Decommissioning phase

Severity of consequence

388. 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 decommissioning phase impact.
389. The severity of consequence is therefore considered to be moderate.

Frequency of occurrence

390. The impact will be present throughout the decommissioning phase which will last for up to eight years. With the same designed in measures as noted for the equivalent construction phase impact, 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.
391. The frequency of occurrence is therefore considered to be extremely unlikely.

Significance of effect

392. 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

393. 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 Third-Party Vessels

Tier 2

Construction phase

Severity of consequence

394. 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 are provided in Table 13.19   Open ▸ .
395. Considering the anticipated deviation options outlined in Table 13.19   Open ▸ , there are five primary deviation options which cover all affected routeing scenarios. Three of these options – passing south of the Proposed Development array area, offshore of the Proposed Development array area, north of Seagreen – result in lower collision risk given that there is sufficient available sea room for vessels to safely navigate a suitable distance from each other and the arrays.
396. For one of the other deviation options – passing inshore of Inch Cape – the following concerns exist relating to collision risk:

• proximity to surface piercing structures (Inch Cape, Bell Rock) result in limited available sea room and subsequently increased collision risk for passing vessels;
• encounters with small craft may be increased with the presence of coastal fishing pots displacing recreational vessels into deviated commercial vessels; and
• passing vessels may be displaced into extensive potting areas and spoil grounds.
  397. Based on the inclusion of a MGN 654 compliant navigation corridor it is considered unlikely that many vessels will pass inshore of Inch Cape. For the last deviation option – utilising the navigation corridor between the Proposed Development array area and Inch Cape – the proximity to surface piercing structures to both port and starboard introduce increased collision risk for passing vessels.
  398. For the navigation corridor between the Proposed Development array area and Inch Cape, a safety case has been undertaken in the NRA (see section 19.1) and concluded that the corridor meets safety of navigation expectations. In particular, the corridor is not expected to experience a high volume of passing traffic (given alternative safe options are available – passing offshore of the Proposed Development) and is compliant with various relevant guidance which has been applied including from MGN 654, Permanent International Association of Navigation Congresses (PIANC) (PIANC, 2018), and Maritime Institute Netherlands (MARIN) (Nautical Institute, 2013) and the COLREGs (IMO, 1972/77). This includes the assurance that there is sufficient sea room available within the corridor to allow any necessary collision avoidance action in the event of an encounter between transiting vessels (minimum width of 4.1 nm).
  399. Moreover, the shape of the navigation corridor between the Proposed Development array area and Inch Cape contains a compliant parallelogram. This means that vessels using the corridor have a clear view of each other when passing and also of any non-transiting small craft located at either side of the corridor, including in low visibility, further reducing collision risk.
  400. There is also a potential for encounters with small craft within the navigation corridor including active fishing vessels which may be unable to make a manoeuvre in sufficient time to avoid an oncoming commercial vessel. However, given the available sea room within the corridor, it is anticipated that the passing vessel would comfortably be able to pass safely around any small craft in the corridor.
  401. The most likely consequences in the event of a collision incident between third-party vessels are minor contact between the vessels resulting in minor damage to property and minor reputational effects on business but no perceptible effect on people. The maximum adverse scenario may include one of the vessels foundering resulting in PLL and the environmental consequence of pollution. Such a scenario would be more likely if one of the vessels involved was a small craft which may have lower structural integrity than a commercial vessel. The Project’s Marine Pollution Contingency Plan will be implemented to minimise the environmental effects should pollution occur.
  402. The severity of consequence is therefore considered to be moderate.

Frequency of occurrence

403. The impact will be present throughout the construction phase which will last for up to eight years. For passing commercial vessels alone, from the vessel traffic data it is anticipated that for the future case scenario an average of three to four transits per day through the navigation corridor may be made by potential users. The likelihood of an encounter between passing vessels (either overtaking or head-on) is therefore very low, with sufficient sea room as per MGN 654 to allow interactions with small craft to be mitigated. The promulgation of information and charting of the buoyed construction area will also maximise awareness of ongoing construction activities, thus allowing third-party vessels to passage plan in advance.
404. The frequency of occurrence is therefore considered to be remote.

Significance of effect

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

Further mitigation and residual effect

406. No shipping and navigation mitigation is considered necessary because the likely effect in the absence of mitigation is not significant in EIA terms.

Operation and maintenance phase

Severity of consequence

407. Since all CEA tier 2 projects will be in situ during the operation and maintenance phase, the anticipated deviation options 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 ▸ .
408. 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.
409. The size and location of the buoyed construction area will be slightly larger (given 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 of shipping and navigation will be equal to or less.
410. Therefore, the most likely consequences and consequences associated with the maximum adverse scenario are slightly lower than the equivalent construction phase impact. However the severity of consequence is still considered to be moderate.

Frequency of occurrence

411. The impact will be present throughout the operation and maintenance phase which will last for up to 35 years. Again, from the vessel traffic data and interpretation of potential navigation corridor users it is anticipated that the likelihood of an encounter between passing vessels or small craft is very low.
412. The promulgation of information and charting of infrastructure will maximise awareness of ongoing operation and maintenance activities, thus allowing third-party vessels to passage plan in advance.
413. The frequency of occurrence is therefore considered to be remote.

Significance of effect

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

Further mitigation and residual effect

415. 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

416. Since the methods used to remove infrastructure are expected to be similar to those used for installation, this impact is expected to be similar 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 ▸ .
417. Therefore, the most likely consequences and consequences associated with the maximum adverse scenario are as per the equivalent construction phase impact.
418. The severity of consequence is therefore considered to be moderate.

Frequency of occurrence

419. Again, from the vessel traffic data and interpretation of potential navigation corridor users it is anticipated that the likelihood of an encounter between passing vessels or small craft is very low.
420. The promulgation of information and charting of the buoyed decommissioning area will maximise awareness of ongoing operation and maintenance activities, thus allowing third-party vessels to passage plan in advance.
421. The frequency of occurrence is therefore considered to be remote.

Significance of effect

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

Further mitigation and residual effect

423. 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

424. 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 construction phase impact.
425. The severity of consequence is therefore considered to be moderate.

Frequency of occurrence

426. The impact will be present throughout the construction phase which will last for up to eight years. Again, given the distance from the Proposed Development array area and that this project is located within a different sea area, the likelihood of a third-party collision incident is as per the equivalent CEA tier 2 construction phase impact.
427. The frequency of occurrence is therefore considered to be remote.

Significance of effect

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

Further mitigation and residual effect

429. No shipping and navigation mitigation is considered necessary because the likely effect in the absence of mitigation is not significant in EIA terms.

Operation and maintenance phase

Severity of consequence

430. 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.
431. The severity of consequence is therefore considered to be moderate.

Frequency of occurrence

432. The impact will be present throughout the operation and maintenance phase which will last for up to 35 years. Again, given the distance from the Proposed Development array area and that this project is located within a different sea area, the likelihood of a third-party collision incident is as per the equivalent CEA tier 2 construction phase impact.
433. The frequency of occurrence is therefore considered to be remote.

Significance of effect

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

Further mitigation and residual effect

435. 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

436. 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 decommissioning phase impact.
437. The severity of consequence is therefore considered to be moderate.

Frequency of occurrence

438. The impact will be present throughout the decommissioning phase which will last for up to eight years. Again, given the distance from the Proposed Development array area and that this project is located within a different sea area, the likelihood of a third-party collision incident is as per the equivalent CEA tier 2 decommissioning phase impact.
439. The frequency of occurrence is therefore considered to be remote.

Significance of effect

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

Further mitigation and residual effect

441. 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.

Vessel to Structure Allision Risk

Tier 2

Construction phase

Severity of consequence

442. Allision incidents are local in nature, occurring only when a vessel is located in proximity to a surface piercing structure. Accounting for the distance between the Proposed Development array area and the CEA tier 2 projects, it is therefore anticipated that the vessels navigating within the navigation corridor between the Proposed Development array area and Inch Cape will be subject to a cumulative allision risk.
443. A drifting allision risk exists within the corridor in the event of mechanical failure or technical failure, adverse weather and/or navigational system error. A vessel adrift may only develop into an allision situation if in proximity to a wind farm structure (including pre-commissioned structure) and this is only the case where the adrift vessel is located in proximity to the navigation corridor and the wind and/or tide directs the vessel towards a structure.
444. The most likely consequences and consequences associated with the maximum adverse scenario in the event of an allision incident (powered and drifting) are as per the equivalent construction phase impact for the Proposed Development in isolation.
445. The severity of consequence is therefore considered to be moderate.

Frequency of occurrence

446. The impact will be present throughout the construction phase which will last for up to eight years and will cover a greater spatial extent as more structures are installed. For powered allision incidents, safety zones of up to 50 m around partially completed or completed but not yet fully commissioned surface piercing structures (at the Proposed Development array area) will be in place and assist with ensuring that vessels are aware of the presence of structures. If on-site, guard vessels will assist with monitoring safety zones. Furthermore, the use of lighting and marking as required by the NLB and the MCA (including for partially completed structures), charting of the buoyed construction area and promulgation of information will allow vessels to passage plan a safe route in advance. The NLB stated during consultation that further discussions on lighting and marking will be appropriate once final layouts are under consideration. The final array layout will be agreed through the DSLP which will include consultation with the MCA and NLB. With these designed in measures in place it is considered unlikely that a powered allision incident will occur.
447. For drifting allision incidents, the adrift vessel would initiate its emergency response procedures to avoid a closing CPA with a structure resulting in an allision. This may include emergency anchoring following a check of the relevant nautical charts (thus ensuring that the anchor deployment does not lead to other impacts such as anchor snagging on a subsea cable). Moreover, under SOLAS obligations (IMO, 1974), other nearby vessels including project vessels (via marine coordination) for all relevant CEA tier 2 projects may be able to render assistance. There is also a possibility that a drifting vessel could regain power prior to alliding with a structure.
448. Since a vessel utilising the navigation corridor may have surface piercing structures to both port and starboard (depending upon the status of wind turbine installation of the Proposed Development), the likelihood of an allision incident is greater. This is particularly notable for drifting allision given the closer proximity a vessel is likely to attain to a structure when becoming adrift and the greater potential for the wind and/or tide to direct the vessel towards a structure.
449. The frequency of occurrence is therefore considered to be remote.

Significance of effect

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

Further mitigation and residual effect

451. 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

452. As per the equivalent construction phase impact, allision incidents are local in nature, occurring only when a vessel is located in proximity to a surface piercing structure. Accounting for the distance between the Proposed Development array area and the CEA tier 2 projects, it is therefore anticipated that the vessels navigating within the navigation corridor between the Proposed Development array area and Inch Cape will be subject to a cumulative allision risk.
453. Some of the CEA tier 2 projects (including Seagreen and Inch Cape) 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.
454. In relation to the navigation corridor, the same points outlined for the equivalent construction phase impact exist. A drifting allision risk also exists, although a vessel adrift may only develop into an allision situation if in proximity to a structure and this is only the case where the adrift vessel is located in proximity to the navigation corridor and the wind and/or tide directs the vessel towards a structure.
455. The most likely consequences and consequences associated with the maximum adverse scenario in the event of an allision incident (powered and drifting) are as per the equivalent construction phase impact.
456. The severity of consequence is therefore considered to be moderate.

Frequency of occurrence

457. The impact will be present throughout the operation and maintenance phase which will last for up to 35 years. For powered allision incidents, major maintenance safety zones of up to 500 m will be in place (at the Proposed Development array area) and assist with ensuring that vessels are aware of the presence of structures. If on-site, guard vessels will assist with monitoring safety zones. Furthermore, the use of lighting and marking as required by the NLB and the MCA, charting of infrastructure and promulgation of information will allow vessels to passage plan a safe route in advance. The NLB stated during consultation that further discussions on lighting and marking will be appropriate once final layouts are under consideration. The final array layout will be agreed through the DSLP which will include consultation with the MCA and NLB. With these designed in measures in place, it is considered unlikely that a powered allision incident will occur.
458. For drifting allision incidents, the adrift vessel would initiate its emergency response procedures to avoid a closing CPA with a structure resulting in an allision. This may include emergency anchoring following a check of the relevant nautical charts (thus ensuring that the anchor deployment does not lead to other impacts such as anchor snagging on a subsea cable). Moreover, under SOLAS obligations (IMO, 1974), other nearby vessels including project vessels (via marine coordination) for all relevant CEA tier 2 projects may be able to render assistance. There is also a possibility that a drifting vessel could regain power prior to alliding with a structure.
459. As for the equivalent construction phase impact, since a vessel utilising the navigation corridor may have surface piercing structures to both port and starboard, the likelihood of an allision incident is greater. This is particularly notable for drifting allision given the closer proximity a vessel is likely to be to a structure when becoming adrift and the greater potential for the wind and/or tide to direct the vessel towards a structure.
460. Although internal allision risk is not directly considered relevant to the cumulative impact (since it is specific to each individual array), there is potential for small craft to navigate through one array and into another. This is of particular note for vessels navigating between the Proposed Development array area and Inch Cape. Both projects include a layout with two lines of orientation (noting that a final array layout for Inch Cape has not yet been published but the project was consented with two lines of orientation layout) and similar minimum spacing. Therefore, it is anticipated that any small craft navigating between the arrays will be able to adapt effectively. The bearing of the lines of orientation in each array may be different, but the 4.1 nm minimum distance between the adjacent arrays is considered suitable to allow small craft to orientate themselves suitably after existing one array and prior to entering another, noting that MGN 654 states that the need for lines of orientation suitable for continuous passage applies for “adjacent boundaries less than 1 nm apart” (MCA, 2021).
461. The frequency of occurrence is therefore considered to be remote.

Significance of effect

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

Further mitigation and residual effect

463. 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

464. As per the equivalent construction phase impact, allision incidents are local in nature, and accounting for the distance between the Proposed Development array area and the CEA tier 2 projects, it is therefore anticipated that vessels navigating within the navigation corridor between the Proposed Development array area and Inch Cape will be subject to a cumulative allision risk.
465. Some of the CEA tier 2 projects (including Seagreen and Inch Cape) may be decommissioned during or prior to the decommissioning phase, although for the maximum adverse scenario it is assumed that all CEA tier 2 projects will remain in situ throughout the decommissioning phase.
466. In relation to the navigation corridor, the same points outlined for the equivalent construction phase impact exist. A drifting allision risk also exists, although a vessel adrift may only develop into an allision situation if in proximity to a structure and this is only the case where the adrift vessel is located in proximity to the navigation corridor and the wind and/or tide directs the vessel towards a structure.
467. With the presence of safety zones, use of guard vessels where on-site, use of lighting and marking as required by the MCA and NLB (including for partially removed structures), charting of the buoyed decommissioning area and promulgation of information, the most likely consequences and consequences associated with the maximum adverse scenario are as per the equivalent construction phase impact.
468. The severity of consequence is therefore considered to be moderate.

Frequency of occurrence

469. The impact will be present throughout the decommissioning phase which will last for up to eight years and will cover a lesser spatial extent as more structures are removed. For powered allision incidents, safety zones of up to 50 m around partially removed surface piercing structures (at the Proposed Development array area) will be in place and assist with ensuring that vessels are aware of the presence of structures. If on-site, guard vessels will assist with monitoring safety zones. Furthermore, the use of lighting and marking as required by the NLB and the MCA (including for partially removed structures), charting of the buoyed decommissioning area and promulgation of information will allow vessels to passage plan a safe route in advance. With these designed in measures in place, it is considered unlikely that a powered allision incident will occur.
470. For drifting allision incidents, the adrift vessel would initiate its emergency response procedures to avoid a closing CPA with a structure resulting in an allision. This may include emergency anchoring following a check of the relevant nautical charts (thus ensuring that the anchor deployment does not lead to other impacts such as anchor snagging on a subsea cable). Moreover, under SOLAS obligations (IMO, 1974), other nearby vessels including project vessels (via marine coordination) for all relevant CEA tier 2 projects may be able to render assistance. There is also a possibility that a drifting vessel could regain power prior to alliding with a structure.
471. Since a vessel utilising the navigation corridor may have surface piercing structures to both port and starboard (depending upon the status of wind turbine removal of the Proposed Development), the likelihood of an allision incident is greater. This is particularly notable for drifting allision given the closer proximity a vessel is likely to be to a structure when becoming adrift and the greater potential for the wind and/or tide to direct the vessel towards a structure.
472. The frequency of occurrence is therefore considered to be remote.

Significance of effect

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

Further mitigation and residual effect

474. 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

475. 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 construction phase impact.
476. The severity of consequence is therefore considered to be moderate.

Frequency of occurrence

477. The impact will be present throughout the construction phase which will last for up to eight years. Again, given the distance from the Proposed Development array area and that this project is located within a different sea area, the likelihood of a third-party collision incident is as per the equivalent CEA tier 2 construction phase impact.
478. The frequency of occurrence is therefore considered to be remote.

Significance of effect

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

Further mitigation and residual effect

480. 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

481. 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.
482. The severity of consequence is therefore considered to be moderate.

Frequency of occurrence

483. The impact will be present throughout the operation and maintenance phase which will last for up to 35 years. Again, given the distance from the Proposed Development array area and that this project is located within a different sea area, the likelihood of a third-party collision incident is as per the equivalent CEA tier 2 operation and maintenance phase impact.
484. The frequency of occurrence is therefore considered to be remote.

Significance of effect

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

Further mitigation and residual effect

486. 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

487. 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 decommissioning phase impact.
488. The severity of consequence is therefore considered to be moderate.

Frequency of occurrence

489. The impact will be present throughout the decommissioning phase which will last for up to eight years. Again, given the distance from the Proposed Development array area and that this project is located within a different sea area, the likelihood of a third-party collision incident is as per the equivalent CEA tier 2 decommissioning phase impact.
490. The frequency of occurrence is therefore considered to be remote.

Significance of effect

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

Further mitigation and residual effect

492. 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.

Reduced Access to Local Ports

Tier 2

Construction phase

Severity of consequence

493. 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 are provided in Table 13.19   Open ▸ .
494. Given the relative distance to ports in the area and the anticipated deviations for the main commercial routes, it is anticipated that there may be some disruption to port access, particularly for vessels accessing the Firth of Forth from the north. This is due to the navigation corridor between the Proposed Development array area and Inch Cape potentially being discounted as an option for many vessels (particularly larger commercial vessels) as discussed in the cumulative vessel displacement impact, leaving only options with greater deviations. This may make ports located within the Firth of Forth less attractive to operators; however the large-scale and importance of the Firth of Forth for ports is noted, with it considered unlikely that the greater deviations will be sufficient to discourage operators from using the Firth of Forth, particularly when noting that passage planning may assist with minimising timing impacts.
495. Additionally, during consultation Forth Ports noted that if vessels deviate inshore of Inch Cape, then there may be a need for Forth Ports (as the VTS operator for the Firth of Forth) to contact such vessels to ask for intentions.
496. The construction of Inch Cape could overlap with the construction phase, noting that dates for construction are unknown. Likewise, there will be overlap between the operation and maintenance phases for all CEA tier 2 developments (with the possible exception of Inch Cape depending on timescales). Therefore, the cumulative presence of project vessels will be greater than for the Proposed Development in isolation. However, 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 (for the Proposed Development and potentially Inch Cape) and from the array (for all CEA tier 2 projects), designated routes to and from maintenance ports and liaison with project vessels for the other Outer Firth of Forth developments. This latter measure is particularly relevant in the event of overlap with the construction works for Inch Cape. Project vessels will also carry AIS and be compliant with Flag State regulations including the COLREGs.
497. With the designed in measures listed above and lessons learnt from construction vessel movements associated with the Seagreen construction phase, the effect due to the presence of CEA tier 2 projects is anticipated to be manageable.
498. The most likely consequences are as per the equivalent operation and maintenance phase impact for the Proposed Development in isolation. The consequences associated with the maximum adverse scenario are largely as per the equivalent construction phase impact for the Proposed Development in isolation but also include increased business effects relating to loss of custom and additional third-party workload.
499. The severity of consequence is therefore considered to be minor.

Frequency of occurrence

500. The impact will be present throughout the construction phase which will last for up to eight years. The busiest main commercial route identified within the Proposed Development array area shipping and navigation study area accessing a local port for which an increased passage distance is required is Route 5, with an average of one vessel per day. In total, across all the routes accessing a local port for which an increased passage distance is required, there is an average of two vessels per day. Additionally, a proportion of the non-commercial vessel traffic may be affected, noting that an average of one to two unique fishing vessels per day were recorded within the Proposed Development array area shipping and navigation study area throughout the vessel traffic surveys.
501. Therefore, it is anticipated that vessels will be exposed to the impact on a daily basis, particularly commercial vessels such as tankers and cargo vessels which constitute the majority of the vessel traffic, including those assigned to the main commercial routes.
502. The frequency of occurrence is therefore considered to be frequent.

Significance of effect

503. 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

504. 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

505. 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 ▸ .
506. Therefore, concerns raised for the equivalent construction phase impact are directly applicable. This includes disruption to port access due to the navigation corridor between the Proposed Development array area and Inch Cape potentially being discounted as an option for many vessels, with the resulting potential for lost business.
507. Additionally, there is potential for additional third-party workload for Forth Ports due to a need to contact vessels deviating inshore of Inch Cape, as per the equivalent construction phase impact.
508. The construction of Inch Cape could overlap with the operation and maintenance phase, noting that dates for construction are unknown. Likewise, there will be overlap between the operation and maintenance phases for all CEA tier 2 projects. Therefore, the cumulative presence of project vessels will be greater than for the Proposed Development in isolation. However, 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 arrays (for all CEA tier 2 projects) and the buoyed construction area (potentially for Inch Cape), designated routes to and from maintenance ports and liaison with project vessels for the other Outer Firth of Forth developments. This latter measure is particularly relevant in the event of overlap with the construction works for Inch Cape. Project vessels will also carry AIS and be compliant with Flag State regulations including the COLREGs.
509. With the designed in measures listed above and lessons learnt from construction vessel movements associated with the Seagreen operation and maintenance phase, the effect due to the presence of CEA tier 2 projects is anticipated to be manageable.
510. The most likely consequences are as per the equivalent operation and maintenance phase impact for the Proposed Development in isolation. The consequences associated with the maximum adverse scenario are largely as per the equivalent construction phase impact but also include increased effects relating to loss of custom and additional third-party workload.
511. The severity of consequence is therefore considered to be minor.

Frequency of occurrence

512. The impact will be present throughout the operation and maintenance phase which will last for up to 35 years. The busiest main commercial route identified within the Proposed Development array area shipping and navigation study area accessing a local port for which an increased passage distance is required is Route 5, with an average of one vessel per day. In total, across all the routes accessing a local port for which an increased passage distance is required, there is an average of two vessels per day. Additionally, a proportion of the non-commercial vessel traffic may be affected, as noted for the equivalent construction phase impact.
513. Therefore, it is anticipated that vessels will be exposed to the impact on a daily basis, particularly commercial vessels such as tankers and cargo vessels which constitute the majority of the vessel traffic, including those assigned to the main commercial routes.
514. The frequency of occurrence is therefore considered to be frequent.

Significance of effect

515. 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

516. 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

517. 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 ▸ . At this time, additional deviation options may be available since CEA tier 2 projects may have been decommissioned; in line with the maximum adverse scenario for port access concerns relating to the presence of infrastructure it is assumed that CEA tier 2 projects will remain in situ throughout the decommissioning phase.
518. Therefore, concerns raised for the equivalent construction phase impact are directly applicable. This includes disruption to port access due to the navigation corridor between the Proposed Development array area and Inch Cape potentially being discounted as an option for many vessels, with the resulting loss of custom.
519. Additionally, there is potential for additional third-party workload for Forth Ports due to a need to contact vessels deviating inshore of Inch Cape, as per the equivalent construction phase impact.
520. The operation and maintenance and decommissioning of the CEA tier 2 projects could overlap the decommissioning phase, resulting in the cumulative presence of project vessels being greater than for the Proposed Development in isolation, particularly in the event of decommissioning CEA tier 2 projects. However, 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 decommissioning areas (for the Proposed Development and potentially CEA tier 2 projects) and the arrays (potentially for CEA tier 2 projects), designated routes to and from decommissioning ports and liaison with project vessels for the other Outer Firth of Forth developments. This latter measure is particularly relevant in the event of overlap with the decommissioning works for CEA tier 2 projects. Project vessels will also carry AIS and be compliant with Flag State regulations including the COLREGs.
521. With the designed in measures listed above and lessons learnt from decommissioning vessel movements associated with the Seagreen decommissioning phase (if this has occurred by the time of the decommissioning phase), there is anticipated to be limited additional effect due to the presence of CEA tier 2 projects.
522. The severity of consequence is therefore considered to be minor.

Frequency of occurrence

523. The impact will be present throughout the decommissioning phase which will last for up to eight years. The busiest main commercial route identified within the Proposed Development array area shipping and navigation study area accessing a local port for which an increased passage distance is required is Route 5, with an average of one vessel per day. In total, across all the routes accessing a local port for which an increased passage distance is required, there is an average of two vessels per day (assuming for the maximum adverse scenario that CEA tier 2 projects remain in situ throughout the decommissioning phase). Additionally, a proportion of the non-commercial vessel traffic may be affected, as noted for the equivalent construction phase impact.
524. Therefore, it is anticipated that vessels will be exposed to the impact on a daily basis, particularly commercial vessels such as tankers and cargo vessels which constitute the majority of the vessel traffic, including those assigned to the main commercial routes.
525. The frequency of occurrence is therefore considered to be frequent.

Significance of effect

526. 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

527. 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

528. The only CEA tier 3 development 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 for the Proposed Development 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.
529. The construction of Forthwind could overlap with the construction phase, noting that dates for construction are unknown. Likewise the potential overlap noted for CEA tier 2 projects in the equivalent CEA tier 2 construction phase impact applies. 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 entry and exit points, designated routes and liaison with project vessels for the other developments in the region. This latter measure is particularly relevant in the event of overlap with the construction works for Inch Cape or Forthwind. Project vessels will also carry AIS and be compliant with Flag State regulations including the COLREGs.
530. With the designed in measures listed above and lessons learnt from construction vessel movements associated with the Seagreen construction phase, the effect due to the presence of CEA tier 2 and tier 3 projects is anticipated to be manageable.
531. The most likely consequences and consequences associated with the maximum adverse scenario are as per the equivalent CEA tier 2 construction phase impact.
532. The severity of consequence is therefore considered to be minor.

Frequency of occurrence

533. The impact will be present throughout the construction phase which will last for up to eight years. The busiest main commercial route identified within the Proposed Development array area shipping and navigation study area accessing a local port for which an increased passage distance is required is Route 5, with an average of one vessel per day. In total, across all the routes accessing a local port for which an increased passage distance is required, there is an average of two vessels per day. Additionally, a proportion of the non-commercial vessel traffic may be affected, as noted for the equivalent CEA tier 2 impact.
534. Therefore, it is anticipated that vessels will be exposed to the impact on a daily basis, particularly commercial vessels such as tankers and cargo vessels which constitute the majority of the vessel traffic, including those assigned to the main commercial routes.
535. The frequency of occurrence is therefore considered to be frequent.

Significance of effect

536. 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

537. 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

538. The only CEA tier 3 development 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.
539. The construction of Forthwind could overlap with the operation and maintenance phase, noting that dates for construction are unknown. Likewise the potential overlap noted for CEA tier 2 projects in the equivalent CEA tier 2 construction phase impact applies. 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 entry and exit points, designated routes and liaison with project vessels for the other developments in the region. This latter measure is particularly relevant in the event of overlap with the construction works for Inch Cape or Forthwind. Project vessels will also carry AIS and be compliant with Flag State regulations including the COLREGs.
540. With the designed in measures listed above and lessons learnt from operation and maintenance vessel movements associated with the Seagreen operation and maintenance phase, the effect due to the presence of CEA tier 2 and tier 3 projects is anticipated to be manageable.
541. The most likely consequences associated with the maximum adverse scenario are as per the equivalent construction phase impact.
542. The severity of consequence is therefore considered to be minor.

Frequency of occurrence

543. The impact will be present throughout the operation and maintenance phase which will last for up to 35 years. The busiest main commercial route identified within the Proposed Development array area shipping and navigation study area accessing a local port for which an increased passage distance is required is Route 5, with an average of one vessel per day. In total, across all the routes accessing a local port for which an increased passage distance is required, there is an average of two vessels per day. Additionally, a proportion of the non-commercial vessel traffic may be affected, as noted for the equivalent CEA tier 2 impact.
544. Therefore, it is anticipated that vessels will be exposed to the impact on a daily basis, particularly commercial vessels such as tankers and cargo vessels which constitute the majority of the vessel traffic, including those assigned to the main commercial routes.
545. The frequency of occurrence is therefore considered to be frequent.

Significance of effect

546. 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

547. 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

548. The only CEA tier 3 development 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 decommissioning 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.
549. The operation and maintenance and decommissioning of Forthwind could overlap with the decommissioning phase, noting that dates for decommissioning are unknown. Likewise the potential overlap noted for CEA tier 2 projects in the equivalent CEA tier 2 decommissioning phase impact applies. However, as outlined for the equivalent CEA tier 2 decommissioning phase impact, project vessels will be managed by marine coordination, including the use of designated entry and exit points, designated routes and liaison with project vessels for the other developments in the region. This latter measure is particularly relevant in the event of overlap with the decommissioning works for CEA tier 2 and tier 3 projects. Project vessels will also carry AIS and be compliant with Flag State regulations including the COLREGs.
550. With the designed in measures listed above and lessons learnt from decommissioning vessel movements associated with the Seagreen decommissioning phase (if this has occurred by the time of the decommissioning phase), the effect due to the presence of CEA tier 2 and tier 3 projects is anticipated to be manageable.
551. The most likely consequences and consequences associated with the maximum adverse scenario are as per the equivalent construction phase impact.
552. The severity of consequence is therefore considered to be minor.

Frequency of occurrence

553. The impact will be present throughout the decommissioning phase which will last for up to eight years. The busiest main commercial route identified within the Proposed Development array area shipping and navigation study area accessing a local port for which an increased passage distance is required is Route 5, with an average of one vessel per day. In total, across all the routes accessing a local port for which an increased passage distance is required, there is an average of two vessels per day. Additionally, a proportion of the non-commercial vessel traffic may be affected, as noted for the equivalent CEA tier 2 impact.
554. Therefore, it is anticipated that vessels will be exposed to the impact on a daily basis, particularly commercial vessels such as tankers and cargo vessels which constitute the majority of the vessel traffic, including those assigned to the main commercial routes.
555. The frequency of occurrence is therefore considered to be frequent.

Significance of effect

556. 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

557. 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 Under Keel Clearance