Frequency of Occurrence

239. The likelihood of an underwater allision is greater for large commercial vessels with greater draughts, noting that only a minority of vessels recorded in the vessel traffic survey data were deep draught.
240. When considered with compliance with the requirements in MGN 654 any change to water depth of more than 5% chart datum will require consultation with the MCA and NLB and therefore reduce the likelihood of an underwater allision to very low for all vessel types, with sufficient clearance to avoid any effect.
241. The frequency of occurrence is therefore considered to be extremely unlikely.

Significance of the Effect

242. Overall, the severity of consequence is deemed to be moderate and the frequency of occurrence is considered to be extremely unlikely. The effect will, therefore, be of broadly acceptable adverse significance, which is not significant in EIA terms.

Secondary Mitigation and Residual Effect

243. No shipping and navigation mitigation is considered necessary because the likely effect in the absence of further mitigation (beyond the designed in measures outlined in Table 13.15   Open ▸ ) is not significant in EIA terms.

Interaction with Subsea Cables

Operation and Maintenance Phase

Severity of Consequence

244. Up to 661 nm (1,230 km) of inter-array cables, 51 nm (94 km) of interconnector cables and eight offshore export cables with total length 471 nm (872 km) will be in place during the operation and maintenance phase. The target minimum burial depth for subsea cables will be 0.5 m with a maximum cable protection height of 3 m (excluding crossings). Cable burial is the preferred option of safeguarding the subsea cables, with up to 15% of all subsea cables anticipated to require cable protection.
245. A cable burial risk assessment will be undertaken to determine the implementation and monitoring of cable protection.
246. There are three anchoring scenarios which are considered for this impact:

• planned anchoring – most likely as a vessel awaits a berth to enter port but may also result from adverse weather conditions, machinery failure or subsea operations;
• unplanned anchoring – generally resulting from an emergency situation where the vessel has experienced steering failure; and
• anchor dragging – caused by anchor failure.
  247. Although there may be limited decision-making time if a vessel is drifting towards a hazard, it is anticipated that the charting of infrastructure including all subsea cables will inform any decision to anchor, as per Regulation 34 of SOLAS (IMO, 1974).
  248. There is also a similar interaction risk associated with fishing gear. It is the responsibility of the fishermen to dynamically risk assess whether it is safe to undertake fishing activities within the array and to make a decision as to whether or not to fish. Active fishing activity is considered further in volume 2, chapter 12.
  249. The most likely consequences are negligible damage to property (anchoring vessel, fishing vessel engaged in activity, subsea cable or fishing gear). The maximum adverse scenario may include damage to property including to the vessel’s anchor, subsea cable and/or fishing gear (loss of). Additionally, in the case of a commercial fishing vessel the stability of the vessel could be compromised.
  250. The severity of consequence is therefore considered to be minor.

Frequency of Occurrence

251. From the vessel traffic survey data, anchoring activity was identified using the AIS navigational status, a speed analysis of vessels travelling at a speed of less than one knot for more than 30 minutes, and a visual check for patterns characteristic of anchoring movements. Applying this criterion, only one anchored vessel was identified throughout the vessel traffic surveys. This was a recreational vessel located approximately 750 m off the coast between Dunbar and Skateraw.
252. Taking the low likelihood of a vessel anchoring in the area into account, alongside the burial and protection of cables as outlined above which will be determined by the cable burial risk assessment, it is considered highly unlikely that an anchor interaction incident would occur.
253. In the event that reburial of subsea cables is required, a guard vessel may be deployed, as determined by risk assessment, whilst awaiting the work to be undertaken to ensure that passing vessels are suitably aware of the increased interaction risk. This will ensure that the likelihood of a snagging incident is minimised, noting that any damage, destruction or decay of subsea cables will be notified to the MCA, NLB, Kingfisher and the UKHO no later than 24 hours after discovered.
254. The frequency of occurrence is therefore considered to be negligible.

Significance of the Effect

255. Overall, the severity of consequence is deemed to be minor and the frequency of occurrence is considered to be negligible. The effect will, therefore, be of broadly acceptable adverse significance, which is not significant in EIA terms.

Secondary Mitigation and Residual Effect

256. No shipping and navigation mitigation is considered necessary because the likely effect in the absence of further mitigation (beyond the designed in measures outlined in Table 13.15   Open ▸ ) is not significant in EIA terms.

Reduction of Emergency Response Capability

Operation and Maintenance Phase

Severity of Consequence

257. Up to 2,323 return trips per year by operation and maintenance vessels may be made throughout the operation and maintenance phase. The presence of project vessels will increase the likelihood of an incident, with the potential to diminish emergency response capability.
258. The closest SAR helicopter service base location is at Inverness Airport, approximately 94 nm (174 km) to the north-west of the Proposed Development array area, although incidents occurring within the Proposed Development export cable corridor are typically responded to out of Prestwick (100 nm (185 km) to the west). The closest RNLI station is at Eyemouth, approximately 19 nm (35 km) to the south-west, with numerous other stations located along the coast. The closest MRCC is at Aberdeen, approximately 40 nm (74 km) to the north.
259. From historical MAIB and RNLI incident data, the frequency of incidents in the area is relatively low, with the majority of cases occurring inshore of the Proposed Development array area. Given the distance offshore, the RNLI are frequent responders, with an average of one unique incident per year responded to within the Proposed Development array area shipping and navigation study area. Casualty vessels are typically fishing vessels and recreational vessels.
260. From SAR helicopter taskings data, the frequency of incidents in the area responded to by a SAR helicopter is relatively low, with only two taskings reported within the Proposed Development array area shipping and navigation study area in the six-year period between April 2015 and March 2021, both out of the Inverness base.
261. The Proposed Development array area is a large area to search (approximately 294 nm2 (1,008 km2)) compared to other existing offshore wind farms. However, it is unlikely that a SAR operation will require a search of the entire Proposed Development array area; it is much more likely that a search could be restricted to a specific area within the array where a casualty is known to be located (inclusive of considerations and assumptions made relating to the drift of the casualty).
262. With the presence of the array, the likelihood of an incident requiring emergency response will be greater given the presence of some of the impacts already outlined (collision, allision, underwater allision and snagging risks). During consultation, the RNLI noted that this may change the general location of incidents in the area which may then require a review of the future location of emergency response assets.
263. However, given that project vessels will be managed by marine coordination and be complaint with Flag State regulations including the COLREGs, it is anticipated that an incident can be suitably managed. In particular, project vessels will be equipped to assist in the event of an incident, either through self-help capability or – in the case of a third-party vessel – through SOLAS obligations (IMO, 1974), in liaison with the MCA. From historical incident data, there are 13 known instances of incidents responded to by vessels associated with UK offshore wind farm developments. Therefore, the additional demand for dedicated emergency response assets is not likely to be substantial.
264. During consultation, the MCA highlighted the need for consideration of effects on emergency response including completion of a SAR Checklist. The Applicant intends to comply with MGN 654 and its annexes (in particular SAR annex 5) (MCA, 2021) including completion of a SAR Checklist and Emergency Response Cooperation Plan (ERCoP). The minimum spacing between wind turbines is 1,000 m which is large compared to many existing offshore wind farms, comparable to the minimum spacing which will exist at NnG (903 m) and Seagreen (996 m) once constructed, and comparable to the minimum spacing consented at Inch Cape (1,278 m). Furthermore, the structures (wind turbines and offshore substation platforms/offshore convertor station platforms) are arranged in a grid pattern with two lines of orientation (as requested by MGN 654) to further assist safe navigation by SAR helicopters. The final array layout will be agreed through the DSLP which will include consultation with the MCA and NLB. Lighting and marking of the array for SAR purposes will also be discussed with the MCA and NLB.
265. In terms of internal navigation by SAR assets, SAR annex 5 states that it is “highly likely that a helicopter refuge area will be required between adjacent developments” and “distances less than 1 nm are unlikely to be considered acceptable” (MCA, 2021). On this basis, the 2.7 nm separation between the Proposed Development array area and Seagreen is considered a suitable helicopter refuge area, with SAR helicopters able to reorientate upon exiting one array and prior to entering another.
266. The most likely consequences are a delay to an emergency response request due to strained emergency response resources with minor effects on business but ultimately no issue executing the request and so no perceptible effect on people or the environment. The maximum adverse scenario may include a delay to an emergency response due to an inability to undertake an effective search resulting in PLL and the environmental consequence of pollution. The Project’s Marine Pollution Contingency Plan will be implemented to minimise the environmental effects should pollution occur.
267. The severity of consequence is therefore considered to be moderate.

Frequency of Occurrence

268. As of August 2022, there have been no collisions as a result of the presence of an offshore wind farm in the UK and ten reported cases of an allision between a vessel and a wind turbine in the UK, corresponding to an average of 1,570 years of wind turbine operation per allision incident in the UK. Although this analysis considers only collision and allision incidents, it is not anticipated that the presence of the Proposed Development will result in any substantial increase in the need for SAR operations, and it is noted that the baseline level of incidents requiring emergency response is relatively low.
269. The frequency of occurrence is therefore considered to be remote.

Significance of the Effect

270. Overall, the severity of consequence is deemed to be moderate and the frequency of occurrence is considered to be remote. The effect will, therefore, be of tolerable adverse significance, which is not significant in EIA terms.

Secondary Mitigation and Residual Effect

271. No shipping and navigation mitigation is considered necessary because the likely effect in the absence of further mitigation (beyond the designed in measures outlined in Table 13.15   Open ▸ ) is not significant in EIA terms.

Interference with Magnetic Position Fixing Equipment

Operation and Maintenance Phase

Severity of Consequence

272. A magnetic compass is a navigational instrument for determining direction relative to the earth's magnetic poles. It consists of a magnetised pointer (usually marked on the north end) free to align itself with the earth's magnetic field. Like any magnetic device, compasses are affected by nearby ferrous materials as well as by local electromagnetic forces, such as magnetic fields emitted from power cables. As the compass still serves as an essential means of navigation in the event of power loss or as a secondary source, it must not be affected to the extent that safe navigation is prohibited.
273. However, the majority of commercial vessel traffic uses non-magnetic gyrocompasses as the primary means of navigation, which are unaffected by Electromagnetic Field (EMF). Therefore, in general it is considered unlikely that any EMF interference created by subsea cables will have a significant impact on vessel navigation in the Proposed Development array area and export cable corridor. Nevertheless, since magnetic compasses can still serve as an essential means of navigation in the event of power loss, as a secondary source, or as some smaller craft (fishing or leisure) may rely on it as their sole means of navigation, it has been assessed within this EIA Report.
274. The important mitigating factors with respect to severity of consequence and EMF effects on magnetic compasses are listed below noting that section 13 of NRA concludes that for both buried and protected Direct Current (DC) cables the magnetic field will decrease exponentially with vertical distance between a vessel and the seabed (cable location):

• water depth;
• burial depth (or protection); and
• type of current (alternating or direct) running through the cables.
  275. The offshore export cables and inter-array cables for the Proposed Development could be Alternating Current (AC), DC or a combination of both. As shown in section 13 of the NRA, studies indicate that AC does not emit an EMF significant enough to impact marine magnetic compasses; therefore the following assessment relates to DC cables only.
  276. Regarding water depth, approximately 98.5% of the Proposed Development export cable corridor is in water depths greater than 6 m (below chart datum (CD)) and approximately 97.9% is in depths greater than 20 m below CD. Therefore, there is a significant vertical distance along the majority of the Proposed Development export cable corridor.
  277. Evidence suggested (section 13 of the NRA) where subsea cables are buried or protected the magnetic field will also decrease exponentially with vertical distance. Where subsea cables cannot be buried and are instead protected, the magnetic field is expected to be below the Earth’s magnetic field within 5 m from the seabed. Within shallow waters effects of EMF will also be mitigated by the installation of the offshore export cables by a trenchless technique (e.g. Horizontally Direction Drilled (HDD)) (out to between 488 m and 1,500 m from MHWS).
  278. Inter-array cables are considered within acceptable limits given the water depths within the Proposed Development array area and use of burial/protection methods as required.
  279. Therefore, given that 98.5% of the offshore export cable(s) will be buried and approximately 99.0% of the Proposed Development export cable corridor is in water depths greater than 6 m, there are not anticipated to be any effects on compass deviation for the majority of the Proposed Development export cable corridor (or the subsea cable(s) laid within it). The most likely consequences associated with the maximum adverse scenario are anticipated to be limited noting the substantial vertical distances along the majority of the Proposed Development export cable corridor and the offshore export cable(s) being installed by a trenchless technique (e.g. HDD) in the nearshore area (out to between 488 m and 1,500 m from MHWS).
  280. The severity of consequence is therefore considered to be minor.

Frequency of Occurrence

281. Along the Proposed Development export cable corridor vessel traffic is assumed to pass (in the majority) perpendicular to the direction of the offshore export cable(s). For vessels not transiting over the offshore export cable(s), time spent directly above the cable(s) will be limited given the width of the cable(s), noting this increases horizontal distance.
282. Given DC cables produce static magnetic fields which decrease with the horizontal distance from the cables, by assuming a horizontal distance of 450 m (maximum adverse scenario from assuming eight offshore export cables buried side by side with minimum 50 m spacing), magnetic compass interference should only be experienced directly above or in direct proximity to the offshore export cables, noting again that effects decrease quickly with horizontal distance as the vessel moves away from the offshore export cables location.
283. The frequency of occurrence is therefore considered to be negligible.

Significance of the Effect

284. During consultation, the MCA stated that a deviation of three degrees will be accepted for 95% of the cable route and a five degree deviation accepted for the remaining 5%. In summary, based on designed in measures of water depth, burial and use of trenchless technique (e.g. HDD)/direct pipes within the shallow water, the Proposed Development is anticipated to be within the requirements defined by the MCA.
285. Overall, the severity of consequence is deemed to be minor and the frequency of occurrence is considered to be negligible. The effect will, therefore, be of broadly acceptable adverse significance, which is not significant in EIA terms.

Secondary Mitigation and Residual Effect

286. No shipping and navigation mitigation is considered necessary because the likely effect in the absence of further mitigation (beyond the designed in measures outlined in Table 13.15   Open ▸ ) is not significant in EIA terms.

13.11.1.         Proposed Monitoring

287. No additional monitoring is required.

13.12. Cumulative Effects Assessment

13.12.1.         Methodology

288. The CEA assesses the impact associated with the Proposed Development together with other relevant plans, projects and activities. Cumulative effects are therefore the combined effect of the Proposed Development in combination with the effects from a number of different projects, on the same receptor or resource. Please see volume 1, chapter 6 for detail on CEA methodology.
289. The projects and plans selected as relevant to the CEA presented within this chapter are based upon the results of a screening exercise (see volume 3, appendix 6.4 of the Offshore EIA Report). Volume 3, appendix 6.4 further provides information regarding how information pertaining to other plans and projects is gained and applied to the assessment. Each project or plan has been considered on a case by case basis for screening in or out of this chapter’s assessment based upon data confidence, effect-receptor pathways and the spatial/temporal scales involved.
290. In undertaking the CEA for the Proposed Development, it is important to bear in mind that other projects and plans under consideration will have differing potential for proceeding to an operational stage and hence a differing potential to ultimately contribute to a cumulative impact alongside the Proposed Development. Therefore, a tiered approach has been adopted. This provides a framework for placing relative weight upon the potential for each project/plan to be included in the CEA to ultimately be realised, based upon the project/plan’s current stage of maturity and certainty in the projects’ parameters. The tiered approach which will be utilised within the Proposed Development CEA employs the following tiers:

• tier 1 assessment – Proposed Development (Berwick Bank Wind Farm offshore) with Berwick Bank Wind Farm onshore;
• tier 2 assessment – All plans/projects assessed under Tier 1, plus projects which became operational since baseline characterisation, those under construction, those with consent and submitted but not yet determined;
• tier 3 assessment – All plans/projects assessed under Tier 2, plus those projects with a Scoping Report; and
• tier 4 assessment – All plans/projects assessed under Tier 3, which are reasonably foreseeable, plus those projects likely to come forward where an Agreement for Lease (AfL) has been granted.
  291. The specific projects scoped into the CEA for shipping and navigation are outlined in Table 13.17   Open ▸ , with this scoping based upon data confidence, effect-receptor pathways, surface piercing infrastructure and the spatial/temporal scales involved. In particular, projects over 50 nm from the Proposed Development array area or with low data confidence have been excluded.
  292. The range of potential cumulative impacts that are identified and included in Table 13.18   Open ▸ is a subset of those considered for the Proposed Development alone CEA assessment. This is because some of the potential impacts identified and assessed for the Proposed Development alone, are localised and temporary in nature. It is considered therefore, that these potential impacts have limited or no potential to interact with similar changes associated with other plans or projects. These have therefore not taken forward for detailed assessment.
  293. Similarly, some of the potential impacts considered within the Proposed Development alone assessment are specific to a particular phase of development (e.g. construction, operation and maintenance or decommissioning). Where the potential for cumulative effects with other plans or projects only have potential to occur where there is spatial or temporal overlap with the Proposed Development during certain phases of development, impacts associated with a certain phase may be omitted from further consideration where no plans or projects have been identified that have the potential for cumulative effects during this period.
  294. For the CEA for shipping and navigation, reference is made to ‘Seagreen’ (the collective 150 consented wind turbines that will be installed for Seagreen 1 and Seagreen Project 1A). This is on the basis Seagreen Project 1A is captured within the displacement footprint of Seagreen 1, which invalidates the need to distinguish the sub-projects.
  295. As described in volume 1, chapter 3, the Applicant is developing an additional export cable grid connection to Blyth, Northumberland (the Cambois connection). Applications for necessary consents (including marine licenses) will be applied for separately. The CEA for the Cambois connection is based on information presented in the Cambois connection Scoping Report (SSER, 2022e), submitted in October 2022. The Cambois connection has not been scoped into the CEA for shipping and navigation on the basis that Cambois connection does not adequately satisfy the effect-receptor pathway criteria (given the lack of surface infrastructure).

Table 13.17: List of Other Projects and Plans Considered Within the CEA for Shipping and Navigation

Figure 13.9: Other Projects/Plans Screened into the Cumulative Effects Assessment for Shipping and Navigation

13.12.2.         Maximum Design Scenario

296. The maximum design scenarios identified in Table 13.18   Open ▸ have been selected as those having the potential to result in the greatest effect on an identified receptor or receptor group. The cumulative effects presented and assessed in this section have been selected from the details provided in volume 1, chapter 3 of the Offshore EIA Report as well as the information available on other projects and plans (see volume 3, appendix 6.4), to inform a ‘maximum design scenario’. Effects of greater adverse significance are not predicted to arise should any other development scenario, based on details within the Project Design Envelope (e.g. different wind turbine layout), to that assessed here, be taken forward in the final design scheme.

Table 13.18: Maximum Design Scenario Considered for the Assessment of Potential Cumulative Effects on Shipping and Navigation

13.12.3.         Cumulative Effects Assessment

297. A description of the significance of cumulative effects upon shipping and navigation receptors arising from each identified impact is given below.

Vessel Displacement

Tier 2

Construction phase

Severity of consequence

298. For those CEA tier 2 projects already in situ, the anticipated deviations for the main commercial routes identified from the vessel traffic data are as per those defined for the assessment of the Proposed Development in isolation, as presented in Figure 13.8   Open ▸ and detailed in Table 13.16   Open ▸ . This includes the under construction NnG and Seagreen which had a buoyed construction area in place at the time of data collection (summer 2022 only in the case of Seagreen) and based on experience at under construction and operational offshore wind farms the vessel deviations will be equivalent.
299. With the presence of those CEA tier 2 projects not yet in situ (Inch Cape), anticipated deviation options for the main commercial routes identified from the vessel traffic data have been defined. The full methodology for main route deviations is provided in section 15.5.1 of the NRA, with deviations established in line with industry experience and consultation feedback. section 15.6 of the NRA provides a detailed (including illustrative) breakdown of the anticipated deviation options; the key findings relating to this impact are provided in Table 13.19   Open ▸ .

Table 13.19: Key Vessel Displacement Findings for Anticipated Deviation Options (CEA Tier 2)

300. Utilising the navigation corridor between the Proposed Development array area and Inch Cape is an option available for multiple routeing scenarios. A safety case for this navigation corridor has been undertaken in section 19.1 of the NRA and concludes the proposed corridor is compliant with MGN 654 and meets safety of navigation expectations. Furthermore, the navigation corridor is shaped such that vessels are able to pass directly through with minimum additional course adjustments, including alignment between the western boundaries of the Proposed Development array area and Seagreen (during consultation RYA Scotland indicated that this alignment makes it obvious how vessels will intend to transit through the area when passage planning).
301. There is potential for increased exposure to radar interference for navigation corridor users. However, the length of the corridor and subsequent distance and duration that any vessel will spend transiting the corridor is minimal. Therefore, the distance (and duration) for which any vessel could be within less than 1.5 nm from wind turbines will be low and it is very unlikely that vessels will navigate within 0.5 nm of a wind turbine. Risk can also be mitigated by adjustment of radar controls, ensuring that the effect is within parameters already safely managed at existing offshore wind farm developments.
302. Given that the corridor is MGN 654 compliant there are several alternatives for vessels, noting that the maximum adverse scenario (which may include the vessel foundering resulting in PLL and the environmental consequence of pollution) is unlikely.
303. Based on experience at existing operational offshore wind farms, it is anticipated that commercial fishing vessels and recreational vessels may choose to navigate internally within the various arrays which are operational, particularly in favourable weather conditions. However, during consultation RYA Scotland commented that recreational users may be discouraged from navigating in and around the navigation corridor given the potential presence of commercial traffic noting that the navigation corridor will be compliant with MGN 654. There is potential that north-south recreational users may choose to navigate internally within the eastern portion of Inch Cape (depending on layout), thus avoiding the navigation corridor.
304. Overall, the most likely consequences are increased journey times and distances leading to the environmental consequence of increased fuel consumption. There is also potential for the business consequence of disruption to schedules, and although changes in total route length may be possible to make up through increased speeds when in open seas and effective passage planning, the deviations are generally slightly greater than for the equivalent impact for the Proposed Development in isolation. This is particularly relevant for vessels where utilising the proposed navigation corridor between the Proposed Development array area and Inch Cape may not be considered suitable. Subsequently the benefits of promulgation of information and charting of the buoyed construction area for passage planning are likely to be more limited than for the Proposed Development in isolation.
305. The severity of consequence is therefore considered to be minor.

Frequency of occurrence

306. The impact will be present throughout the construction phase which will last for up to eight years. Again, since the anticipated deviations associated with the main commercial routes and the volumes of vessel traffic on such routes are as per the assessment of the Proposed Development in isolation, it is again anticipated that vessels will be exposed to the impact on a daily basis.
307. The frequency of occurrence is therefore considered to be frequent.

Significance of effect

308. Overall, the severity of consequence is deemed to be minor and the frequency of occurrence is considered to be frequent. The cumulative effect will, therefore, be of tolerable adverse significance, which is not significant in EIA terms.

Further mitigation and residual effect

309. No shipping and navigation mitigation is considered necessary because the likely effect in the absence of further mitigation(beyond the designed in measures outlined in Table 13.15   Open ▸ ) is not significant in EIA terms.

Operation and maintenance phase

Severity of consequence

310. Since all CEA tier 2 projects will be in situ during the operation and maintenance phase, the anticipated deviation options identified for the construction phase (around the buoyed construction area in the case of the Proposed Development) are directly applicable for the operation and maintenance phase, as detailed in Table 13.19   Open ▸ .
311. Some of the CEA tier 2 projects may be decommissioned during the operation and maintenance phase, although for the maximum adverse scenario it is assumed that all CEA tier 2 projects will remain in situ throughout the operation and maintenance phase.
312. The size and location of the buoyed construction area will be slightly larger (given that buoys will be placed between 500 and 1000 m from the Proposed Development array area) than the operational Proposed Development array area and therefore the impacts on shipping and navigation will be equal to or less than during the construction phase.
313. This includes concerns relating to use of the navigation corridor between the Proposed Development array area and Inch Cape as well as the potential for small craft to be displaced from the area noting that the navigation corridor is MGN 654 compliant.
314. Therefore, the most likely consequences associated with the maximum adverse scenario are as per the equivalent construction phase impact.
315. The severity of consequence is therefore considered to be minor.

Frequency of occurrence

316. The impact will be present throughout the operation and maintenance phase which will last for up to 35 years. Again, since the anticipated deviation options associated with the main commercial routes and the volumes of vessel traffic on such routes are as per the assessment of the Proposed Development in isolation, it is again anticipated that vessels will be exposed to the impact on a daily basis.
317. The frequency of occurrence is therefore considered to be frequent.

Significance of effect

318. Overall, the severity of consequence is deemed to be minor and the frequency of occurrence is considered to be frequent. The cumulative effect will, therefore, be of tolerable adverse significance, which is not significant in EIA terms.

Further mitigation and residual effect

319. No shipping and navigation mitigation is considered necessary because the likely effect in the absence of further mitigation (beyond the designed in measures outlined in Table 13.15   Open ▸ ) is not significant in EIA terms.

Decommissioning phase

Severity of consequence

320. Since the methods used to remove infrastructure are expected to be similar to those used for installation, this impact is expected to be similar in nature to the equivalent construction phase impact. In particular, a buoyed decommissioning area analogous to the buoyed construction area will be in place resulting in the anticipated deviation options identified for the construction phase being directly applicable for the decommissioning phase, as detailed in Table 13.19   Open ▸ .
321. Therefore, the most likely consequences associated with the maximum adverse scenario are as per the equivalent construction phase impact.
322. The severity of consequence is therefore considered to be minor.

Frequency of occurrence

323. The impact will be present throughout the decommissioning phase which will last for up to eight years. Again, since the anticipated deviation options associated with the main commercial routes and the volumes of vessel traffic on such routes are the same as for the equivalent construction phase impact, it is again anticipated that vessels will be exposed to the impact on a daily basis.
324. The frequency of occurrence is therefore considered to be frequent.

Significance of effect

325. Overall, the severity of consequence is deemed to be minor and the frequency of occurrence is considered to be frequent. The cumulative effect will, therefore, be of tolerable adverse significance, which is not significant in EIA terms.

Further mitigation and residual effect

326. No shipping and navigation mitigation is considered necessary because the likely effect in the absence of further mitigation (beyond the designed in measures outlined in Table 13.15   Open ▸ ) is not significant in EIA terms.

Tier 3

Construction phase

Severity of consequence

327. The only CEA tier 3 project is Forthwind, located approximately 37 nm (69 km) from the Proposed Development array area within the Firth of Forth. Given the distance from the Proposed Development array area and that this project is located within a different sea area, the most likely consequences are as per the equivalent CEA tier 2 construction phase impact.
328. The severity of consequence is therefore considered to be minor.

Frequency of occurrence

329. The impact will be present throughout the decommissioning phase which will last for up to eight years. Again, since the anticipated deviation options associated with the main commercial routes and the volumes of vessel traffic on such routes are as per the assessment of the Proposed Development in isolation, it is again anticipated that vessels will be exposed to the impact on a daily basis.
330. The frequency of occurrence is therefore considered to be frequent.

Significance of effect

331. Overall, the severity of consequence is deemed to be minor and the frequency of occurrence is considered to be frequent. The cumulative effect will, therefore, be of tolerable adverse significance, which is not significant in EIA terms.

Further mitigation and residual effect

332. No shipping and navigation mitigation is considered necessary because the likely effect in the absence of further mitigation (beyond the designed in measures outlined in Table 13.15   Open ▸ ) is not significant in EIA terms.

Operation and maintenance phase

Severity of consequence

333. The only CEA tier 3 project is Forthwind, located approximately 37 nm (69 km) from the Proposed Development array area within the Firth of Forth. Given the distance from the Proposed Development array area and that this project is located within a different sea area, the most likely consequences and consequences associated with the maximum adverse scenario are as per the equivalent CEA tier 2 operation and maintenance phase impact.
334. The severity of consequence is therefore considered to be minor.

Frequency of occurrence

335. The impact will be present throughout the decommissioning phase which will last for up to eight years. Again, since the anticipated deviation options associated with the main commercial routes and the volumes of vessel traffic on such routes are as per the assessment of the Proposed Development in isolation, it is again anticipated that vessels will be exposed to the impact on a daily basis.
336. The frequency of occurrence is therefore considered to be frequent.

Significance of effect

337. Overall, the severity of consequence is deemed to be minor and the frequency of occurrence is considered to be frequent. The cumulative effect will, therefore, be of tolerable adverse significance, which is not significant in EIA terms.

Further mitigation and residual effect

338. No shipping and navigation mitigation is considered necessary because the likely effect in the absence of further mitigation (beyond the designed in measures outlined in Table 13.15   Open ▸ ) is not significant in EIA terms.

Decommissioning phase

Severity of consequence

339. The only CEA tier 3 project is Forthwind, located approximately 37 nm (69 km) from the Proposed Development array area within the Firth of Forth. Given the distance from the Proposed Development array area and that this project is located within a different sea area, the most likely consequences associated with the maximum adverse scenario are as per the equivalent CEA tier 2 operation and maintenance phase impact.
340. The severity of consequence is therefore considered to be minor.

Frequency of occurrence

341. The impact will be present throughout the decommissioning phase which will last for up to eight years. Again, since the anticipated deviation options associated with the main commercial routes and the volumes of vessel traffic on such routes are as per the assessment of the Proposed Development in isolation, it is again anticipated that vessels will be exposed to the impact on a daily basis.
342. The frequency of occurrence is therefore considered to be frequent.

Significance of effect

343. Overall, the severity of consequence is deemed to be minor and the frequency of occurrence is considered to be frequent. The cumulative effect will, therefore, be of tolerable adverse significance, which is not significant in EIA terms.

Further mitigation and residual effect

344. No shipping and navigation mitigation is considered necessary because the likely effect in the absence of further mitigation (beyond the designed in measures outlined in Table 13.15   Open ▸ ) is not significant in EIA terms.

Increased Vessel to Vessel Collision Risk Between a Third-Party Vessel and a Project Vessel

Tier 2

Construction phase

Severity of consequence

345. Up to 10,964 return trips by construction vessels (excluding site preparation activities) may be made throughout the construction phase and will include vessels which are RAM. Project vessels will be managed by marine coordination, including the use of traffic management procedures such as the designation of entry and exit points to and from the buoyed construction area, designated routes to and from construction ports and liaison with project vessels for the other Outer Firth of Forth developments. Project vessels will also carry AIS and be compliant with Flag State regulations including the COLREGs.
346. Collision incidents are local in nature, occurring only when two (or more) vessels pass within a small distance of each other within the same sea area. Accounting for the distance between the Proposed Development array area and the CEA tier 2 projects, it is therefore anticipated that the proposed navigation corridor between the Proposed Development array area and Inch Cape is a potential location where this impact may be exacerbated compared to the equivalent impact for the Proposed Development in isolation.
347. In particular, should a project vessel operate within the navigation corridor then a third-party vessel utilising the corridor may be faced with fewer options for collision avoidance given the reduced sea room available. A safety case for this navigation corridor has been undertaken in section 19.1 of the NRA and included consideration of the presence of project vessels. It was noted that any movements by project vessels within or in proximity to the corridor will be made in line with the designed in measures including compliance with the COLREGs, as outlined above. A similar measure is provided in the Inch Cape EIA Report (ICOL, 2018) and marine coordination will include communication with the developer of Inch Cape which may also be operating project vessels.
348. With these designed in measures in place, it is not anticipated that project vessels (for either the Proposed Development or Inch Cape) will have any detrimental effect on the ability of navigation corridor users to make passage safely.
349. Therefore, the most likely consequences associated with the maximum adverse scenario are as per the equivalent construction phase impact for the Proposed Development in isolation.
350. The severity of consequence is therefore considered to be moderate.

Frequency of occurrence

351. The impact will be present throughout the construction phase which will last for up to eight years. With the designed in measures noted above implemented, it is considered unlikely that an encounter between a third-party vessel and a project vessel will occur. In the event that such an encounter does occur, collision avoidance action would be implemented by the vessels as per the COLREGs, thus ensuring that the likelihood of the encounter developing into a collision incident is very low. In the case of the navigation corridor, implementation of the COLREGs may be more difficult but the traffic management procedures implemented by project vessels should ensure that navigation corridor users are unimpeded.
352. The frequency of occurrence is therefore considered to be extremely unlikely.

Significance of effect

353. Overall, the severity of consequence is deemed to be moderate and the frequency of occurrence is considered to be extremely unlikely. The cumulative effect will, therefore, be of broadly acceptable adverse significance, which is not significant in EIA terms.

Further mitigation and residual effect

354. No shipping and navigation mitigation is considered necessary because the likely effect in the absence of further mitigation (beyond the designed in measures outlined in Table 13.15   Open ▸ ) is not significant in EIA terms.

Operation and maintenance phase

Severity of consequence

355. Up to 2,323 return trips per year by operation and maintenance vessels may be made throughout the operation and maintenance phase and will include vessels which are RAM. As per the construction phase, project vessels will be managed by marine coordination, carry AIS and be compliant with Flag State regulations.
356. As per the equivalent construction phase impact, collision incidents are local in nature, occurring only when two (or more) vessels pass within a small distance of each other within the same sea area. Accounting for the distance between the Proposed Development array area and the CEA tier 2 projects, it is therefore anticipated that the navigation corridor between the Proposed Development array area and Inch Cape is a potential location where this impact may be exacerbated compared to the equivalent impact for the Proposed Development in isolation.
357. As per the equivalent construction phase impact, should a project vessel operate within the navigation corridor then a third-party vessel may be faced with fewer options for collision avoidance given the reduced sea room available. As outlined for the equivalent construction phase impact, a safety case for this navigation corridor has been undertaken in section 19.1 of the NRA and included consideration of the presence of project vessels. In particular, measures such as compliance with the COLREGs and communication with the developer of Inch Cape will be implemented.
358. With these designed in measures in place, it is not anticipated that project vessels (for either the Proposed Development or Inch Cape) will have any detrimental effect on the ability of navigation corridor users to make passage safely.
359. Therefore, the most likely consequences and consequences associated with the maximum adverse scenario are as per the equivalent construction phase impact.
360. The severity of consequence is therefore considered to be moderate.

Frequency of occurrence

361. The impact will be present throughout the operation and maintenance phase which will last for up to 35 years. With the designed in measures noted above implemented, it is considered unlikely that an encounter between a third-party vessel and a project vessel will occur. In the event that such an encounter does occur, collision avoidance action would be implemented by the vessels as per the COLREGs, thus ensuring that the likelihood of the encounter developing into a collision incident is very low.
362. The likelihood of an encounter is decreased compared to in the construction phase given that much fewer project vessels will generally be on-site at any time, although this is somewhat balanced by the much longer duration of the operation and maintenance phase.
363. The frequency of occurrence is therefore considered to be negligible.

Significance of effect

364. Overall, the severity of consequence is deemed to be moderate and the frequency of occurrence is considered to be negligible. The cumulative effect will, therefore, be of broadly acceptable adverse significance, which is not significant in EIA terms.

Further mitigation and residual effect

365. No shipping and navigation mitigation is considered necessary because the likely effect in the absence of further mitigation (beyond the designed in measures outlined in Table 13.15   Open ▸ ) is not significant in EIA terms.

Decommissioning phase

Severity of consequence

366. Since the numbers and types of vessel used to remove infrastructure are expected to be similar to those used for installation, this impact is expected to be similar in nature to the equivalent construction phase impact. In particular, project vessels will be managed by marine coordination, safety zones will be applied for and decommissioning activities will generally be located within the buoyed decommissioning area.
367. Therefore, the most likely consequences associated with the maximum adverse scenario are as per the equivalent construction phase impact, including in relation to the navigation corridor between the Proposed Development array area and Inch Cape.
368. The severity of consequence is therefore considered to be moderate.

Frequency of occurrence

369. The impact will be present throughout the decommissioning phase which will last for up to eight years. With the designed in measures noted above implemented, it is considered unlikely that an encounter between a third-party vessel and a project vessel will occur. As per the equivalent construction phase impact, in the event that such an encounter does occur, collision avoidance action would be implemented by the vessels as per the COLREGs, thus ensuring that the likelihood of the encounter developing into a collision incident is very low.
370. The frequency of occurrence is therefore considered to be extremely unlikely.

Significance of effect

371. Overall, the severity of consequence is deemed to be moderate and the frequency of occurrence is considered to be extremely unlikely. The cumulative effect will, therefore, be of broadly acceptable adverse significance, which is not significant in EIA terms.

Further mitigation and residual effect

372. No shipping and navigation mitigation is considered necessary because the likely effect in the absence of further mitigation (beyond the designed in measures outlined in Table 13.15   Open ▸ ) is not significant in EIA terms.

Tier 3

Construction phase

Severity of consequence

373. The only CEA tier 3 project is Forthwind, located approximately 37 nm (69 km) from the Proposed Development array area within the Firth of Forth. Given the distance from the Proposed Development array area and that this project is located within a different sea area, this impact is only considered relevant in the event that construction vessels operate in and out of ports within the Firth of Forth. In particular, Forthwind is located close to the Port of Methil and Energy Park Fife.
374. However, as outlined for the equivalent CEA tier 2 construction phase impact, project vessels will be managed by marine coordination, including the use of designated routes to and from construction ports. Project vessels will also carry AIS and be compliant with Flag State regulations including the COLREGs. With these designed in measures in place, the most likely consequences associated with the maximum adverse scenario are as per the equivalent CEA tier 2 construction phase impact.
375. The severity of consequence is therefore considered to be moderate.

Frequency of occurrence

376. The impact will be present throughout the construction phase which will last for up to eight years. With the designed in measures noted above implemented, it is considered unlikely that an encounter between a third-party vessel and a project vessel will occur. In the event that such an encounter does occur, collision avoidance action would be implemented by the vessels as per the COLREGs, thus ensuring that the likelihood of the encounter developing into a collision incident is very low.
377. The frequency of occurrence is therefore considered to be extremely unlikely.

Significance of effect

378. Overall, the severity of consequence is deemed to be moderate and the frequency of occurrence is considered to be extremely unlikely. The cumulative effect will, therefore, be of broadly acceptable adverse significance, which is not significant in EIA terms.

Further mitigation and residual effect

379. No shipping and navigation mitigation is considered necessary because the likely effect in the absence of further mitigation (beyond the designed in measures outlined in Table 13.15   Open ▸ ) is not significant in EIA terms.

Operation and maintenance phase

Severity of consequence

380. The only CEA tier 3 project is Forthwind, located approximately 37 nm (69 km) from the Proposed Development array area within the Firth of Forth. Given the distance from the Proposed Development array area and that this project is located within a different sea area, this impact is only considered relevant in the event that operation and maintenance vessels operate in and out of ports within the Firth of Forth. In particular, Forthwind is located close to the Port of Methil and Energy Park Fife.
381. With the same designed in measures in place as outlined for the equivalent construction phase impact, the most likely consequences and consequences associated with the maximum adverse scenario are as per the equivalent CEA tier 2 construction phase impact.
382. The severity of consequence is therefore considered to be moderate.

Frequency of occurrence

383. The impact will be present throughout the operation and maintenance phase which will last for up to 35 years. With the designed in measures noted above implemented, it is considered unlikely that an encounter between a third-party vessel and a project vessel will occur. In the event that such an encounter does occur, collision avoidance action would be implemented by the vessels as per the COLREGs, thus ensuring that the likelihood of the encounter developing into a collision incident is very low.
384. The likelihood of an encounter is decreased compared to in the construction phase given that much fewer project vessels will generally make transit to and from the Proposed Development, although this is somewhat balanced by the much longer duration of the operation and maintenance phase.
385. The frequency of occurrence is therefore considered to be negligible.

Significance of effect

386. Overall, the severity of consequence is deemed to be moderate and the frequency of occurrence is considered to be negligible. The cumulative effect will, therefore, be of broadly acceptable adverse significance, which is not significant in EIA terms.

Further mitigation and residual effect

387. No shipping and navigation mitigation is considered necessary because the likely effect in the absence of further mitigation (beyond the designed in measures outlined in Table 13.15   Open ▸ ) is not significant in EIA terms.