Thanet Extension Offshore Wind Farm Shipping and Navigation - Pilotage Study

Transcription

1 Thanet Extension Offshore Wind Farm Shipping and Navigation - Pilotage Study Volume 4, Annex 10-1 Thanet Extension Offshore Wind Farm

2 Vattenfall Wind Power Ltd Thanet Extension Offshore Wind Farm November 2017 Copyright 2017 Vattenfall Wind Power Ltd All pre-existing rights retained Drafted By: Marico Marine Approved By: Helen Jameson Date of Approval November 2017 Revision A Vattenfall Wind Power Ltd First Floor 1 Tudor Street London EC4Y 0AH T Liability In preparation of this document Vattenfall Wind Power Ltd (VWPL) and their consultants have made reasonable efforts to ensure that the content is accurate, up to date and complete for the purpose for which it was prepared. Neither VWPL nor their contractors make any warranty as to the accuracy or completeness of material supplied. Other than any liability on VWPL or their contractors detailed in the contracts between the parties for this work, neither VWPL or their contractors shall have any liability for any loss, damage, injury, claim, expense, cost or other consequence arising as a result of use or reliance upon any information contained in or omitted from this document. Any persons intending to use this document should satisfy themselves as to its applicability for their intended purpose. Where appropriate, the user of this document has the obligation to employ safe working practices for any activities referred to and to adopt specific practices appropriate to local conditions. Thanet Extension Offshore Wind Farm

3 GOBE CONSULTANTS LTD THANET EXTENSION OFFSHORE WIND FARM: PILOTAGE STUDY TECHNICAL NOTE Report Number: 16UK1255 Issue: 02 Date: 23 May 2017 MARINE AND RISK CONSULTANTS LTD

4 GOBE CONSULTANTS LTD THANET EXTENSION OFFSHORE WIND FARM: PILOTAGE STUDY TECHNICAL NOTE Prepared for: Author(s): Checked By: GoBe Consultants Ltd 34 Devon Square Newton Abbot Devon TQ12 2HH Andrew Rawson and Rebecca Worbey Jamie Holmes Date Release Prepared Authorised Notes 03/05/2017 Draft A AR & RW JJH 12/05/2017 Issue 01 AR &RW JJH 23/05/2017 Issue 02 AR & RW JJH Marine and Risk Consultants Ltd Marico Marine Bramshaw Lyndhurst SO43 7JB Hampshire United Kingdom Tel (0) /05/2017 GoBe Consultants Ltd i

5 EXECUTIVE SUMMARY This study considers the pilotage operations in the Thames Estuary around the existing Thanet Offshore Wind Farm and how a proposed extension might impact upon them. The current wind farm consists of 100 Vestas 3 MW wind turbine generators (WTG) with a proposal to develop up to an additional 34 WTGs with a capacity of up to 12 MW. A proposed layout, defined by the red line boundary in the Scoping Report is being adopted for assessment at PEIR stage and thus is being assessed in this study (Figure 1). Concerns have been raised by consultees at an early stage on this layout and that the extension would impact upon the feasibility of pilot boardings at North East Spit and Tongue stations. This study will investigate these concerns. Analysis was conducted on three months of data from the Automatic Identification System (AIS) to better understand the current use of the pilot stations, including the frequency and types of vessels using it. Examples were taken to look at the distance and time required to conduct a transfer and the locations where they take place. It was found that the majority of transfers take place at, and centred around, North East Spit pilot station and are typically vessels up to 250m navigating through the Princes Channel. The westernmost part of the proposed extension is located close to North East Spit pilot station and would reduce the available sea room for both vessels to transit and for transfers to take place. This reduction, of approximately 50%, would still be adequate for most operations, however the analysis detected several existing examples where this would not be sufficient. An alternative is to relocate the boarding station to the north or south east to increase the space available. This would however have implications on the time and distance of the pilot boat trips which would increase wear and tear, impact rostering and working hours or be in locations of less favourable conditions. A second alternative is to alter the layout of the extension, particularly removing or relocating the western rows of turbines to increase the available space. Further study, which may include full bridge simulation may be necessary to confirm that the available sea room is adequate to conduct pilot boarding operations with a variety of vessel types and weather conditions. This pilotage study therefore identifies that there are three further courses of action for consideration by Vattenfall Wind Power Ltd in relation to the layout: 1. Maintain the PEIR layout and undertake further confirmatory and/or validation studies in recognition of the reduction in available sea room inshore of the site and impacts on traffic flow, safety and pilot transfers. Consultation and navigation simulation exercises with the GoBe Consultants Ltd ii

6 PLA and ESL may be required to confirm and/or validate whether operations can still be conducted around North East Spit pilot station. This will likely pose a significant consenting risk to the project. 2. Investigate relocation of the North East Spit pilot station with the PLA and ESL to fully understand the feasibility and operational implications on both the PLA and ESL. 3. Reconsider the layout of the wind farm at its western most point to increase the sea room available at the North East Spit pilot station. By reducing the footprint of the western portion of the site, the impacts to traffic flow and pilotage would be reduced. GoBe Consultants Ltd iii

7 CONTENTS Executive Summary... ii Contents iv Abbreviations... vi 1 Introduction Scope Thanet Extension Offshore Wind Farm Consultation Responses Concerning Pilotage Analysis Current Pilotage in the Thames Estuary Requirements Providers Pilot Transfers Vessel Traffic passing Existing Wind Farm Pilotage Analysis Frequency of Transfers Locations of Transfers Duration of Pilot Trips Sea Room Future Changes to Pilotage in Thames Estuary Possible Impacts of Extension on Pilotage Operations Introduction Reduction in Sea Room Transiting Vessels Pilotage Acts Comparison of Pilotage Areas Layout Modification Alternative Pilotage Arrangements Conclusions and Summary Summary GoBe Consultants Ltd iv

8 FIGURES Figure 1: Indicative site layout Figure 2: Pilot transfer (source: PLA) Figure 3: All vessel tracks Figure 4: Tracks of vessels requiring pilots (Greater than 90m LOA, dredgers removed) Figure 5: Transits per Month by Vessel Type (Pilot Vessels Excluded) Figure 6: Transits per Month by Length Over-All (Pilot Vessels Excluded) Figure 7: Transits per Month by Draught (Pilot Vessels Excluded) Figure 8: Tracks of vessels greater than 200 m LOA Figure 9: Example Routes, Grande Brasile 214m Cargo (top), Magellan 221m Cruise (Bottom) Figure 10: Tracks of ESL pilot launches Figure 11: Pilot vessel trips per day (entry and exit counts as one) Figure 12: Transfers per month (source: PLA) Figure 13:Number and Location of Pilot Transfers Point of Transfer Figure 14: Number and Location of Pilot Transfers- Duration of Transfer Figure 15: Pilot trip duration Figure 16: Likya C and Estuary Elan Pilot Transfer 4 th December Figure 17: CMA CGM Africa One and Estuary Leader Pilot Transfer, 12 th December Figure 18: Astrid Schulte and Estuary Leader Pilot Transfer 17 th December Figure 19: Georgia Trader and Estuary Escort Pilot Transfer, 24 th December Figure 20: Approximate fairway with >8m chart datum and avoiding anchorages, vessel tracks for >90m LOA excluding dredgers Figure 21: Schematic of sea room between extension and North East Spit Figure 22: Pilot Vessel Tracks Sunk, North East Spit and Sea Reach Figure 23: Pilot Boarding Area Liverpool Figure 24: Pilot Boarding Area - Humber Figure 25: Indicative turbine positions and transfer density Figure 26: Alternative pilot stations TABLES Table 1: Pilot Vessels Table 2: Pilot Transfer Area Table 3: Comparison of distances and times between pilot stations from Ramsgate Breakwater GoBe Consultants Ltd v

9 ABBREVIATIONS Abbreviation AIS ALARP CHA DW EIA ESL HW IMO Km Detail Automatic Identification System As Low As Reasonably Practicable Competent Harbour Authority Deep Water Environmental Impact Assessment Estuary Services Ltd High Water International Maritime Organisation Kilometre kt Knot (unit of speed equal to nautical mile per hour, approximately 1.15 mph) LOA LW m Marico Marine MCA MGN MW nm NRA PEC PLA TEOW UKC VHF VTS WTG Length Over-All Low Water Metre Marine and Risk Consultants Ltd Maritime and Coastguard Agency Marine Guidance Note Megawatt Nautical Mile Navigation Risk Assessment Pilotage Exemption Certificate Port of London Authority Thanet Extension Offshore Wind Farm Under Keel Clearance Very High Frequency (radio communication) Vessel Traffic Service Wind Turbine Generator GoBe Consultants Ltd vi

10 1 INTRODUCTION GoBe Consultants Ltd and Vattenfall Wind Power Ltd (Vattenfall) have commissioned this technical note by Marine and Risk Consultants Ltd (Marico Marine) to better understand pilotage around the existing Thanet Offshore Wind farm and to consider the possible impacts of the proposed extension. This technical note has been produced at a preliminary stage of the project to address concerns raised by the Port of London Authority (PLA) and Estuary Services Ltd (ESL) in their responses to the Scoping Report. 1.1 SCOPE The outline of this report is as follows: 1. Identify the current pilotage operations around the existing wind farm; and 2. Consider the possible impacts that the extension would have upon these operations. Wider impacts on shipping and navigation, including to vessel routeing, anchorages, search and rescue and small boat traffic (such as fishing and recreational craft) will be considered as part of the full Navigation Risk Assessment (NRA) submitted as part of the Environmental Impact Assessment (EIA). 1.2 THANET EXTENSION OFFSHORE WIND FARM The existing Thanet Offshore Wind Farm has been operational since 2010 and comprises 100 Vestas V MW turbines, situated 11 km off the Kent coast. In 2015, Vattenfall undertook feasibility studies for the extension of this wind farm. The indicative layout of this development is given in Figure 1 and was used in the Scoping Report. This will consist of up to 34 turbines (up to 12 MW) surrounding the existing wind farm with an approximate 20 km export cable to Kent. It is anticipated that an EIA is to be produced and submitted in 2018 and, at the time of this report being authored, a PEIR is underway based on this layout. GoBe Consultants Ltd 1

11 Figure 1: Indicative site layout. 1.3 CONSULTATION RESPONSES CONCERNING PILOTAGE Consultation has been ongoing throughout the design of the extension, which included shipping and navigation bodies. Several areas of impacts were raised by the consultees (MCA, Trinity House, PLA and ESL) during early meetings and in the scoping responses: Safety and commercial impacts of shipping/port operations, including loss of manoeuvrable sea room inshore of the wind farm and around the North East Spit pilot boarding station; Radar interference and the impact resulting from loss of visibility for search and rescue; Cumulative impacts of the London Array Offshore Wind Farm; and Marking and lighting arrangements of the turbines. Issues associated with pilotage were identified at an early stage, including: The PLA noted that the impacts on the safety of pilot boarding and landing operations in the area need to be fully assessed within the navigational risk assessment An extension to the windfarm is likely to push the boarding and landing area further out from the shore, causing a further impact on boarding and landing GoBe Consultants Ltd 2

12 1.4 ANALYSIS operations and consequently on PLA pilot operations. As well as the increased navigational risk, which should be identified in the Navigational Risk Assessment, there is also a risk to the business for ESL and consequently to the PLA, Medway Ports and all commercial shipping using the North East Spit boarding and landing areas. (Scoping Opinion Responses, 2 nd February 2017). The MCA noted that We are very concerned over the available sea room it leaves along the south western edge, for instance the distance between the Elbow cardinal mark and turbines will be reduced by approximately a half. We also have concerns on the impacts this will have on the safety of both commercial vessels and pilot boats during pilotage operations in the NE Spit and Tongue pilot boarding areas. (Scoping Opinion Responses, 16 th January 2017). Trinity House noted that The possible cumulative and in-combination effects on shipping routes and patterns should be fully assessed, paying particular attention to the safe navigable sea room to the west of this proposed developed. The impact this proposal will have on the operating practices of Port of London Authority, Peel Ports Medway, Port of Ramsgate and Dover Harbour Board and how this project will affect their customers. (Scoping Opinion Responses, 26 th January 2017). As part of the NRA and Marine Guidance Note (MGN) 543 requirements, a radar and AIS vessel traffic survey is being undertaken for representative winter and summer 14 day periods. Prior to the receipt of this data, analysis for the purposes of this report has been undertaken on three months of AIS data recorded by Vattenfall from Ramsgate between the 1 st December 2016 and the 28 th February GoBe Consultants Ltd 3

13 2 CURRENT PILOTAGE IN THE THAMES ESTUARY 2.1 REQUIREMENTS The PLA, as a Competent Harbour Authority (CHA) within the meaning of the Pilotage Act 1987, have determined that the following vessels are subject to compulsory pilotage to the east of Sea Reach No.1 Buoy (PLA Pilotage Directions, 2013): a) Vessels or Tugs and Tows of 90 metres or more in LOA; b) Vessels or Tugs and Tows of 50 metres or more in LOA which are Specified Vessels, Passenger Vessels and vessels carrying Marine Pollutants in Bulk; c) Vessels or Tugs and Tows of 50 metres and up to 90 metres in LOA with an Operating Draught of 6 metres or more; d) Vessels or Tugs and Tows of 50 metres and up to 90 metres in LOA with an Operating Draught of 4 metres or more when Restricted Visibility exists within that part of the London Pilotage District to the east of Sea Reach 1 Buoy where the vessel is planning to navigate. Furthermore, pilots are normally boarded or landed at one of two locations (PLA Pilotage Directions, 2013): a) At the North East Spit Pilot Station by: i. All vessels entering from or leaving the London Pilotage District for the south or east, whose Operating Draught allows use of the Princes Channel, Fisherman s Gat or the Long Sand Head; and ii. All other vessels with an operating draught of less than 7.5 metres unless bound to or from ports in Essex or Suffolk. b) At the Sunk Pilot Station by: i. Vessels of 7.5 metres draught and more entering from or leaving for ports to the north and north east of the Thames; ii. Vessels entering from or leaving for ports to the south and east of the Thames, which are unable to use the Princes Channel or Fisherman s Gate because their operating draught is too great; iii. Vessels less than 7.5 metres in draught, which agree to pay an additional pilotage charge for such service; and iv. Vessels entering from or leaving for ports in Essex or Suffolk. c) At the Warp and Sea Reach No.1 Pilot Stations by vessels for which pilotage is compulsory only to the west of Sea Reach No. 1 Buoy; GoBe Consultants Ltd 4

14 d) At the Gravesend Pilot Station by vessels for which pilotage is compulsory to the west of the Margaretness Limit. Some masters may be issued with a Pilotage Exemption Certificate (PEC) following completion of a number of qualifying trips and completion of exams. In 2016, a total of 153 pilotage exemption certificates have been issued (PLA Annual Report, 2017). 2.2 PROVIDERS ESL is a private enterprise operating on behalf of the PLA from Ramsgate, servicing pilotage in the southern Thames Estuary. ESL operate 5 pilot vessels, given in Table 1. These vessels are rotated between Ramsgate and Sheerness. The vessels are crewed by two coxswains and one Able Seaman who rotate with two on watch and one at rest. The pilot boats are capable of speeds of 25 knots. A modernisation programme is currently underway to replace the pilot boats one by one with more modern and fuel efficient equivalents. Table 1: Pilot Vessels. Name Length Currently Based Estuary Escort 15m Ramsgate/Sheerness Estuary Guide 15m Ramsgate/Sheerness Estuary Leader 15m Sheerness Estuary Elan 17m Ramsgate Estuary Elite 17m Ramsgate Estuary Warden 15m Sheerness 2.3 PILOT TRANSFERS The transfer of a pilot from a pilot boat to a vessel can be one of the most hazardous activities within a port. As such both international and local codes of practice have been developed to minimise these risks (see PLA s Code of Practice for the Embarkation and Disembarkation of Pilots on the Thames, 2008). The pilot would contact the vessel via VHF to develop a safe plan for conducting pilot transfers. The pilot boat Coxswain should advise the ship of the side on which to rig the pilot ladder, the required distance of the lower step above the water and the heading/speed in order to establish the best lee for the pilot transfer. In adverse conditions where there is significant risk to GoBe Consultants Ltd 5

15 personnel or the pilot boat, the Coxswain should make the ultimate decision whether to place the boat alongside the ship. During the pilot transfer the supervising ship s officer should be in direct contact with the bridge. The ship should maintain steerage way at a speed that allows the pilot vessel to remain comfortably alongside, in general transfers occur at approximately 6 knots. The pilot then steps off the pilot boat onto the ladder when timed at the top of a wave or roll. The pilot boat may remain alongside for a short climb, though for a high sided ship, may move away to avoid serious injury in the event of a fall. For disembarkation, the principles remain the same. Figure 2: Pilot transfer (source: PLA). 2.4 VESSEL TRAFFIC PASSING EXISTING WIND FARM Figure 3 and Figure 4 give the tracks of vessels around the wind farm between December 2016 and February 2017 for all vessels and those over 90m (excluding dredgers). Figure 4 is created to show the vessels which meet pilotage criteria, with dredgers excluded who are assumed to carry PECs. The footprint of the extension is generally clear of vessel traffic with the exception of the westernmost corner where a significant number of vessels are recorded transiting through. GoBe Consultants Ltd 6

16 Figure 3: All vessel tracks. Figure 4: Tracks of vessels requiring pilots (Greater than 90m LOA, dredgers removed). GoBe Consultants Ltd 7

17 Transits per Month A vessel traffic gate was drawn between North Foreland and the existing wind farm boundary, and vessel transit information extracted in order to analyse vessel traffic passing landward of the wind farm. Figure 5 shows the number of transits per month through the gate by vessel type (please note pilot vessels have been excluded). The majority of transits were made by cargo vessels which accounted for 50% of all transits. The next most common vessel category was tugs and service craft which is composed primarily of dredgers Cargo Tugs & Service Craft Fishing Tanker Recreational Passenger Naval Unknown Figure 5: Transits per Month by Vessel Type (Pilot Vessels Excluded). Transits by LOA are given in Figure 6. There are two clear frequency peaks in vessel lengths; m and m with the latter composed primarily of cargo vessels and dredgers. Figure 7 shows the number of transits by draught. The most common vessel draught is 6 7 m, corresponding to cargo vessels and dredgers, which are not tidally constrained for this route. GoBe Consultants Ltd 8

18 0 to 1 1 to 2 2 to 3 3 to 4 4 to 5 5 to 6 6 to 7 7 to 8 8 to 9 9 to to to to 13 Transits per Month 00 to to to to to to to to to to to to to to to to to to to to to to to to to to to to to to 300 Transits per Month LOA Figure 6: Transits per Month by Length Over-All (Pilot Vessels Excluded) Draught (m) Figure 7: Transits per Month by Draught (Pilot Vessels Excluded). For the largest vessels transiting near to the wind farm, greater than 200 m, their tracks are given in Figure 8. Typically, these vessels are passing into the Princes Channel or transiting to the east of the wind farm. Those vessels taking a pilot or anchoring at Tongue are clearly visible. GoBe Consultants Ltd 9

19 Figure 8: Tracks of vessels greater than 200 m LOA. Figure 9 shows two typical examples of vessels using the North East Spit pilot station. The first example is an outbound cargo vessel, passing through the Princes Channel and then between the East Margate red lateral and the North East Spit east cardinal, over the North-East Spit shallows. She drops off her pilot half a mile to the north of the pilot station and proceeds north east keeping 0.9 nm clear of the wind farm towards the West Hinder TSS. The second example is an inbound cruise ship approaching from the Dover Straits eastbound lane, passing to the south west of the wind farm. She collects her pilot 1.5 nm to the west of the pilot station and then passes between the East Margate red lateral and North East Spit cardinal and enters the Princes Channel. GoBe Consultants Ltd 10

20 Figure 9: Example Routes, Grande Brasile 214m Cargo (top), Magellan 221m Cruise (Bottom). 2.5 PILOTAGE ANALYSIS Three months of AIS data was analysed to better understand the current pilotage arrangements surrounding the Thanet Offshore Wind Farm. The data for the ESL pilot launches identified in Section 2.3 were extracted and their behaviour analysed (Figure 10). A pilot transfer generally follows that the launch would depart from Ramsgate, transit at approximately 20 knots to the ship, reduce speed to approximately 6 knots and come alongside the vessel to conduct the transfer, and then transit at 20 knots to either another vessel or to return to Ramsgate. As an approximation of where transfers were taking place, the dataset was interrogated to identify AIS positions with speeds of less than 9 knots, and using a time filter to ensure subsequent positions are counted as only a single transfer. This is necessarily an approximation as a pilot vessel may slow down to await another vessel which would be incorrectly counted as a transfer. Furthermore, transfers taking place at a great distance from Ramsgate may be beyond AIS reception of the dataset, in particular if the pilot boat is on the north-east side of a commercial ship and the transmissions are blanketed by the hull. GoBe Consultants Ltd 11

21 Figure 10: Tracks of ESL pilot launches Frequency of Transfers Whilst specific figures for each boarding station are unknown, the PLA Annual Report states that there were 13,123 pilotage acts in total in 2016, up from 11,745 in A query was conducted on the pilot vessels leaving and entering Ramsgate to identify the number of trips they made during the months of data. Figure 11 shows the frequency of trips per day for all the pilot vessels based in Ramsgate, with on average 10 pilot vessel trips in total (entry and exit count as one) per day. Figure 12 shows the number of vessels served by the pilots and North East Spit pilot station per month, as provided by the PLA. On average 545 vessels are serviced each month from this pilot station, which if compared with Figure 11 gives between one and two transfers per pilotage trip. GoBe Consultants Ltd 12

22 FREQUENCY PER MONTH 01/12/ /12/ /12/ /12/ /12/ /01/ /01/ /01/ /01/ /02/ /02/ /02/ /02/2017 FREQUENCY Figure 11: Pilot vessel trips per day (entry and exit counts as one) Figure 12: Transfers per month (source: PLA). GoBe Consultants Ltd 13

23 2.5.2 Locations of Transfers Figure 13 and Figure 14 show the location of pilot transfers using two different measures. The first plot (Figure 13) shows the locations where a pilot vessel has reduced speed to less than 10 knots for a period of time, presumably to conduct a transfer. These are centred around the North East Spit pilot station and are generally clear of the wind farm. Given the issues identified with AIS coverage of the pilot vessels, Figure 14 was also constructed which shows the tracks of vessels meeting the pilotage criteria at less than 10 knots. The density in this case shows the whole track of a vessel, aligning for a transfer and therefore is more accurate at showing the full footprint required to conduct a pilot transfer. It should be noted that this would likely include vessels slow steaming, waiting for a pilot to arrive. Both of these plots show good agreement, with North East Spit pilot station as the concentration of transfers and some overlap of current operations on the western most section of the proposed extension. Figure 13:Number and Location of Pilot Transfers Point of Transfer. GoBe Consultants Ltd 14

24 Figure 14: Number and Location of Pilot Transfers- Duration of Transfer Duration of Pilot Trips To better understand the impacts that any relocation of pilot activities would have, analysis was conducted on the trip length. A transect across the entrance of Ramsgate Harbour was taken and a query built which calculated the time difference between departing and arriving pilot vessels. Figure 15 gives a frequency distribution of pilot trips from the entrance of Ramsgate. The average trip length is between 30 minutes and an hour, typically about 45 minutes. Some trips however can go for several hours. The time between the berth and the entrance to Ramsgate, not included in the calculated trip length, is between 5 and 10 minutes. GoBe Consultants Ltd 15

25 00:00 00:07 00:14 00:21 00:28 00:35 00:42 00:49 00:56 01:03 01:10 01:17 01:24 01:31 01:38 01:45 01:52 01:59 02:06 02:13 02:20 02:27 02:34 02:41 02:48 02:55 Frequency 6% 5% 4% 3% 2% 1% 0% Trip Duration (Ramsgate to Ramsgate) Figure 15: Pilot trip duration Sea Room The swept paths of vessels of varying size and type during pilot transfer are given in Figure 16 to Figure 19. The plots indicate the various locations at which and methods by which transfers take place. Historical weather data from Manston airport was collected and compared to the swept paths to assess the impact of wind conditions on pilot transfers. Figure 16 depicts the swept path of Likya C, a tanker of 100 m LOA and Estuary Elan during pilot transfer on 4 th December 2016 at 18:00. The total time and distance to align for the transfer was 8 minutes and 1.8 km respectively, while the pilot transfer occurred over 2 minutes over a distance of 300 m. The wind speed and direction during the transfer was 9 knots ESE. Figure 17 depicts the swept path of CMA CGM Africa One, a cargo vessel of 280 m LOA during pilot transfer on 12 December 2016 at approximately 14:30. The total time and distance to align for the transfer was 20 minutes and 4 km, while the pilot transfer occurred over 6 minutes over a distance of 800 m. The wind speed and direction during the transfer was southerly 12 knots. GoBe Consultants Ltd 16

26 Figure 16: Likya C and Estuary Elan Pilot Transfer 4th December Figure 17: CMA CGM Africa One and Estuary Leader Pilot Transfer, 12th December 2016 GoBe Consultants Ltd 17

27 Figure 18 depicts the swept path of Astrid Schulte, a cargo vessel of 204m LOA and Estuary Escort during pilot transfer on 14 th December 2016 at 10:00. The total time and distance to align for the transfer was approximately 20 minutes and 13.5 km respectively, while the pilot transfer occurred over 3 minutes over a distance of 700 m. The wind speed and direction during the transfer was 8 knots W. Figure 19 depicts the swept path of Georgia Trader, a cargo vessel of 280 m LOA during pilot transfer on 24th December 2016 at 19:15. The total time and distance to align for the transfer was 7 minutes and 2.5 km, while the pilot transfer occurred over 2 minutes over a distance of 300 m. The wind speed and direction during the transfer was 15 knots WSW. Figure 18: Astrid Schulte and Estuary Leader Pilot Transfer 17 th December GoBe Consultants Ltd 18

28 Figure 19: Georgia Trader and Estuary Escort Pilot Transfer, 24 th December FUTURE CHANGES TO PILOTAGE IN THAMES ESTUARY The number of pilotage movements in the Thames Estuary is expected to alter in 2017/2018 following the relocation of some container services from Felixstowe and Harwich to London Gateway. In particular, this is expected to include the Maersk EEE ultra large container ships. Due to the nature of their size, these vessels require up to three pilots per transit. As such, the Port of London is recruiting an additional 24 pilots over the next two years to meet this demand. Given the size of these vessels and the Under Keel Clearance (UKC) requirements, it is unlikely that they will transit south of the wind farm or use the North East Spit pilot station. It is expected that these vessels will either use the Sunk pilot station or, if approaching from Dover or the east, take a pilot at North East Goodwin or Tongue pilot stations and pass to the east of the wind farm before entering the deep-water channel. GoBe Consultants Ltd 19

29 3 POSSIBLE IMPACTS OF EXTENSION ON PILOTAGE OPERATIONS 3.1 INTRODUCTION The Thanet Extension Offshore Wind Farm has the potential to impact upon pilotage operations in the Thames Estuary. There are two possible outcomes if the development with the proposed layout were consented; firstly, that operations continue as they are but with reduced sea room. Secondly, operations are changed through alternative routeing and piloting arrangements. There are no requirements or legislation determining the correct layout of a pilot boarding and landing area. However, a code of safe practice does exist, published by the British Ports Association, UK Marine Pilots Association and UKMPG (2013). It states that: CHAs have a responsibility to identify and evaluate areas for the boarding and landing of Pilots with regard to there being sufficient sea-room for manoeuvre, depth of water and, where possible, these areas sheltered from the more exposed elements of predominant winds and weather. Additionally, where possible, these areas should be located where there is little seabed gradient. It should also be recognised that boarding and landing areas can be affected by wash from passing traffic. 3.2 REDUCTION IN SEA ROOM Transiting Vessels Figure 20 gives the approximate fairway for vessels transiting passed the extended wind farm. With the extension, and bounded by shallow waters and an anchorage to the west, the North East Spit pilot station is located in a fairway of 2 nm width. GoBe Consultants Ltd 20

30 Figure 20: Approximate fairway with >8m chart datum and avoiding anchorages, vessel tracks for >90m LOA excluding dredgers. Figure 21 gives a schematic of the reduction in sea room the extension would impose between the wind farm and North East Spit pilot station. At present, there is 4.3 nm of available water between the limits of the wind farm and the most westerly transit of a vessel greater than 200 m LOA in the dataset. If we assume that no vessel will transit within 0.5 nm of the wind farm this gives 3.8 nm of sea room between the wind farm and the furthest westerly transit. The extension would increase the footprint of the wind farm by 2 nm, which with a 0.5 nm buffer, gives a new sea room distance of 1.8 nm, a reduction of 53%. For a vessel bound for the Port of London, the most constrained aspect of that route is the Princes Channel at 0.5 nm wide, albeit well marked and under pilotage. GoBe Consultants Ltd 21

31 Figure 21: Schematic of sea room between extension and North East Spit Pilotage Acts As discussed in Section 3.2.1, the extension would reduce the fairway to 2 nm across. There is some concern that this would be insufficient to safely conduct boarding operations. Section 2.5 has analysed the location of current pilotage activities in the vicinity of the wind farm. The results show that at present, the majority of pilotage acts are clear of the extended layout. Where they do overlap, this is almost entirely contained in the western section of the extension s footprint. For pilotage acts where a transfer is able to take place in a NW/SE orientation, the reduction in fairway width would not have an impact. For transfers where a E/W orientation is required, 2 nm is still an adequate distance for the majority of cases. However, in the event of a particularly difficult transfer, there would not be sufficient sea room for pilotage acts to be conducted safely without the vessel approaching the shallows to the west or the wind farm extent to the east. In this event, it may be the case that the pilot wishes for an alternative boarding point to the south or north of the wind farm (see Section 3.3). It is not possible at this stage to determine whether there is or isn t sufficient sea room in all cases to conduct pilotage operations at North East Spit pilot station. The analysis suggests that it is likely that the majority could still take place but additional investigation is warranted, through for example simulator trials with PLA pilots of the new arrangement using a variety of vessel sizes and weather conditions. GoBe Consultants Ltd 22

32 Given the concern expressed by the stakeholders and the clear reduction in the available sea room, any effort made to reduce the footprint of the extension at its western most point would alleviate the problem and should therefore be considered Comparison of Pilotage Areas Analysis of pilot boarding station activity across the UK was undertaken for comparison to the North East Spit to judge the feasability of pilotage with reduced sea room. Table 2 lists the approximate transfer area at various UK ports. There is a discernable difference in the area over which transfers take place with transfer areas found to vary between 8 (Humber) to 25 sq.km (North East Spit). Of all pilot boarding areas assessed, North East Spit, has the largest transfer footprint. The location and transfer area of Thames Estuary Pilot transfers are given in Figure 22. Figure 22: Pilot Vessel Tracks Sunk, North East Spit and Sea Reach Figure 23 shows the locations of pilot transfers at Liverpool. Liverpool pilot transfers are constrained by anchorages to the north and south and the Burbo Bank Extension Wind Farm to the south. The remaining channel width within which transfers may occur is 5 km, of which, pilot vessels occupy approximately 2.5 km. GoBe Consultants Ltd 23

33 Figure 23: Pilot Boarding Area Liverpool. Figure 25 shows pilot vessel transfers at the Humber, the most constrained assessed transfer area with an available transfer width of 2.3 km of which approximately 2 km is utilised for pilot transfers. The Humber is constrained by the Humber Gateway wind farm to the north and the Humber Deep Water (DW) anchorage to the south. GoBe Consultants Ltd 24

34 Figure 24: Pilot Boarding Area - Humber Table 2: Pilot Transfer Area Location Approximate Transfer Area (sq.km) North East Spit 25 Sea Reach 21 Sunk 15 Southampton Deep Draught 16 NAB West 10 NAB East 14 Humber 8 Humber Deep Draught 23 Liverpool 15 Milford Haven 19 GoBe Consultants Ltd 25

35 3.2.4 Layout Modification Figure 25 shows the locations of pilotage transfers and indicative turbine positions. If the westernmost extent of the wind farm was reconsidered to increase the width between the East Margate red lateral mark and the wind farm layout, this would improve the flow of traffic and increase the distance between the North East Spit pilot station and the wind farm. This should be considered by the design team in conjunction with other receptors to produce the layout carried through to the EIA. Figure 25: Indicative turbine positions and transfer density. 3.3 ALTERNATIVE PILOTAGE ARRANGEMENTS If it is deemed necessary to relocate the pilot station, there are two possible alternatives, albeit with negative impacts to current operations. These are: 1. Board pilots to the south of the wind farm, between Ramsgate and North East Goodwin; 2. Board pilots near to North East Spit east cardinal, to the west of the wind farm and the Tongue station. GoBe Consultants Ltd 26

36 Table 3 gives the increase in transit time to or from the pilot station options. When combined with the trip duration time analysis within Section Table 3: Comparison of distances and times between pilot stations from Ramsgate Breakwater. Option Name Distance Time (24kts) Increase Existing North East Spit 6.5 nm mins 0% 1 North East Goodwin 6.5 nm mins 0% 2 Tongue 9.4 nm 23.5 mins 45% Figure 26: Alternative pilot stations. Whilst Option 1 results in no increase in transit distance or time for pilot vessels, it would increase the trip duration of a pilot once on board a vessel by 5 nm which may impact upon hours of rest and rostering. Furthermore, vessels approaching from the north east would be rerouted into transiting to the east and then south of the wind farm as opposed to currently passing to the north and dipping into the pilot station (see Figure 9). Option 1 is also located in less sheltered waters from the south west and this may make pilot transfers more hazardous or increase wear and tear on the pilot vessels. GoBe Consultants Ltd 27

37 Option 2, located to the north west of the site is further from Ramsgate than is currently operated, increasing transit time and distance for pilots and pilot vessels. Furthermore, as the boarding point is closer to the Princes Channel, there is less time to conduct a master-pilot exchange, albeit this is not considered to be a significant impact. A further impact would be in requiring vessels to pass the now constrained fairway between the extended wind farm boundary and East Margate red lateral without a pilot, having possible navigational safety implications. The proximity of this relocated station and the Tongue pilot station and anchorage is not considered significant given the greater available sea room than is currently the case with the existing wind farm. Both alternative arrangements have the additional advantage that they are moved clear of this increasingly constrained fairway and allows for transfers to be taken away from the main passage of vessel traffic, which could hinder transfers in terms of both congestion and increased wash. However, there would be a significant administrative burden for several parties to obtaining the consents and undertaking due process for relocating the pilot station. GoBe Consultants Ltd 28

38 4 CONCLUSIONS AND SUMMARY This study has considered the current pilotage arrangements around the Thanet Offshore Wind Farm and the possible impacts upon them of the proposed extension. The study has reached the following conclusions: 1. The North East Spit pilot station is one of the main boarding points into the Port of London and serves a variety of vessel types and sizes; 2. The Tongue pilot boarding station is used infrequently; 3. ESL conduct more than 10 pilot vessel trips from Ramsgate each day; 4. On average, 13 vessels transit inshore of the Thanet Offshore Wind Farm each day; 5. The proposed extension of the wind farm would reduce the available sea room for vessels transiting to the south and west of the wind farm by approximately 50%; 6. The majority of pilotage operations could be conducted within the reduced sea room; however, several examples were identified where more than 2 nm was required for a pilot transfer and the extension would prevent this. However, it is not known whether the transfer could be conducted in less distance had there been an obstacle; 7. North East Spit pilot station has a larger transfer footprint than other comparative pilot boarding stations; 8. Alternative pilot stations could be implemented, however would have impacts such as transit time, pilot hours, reduction in shelter and increased wear and tear on pilot vessels; and 9. The impacts of the extension on Thames Estuary pilotage operations could be significantly reduced if the western extent of the project area were modified. 4.1 SUMMARY This pilotage study therefore identifies that there are three further courses of action for consideration by Vattenfall Wind Power Ltd in relation to the layout: 1. Maintain the PEIR layout and undertake further confirmatory and/or validation studies in recognition of the reduction in available sea room inshore of the site and impacts on traffic flow, safety and pilot transfers. Consultation and navigation simulation exercises with the PLA and ESL may be required to confirm and/or validate whether operations can still be conducted around North East Spit pilot station. This will likely pose a significant consenting risk to the project. GoBe Consultants Ltd 29

39 2. Investigate relocation of the North East Spit pilot station with the PLA and ESL to fully understand the feasibility and operational or commercial implications on both the PLA and ESL. 3. Reconsider the layout of the wind farm at its western most point to increase the sea room available at the North East Spit pilot station. By reducing the footprint of the western portion of the site, the impacts to traffic flow and pilotage would be reduced. GoBe Consultants Ltd 30