsea Project
Two, a qualitative assessment has been included within the CIA section of Volume 2
Chapter 8 Shipping and Navigation. As per MGN 371, a full quantitative NRA will be
completed for Hornsea Project Two as part of its application for development
consent.
23 CONCLUSION
23.1.1 An initial assessment on 6 potential locations within a study area was undertaken to
identify a location for the offshore HVAC reactive compensation substation that
considered both shipping and navigation safety risk and engineering requirements.
23.1.2 The selected location following this initial site assessment identified a location to the
north and east of key routes in the area. AIS surveys indicated a small number of
vessels transiting in proximity to the proposed location but that any deviation would
be negligible.
23.1.3 The allision return period ranged from 1 every 15,687 years for a drifting vessel to 1
every 186 years for allisions with powered vessel. The allision return period are both
considered high when compared to other isolated structures in the North Sea area
dues to the density traffic routes passing to the south and west of the proposed
location and the size of the structure.
23.1.4 When considering the allision return period and the isolated nature of the structure,
impacts have been identified with regard to the structure.
23.1.5 Lighting and marking will be discussed with THLS to ensure the structure is visible
and does not become an isolated navigational hazard.
23.1.6 Surveys results showed limited recreational or commercial fishing activity in the area
– therefore there are not expected to be any impacts with recreational or commercial
fishing. Commercial fishing vessels not in transit are considered within the
commercial fishing impacts within Volume 2, Chapter 7: Commercial Fisheries. There
are not anticipated to be any cumulative impacts associated with the offshore HVAC
reactive compensation substation, due to isolated nature and comparison to existing
offshore infrastructure. Although awaiting its own separate NRA, there is the potential
for a second offshore HVAC reactive compensation substation to be located within
proximity to the Project One offshore HVAC reactive compensation substation as part
of the design envelope for Hornsea Project Two. In terms of assessing cumulative
impacts of Project One which consider the potential second offshore HVAC reactive
compensation substation within Hornsea Project Two, a qualitative assessment has
been included within the CIA section of Volume 2 Chapter 8 Shipping and Navigation.
As per MGN 371, a full quantitative NRA will be completed for Hornsea Project Two
as part of its application for development consent.
23.1.7 It is assumed that apart from periods of maintenance the offshore HVAC reactive
compensation substation will be unmanned and therefore not present any significant
impact associated with emergency response provision for personnel on board.
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24 NEXT STEPS – IMPACT ASSESSMENT FOR EIA
24.1.1 The requirement for an EIA is set out in the Infrastructure Planning EIA regulations
2009 within implement EC Directive 85/337/EEC as amended by Directive 97/11/EC
(European Commissions, 2009).
24.1.2 Following identification of impacts within this Navigational Risk Assessment, an
impact assessment in line with EIA guidance has been undertaken. This impact
assessment screened the identified impacts from the NRA with effective pathways.
24.1.3 The EIA process required a data review including compiling and reviewing available
data. For Shipping and Navigation this included the Marine Traffic Surveys, base
case assessment and the Navigational Risk Assessment.
24.1.4 The likely and significant effects of the Project One offshore HVAC reactive
compensation substation development during pre-construction, construction,
operation and decommissioning stages of the project have been assessed and
feedback has been provided to reduce and, where possible, offset any significant
adverse effects on the shipping and navigation environment.
24.1.5 Following this, any residual effects and further mitigation measures that may be
required have been identified.
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REFERENCES
DECC (2005). Methodology for Assessing the Marine Navigational Safety Risks of Offshore Wind farms. London: DECC.
European Commissions (2009). The infrastructure and Planning Regulations, SI 2009 No.2263.
International Maritime Organisation (IMO) (1977). Convention on the International regulations for Preventing Collisions at Sea – Annex 3. London: International Maritime Organisation (IMO).
International Maritime Organisation (IMO) (2002). Guidelines for Formal Safety Assessment (FSA) for use in the IMO Rule Making Process. London. (IMO).
IALA (2008). 0-139 the Marking of Man-Made Offshore Structures. Edition 1 . Saint Germain en Laye, France: Internal Association of Marine Aids to Navigation and Light House Authorities.
Maritime and Coastguard Agency (MCA) (2008a). Marine Guidance Notice 371, Offshore Renewable Energy Installations (OREIs) - Guidance on UK Navigational Practice, Safety and Emergency Response Issues. London: MCA.
Maritime and Coastguard Agency (MCA) (2008b). Marine Guidance Notice 372, Guidance to Mariners Operating in the Vicinity of UK OREIs. London: MCA.
Royal National Lifeboast Institution (RNLI) (2010). RNLI Annual Report and Accounts 2010. Poole:RNLI.
Royal Yatching Association (RYA) (2009). UK Coastal Atlas of Recreational Boating. Updated 2008. Southampton: RYA. GIS Shapes files dated 2010.
Royal Yatching Association (RYA) & CA (2004). Identification of recreational boating interests in the Thames Estuary, Greater Wash and North West (Liverpool Bay). Southampton: RYA.
Royal Yatching Association (RYA) (2012), The RYA’s Position on Offshore Energy Developments. Southampton: RYA.
United Kingdom Hydrographic Office (UKHO) (2009). Admiralty Sailing Directions – North Sea (West) Pilot. Taunton: UKHO.
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APPENDIX A – RIDLEY THOMAS DATA VALIDATION REPORT
Introduction
Background
A.1. SMart Wind is the developer of the 4 giga-watt (GW) Hornsea Round 3 Zone which is
located between 31 kilometres (km) and 190 km off the Yorkshire coast. This report
provides a validation of the Automatic Identification System (AIS) data and main
routes used in the Offshore HVAC Reactive Compensation Substation Navigational
Risk Assessment (NRA) by comparing them with data obtained from the Ridley
Thomas survey work undertaken between 11th August and 12th September 2012.
Data Sources for Comparison
A.2. Shipping data used in the HVAC Reactive Compensation Substation NRA and
subsequently in the HVAC Reactive Compensation Substation NRA validation, is
presented in Table 6.1 of the HVAC Reactive Compensation Substation NRA. The
shipping data used in the HVAC Reactive Compensation Substation NRA comprised
AIS (28 days) which was collected during July/August 2011 (14 days) and February
2012 (14 days). During August and September 2012, a geophysical survey of the
cable route was carried out by the Ridley Thomas. 33 days of Ridley Thomas data
has been recorded and analysed. In house data recorded for the same 33 days has
been included to validate the routeing of vessels and the level of vessel activity
previously observed around the area.
Vessel Types and Numbers
Introduction
A.3. This section presents plots of the vessels recorded on AIS and Radar, daily counts of
unique vessels and a breakdown of vessels types identified during the survey period.
A.4. In all AIS and Radar plots, tracks of temporary (non-routine) vessels such as survey
vessels and traffic associated with temporary drilling rigs have been removed and
excluded from further analysis.
Navigational Risk Assessment Data – 28 days July/August 2011 (14 days) and February 2012 (14 days)
A.5. A plot of the vessel tracks within 10 NM of the offshore HVAC reactive compensation
substation location recorded during 28 days in July/August 2011 and February 2012,
colour-coded by vessel type, is presented in Figure A.1.
Figure A.1 AIS and Radar data excluding temporary traffic (28 days July/August 2011 and February 2012).
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A.6. Figure A.2 shows the daily number of vessels passing through the 10 NM buffer
during 28 days in July/August 2011 and February 2012.
Figure A.2 Unique vessels per day (28 days July/August 2011 and February 2012).
A.7. There were an average of 39 to 40 unique vessels per day passing within 10 NM of
the offshore HVAC reactive compensation substation location, recorded on AIS
(excluding temporary traffic).
A.8. Analyses of the vessel types during 28 days in July/August 2011 and February 2012
is presented in Figure A.3.
A.9. It can be seen from the above pie chart that the majority of vessels were cargo
vessels (67%) and tankers (23%).
Figure A.3 Vessel types intersecting the proposed offshore HVAC reactive compensation substation site 10NM buffer (28 days July/August 2011 and February 2012).
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Ridley Thomas Survey Data – 33 days August and September 2012
A.10. A plot of the vessel tracks within 10 NM of the proposed HVAC reactive
compensation substation site recorded during 33 days in August and September
2012, colour-coded by vessel type, is presented in Figure A.4.
Figure A.4 AIS data excluding temporary traffic (33 days August and September 2012).
A.11. Figure A.5 shows the daily number of vessels passing through the 10 NM buffer
during 33 days in August and September 2012.
A.12. There were an average of between 33 and 34 unique vessels per day passing within
10 NM of the proposed HVAC reactive compensation substation site, recorded on
AIS (excluding temporary traffic).
A.13. Analyses of the vessel types recorded passing within 10 NM of the HVAC reactive
compensation substation during 33 days in August and September 2012 is presented
in Figure A.6.
Figure A.5 Unique vessels per day (33 days August and September 2012).
Figure A.6 Vessel types within 10 NM of the proposed HVAC reactive compensation substation (33 days August and September 2012).
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A.14. It can be seen from the above pie chart that the majority of vessels within 10 NM of
the proposed HVAC reactive compensation substation during 33 days in August and
September 2012 were cargo vessels (56%) and tankers (33%).
Discussion of Vessel Types and Numbers
A.15. During the 28 days in July/August 2011 and February 2012, there were an average of
39 to 40 vessels per day passing within 10 NM of the offshore HVAC reactive
compensation substation location. By comparison, during the 33 days in August to
September 2012, an average of 33 to 34 unique vessels per day were recorded
within this area.
A.16. The vast majority of vessels recorded within 10 NM of the proposed offshore HVAC
reactive compensation substation location were found to be cargo vessels and
tankers in both sets of data.
A.17. Figure A.7 presents the difference in vessel types recorded within 10 NM of the
proposed HVAC reactive compensation substation location.
Figure A.7 Comparison of vessel types within 10 NM of proposed HVAC reactive compensation substation site.
Main Routes
A.18. Main routes have been identified by principles set out in MCA guidance MGN 371.
AIS data are assessed and vessels transiting at similar headings and locations are
identified as a route. To help clarify routes, AIS data can also be interrogated to show
vessels (by name and/or operator) that frequently transit those routes identifying
‘regular runner/operator’ routes.
A.19. Main routes have been identified from the collected AIS data and have also been
considered against charted features within the Southern North Sea that define the
routes vessels take and eight main commercial routes were identified. Plots of the
main routes used in the NRA within a 10 NM buffer around the proposed HVAC
reactive compensation substation are presented in Figure A.8.
Figure A.8 Main Routes used in NRA.
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A.20. A brief description of the traffic on each of the main routes is presented in Table A.1.
Table A.1 Description of Main Routes used in Navigation Risk Assessment.
Route Number
Average Ships per
Day Description
Route 1 4
Humber (east approaches) to ports in Germany / Denmark. Route 1 is used predominantly by cargo vessels and includes DFDS Ro-Ro freight services from Immingham to Esbjerg and Cuxhaven.
Route 2 3 Humber ports (east approaches) to Germany. The vast majority of vessels on Route 2 are cargo vessels.
Route 3 12 to 13
Main east coast traffic route. Route 3 consists of a variety of vessel types (49% tankers and 41% cargo) generally transiting between two UK ports of between northeast UK ports and ports in The Netherlands and Belgium. It contains a Ro-Ro freight service from Rosyth to Zeebrugge. Route 3 passes to the east of the Amethyst development area and passes through the Outer Dowsing Channel.
Route 4 1 Route 4 is mainly used by Tankers travelling from Immingham to Rotterdam.
Route 5 1
Immingham to Cuxhaven, Germany. Route 5 is used by cargo vessels using the northeast approaches of the Humber Traffic Separation Scheme (TSS) ‘New Sand Hole’ and includes a DFDS Ro-Ro freight service.
Route 6 2
Northeast UK ports to ports in The Netherlands and Belgium. Route 6 is used generally by cargo vessels (86%) and includes a P&O Ro-Ro freight service between Teesport and Zeebrugge. Route 6 passes to the west of the Amethyst development area and passes through the Outer Dowsing Channel.
Route 7 1 to 2 Route 7 is used by a variety of vessels including tankers (51%) and cargo vessels (43%), and routes via the Outer Dowsing Channel.
Route 8 1 Route 8 is generally used by vessels associated with Tees, and is used by cargo vessels (40%) and tankers (46%).
A.21. Using the 33 days data collected from the Ridley Thomas survey in August and
September 2012 to identify main routes, it has been found that generally there is a
good correlation between the main routes used in the NRA and those identified with
the validation data (see Figure A.9).
Figure A.9 Main Routes used in NRA and from validation data.
A.22. A description of the traffic recorded on each of the main routes from the validation
data is presented in Table A.2.
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Table A.2 Description of Main Routes from Validation Data.
Route Number
Average Ships per
Day Difference in Average Ships Per Day Description Significant Changes
1 4 The same number of average vessels per day were recorded on this route by the validation data and the data used in the NRA.
Humber (east approaches) to ports in Germany / Denmark. Route 1 is used predominantly by cargo vessels and includes DFDS Ro-Ro freight services from Immingham to Esbjerg and Cuxhaven.
There are no significant changes on this route from the validation data compared to the data used within the NRA.
2 3 The same number of average vessels per day were recorded on this route by the validation data and the data used in the NRA.
Humber ports (east approaches) to Germany. The vast majority of vessels on Route 2 are cargo vessels.
There are no significant changes on this route from the validation data compared to the data presented in the NRA.
3 9
On average, 3 to 4 fewer vessels were recorded per day from the validation data compared to the data used in the NRA.
Main east coast traffic route. Route 3 consists of a variety of vessel types (49% cargo and 45% tankers) generally transiting between two UK ports of between NE UK ports and ports in The Netherlands and Belgium. It contains a Ro-Ro freight service from Rosyth to Zeebrugge. Route 3 passes to the east of the Amethyst development area and passes through the Outer Dowsing Channel.
By comparing the two data sets, there are no significant differences between the destinations of vessels and type distribution of vessels recorded on this route.
4 1
The same number of average vessels per day were recorded on this route by the validation data and the data used in the NRA.
Route 4 is mainly used by Tankers travelling from Immingham to Antwerp.
Tankers were recorded operating on this route during both data sets. The main destinations recorded from the validation data showed vessels travelling between Immingham and Antwerp, compared to vessels recorded travelling between Immingham and Rotterdam from the NRA data.
5 1 The same number of average vessels per day were recorded on this route by the validation data and the data used in the NRA.
Immingham to Cuxhaven, Germany. Route 5 is used by cargo vessels and tankers using the northeast approaches of the Humber Traffic Separation Scheme (TSS) ‘New Sand Hole’.
The DFDS Ro-Ro freight service was not recorded operating on this route during the validation data.
6 2
The same number of average vessels per day were recorded on this route by the validation data and the data used in the NRA.
Northeast UK ports to ports in The Netherlands and Belgium. Route 6 is used generally by cargo vessels (70%) and includes a P&O Ro-Ro freight service between Teesport and Zeebrugge. Route 6 passes to the west of the Amethyst development area and passes through the Outer Dowsing Channel.
There are no significant changes recorded on this route from the validation data compared to the data used within the NRA. The only difference was the percentage of cargo vessels which slightly decreased during the validation data period.
7 1 to 2
The same number of average vessels per day were recorded on this route by the validation data and the data used in the NRA.
Route 7 is used by a variety of vessels including tankers (57%) and cargo vessels (36%), and routes via the Outer Dowsing Channel. Route 12 includes vessels using the northeast approaches of the Humber Traffic Separation Scheme (TSS) ‘New Sand Hole’.
There are no significant changes recorded on this route between the two periods. The only recorded difference was the percentage of cargo vessels and tankers.
8 1 The same number of average vessels per day were recorded on this route by the validation data and the data used in the NRA.
Route 8 is generally used by vessels associated with Tees, and is used by cargo vessels (40%) and tankers (46%).
There are no significant changes on this route from the validation data compared to the data used within the NRA.
9 1 This route is an additional route identified from the validation data.
Route 9 is used by a Ro-Ro cargo service between Killingholme and Gothenburg used by the vessel Longstone.
New Route.
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A.23. An additional route has been added to the north of the proposed HVAC reactive
compensation substation (Route 9) which is a Ro-Ro cargo service between
Killingholme and Gothenburg. Tracks of the vessel recorded on this route during the
25 day survey period are presented in Figure A.10 and the vessel is pictured in
Figure A.11. It should be noted that shipping operations on this route were terminated
on 9th March 2013 by the operator North Sea Ro Ro and therefore this route will no
longer exist.
Figure A.10 New Main Route: Killingholme to Gothenburg.
Figure A.11 Ro-Ro Cargo Vessel Longstone.
Conclusions
A.24. Ridley Thomas data (33 days August to September 2012) was used to validate the
routeing of vessels and the level of vessel activity recorded over 28 days in
July/August 2011 and February 2012.
A.25. During 28 days in July/August 2011 and February 2012, there were an average of 39
to 40 vessels per day passing within 10 NM of the offshore HVAC reactive
compensation substation location. By comparison, during 33 days in August to
September 2012, an average of 33 to 34 unique vessels per day were recorded
within this area.
A.26. The types of vessels recorded within the NRA data (28 days July/August 2011 and
February 2012) and the validation data (33 days August to September 2012) were
mainly cargo vessels and tankers.
A.27. There is a good correlation between the main routes used in the NRA and those
identified with the validation data.
A.28. The numbers of vessels on the main routes identified from the Ridley Thomas
validation data are similar to those presented in the offshore HVAC reactive
compensation substation NRA.
A.29. An additional route has been identified from the validation data to the north of the
proposed HVAC reactive compensation substation on which a Ro-Ro cargo service
operates between Killingholme and Gothenburg. However, it should be noted that this
route has since been terminated by the operator.
