Galloper Wind Farm Project - Galloper Wind Farm proposal

Galloper Wind Farm Project 

Preliminary Environmental Report – Chapter 17: Shipping and 

Navigation 

Galloper Wind Farm Limited

Document title Galloper Wind Farm Project 

Preliminary Environmental Report – Chapter 

17: Shipping and Navigation 

Document short title Galloper Wind Farm PER 

Status Final Report 

Date 3 June 2011 

Project name Galloper Wind Farm Project 

Client Galloper Wind Farm Limited 

Royal Haskoning Reference 9V3083/R01/303424/Exet 

Drafted by Peter Gaches, Jon Allen et al. 

Checked by Rob Staniland, Peter Thornton 

Date/initials check RS PT 30.05.2011 

Approved by Dr. Martin Budd (Royal Haskoning) 

Date/initials approval MB 30.05.2011 

GWFL Approved by Kate Tibble 

Date/initials approval KT 1.06.2011 

Galloper Wind Farm PER 9V3083/R01/303424/Exet 

Final Report - i - 3 June 2011

CONTENTS 

Page 

17 SHIPPING AND NAVIGATION 1 

17.1 Introduction 1 

17.2 Guidance and Consultation 1 

17.3 Methodology 6 

17.4 Existing Environment 10 

17.5 Assessment of Impacts – Worst Case Scenario 34 

17.6 Assessment of Impacts during the Construction Phase 36 

17.7 Assessment of Impacts during the Operational Phase 38 

17.8 Assessment of Impacts during the Decommissioning 

Phase 48 

17.9 Inter-relationships 48 

17.10 Cumulative Impacts 49 

17.11 Outline Monitoring 51 

17.12 Summary 51 

17.13 References 53 


Final Report - iii - 3 June 2011

17 SHIPPING AND NAVIGATION 

17.1 Introduction 

17.1.1 The following Chapter of the Preliminary Environmental Report (PER) 

presents the work undertaken to date as part of the Marine Navigation Risk 

Assessment (NRA) for the Galloper Wind Farm (GWF) (Anatec, 2011 In 

prep). The baseline vessel activities and navigational features are assessed, 

and a preliminary assessment presented of the potential impacts that may be 

associated with the different phases of the development. 

17.1.2 The nature of the shipping activities in the area have been established by 

reviewing fishing vessel activity, recreational vessel activity, identifying 

maritime incidents and reviewing Search and Rescue (SAR) resources. In 

addition the navigational features in the vicinity of the GWF are identified and 

real time shipping survey data is analysed. 

17.2 Guidance and Consultation 

Policy and guidance 

17.2.1 The primary guidance documents used during the assessment are as 

follows: 

� Department of Energy and Climate Change (DECC) Guidelines 

“Methodology for Assessing the Marine Navigational Safety Risks of 

Offshore Windfarms”, Version Date: 7th September 2005; 

� Maritime and Coastguard Agency (MCA) Marine Guidance Notice 371, 

Offshore Renewable Energy Installations (OREI) “Guidance on UK 

Navigational Practice, Safety and Emergency Response Issues”. 

17.2.2 Other forms of guidance used in the assessment are listed below: 

� International Maritime Organisation (IMO), Guidelines for Formal 

Safety Assessment (FSA) (IMO, 2002); 

� MCA Marine Guidance Notice 372 (M+F), Guidance to Mariners 

Operating in the Vicinity of UK OREIs, August 2008; 

� MCA North Hoyle Trials (MCA, 2004; MCA, 2005); 

� International Association of Lighthouse Authorities (IALA) 

Recommendation O-139 On The Marking of Man-Made Offshore 

Structures, Edition 1, Dec 2008; 

� Trinity House Lighthouse Service Guidance (Trinity House, 2005); 

� Kentish Flats Trials (British Wind Energy Association (BWEA), 2007); 

� The RYA’s position on offshore energy developments (Royal Yachting 

Association (RYA), 2009); and 

� DECC Guidance Notes on Safety Zones (DECC, 2007). 


Final Report Chapter 17 - Page 1 3 June 2011

17.2.3 The Draft National Policy Statement (NPS) for Renewable Energy 

Infrastructure (EN-3) also includes specific guidance on the assessment of 

navigation and shipping impacts. EN-3 highlights the importance of thorough 

consultation and stakeholder engagement, including consultation with the 

MFA, Marine Management Organisation (MMO), MCA, relevant General 

Lighthouse Authority and industry bodies and any representatives of 

recreational users of the sea (e.g. the RYA). In addition the assessment 

should include: 

� Information on internationally recognised sea lanes; 

� A NRA in accordance with the relevant guidance, this should 

necessitate: 

o A survey of vessels in the vicinity of the wind farm; 

o A full NRA of the likely impact of the wind farm on navigation in 

the immediate area of the site; and 

o Cumulative risks associated with the development and other 

projects/activities. 

� The assessment of the potential effects as a result of safety zones and 

where this is unknown an assessment of a realistic worse case 

scenario; and 

� An assessment of the potential effect on recreational craft. 

Consultation 

17.2.4 A summary of the consultation carried out, of relevance to the shipping and 

navigation assessment, is presented in Table 17.1. 

Table 17.1 Summary of consultation and issues 

Date Consultee Summary of issue Section 

where 

addressed 

Ongoing 

between 

September 

2009 and 

February 

2011 

Chamber of 

Shipping 

Potential conflict with shipping route – shipping 

surveys required 

The proposed GWF is in direct conflict with 

some of the major shipping routes. The 

extension will bring risk to the ships, where the 

busiest port is located, where hazardous loads 

are carried. 

Safety navigation risks should be assessed in 

relation to narrowing shipping corridors. 

Section 

17.3 




where 

addressed 

04.09.09 

and 

ongoing 

CEMEX 

Marine UK 

Ltd 

04.09.09 Hanson 

Aggregates 

Marine 

04.09.09 

17.08.10 

14.09.09 Cruising 

Association 

23.09.09 Medway 

Ports 

Sheerness 

Ongoing 

between 

September 

2009 and 

March 

2011 

The cumulative impacts with the North Hinder 

South TSS will be minimal 

No issues highlighted 

However, consultation is ongoing with regard to 

their aggregate extraction activities 

No issues highlighted (aggregate area to the 

West of the GWF has been returned to The 

Crown Estate) 

RYA No major concerns. However they would like 

only temporary safety zones put in place when 

wind turbines are being commissioned and 

decommissioned and warning signs for sea 

users. The ‘RYA Position Statement on 

Offshore Renewable Energy Developments’ 

needs to be taken account in Environmental 

Impact Assessment (EIA). 

Harwich 

Haven 

Authority 

(HHA) 

Surveys in summer 2010 should be carried out 

to account for lower numbers of recreational 

vessels during 2009 as a result of the recession. 


Final Report Chapter 17 - Page 3 3 June 2011 

N/A 

N/A 

17.7.2 

No issues highlighted N/A 


Conflict with shipping routes – suggest the 

provision of a fully serviced radar station 

offshore (in the field) from which HHA and MCA 

could access the data which would give both 

organisations better radar coverage than 

currently exists and therefore better monitoring 

the traffic in the proposed area. 

Concerns about interference with fishing vessels 

also highlighted. 

Sections 

17.6, 17.7 

and 17.8


where 

addressed 

16.10.09 

19.08.10 

Ongoing 

between 

September 

2009 and 

February 

2011 

Port of 

London 

Authority 

Norfolkline 

Shipping 

12.11.09 Dover 

Maritime 

Rescue Coordination 

Centre 

(MRCC) 

26.07.10 Stena Line 

Ferries 

27.07.10 UK 

Hydrographic 

Office 

August 

2010 

August 

2010 

IPC and 

Trinity 

House; MCA 

IPC and 

Trinity House 



Concerns regarding the potential impact on 

Round 3 developments and subsequent 

potential for further amendments to the traffic in 

the area – TSS should be amended as a result. 

MCA would like to see a robust assessment 

prepared that meets the IMO objectives and 

would like the export cable to be buried 

sufficiently. 

Concern about conflict with shipping routes 

although site was much improved over the 

original plans. 

TSS would need to be extended and no 

problems on ships radar to date with the 

GGOWF project. 

A concern was expressed regarding the 

interaction with the East Anglia Round 3 Zone 

Section 

17.7 



N/A 


Cumulative impacts should be addressed, 

including any interaction with the Norfolk Zone 

Impacts on existing aids to navigation should be 

addressed (i.e. Outer Gabbard buoy) 

Section 

17.9 

Section 

17.4


where 

addressed 

August 

2010 

November 

2009 to 

April 2011 

August 

2010 

Trinity House 

Maritime and 

Coastguard 

Agency 

East of 

England 

Development 

Agency 

Particular interest is concerned with the 

interaction between the development (during 

construction, operation, decommissioning and 

removal if thereafter any obstruction remains 

which is considered at the time to be a danger 

to navigation) and all types of shipping 

(including commercial, commercial fishing and 

leisure). 

Concerned about potential impacts to shipping 

routes close to GWF and as far east as North 

Hinder Junction 

Requirement for shipping and navigation 

studies, including a 28 day survey of all shipping 

which should take account of any seasonal 

variation in shipping activity 

Primary concerns relate to: 

Conflict with shipping routes. 

Requirement for traffic surveys. 

Cumulative issues between Galloper and East 

Anglia Offshore Wind Farm and the proximity of 

the route to the northern boundary and the 

mean passing distance to the sandbank to the 

North West (which vessels are passing to the 

south of). 

TSS extension is supported and as of April 2011 

the IMO have accepted the TSS extension 

paper, and it will go to NAV57 in June 2011. 

The expansion of port functions of Haven 

Gateway (including expansions at Felixstowe 

South and Bathside Bay) may be relevant in the 

assessment of shipping impacts 

Section 

17.7 

Section 

17.3 

17.7.3 



17.3 

17.9 

17.7.8 

17.4.23

17.2.5 Ship management companies that use the shipping routes around the GWF 

have been consulted as part of the shipping and navigation assessment 

process, the responses, none of which highlighted any concerns, are 

summarised in Table 17.2. 

Table 17.2 Consultation with Ship management companies of relevance to the GWF 

Date Ship management 

Company 

Summary of response 

10.02.11 Oldenburg-Portugiesische No objections/concerns regarding the 

GWF of the proposed extension to the 

TSS 

15.02.11 Wilson Euro Carriers AS GWF is likely to have a limited effect 

on navigation routing 

18.02.11 Arklow Shipping Ltd The GWF proposal looks sound and 

the extension of the existing traffic 

separation scheme seems a safe and 

prudent measure 

10.02.11 Eitzen Gas AS No issues highlighted 

17.3 Methodology 

Study area 

17.3.1 The study area considered is a 10 nautical mile (nm) (18.5km) buffer around 

the GWF site. This is considered sufficient to identify and assess all potential 

shipping and navigational impacts of the project. 

17.3.2 With regard to the cumulative impact assessment, the wider area of the 

Outer Thames Estuary has been studied in order to capture all 

activities/projects which may be relevant to the shipping and navigation 

assessment. 

Characterisation of existing environment 

17.3.3 The existing environment was primarily characterised by the Automatic 

Identification System (AIS) and Radar survey, which was carried out by 

survey vessels at the GWF site between August and December 2009, thus 

covering summer in winter seasons. The effective survey duration was 36 

days (this is greater than the minimum of 28 days required by the MCA). 

Validation of the survey was undertaken using more recent AIS data from 

2010 (Anatec, 2011 In prep). 

Other information sources used during the characterisation of the existing 

environment are listed below: 



� UK Coastal Atlas (RYA, 2009); 

� MMO Fisheries Sightings and Satellite Data (from DMSL, 2011); 

� The Crown Estate Aggregates Dredging Charts; 

� Admiralty Charts and Sailing Directions; and 

� SAR Framework (MCA, 2002). 

Assessment of impacts 

17.3.4 The approach to the shipping and navigation assessment uses two 

methodologies which is dependant on the potential impact being considered. 

Those associated with collision risk are assessed in accordance with 

methodology set out in the DTI Guidelines “Methodology for Assessing the 

Marine Navigational Safety Risks of Offshore Windfarms”, (Department of 

Trade and Industry (DTI), 2005). Those impacts that are not collision related 

are assessed in accordance with the standard EIA methodology as set out in 

Chapter 5 EIA Process. Table 17.3 provides further detail on the 

methodology used for each potential impact which has been identified. 

Table 17.3 Impact Assessment Approach 

Potential impact Assessment approach 

Construction phase 

Collision risk with vessels Risk based approach in line with DTI (2005) 

Collision risk with structures Risk based approach in line with DTI (2005) 

Operation phase 

Re-routing of shipping EIA methodology (Chapter 5) 

Ship to ship collision (change) Risk based approach in line with DTI (2005) 

Collision with structures Risk based approach in line with DTI (2005) 

Impact on Dredging EIA methodology (Chapter 5) 

Recreational vessel collision Risk based approach in line with DTI (2005) 

Fishing vessel collision Risk based approach in line with DTI (2005) 

Cable route interaction EIA methodology (Chapter 5) 

Interference with marine radar EIA methodology (Chapter 5) 

Search and Rescue EIA methodology (Chapter 5) 

Decommissioning 

As per construction phase Risk based approach in line with DTI (2005) 



17.3.5 For the risk-based approach, collision risks have been assessed using the 

following matrix. The “X” represents the predicted risk which has been 

identified as a result of the consequence and frequency. 

17.3.6 The current matrices are based on expert judgment. They will be revised 

following the Hazard Review Workshop later in May and finalised in the full 

NRA report. Some of the higher risk scenarios will be subject to quantitative 

modelling within the NRA. 

Plot 17.1 Risk matrix 

Consequence 

5 

4 

3 

2 x 

1 

1 2 3 4 5 

Frequency 

Broadly Acceptable Region 

(Low Risk) 

Tolerable Region (Moderate 

Risk) 

Unacceptable Region (High 

Risk) 

17.3.7 The following definitions apply to the collision risk matrix. 

Generally regarded as insignificant and adequately controlled. Nonetheless, the law still 

requires further risk reductions if it is reasonably practicable. However, at these levels 

the opportunity for further risk reduction is more limited. 

Typical of the risks from activities which people are prepared to tolerate. There is 

however an expectation that these hazards are properly assessed, appropriate control 

measures are in place and that the residual risks are as low as is reasonably practicable 

(ALARP). These risks require periodic review to investigate whether further controls are 

appropriate. 

Generally regarded as unacceptable whatever the level of benefit associated with the 

activity. 



17.3.8 The following frequency and consequence definitions apply within the risk 

rankings (Table 17.4 and 17.5). 

Table 17.4 Frequency Bands 

Rank Description Definition 

1 Negligible < 1 occurrence per 10,000 years 

2 Extremely Unlikely 1 per 100 to 10,000 years 

3 Remote 1 per 10 to 100 years 

4 Reasonably Probable 1 per 1 to 10 years 

5 Frequent Yearly 

Table 17.5 Consequence Bands 

Rank Description Definition 

People Property Environment Business 

1 Negligible No injury

17.3.9 The four consequence scores were averaged and multiplied by the frequency 

to obtain an overall ranking (or score) which determined the hazard’s position 

within the risk matrix (score between 1 and 25). 

17.4 Existing Environment 

Overview 

17.4.1 The main navigational features in the vicinity of the GWF site are the Sunk 

Area (including TSS) and the Port Operations at HHA and Port of London 

Authority (PLA). Route deviation due to GWF possibly affecting traffic as far 

east as North Hinder was raised as a concern by some stakeholders (Trinity 

House and the MCA) with the potential cumulative impact from East Anglia 

Offshore Wind Zone a particular concern. These issues will be discussed in 

the NRA, but at this stage it is considered that there will be no significant 

knock-on impact on North Hinder as it is sufficiently far away from GWF 

(minimum of 8nm). 

17.4.2 The Sunk Area to the east of Felixstowe consists of five sets of approach and 

departure routes for shipping (see Figure 17.1(a)). 

� Sunk TSS North; 

� Sunk TSS East; 

� Sunk Recommended Route for Ferries; 

� Sunk TSS South; and 

� Long Sand Head Two Way Route. 

17.4.3 The Sunk TSS East traffic lanes route ships between the two areas of the 

GGOWF site and the eastern boundary of the Sunk TSS East is aligned with 

the eastern boundary of the GGOWF site. 

17.4.4 To the Northwest of the Sunk TSS there is the Sunk Deep Water (DW) 

Anchorage, which is used by large vessels bound for Felixstowe. The 

charted water depth ranges from 14m to 21m lowest astronomical tide (LAT). 

This anchorage is located approximately 15km from the GWF site, all other 

anchorages are over 25km from the GWF. 

17.4.5 The Sunk TSS is covered by the Sunk Vessel Traffic Service (VTS) operated 

by Dover Coastguard, which covers the Sunk Inner Precautionary Area, the 

Sunk Outer Precautionary Area and the Sunk TSS lanes. 

17.4.6 Further south, there are several well-established shipping channels between 

sand banks in the area, including Barrow Deep, Black Deep and Fisherman’s 

Gat, used by shipping to/from ports within the Thames Estuary. A full 

discussion and description of all relevant features will be included in the full 

NRA. Figure 17.1(a) and (b) present the main navigational features within 

the area surrounding the GWF. 




Final Report Chapter 17 – Page 11 3 June 2011


Final Report Chapter 17 – Page 12 3 June 2011

Shipping analysis 

17.4.7 The majority of vessels confirmed during the AIS and radar survey were 

recorded on AIS. AIS is now fitted on the vast majority of commercial ships 

operating in UK waters, including all ships of 300 Gross Tonnage (GT) and 

upwards engaged on international voyages, which covers the vast majority of 

merchant shipping passing through the area. Small vessels not broadcasting 

on AIS were recorded on radar, with visual observations made of type and 

size when possible. 

17.4.8 Figures 17.2 to 17.7 show all tracks within 10nm of the GWF for context, but 

the analysis by daily numbers, types, sizes, etc., only includes tracks passing 

through the GWF as these would be most directly affected by GWF. 

17.4.9 There was significant wind farm support vessel and survey activity being 

carried out in the area during the shipping survey, due to the construction of 

GGOWF. This activity, due to its temporary nature, has been filtered out for 

the shipping analysis. Figure 17.2 shows the overall survey results within 

the 10nm study area, using combined AIS and radar tracks, mapped by type 

of vessel. 

Vessel type 

17.4.10 Excluding vessels associated with GGOWF, there were on average 12 

vessels per day passing within 10nm of the GWF. This can be further 

divided to an average of five per day through Area A and seven per day 

through Areas B/C (some tracks crossed both sections). 

17.4.11 The busiest day during the survey period was 15 th October 2009 when 25 

vessels travelled through the GWF site. 

17.4.12 With regard to the number of vessels by type recorded within the study area, 

cargo vessels were the most common, comprising 62% of traffic (Plot 17.2). 

An average of 216 cargo vessels per day passed through the GWF site, the 

majority within the Sunk TSS. The most regular cargo vessels, which also 

passed through the GWF site, were the Cobelfret Ro-Ro ferries, such as 

Taurine, operating between Ipswich and Zeebrugge. Other regular vessels 

were vehicle carrier Autoprogress; en route to Emden and Ro-Ro cargo ship 

Ortviken; en route to Tilbury. 

17.4.13 Tankers made up 22% of traffic and primarily used the Sunk North and Sunk 

South TSS to the west and also the North Hinder TSS to the east. Vessels 

travelling through the GWF site were predominantly en route to / from the 

Thames. 

17.4.14 7% of vessels recorded within the study area were “other” ships, comprising 

of salvage, research and pilot vessels. The remaining 8% included 

passenger vessels, fishing vessels, dredging vessels and tugs (Plot 17.2). 

Galloper Wind Farm PERPER 9V3083/R01/303424/Exet 


Plot 17.2 Vessel type distribution recorded within the study area 

Vessel size, speed and destination 

17.4.15 Figure 17.2 shows the combined AIS and radar tracks by ship length. The 

average length of vessel passing within the GWF during the survey period 

was 115m. The longest vessel crossing the GWF was the container ship 

Cosco Indian Ocean at 348.5m. This vessel is 46m wide at the beam and 

has a maximum draught of 14.5m. 

17.4.16 The average speed of vessels travelling through the study area was 11.6 

knots. The maximum speeds were between 22 - 24 knots, however less than 

1% of vessels were recorded travelling at this speed. The highest 

percentage of vessels (over 40%) were recorded travelling at between 14 - 

19 knots (Plot 17.3). 

17.4.17 The main destinations of the vessels recorded were Harwich Haven (Ipswich, 

Felixstowe and Harwich), The Netherlands (ports in and around Rotterdam) 

and ports in the Thames and Medway (Chatham, Tilbury and Sheerness) 

(Plot 17.4). 





Plot 17.3 Speed Distribution of Vessels Passing Within Galloper Wind Farm 

Percentage 

24% 

22% 

20% 

18% 

16% 

14% 

12% 

10% 

8% 

6% 

4% 

2% 

0% 

0-2 2-4 4-6 6-8 8-10 10-12 12-14 14-16 16-18 18-20 20-22 22-24 

Speed (knots) 

Plot 17.4 Main destination ports of vessels passing through Galloper Wind Farm 

Percentage 

7% 

6% 

5% 

4% 

3% 

2% 

1% 

0% 

Ipswich 

Tilbury 

Tees 

Rotterdam 

East – west traffic analysis (via TSS) 

Immingham 



Sheerness 

Destination 

17.4.18 This section presents analysis of east–west traffic through the Sunk TSS 

East. Figure 17.3(a) presents the number of vessels per day observed 

eastbound and westbound within the TSS, and Figure 17.3(b) shows these 

movements as vessel type. Taking into account the effective survey duration 

of 36 days, an average of 10 vessels per day were eastbound and 5 per day 

westbound. The higher number of eastbound vessels is largely due to 

Chatham 

Felixstowe 

Harwich 

Zeebrugge 

Braviken 

Fawley

egular ferries, which use the TSS when travelling to Rotterdam but on their 

return to Harwich take a more northerly route avoiding the TSS. 

17.4.19 Vessels using the westbound lane of the TSS were mainly headed to 

Felixstowe, Harwich and ports in the Thames. Eastbound vessels were 

predominantly destined for ports in The Netherlands (especially Rotterdam) 

and Germany. 

17.4.20 The majority of tracks were made by cargo vessels (68%), followed by 

passenger vessels (21%) and tankers (7%). The remaining vessels fell 

within the “other” group, military vessels, dredging vessels, or were 

unspecified. 

17.4.21 The westbound TSS lane is generally used by deeper draught vessels with 

almost 60% of vessels in the 8-16m draught bracket. Approximately 40% of 

vessels in the eastbound TSS fall into the same size bracket. 

North – South traffic analysis 

17.4.22 Figure 17.4 presents the number of vessels per day observed heading northsouth, 

intersecting the GWF boundary. Taking into account the effective 

survey duration of 36 days, an average of 6 vessels per day passed through 

GWF in a north–south direction. Most ships were seen travelling between 

UK east coast ports (e.g., Humber and Tees) and ports to the south (mainly 

via the Dover Strait). 

17.4.23 The majority of tracks were made by cargo vessels (54%), followed by 

tankers (32%) and fishing vessels (8%) and the average draught of tracks 

heading north–south was 5.7m. The deepest-draught vessel was the crude 

oil tanker Hengam, with a broadcast draught of 21.9m. In addition, vessels 

with deeper draughts tended to navigate further to the east. Future traffic 

levels will be assessed in the NRA. There is no indication of a significant 

increase in traffic in the area based on known proposals (Anatec, 2011 In 

prep). 







Fishing vessel activity 

Site survey results 

17.4.24 The maritime traffic survey identified fishing activity in the vicinity of the GWF 

and overall, 77 fishing vessel tracks were recorded during the survey period, 

averaging approximately two tracks per day. A plot of the combined tracks is 

presented in Figure 17.5. 

17.4.25 A total of 34 fishing vessel tracks were logged passing through the GWF 

during the survey, in addition a proportion of the unidentified vessels tracked 

on radar (non-AIS) are also likely to be fishing vessels. 

Surveillance data results 

17.4.26 Fisheries statistics in the UK are reported by ICES statistical Rectangles and 

Sub-squares. The GWF is located within ICES Rectangles 32F1 and 32F2, 

straddling four Sub-squares (see Figure 17.6). Further details on fisheries 

and the activities associated with this resource can be found in Chapter 14 

Fish and Shellfish Resource and Chapter 16 Commercial Fisheries. 

17.4.27 Data on fishing vessel sightings were obtained from the Marine Management 

Organisation (MMO). The Sea Fisheries Inspectorate (SFI) monitor the 

fishing industry’s compliance with UK, EU and international fisheries laws 

through the deployment of patrol vessels, surveillance aircraft and the sea 

fisheries inspectorate. Data were obtained for the five-year period 2005 to 

2009 and showed that between one and two fishing vessels recorded per 

patrol. Sub-square 32F1/4 had the highest average sightings per patrol at 

1.9 vessels, which includes the north-western tip of Area A and the majority 

of Area C. 

17.4.28 The MMO also operate a satellite-based vessel monitoring system, which 

receives vessel position reports approximately every 2 hours (if vessel has a 

terminal on board that cannot be polled then it must report once per hour). 

The data cover all EC countries within British Fisheries Limits and certain 

Third Countries, e.g., Norway and Faeroes. 

17.4.29 From 2005 to 2009, a total of 117 fishing vessel were recorded, the majority 

of which were located in the southern section (58%). The majority of fishing 

vessels were Belgian registered (56%). However, there was a clear 

geographical variation with Belgian vessels predominating in the western 

Sub-squares and Dutch vessels predominating in the eastern two Subsquares, 

as illustrated in Figure 17.6. Within the GWF boundary, the 

majority of vessels sighted were Belgian registered vessels (50%) and Dutch 

vessels (38%). 

17.4.30 With regard to gear type, the main fishing method used throughout the study 

area was beam trawling, accounting for approximately 70% of all sightings. 

Unspecified otter trawlers accounting for 19% of recorded sightings. The 

vast majority of vessels sighted within the GWF boundary were also beam 

trawlers (88%). 



17.4.31 93% of vessels sighted were engaged in fishing (i.e. with gear deployed), 6% 

were steaming (transiting to/from fishing grounds) and 1% were laid 

stationary (vessels at anchor or pair vessels whose partner vessel is taking 

the catch whilst the other stands by). Within the GWF boundary, the 

proportion actively fishing was slightly lower at 79%. 

Satellite data analysis 

17.4.32 The fishing vessel satellite positions recorded in 2009 and 2010, covering 

both UK and non-UK vessels of 15m length and over, have been combined 

to produce a fishing vessel density plot based for this two year period (Figure 

17.7(a)). Vessel nationality information is not available for the 2009 - 2010 

satellite data. However, data from 2006, which include nationality, tend to 

corroborate the sightings data, by indicating that the majority of activity is by 

foreign vessels (Figure 17.7(b)). 

17.4.33 Overall, the majority of fishing vessels tracked by satellite in the ICES Subsquares 

were registered in Belgium (55%) followed by the Netherlands 

(23%). This varies considerably between the western Sub-squares (32F1/2 & 

32F1/4) where the majority were Belgian registered and the eastern Subsquares 

further offshore in which Dutch vessels were the largest fleet. 

17.4.34 The Belgian fishing fleet was the largest within the GWF boundary, 

accounting for 68% of recorded satellite positions. The second largest was 

the Dutch fleet with 23%. 









Recreational activity 

17.4.35 According to the RYA’s “Sharing the Wind” publication (2004), the Thames 

Estuary Strategic Environmental Assessment area has a density of 

recreational sailing second in the UK only to the Solent area. Further details 

on recreational activities are discussed in Chapter 25 Land-use and 

Tourism and Recreation. 

17.4.36 Recreational sailing in the area consists of: 

� Canoeing and sail-boarding in the creeks and minor rivers; 

� Dinghies and other small boats in all rivers and offshore all coasts to 

about 15 nm; 

� Cruiser passage-making, both motor and sail, between all 

combinations of shore facilities; 

� Cruiser day-sailing, both motor and sail, in all coastal areas from 

Whitstable to Harwich; 

� Personal watercrafts are popular but confined to locations inshore 

only; 

� Practical sail training in the area is extensive and based out of most of 

the larger marinas; 

� ‘Traditional’ sailing craft in the area such as smacks, barges and other 

gaff-rigged craft; and 

� Visitors from Scandinavia, the Netherlands and south coast of 

England. 

17.4.37 Recreational boating, both under sail and power is highly seasonal and highly 

diurnal. The division of recreational craft routes into Heavy, Medium and 

Light Use is therefore based on the following classification: 

� Heavy Recreational Routes: very popular routes on which a minimum 

of six or more recreational vessels will probably be seen at all times 

during summer daylight hours. These also include the entrances to 

harbours, anchorages and places of refuge; 

� Medium Recreational Routes: popular routes on which some 

recreational craft will be seen at most times during summer daylight 

hours; and 

� Light Recreational Routes: routes known to be in common use but 

which do not qualify for medium or heavy classification. 

17.4.38 The recreational vessel activity and facilities in the vicinity of the GWF are 

presented in Figure 17.8. 

17.4.39 Based on the RYA published data, the wind farm is well outside the general 

racing and sailing areas off the coast. There are no cruising routes passing 



through the GWF, however, there is one light-use route shown to be heading 

via the Sunk TSS East (Separation Zone) used by traffic between the 

Thames / Harwich Haven and The Netherlands (Figure 17.8). There are 

several marinas and clubs for recreational vessels located along the coast 

near Harwich and Felixstowe. The nearest club is the Bawdsey Haven Yacht 

Club, 20nm west of the western extremity of the northern wind farm. The 

closest marinas are Shotley Marina and Titchmarsh Marina (Figure 17.8). 

17.4.40 The Inner Gabbard and The Galloper sandbanks are visited by recreational 

angling charter parties on a regular basis, where the main attraction is bass 

fishing. Diving activities in this are infrequent due to the distance from the 

shore and the limited interest of the sandbank habitats (see Chapter 25). 





Maritime incidents 

17.4.41 Data from the following sources has been analysed in order to review the 

maritime incidents that have occurred in the vicinity of the GWF site: 

� Marine Accident Investigation Branch (MAIB); and 

� Royal National Lifeboat Institution (RNLI). 

MAIB 

17.4.42 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 within 

territorial waters (i.e. within 12nm) and carrying passengers to a UK port. 

There are no requirements for non-commercial recreational craft to report 

accidents to MAIB. 

17.4.43 The locations 1 of accidents, injuries and hazardous incidents reported to 

MAIB within 10nm of the GWF boundary between January 1994 and March 

2010 are presented in Figure 17.9(a) and are colour-coded by type. 

17.4.44 A total of 53 incidents were reported in the area within 10nm of the GWF site, 

corresponding to an average of 3-4 per year. There was only one collision in 

that period, between two cargo vessels in August 1997 (pre-Sunk TSS). The 

primary causes of collision were that one vessel failed to recognise the risk of 

collision due to fog and the other vessel failed to take early and substantial 

actions to avoid a collision. There was material damage on both vessels but 

no casualties were reported. It is noted that this incident occurred prior to the 

Sunk TSS being established. 

RNLI 

17.4.45 Data on RNLI lifeboat responses within 10nm of the GWF in the ten-year 

period between 2000 and 2009 have been analysed. A total of 80 launches 

to 71 unique incidents were recorded by the RNLI (excluding hoaxes and 

false alarms). 

17.4.46 The overall distribution by casualty type is summarised in Figure 17.9(b). 

The most common vessel types involved were yachts (39%) and fishing 

vessels (23%). Power boats and other sail boats together accounted for 15% 

of all incidents. Merchant vessels accounted for 11% and other boat/vessels 

(mostly diving boats) accounted for 4%. 

17.4.47 The two main causes of incidents were machinery failure (34%) and person 

in danger (14%). The stations and types of lifeboat responding to incidents 

(ALB = all-weather lifeboat and ILB – inshore lifeboat) are detailed in the 

following section (Search and Rescue resources) 

1 MAIB aim for 97% accuracy in reporting the locations of incidents. 



17.4.48 There were seven incidents recorded within the GWF site over the 10 years 

analysed. Details of these incidents are given below: 

� Steering failure of a yacht; Harwich ALB responded on 1 st August 

2001; 

� Machinery failure on a fishing vessel; ALBs from Aldeburgh were 

launched on 10 th August 2002; 

� Machinery failure on a fishing vessel; Harwich ALB responded on 10 th 

August 2002; 

� Steering failure on a yacht; Harwich ALB responded on 13 th August 

2005; 

� Machinery failure on a yacht, Harwich ALB responded on 1 st October 

2005; 

� Machinery failure on a yacht, Ramsgate ALB responded on 19 th July 

2006 and 

� Machinery failure on an angling vessel, Aldeburgh ALB responded on 

9 th July 2007. 





Search and rescue resources 

Coastguard stations 

17.4.49 HM Coastguard 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). 

17.4.50 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. 

17.4.51 Each region is divided into six districts with its own Maritime Rescue Coordination 

Centre (MRCC), which co-ordinates the SAR response for 

maritime and coastal emergencies within its district boundaries (East of 

England Region includes an additional station, London Coastguard, for coordinating 

SAR on the River Thames). 

17.4.52 The GWF lies within the East of England Region with the nearest rescue 

coordination centre being Thames MRCC (located in Walton-on-Naze, 

Essex). MRCC Thames’s area of responsibility provides SAR coverage from 

Southwold to the Reculver towers, Herne Bay. 

17.4.53 As a result of increased congestion of the seas around the UK, increases in 

the size of ships, the increasingly busy coastline and the occurrence of more 

extreme weather conditions, there are currently proposals to modernise the 

coastguard (MCA, 2010). As part of its consultation process the MCA held a 

series of public meetings, concerning the proposed Coastguard 

modernisation, which ended in March 2011. Improvements centre on 

modernising the coastguard structures and systems which includes the 

creation of a nationally networked system of operations centres (MCA, 2010). 

SAR helicopters 

17.4.54 A review of the assets in the area of the wind farm site indicated that the 

closest SAR helicopter base is located at Wattisham, operated by the RAF, 

approximately 37nm to the northwest of the GWF (Figure 17.10). 

17.4.55 This base has Sea King helicopters with a maximum endurance of 6 hours 

and speed of 110mph giving a radius of action of approximately 250nm which 

is well within the range of the GWF. One helicopter is available at 15 minutes 

readiness between 0800 and 2200 hours, with another available at 60 

minutes readiness between 0800 hours and evening civil twilight (ECT). 

Between 2200 and 0800 hours, one helicopter is held at 45 minutes 

readiness. 

RNLI Lifeboats 

17.4.56 The RNLI stations in the vicinity of the GWF are presented in Figure 17.10. 

At each of these stations crew and lifeboats are available on a 24-hour basis 

throughout the year. 



17.4.57 Table 17.6 provides a summary of the facilities at the stations closest to the 

GWF. Based on the offshore position of the development it is likely that 

ALBs would respond to an incident at the wind farm from Aldeburgh and 

Harwich. The time for an all-weather lifeboat to reach GWF would be 

approximately one hour from the nearest RNLI station. 

Table 17.6 Lifeboats held at nearby RNLI stations 

Station Lifeboats ALB Spec ILB Spec Distance to Site 

Boundary 

Aldeburgh ALB/ ILB Mersey D Class 16nm 

Harwich ALB/ ILB Severn 

Walton & 

Frinton 

B Class 

(Atlantic) 

24nm 

ALB Tyne -- 23nm 

Clacton ILB -- 

B Class (Atlantic)/ 

D Class 

27nm 

West Mersea ILB -- B Class (Atlantic) 37nm 





Salvage 

17.4.58 MCA charters four Emergency Towing Vessels (ETV) to provide emergency 

towing cover in winter months in the four areas adjudged to pose the highest 

risk of a marine accident: the nearest being Dover Strait. 

17.4.59 MCA has an agreement with the British Tug owners Association (BTA) for 

emergency chartering arrangements for harbour tugs. The agreement covers 

activation, contractual arrangements, liabilities and operational procedures, 

should MCA request assistance from any local harbour tug as part of the 

response to an incident. 

17.5 Assessment of Impacts – Worst Case Scenario 

17.5.1 Full details on the range of options being considered by GWFL are provided 

throughout Chapter 6 Project Details. For the purpose of the shipping and 

navigation impact assessment, the worst case scenario, taking into 

consideration these options, is detailed in Table 17.6. 

Table 17.6 Worst case project design for shipping and navigation impact assessment 

Impact Realistic worst case scenario Justification 

Construction 

Ship-to-installation 

collision risk 

Ship-to-ship collision 

risk 

Operation 

140 WTGs 

3 met masts 

Up to 4 ancillary structures 

(comprising offshore substation 

platform(s) (OSP), collection 

platform(s) and/or 

accommodation platform) 

All mounted on jacket 

foundations of the largest 

dimensions at sea level (40m x 

30m) 

Largest number of greatest area 

structures, therefore greatest 

collision potential 

Construction vessel traffic* At present it is based on 

experience and expert 

judgment. 

Re-routing Exclusion of all shipping from 

GWF area 

Ship-to-ship collision As for construction 17.7.8 

17.7.3 – 17.7.7 



Impact 

risk 

Realistic worst case scenario Justification 

Ship-to-installation 


As for construction 17.7.12 

Impact on dredging Based on the relative positions 

of the dredge areas to GWF 

Impact on recreation Most vessels still able to pass 

through GWF, although 

assumes 50m operational 

safety zone around structures 

Impact on fishing As for ship-to-installation 


Impact from sub-sea 

cables 

Impact on marine 

radar 

Assuming fishing effort stays at 

current level 

17.7.15 

17.7.20 

17.7.26 

Qualitative. 17.7.32 

It is assumed the cable route will 

be protected against impacts 

from the local anchoring, 

dredging and trawling practices, 

such that the risks are made 

ALARP. 

140 WTGs 17.7.39 – 17.7.47 

Impact on SAR 140 WTGs 17.7.48 – 17.7.54 

Decommissioning 

All impacts as per 

operation 

17.8.1 

* At this stage it is not possible to predict how many vessels will be needed on site and for 

how long 

17.5.2 The current matrices are based on expert judgment. They will be revised 

following the Hazard Review Workshop later in May and finalised in the full 

NRA report. Any higher risk scenarios will be subject to quantitative 

modelling within the NRA. 



17.6 Assessment of Impacts during the Construction Phase 

17.6.1 The GWF will have a potential impact on commercial shipping due to: 

� Increased ship-to-ship collision risk; and 

� Increased ship-to-installation collision risk. 

17.6.2 This section summarises impacts and mitigation specific to the construction 

phase. Impacts and mitigation which apply in all phases are discussed within 

the operational phase assessment, Section 17.7. 

17.6.3 The following risk matrices were developed for the construction phase 

(Anatec, 2011) (Plot 17.5 and 17.6). Refer to Table 17.4 and 17.5 for the 

definitions of frequency and consequence. 

Plot 17.5 Construction phase – collision with wind farm structures 

Consequence 

5 

4 

3 

2 x 

1 

1 2 3 4 5 

Frequency 

Definitions 


(Low Risk) 


Risk) 


Risk) 

Plot 17.6 Construction phase risk results – collision with other vessels 

Consequence 

5 

4 

3 x 

2 

1 

1 2 3 4 5 

Frequency 

Definitions 


(Low Risk) 


Risk) 


Risk) 

17.6.4 Collision with a wind farm structure has a score of 8 (frequency of 4 x 

consequence of 2) and collision with other vessels has a score of 9 



(frequency of 3 x consequence of 3) (see Tables 17.4 and 17.5). The overall 

risk level is assessed to be Moderate (Tolerable) in each case. 

Potential impacts due to vessel collisions 

17.6.5 The presence of construction vessels within the GWF will pose collision risks 

to wind farm structures and other vessels. There may also be increased 

collision risk associated with vessel movements between the GWF and the 

operations base(s). 

17.6.6 This potential impact would be of moderate adverse significance for 

collisions with structures, and moderate/high adverse significance for 

collisions with other vessels. 

Mitigation and residual impact 

17.6.7 The above assessment assumes industry good practice will be applied to 

minimise the construction phase risks. Examples would include: 

� Uniform WTG array in a grid pattern; 

� Guard vessel during construction; 

� Learning lessons from past accidents / near-misses; 

� Stringent selection process for construction and maintenance vessels; 

� AIS traffic monitoring during operation; 

� Promulgation of information to local stakeholders (ports, fishing, 

recreation); and 

� ERCoP developed in consultation with RNLI and MCA. 

17.6.8 Hazard/risk assessment workshops will be carried out as part of the 

construction project-planning process. The objective of the workshops will be 

to identify all of the different activities which will be taking place and identify 

any potential hazards as well as appropriate mitigation measures and 

operating procedures relevant to the selected vessels and construction 

methods, e.g., passage plans for routeing between the site and onshore 

base. 

17.6.9 It is noted that the construction company appointed will have their own 

internal Health and Safety procedures that they will adhere to during the 

work, providing additional security. Experience and lessons learned from the 

construction of other offshore wind farm projects will also be considered, 

most notably the experience gained during the construction of the adjacent 

GGOWF. 

17.6.10 500m safety zones around construction works (as discussed in Chapter 6 

Project Details) will be applied for during the construction phase. This 

precaution will provide a means of regulating the rights of navigation so as to 

preserve the safety of those working in the GWF and those onboard other 



vessels that may be navigating in this area. The safety zones will apply to all 

vessel types not involved in the wind farm operations. 

17.6.11 A guard vessel (or vessels) will be nominated during the construction phase 

with responsibility for monitoring passing traffic and intervening in the event 

of a vessel approaching on an unsafe course. A site-specific collision risk 

management plan will be provided to this vessel. 

17.6.12 Other general mitigation measures that apply to all phases of development, 

such as marking and lighting, are outlined in Section 17.7. Additional 

potential measures will be discussed at the Hazard Review Workshop 

involving local maritime stakeholders which is scheduled as part of the NRA. 

17.6.13 Based on applying these mitigation measures, and by following industry good 

practice, it is considered the residual risks will be As Low As Reasonably 

Practicable (ALARP). 

17.7 Assessment of Impacts during the Operational Phase 

17.7.1 Impacts during operation are discussed in the following paragraphs. 

Mitigation measures are listed at the end as the majority apply to all potential 

impacts described. However, particular mitigation applying to any specific 

impacts is presented where appropriate. Potential impacts during operation 

will be: 

� Re-routeing existing vessel traffic; 

� Increased ship-to-ship collision risk; 

� Increased ship-to-installation collision risk; 

� Impacts on dredging activity; 

� Impacts on recreational vessels; 

� Impacts on fishing vessels; 

� Impacts from sub-sea cables; 

� Impacts on marine radar; and 

� Impacts on SAR. 

Potential impacts on commercial shipping 

Re-routeing of existing traffic 

17.7.2 Based on the analysis of the shipping survey data, it was identified that six 

vessels per day passed through the northern part and seven per day through 

the southern part of the GWF (although some tracks crossed both sections). 

17.7.3 The most potential for impact is upon vessels that pass north – south through 

the GWF. These vessels were mainly travelling between UK east coast 

ports, e.g., Humber, and ports to the South, such as Ostend or via the Dover 

Strait to ports such as Southampton or Le Havre. 



17.7.4 As a result of the GWF development these vessels will have to re-route to the 

east or use the alternative route to the west via the Sunk TSS. For the 

vessels choosing to pass further to the east to avoid the GWF, their overall 

voyage distance increases by less than 1% of the overall distance which is 

not considered to be significant. 

17.7.5 The east-west traffic through the Sunk TSS East will also be affected by the 

operational GWF. An average of 10 vessels per day pass eastbound and 5 

per day pass westbound through the TSS. Vessels using the westbound 

lane of the TSS were mainly headed to Felixstowe, Harwich and ports in the 

Thames, whilst eastbound vessels were predominantly destined for ports in 

The Netherlands (especially Rotterdam) and Germany. The sea room 

available to east-west vessels will be constrained by the GWF WTGs to the 

north and south. However, the TSS extension will manage the traffic passing 

in the vicinity of GWF, routeing it parallel to the GWF WTGs (as is the case at 

GGOWF). This significantly mitigates the impact. 

17.7.6 Based on the EIA Methodology, the significance of this impact is considered 

to be Moderate. The residual impact with mitigation (see below) is Minor. 

Increased ship-to-ship collision risk 

17.7.7 The reduction in sea room as a result of the operational GWF, as well as the 

displacement of traffic, will result in ships potentially passing closer together 

as well as an increased risk of ship-to-ship encounters / collisions. This is 

being modelled as part of the NRA. 

17.7.8 MCA have received approval for the extension from the United Kingdom 

Safety Of Navigation (UKSON). They have now submitted the proposal to 

the International Maritime Organisation (IMO). It will be discussed at the 57 th 

Session of the NAV Sub-Committee (NAV 57) in June 2011. If passed it will 

be ratified in approximately November 2011 and come into effect on 1 st July 

2012. It separates the opposing traffic when in the vicinity of GWF, reducing 

the risk of head-on encounters in an area of restricted sea room. The 

extended TSS will be aligned with the new wind farm boundary so that it 

extends the existing separation at GGOWF to the eastern limit of GWF. 

17.7.9 Risk assessment carried out indicated the TSS extension significantly 

reduced the risk of collision (compared to the wind farm going ahead with no 

TSS extension). 

17.7.10 Although there has been shown to be a net increase in collision risk, the 

planned extension of the Sunk TSS to the east, as illustrated below, 

significantly mitigates this increase. 

17.7.11 In addition to the mitigation measures outlined in paragraphs 17.7.40 to 

17.7.43, an extension to the Sunk TSS is planned in order to mitigate for 

these potential impacts. The extension is illustrated in Figure 17.11. 

17.7.12 The following risk matrix was developed for the change in ship-to-ship 

collision (Plot 17.7). 



Plot 17.7 Operational phase – ship-to-ship collision risk 

5 

4 

3 x 

2 

1 

1 2 3 4 5 

Frequency 

Definitions 

Broadly Acceptable 

Region (Low Risk) 

Tolerable Region 

(Moderate Risk) 

Unacceptable 

Region(High Risk) 

17.7.13 An overall score of 6 was estimated (frequency of 2 x consequence of 3). 

The change in ship-to-ship collision risk is considered to be Low (Broadly 

Acceptable). This takes into account mitigation in the form of the planned 

TSS extension. Other mitigation is discussed at the end of this section. 





Increased ship-to-installation collision risk 

17.7.14 Vessels in the area will also be at risk of collision with the surface structures 

associated with the GWF. This could be as a result of a vessel going off 

course either due to watch-keeper error or mechanical breakdown. 

17.7.15 The following risk matrix was developed for the ship-to-structure collision 

(Plot 17.8). 

Plot 17.8 Operational phase – ship-to-structure collision risk 

Consequence 

5 

4 

3 x 

2 

1 

1 2 3 4 5 

Frequency 

Definitions 





Unacceptable 


17.7.16 With an overall score of 9 estimated (frequency of 3 x consequence of 3), the 

risk would be Moderate (Tolerable). This takes into account mitigation in 

the form of the planned TSS extension. Other mitigation is discussed at the 

end of this section. 

Potential impact on dredging activity 

17.7.17 The vessel traffic surveys identified dredging operations within the Sunk TSS, 

near to the Sunk Centre. The most relevant areas with regard to the GWF 

are the application / prospecting areas in close proximity to the export cable 

corridor, in particular Shipwash 507/5 (Cemex UK Marine Ltd) which is 

located within the cable corridor. 

17.7.18 Consultation with Cemex UK Marine Ltd with regard to their application 

areas, is ongoing at the time of writing the PER, the final ES will incorporate 

the findings of these discussions. 

17.7.19 The closest dredging licence site is Area 119/3 (Inner Gabbard), which is 

operated by Hanson Aggregates Marine Ltd, at approximately 3.9nm to the 

north west of the southern section of the GWF. Given the distance from the 

GWF, there is not anticipated to be any significant impact on the dredging 

operations (e.g. steaming times will not be increased significantly) In 

addition, consultation with Hanson Aggregate did not highlight any specific 

issues (see Table 17.1). 

17.7.20 As there is limited overlap with dredging activities and there will only be a 

small change to steaming times, the impact due to the proposed 

development would be considered to be of negligible significance. This 



assessment is subject to confirmation through further consultation regarding 

the overlap between the cable corridor and a dredging application area. The 

residual impact with mitigation (see below) would also be of negligible 

significance. 

17.7.21 Further information on the potential impacts associated with dredging / 

extraction within the vicinity of the GWF is detailed in Chapter 19 Other 

Human Activities. 

Potential impact on recreational vessels 

17.7.22 The air clearance between WTG rotors and sea level conditions at Mean 

High Water Springs (MHWS) will not be less than 22m, as recommended by 

the MCA and RYA. This minimises the risk of interaction between rotor 

blades and yacht masts. 

17.7.23 In terms of vessel routeing, recreational vessels should be able to pass 

between WTGs in suitable conditions. Based on the activity review and 

consultation, the level of activity is not considered to be significant (light and 

medium-use as defined by RYA/CA). Recreational vessels heading eastwest 

through the area will be able to continue to avoid commercial shipping 

by using the separation zone of the extended TSS. They may also pass 

between WTGs in suitable conditions. 

17.7.24 The following matrix was developed for the risk of collision between a 

recreational vessel and a wind farm structure (Plot 17.9). 

Plot 17.9 Operational phase – recreational vessel collision risk 

Consequence 

5 

4 

3 

2 x 

1 

1 2 3 4 5 

Frequency 

Definitions 


(Low Risk) 


Risk) 

Unacceptable Region(High 

Risk) 

17.7.25 An overall score of 6 was estimated (frequency of 3 x consequence of 2). 

The risk is considered to be ‘Broadly Acceptable’. This assumes standard 

mitigation, such as appropriate marking and lighting of the structures, which 

is discussed at the end of this section. 

17.7.26 Further impacts associated with recreational activities are assessed within 

Chapter 25 Land use, tourism and recreation. 



Potential impact on fishing vessels 

17.7.27 The commercial fisheries study identified the potentially impacted fishing fleet 

as the offshore passive gear sector as well as trawlers based in Belgium, the 

Netherlands and France (see Chapter 16). 

17.7.28 No restriction is to be placed on fishing vessel activity once the site is 

operational (apart from 50m safety zones around WTGs), therefore this 

assessment assumes (using a precautionary approach) that the level of 

fishing will remain the same. Therefore there will be an increased risk of 

fishing vessel collision in the area (i.e. the potential for fishing vessels to 

collide with WTGs). In practice, the increased risk of collision or snagging of 

gear may well lead to a reduction in the use of the site (see Chapter 16 for 

details). Fishing vessel activity within the site is likely to be limited given the 

location of cables and the offshore structures. 

17.7.29 The following matrix was developed for the risk of collision between a fishing 

vessel and a wind farm structure (Plot 17.10). 

Plot 17.10 Operational phase – fishing vessel collision risk 

Consequence 

5 

4 

3 x 

2 

1 

1 2 3 4 5 

Frequency 

Definitions 


(Low Risk) 


Risk) 

Unacceptable Region(High 

Risk) 

17.7.30 With an overall score of 9 was estimated (frequency of 3 x consequence of 

3), the risk would be considered as Moderate (‘Tolerable’). This assumes 

standard mitigation, such as appropriate marking and lighting of the 

structures, which is discussed at the end of this section. 

17.7.31 Further impacts associated with commercial fisheries are assessed in 

Chapter 16. 

Potential impact as a result of subsea cables 

17.7.32 All the subsea cables associated with the GWF will be buried or trenched to 

protect against hostile seabed interaction, such as fishing activity, dragging of 

anchors and dropped objects and there will be periodic inspections to ensure 

cables do not become exposed. Cable crossings will require additional 

protection such as rock dump or mattressing. All cables will also be marked 

on Admiralty Charts. 

17.7.33 The export cable corridor to shore is likely to run from the north-western 

boundary of the site to a planned landfall in Sizewell (see Chapter 6). There 



will also be inter and intra-array cables connecting Development Areas A, B 

and C as well as intra-array cabling connecting individual wind turbine 

generators (WTGs). 

17.7.34 As the cable routes are not routed through any existing anchorage area they 

are unlikely to impact shipping in the area. There will be a risk of a vessel 

dropping anchor on a cable in an emergency, however, the cables will be 

marked on hydrographic charts and vessels should be aware of their 

location. 

17.7.35 As noted above, an aggregate dredging application area overlaps the cable 

corridor, the potential impact of this is to be discussed during ongoing 

consultation (see 17.7.21) 

17.7.36 The following matrix was developed for the risk of fishing gear or anchor 

interaction with subsea cables (Plot 17.11). 

Plot 17.11 Operational phase – risk associated with subsea cables 

Consequence 

5 

4 

3 

2 x 

1 

1 2 3 4 5 

Frequency 

Definitions 





Unacceptable 


17.7.37 With an overall score of 6 was estimated (frequency of 3 x consequence of 

2), the risk would be considered to be Low (‘Broadly Acceptable’). This 

assumes standard mitigation, such as inclusion on Kingfisher charts, which is 

discussed at the end of this section. 

17.7.38 Further impacts associated with subsea cables are assessed within Chapter 

19. 

Potential impact on marine radar systems 

17.7.39 Radar is the only equipment expected to be significantly affected based on 

the trials carried out to date (Anatec 2011, In prep). A full justification for this 

assessment will be documented in the NRA and reported in the ES. 

17.7.40 Trials carried out by the MCA at North Hoyle in 2004 identified areas of 

concern with regard to the potential impact of WTGs on ship borne and shore 

based radar systems. This is due to the large vertical extent of the WTGs 

returning radar responses strong enough to produce interfering side lobe, 

multiple and reflected echoes (ghosts). 



17.7.41 Based on the results of the North Hoyle trial, the MCA produced a wind farm / 

shipping route template to give guidance on the distances which should be 

established between shipping routes and offshore wind farms. A second trial 

was conducted at Kentish Flats on behalf of BWEA (BWEA, 2007). 

17.7.42 The radar effects described are only likely to pose a potential safety risk 

within 2nm of the WTGs in reduced visibility when the ship watch-keeper is 

unable to verify the radar information visually. AIS information can be used 

to verify the targets of larger vessels, generally ships above 300 tonnes. 

17.7.43 Experienced mariners should be able to suppress the observed problems to 

an extent and for short periods by careful adjustment of the receiver 

amplification (gain), sea clutter and range settings of the radar. However, 

there is a consequent risk of losing targets with a small radar cross section, 

which may include buoys or small craft, particularly yachts or Glass 

Reinforced Plastic (GRP) constructed craft, therefore due care is needed in 

making such adjustments. 

17.7.44 Similar impacts on marine radar are anticipated at the operational GWF. For 

ships passing east to west between the sites, the impact is anticipated as 

being the same as for the GGWOF (extending the duration). For the other 

main shipping routes, vessels are able to pass further from the GWF 

boundary. 

17.7.45 Based on the EIA Methodology (see Chapter 5 EIA Process), the 

significance of this impact would be considered to be of moderate adverse 

significance. The residual impact with mitigation (see below) considered of 

minor adverse significance. 

17.7.46 Following consultation with Harwich Haven Authority and MCA, consideration 

is being given to an additional radar scanner to provide radar coverage 

further to the east of the GWF. This will help to mitigate for the potential 

impacts by maintaining / enhancing VTS coverage. 

17.7.47 In addition the TSS extension will also reduce the potential impacts 

associated with marine radar systems. The onset range from turbines of 

false radar returns is estimated to be about 1.5 nautical miles, with 

progressive deterioration in the radar display as the range closes. The TSS 

will help control the minimum passing distances for eat-west shipping. Ships 

using the TSS will maintain a minimum offset of 1.5-2nm from turbines. 

Without the TSS, some vessels would pass much closer and thus experience 

more severe radar interference. 

Impact on Search and Rescue (SAR) 

17.7.48 The GWF lies within the East of England Region with the nearest Maritime 

Rescue Co-ordination Centre, being MRCC Thames (located in Walton on 

the Naze). 

17.7.49 In the event of an emergency arising within or adjacent to the GWF the main 

types of search and rescue would be carried out by RNLI all-weather lifeboat 



and/or SAR helicopter. A review of the assets in the area of the GWF 

indicated that the closest all-weather lifeboat is 16nm away at Aldeburgh, 

whilst there is a SAR helicopter base located at Wattisham, approximately 

37nm NW from the GWF. This RAF base has Sea King helicopters with a 

maximum endurance of 6 hours giving a radius of action of approximately 

250 nm which is well within the range of the GWF. 

17.7.50 A review of historical incidents indicated that the incident levels in the vicinity 

of the GWF have been relatively low. 

17.7.51 The GWF could impact upon SAR in two ways. Firstly the rotating blades of 

the WTGs could interfere with the ability of SAR aircraft to respond to an 

incident within or near to the wind farm. Secondly, the wind farm itself could 

lead to an increase in the level of incidents which could stretch SAR 

resources in the area (RNLI lifeboats and SAR helicopter). 

17.7.52 Based on the EIA Methodology, the significance of this impact would be 

considered to be of moderate adverse significance. The residual impact 

with mitigation (see below) considered of minor adverse significance. 

17.7.53 However, as a result of the design features associated with the GWF, and 

commitments by the developer to meet the MCA MGN 371 guidance and 

industry best-practice, GWFL will meet all the requirements of MGN 371 

Annex 5 “Standards and procedures for generator shutdown and other 

operational requirements in the event of a search and rescue, counter 

pollution or salvage incident in or around an OREI”. This includes having an 

Emergency Response Co-operation Plan (ERCoP) in place for each phase of 

the development. 

17.7.54 The above is standard practice and the wind farm will not be granted consent 

without a commitment to meet these requirements including the development 

of an Emergency Response Co-operation Plan (ERCoP) pre-construction, it 

is considered that SAR issues can be well managed. 

Mitigation and residual impact 

17.7.55 The original proposal for the GWF covered an area of 68nm 2 (233km 2 ) and 

encroached on busy shipping lanes. Following collection of preliminary 

maritime traffic survey data in 2009 and consultation with stakeholders (e.g. 

MCA, Trinity House and Chamber of Shipping) the GWF was resized to 

cover an area of 53nm 2 (183km 2 ), to reduce the impact on the adjacent 

shipping routes. 

17.7.56 The extension of Sunk TSS East would significantly reduce the collision risks 

identified in the preceding paragraphs. 

17.7.57 A list of other planned mitigation measures, of relevance to all the potential 

impacts described, is presented below: 



� Information Circulation – appropriate liaison to ensure information on 

the wind farm and special activities is circulated in Notices to Mariners, 

Navigation Information Broadcasts and other appropriate media; 

� Monitoring of vessels by Marine Coordination Centre; 

� Radar coverage from Dover Coastguard maintaining Sunk VTS 

coverage; 

� Marking and Lighting – throughout the project marine navigational 

marking will be provided in accordance with Trinity House 

requirements, which will comply with the IALA standards and the 

additional requirements of MGN 371; 

� Minimum blade clearance to avoid potential yacht mast interaction; 

� Cable burial and protection; 

� Compliance with MCA MGN 371; and 

� Formulation of an Emergency Response Cooperation Plan (ERCoP). 

17.7.58 As a result of the mitigation measures outlined above, and the additional 

measures described under the relevant impacts, it is anticipated that the 

residual impacts for all potential impacts would be of minor adverse 

significance. The exception to this is the potential for ship collision with wind 

farm structures, where the residual impact would be of moderate adverse 

significance. 

17.7.59 Additional potential mitigation measures for the operational phase will be 

discussed at the Hazard Review Workshop involving local maritime 

stakeholders which is scheduled as part of the NRA. 

17.8 Assessment of Impacts during the Decommissioning Phase 

17.8.1 The discussions presented on impacts during operation are considered to 

apply to the decommissioning phase. As a result the potential collision risk 

during this phase, after the application of the appropriate mitigation 

measures, is anticipated to be ALARP. 

17.9 Inter-relationships 

17.9.1 The inter-relationships between the shipping and navigation and other 

physical, environmental and human receptors are inherently considered 

throughout the assessment of impacts within this Chapter where they have 

influence on shipping and navigation. Where shipping and navigation has 

the potential to influence other receptors, and these have been duly 

considered within the respective Chapters and indirect effects. Table 17.3 

summarises those inter-relationships that are considered of relevance to 

shipping and navigation and identifies where within the PER these 

relationships have been considered. 



Table 17.3 Inter-relationships for Shipping and Navigation 

Inter-relationship Section where addressed Linked Chapter 

Impacts on fisheries 

activities 

Impacts on recreational 

activities 

Impacts associated with 

subsea cables 

Impacts associated with 

dredging activities 

Section 17.7 (Paragraphs 

17.7.17 - 19) 

Section 17.7 9 (Paragraphs 

17.7.13 – 16) 

Section 17.2 (Paragraphs 

17.7.20 – 24) 

Section 17.7 )Paragraphs 

17.7.12 – 15) 

Chapter 16 

Chapter 25 

Chapter 19 

Chapter 19 

17.9.2 Chapter 29 Inter-relationships provides a more detailed consideration of 

the spatial and temporal scale under which inter-related impacts may be 

experienced by the receptor. 

17.10 Cumulative Impacts 

17.10.1 Figure 17.12 presents the wind farm developments in the vicinity of the 

GWF. The GGOWF site has been considered intrinsically within the analysis 

(i.e. as part of the baseline). 

17.10.2 The offshore wind farms in the Thames Estuary are of a scale and at a 

sufficient distance from the GWF site that it is not considered there will be a 

significant cumulative impact on shipping and navigation. The main issue for 

the NRA is safety of navigation rather than financial cost. However, the fact 

that the deviation is only about 1% for north-south ships (the main route 

affected) and none of the shipping operators highlighted the issue during 

consultation suggests the financial impact is minimal. 

17.10.3 The only site currently with the potential to result in a cumulative navigational 

impact with GWF is the proposed East Anglia ONE (the location of further 

development within the East Anglia Zone has not been determined at the 

time of writing therefore it has not been possible to assess potential impacts 

at this juncture). The East Anglia ONE site is located at a distance of 15nm 

northeast of the proposed Sunk TSS east extension. Both wind farm 

developments will lead to north-south shipping being displaced and therefore 

passing between the two sites. However, there is approximately 13nm of sea 

room available between the GWF and East Anglia ONE which will reduce the 

potential for cumulative impacts. 

17.10.4 No potential for significant cumulative impacts on shipping and navigation, 

due to the GWF and other activities in the area, have been identified. 





17.11 Outline Monitoring 

17.11.1 Monitoring relevant to shipping and navigation will take place throughout the 

development programme, this will comprise of: 

� Traffic monitoring during the construction phase of the project, with a 

vessel (or vessels) assigned for guard duties; 

� Vessel monitoring during the operation phase which will be carried out 

using AIS from the marine coordination centre; and 

� Regular cable inspections to ensure adequate burial is maintained. 

17.12 Summary 

17.12.1 This Chapter discusses the existing shipping and navigation interests within 

the vicinity of the GWF site through a review of fishing vessel activity, 

recreational vessel activity, maritime incidents and Search and Rescue 

(SAR) resources. The main navigational features in the vicinity of the GWF 

are the Sunk Area (including Traffic Separation Schemes) and the Port 

Operations at Harwich Haven Authority (HHA) and Port of London Authority 

(PLA). A variety of vessels use the shipping lanes surrounding the GWF site 

including fishing vessels, cargo vessels and passenger ferries. 

17.12.2 A summary of the results is presented in the following table. It should be 

noted that the risk rankings for the shipping and navigation assessment 

assume standard mitigation will apply based on industry good practice. 

Therefore the pre-mitigation risk/impact in Table 17.4 is shown as N/A. The 

rankings may be revised if additional mitigation is identified at the Hazard 

Review Workshop involving local maritime stakeholders, which has been 

scheduled as part of the NRA. 

Table 17.4 Impact assessment summary 

Description of Impact 

Construction Phase 

Collision risk 

/structures 

Collision Risk/Other 

Vessels 

Risk / 

Impact 

N/A (see 

Paragraph 

17.12.2) 

N/A (see 

Paragraph 

17.12.2) 

Potential Mitigation Measures 

Operating Procedures 

Selection of vessels 

Lessons learnt from other projects 

Guard Vessel 

Passage Planning 

Marking/Lighting 

Safety Zones 

Notices to Mariners 

Residual 

Impact 

8 (Tolerable) 

9 (Tolerable) 




Operational Phase 

Re-Routeing of 

shipping 

Ship to Ship collision 

risk 

Ship collision with 

Structures 

Risk / 

Impact 

Moderate 

adverse 

N/A (see 

Paragraph 

17.12.2) 

N/A (see 

Paragraph 

17.12.2) 


TSS Extension 


Aids to Navigation 

Site boundary modification 

TSS Extension 

Marking and Lighting 


Alignment of turbines 


TSS Extension 



Marked on Hydrographic Charts 


Impact on Dredging Negligible Marking and Lighting 

Recreational vessel 

collision 

N/A (see 

above) 

Fishing vessel collision N/A (see 

Paragraph 

17.12.2) 



Minimum Blade Clearance 

TSS Extension 









Residual 

Impact 

Minor 

adverse 

6 (Broadly 

Acceptable) 

9 (Tolerable) 

Negligible 

6 (Broadly 

Acceptable) 

9 (Tolerable) 




Risk / 

Impact 

Cable route interaction N/A (see 

Paragraph 

17.12.2) 

Interference with 

Marine Radar 

Moderate 

adverse 

Search & Rescue Moderate 

adverse 

Decommissioning Phase 

Impacts as 

construction 


Cable Burial 



Kingfisher notifications 

Regular inspection/surveying of route 

Cable corridor selection 


TSS Extension 

Radar Scanner 


Meet MGN 371 requirements. 

ERCoP in place 

Alignment and marking/lighting of 

turbines. 

Residual 

Impact 

6 (Broadly 

Acceptable) 

Minor 

adverse 

Minor 

adverse 

N/A N/A N/A 

17.12.3 No potential cumulative impacts on shipping and navigation due to the GWF 

and other activities in the area have been identified. 

17.12.4 Monitoring relevant to shipping and navigation, including vessels and traffic 

monitoring, will take place throughout the development programme. In 

addition, regular cable inspections will be undertaken. 

17.13 References 

Anatec Limited (2011). Galloper Navigation Risk Assessment, Report No. 

A2258-GWF-NRA-1, In prep. 

BWEA (now RenewableUK) (2007). Investigation of Technical and 

Operational Effects on Marine Radar close to Kentish Flats Offshore Wind 

Farm, BWEA, April 2007. 

Danbrit Ship Management Ltd (DSML) (2011). Galloper Wind Farm Project 

Commercial Fisheries Assessment Draft V5 26032011.doc 



DECC (2007). Applying for Safety Zones around Offshore Renewable Energy 

Installations, Guidance notes, August 2007. 

IMO (2002). Guidelines for Formal Safety Assessment (FSA) for use in the 

IMO rule Making Process, 5th April 2002. 

IMO (2007). Consolidated text of the Guidelines for Formal Safety 

Assessment (FSA) for use in the IMO rule-making process 

(MSC/Circ.1023−MEPC/Circ.392) (14th May 2007). 

MCA (2002). Search and Rescue Framework for the United Kingdom of 

Great Britain and Northern Ireland, June 2002. 

MCA (2004). Results of the EM Investigations and assessments of marine 

radar, communications and positioning systems undertaken at the North 

Hoyle Wind Farm by QinetiQ and the Maritime & Coastguard Agency; 29 

September 2004. 

MCA (2005). Offshore Wind Farm Helicopter Search and Rescue Trials 

undertaken at the North Hoyle Wind Farm, May 2005. 

MCA (2010). Protecting our Seas and Shores in the 21 st Century. 

Consultation on proposals for modernising the Coastguard 2010. Available at 

http://www.dft.gov.uk/mca/consultation_on_the_proposals_for_modernising_t 

he_coastguard.pdf. 

RYA (2004). Sharing the Wind. Recreational Boating in the Offshore Wind 

Farm Strategic Areas. Identification of recreational boating interests in the 

Thames Estuary, Greater Wash and North West (Liverpool Bay) Available at 

http://www.rya.org.uk/sitecollectiondocuments/legal/Web%20Documents/Env 

ironment/Sharing%20the%20Wind%20compressed.pdf. 

RYA (2009). The RYA’S position on offshore energy developments) Available 

at 

http://www.rya.org.uk/SiteCollectionDocuments/legal/Web%20Documents/En 

vironment/RYA%20position%20OREI%20Dec%202009.pdf. 

RYA (2009). Second Edition, UK Coastal Atlas of Recreational Boating 

published by RYA, supported by Trinity House and Cruising Association. First 

published 2005. 

Trinity House (2005). Renewable Energy Installations Farms and Fields, 

Provision and Maintenance of Local Aids to Navigation by Trinity House 

Lighthouse Service; October 2005.

Galloper Wind Farm Project - Galloper Wind Farm proposal

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