1Introduction

1.1Background

1.1.1                          This document is the Outline Construction Traffic Management Plan (CTMP) for the onshore elements of the Ayre Offshore Wind Farm (the ‘Project’). For ease of reference the onshore elements of the Project, landward of Mean Low Water Springs (MLWS), are referred to as the ‘Proposed Development’. This document forms part of the Onshore EIA Report which accompanies the application to The Highland Council (THC) for Planning Permission in Principle (PPP) for the Proposed Development. 

1.1.2                         This Outline CTMP sets out the key management and mitigation measures for traffic and transport that will be implemented during the construction phase of the Proposed Development.

1.1.3                         This Outline CTMP seeks to manage potential impacts that could occur from the construction of the Proposed Development.

1.1.4                        In addition to these elements, this Outline CTMP also considers the temporary construction compounds, welfare, site offices and storage areas required to support the construction of the Proposed Development.

1.2Purpose of the Outline CTMP

1.2.1                         The purpose of this Outline CTMP is to establish the principles and procedures that will be implemented by the Principal Contractor to minimise and manage the adverse impacts associated with the transport of materials, plant and staff required for construction of the Proposed Development. This Outline CTMP also presents the standards and procedures to manage the impact of Heavy Goods Vehicle (HGV) movements during construction of the Proposed Development, including local road improvements and traffic management necessary to facilitate the safe use of the local road network.

1.2.2                       Should PPP consent be granted, this Outline CTMP will evolve and form the basis of a final CTMP which will be prepared in consultation with THC and Transport Scotland prior to approval.

1.2.3                       The measures set out in this Outline CTMP relate to the areas of onshore construction activity identified in Volume 1, Chapter 15: Traffic and Transport of the Onshore EIA Report as potentially leading to adverse traffic and transport effects, including enabling works and main construction activity. This includes measures relating to HGV movements and Travel Plan measures relating to construction staff movements.

1.2.4                       The CTMP pays cognisance to both vehicular and non-vehicular (pedestrian, equestrian, cycle) use of the road network.

1.3Scope of the Outline CTMP

1.3.1                         The scope of this Outline CTMP applies to the areas of onshore construction works of the Proposed Development, including preliminary activities and main construction.

1.3.2                       The key components of the Proposed Development include the below.

• Landfall and Transition Joint Bays (TJBs) - This is the location in which the Offshore Export Cables come ashore and are jointed to the Onshore Export Cables within the TJB.
• Onshore Export Cable Corridor - The area within which the Onshore Export Cables will be located which connects the Landfall and the Substation site.
• The temporary ancillary onshore infrastructure required for the construction phase of the Proposed Development, such as temporary construction compounds and accesses.
• Substation - The proposed Substation containing the components for transforming the power supplied from the Project from between 220/ 275 kV up to 400 kV.
• 400 kV Cable Corridor - The area within which the 400 kV cables will be located providing the onward transmission to Banniskirk Hub which connect the Substation to the National Grid.

1.3.3                       The design parameters for the key elements are set out in Table 1.1   Open ▸ .

1.3.4                       The initial phase of construction works will include preliminary activities to prepare the land for main construction to start, which is likely to include but is not limited to:

• road improvements;
• new site accesses and related signals/signage;
• construction drainage;
• fencing, signing and lighting;
• establishing compounds and site accommodation;
• ecological and archaeological mitigation; and
• vegetation removal where required.

1.3.5                       The main construction activities of the Proposed Development will include the following:

• cut and fill groundworks for the Substation switchyard platform at the Substation site inclusive of screening bund creation;
• construction and completion of the Onshore Export Cable Corridor works and Landfall, including all mitigation and restoration works, except for the Landfall;
• following construction of the Landfall and jointing of Offshore Export Cables with the Onshore Export Cables, the Landfall compound and associated access will be de-mobilised with the removal of all construction equipment;
• construction and commissioning of the Substation, including the associated 400 kV cables, perimeter fencing, security and drainage network;
• landscape works and Biodiversity Enhancement; and
• connection of the 400 kV cables to the national grid via Banniskirk Hub following the commissioning of the Substation.

1.3.6                       The works at the Onshore Export Cable Corridor and at the Substation site will require access routes and related road improvements to be established. Some of which will serve both the Onshore Export Cable Corridor and Substation site. These access routes and infrastructure will form the first main construction activity.

1.3.7                       This first main construction activity for the Proposed Development may be preceded by advanced enabling works which do not require consents or licences, such as geo-environmental, habitat creation and archaeological surveys.

1.3.8                       Once the Substation site has been established, the infrastructure serving the Substation will be constructed. The construction work will be completed in a single phase and there may be periods in the programme when construction work at the Substation site ceases until the Substation is commissioned.

1.3.9                       The construction and commissioning of the Proposed Development will be timed to meet the available connection dates provided by Southern Electricity Networks Transmission (SSEN-T), with the commissioning of the Substation anticipated to be 2032. The earliest date that construction will start is anticipated to be 2029, subject to PPP consent being granted and consent for the offshore aspects of the project.

1.3.10                    The Proposed Development will be constructed in a single phase, consistent with the build-out and commissioning of the generation and transmission infrastructure offshore, together with the connection dates offered by SSEN-T.

1.3.11                      An indicative construction timeline is set out in Table 1.2   Open ▸ .

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

2Construction Activities

2.1Overview

2.1.1                         As set out in Volume 1, Chapter 3: Project Description, temporary construction compounds will be established early in the construction programme within the PPP Application Boundary to support the construction of the Proposed Development.

2.1.2                       A temporary construction compound will be required at Landfall, the Substation site and it is expected that two will be required along the Onshore Export Cable Corridor. A temporary construction compound may also be required where trenchless techniques such as Horizontal Directional Drilling (HDD) are used.

2.1.3                       The temporary construction compounds will provide offices and welfare facilities, as well as space for the storage of plant and equipment and for construction staff car/van parking. A laydown area will also be provided within the Substation site to facilitate the construction of the Substation access road and the temporary bell mouth along the A882.

2.1.4                       Where required, temporary utility connections will be constructed for each temporary construction compound to provide power, water, foul and communications services. The need for these temporary services will be determined by the contractor prior to establishment of the temporary construction compound.

2.1.5                       The temporary construction compounds within the PPP Application Boundary will be prepared by removing and storing topsoil and subsoil and then constructing hardstanding areas using crushed stone. This stone may be sourced locally through existing quarries.

2.1.6                       The design parameters for the temporary construction compounds required at Landfall, the Substation site and the Onshore Export Cable Corridor are set out in Table 2.1   Open ▸ .

2.1.7                       Once construction of the Proposed Development is complete, the temporary construction compounds will be removed and the land restored to its former condition.

2.1.8                       An assessment of the potential environmental effects of the construction of the Proposed Development on traffic and transport has been undertaken and reported  in Volume 1, Chapter 15: Traffic and Transport, the assessment outcomes are summarised as follows:

• Negligible to minor adverse effects on driver delay, including temporary delays to public transport services, severance, non-motorised user delay, non-motorised user amenity and fear and intimidation due to construction HGV movements and construction staff vehicle movements.
• Negligible to minor adverse effects on road safety due to a possible increase in risk to road users from the passage of construction vehicles along existing roads or at site accesses.
• Negligible adverse effects from the movement of Abnormal Indivisible Loads (AILs).

2.1.9                       This Outline CTMP considers the management of construction HGV movements, construction staff vehicle movements and AILs during preliminary activities and main construction activities of the Proposed Development. The proposed routes for construction movements are shown in Figure 2.1   Open ▸ .

Management of Construction Heavy Goods Vehicle Movements

2.1.10                    During construction of the Proposed Development, it is expected that a variety of vehicles will use the road network to access the construction sites within the PPP Application Boundary, including a mixture of cars, vans and rigid and articulated HGVs, as well as HGVs bearing winches, cranes, cars and vans for the separate cable pull-in and jointing operations.

Heavy Goods Vehicle Routeing

2.1.11                      The origin of construction HGVs would be predicated upon the procurement of materials during construction of the Proposed Development. Therefore, construction HGVs would likely arrive to the PPP Application Boundary from a range of origins.

2.1.12                    Material for the Substation, Onshore Export Cable Corridor, 400 kV Cable Corridor and Landfall may be delivered from Scrabster Harbour, Wick Harbour and/or from the south along the A9 and A99.

2.1.13                    The number of construction HGV movements along each road link during construction of the Proposed Development reflects the location of accesses to the Substation, Onshore Export Cable Corridor, 400 kV Cable Corridor and Landfall.

Timing of Heavy Goods Vehicle Movements

2.1.14                    Normal construction working hours will be Monday to Friday 07:00-19:00 and Saturday 07:00-13:00; however, some operations may require work to take place outside of these times. AILs for example may be encouraged or required to travel overnight and crossings of roads may be constructed overnight to minimise disruption to traffic.

2.1.15                    In certain circumstances, specific works may have to be undertaken on a continuous basis (00:00 to 00:00, Monday to Sunday). During this period, the contractor may undertake activities that require continuous working hours, which will be notified to the relevant authority in writing. These activities include, but may not be limited to:

• HDD (or other trenchless technology) operations which may require 24-hour machinery operation, dependent on the ground conditions;
• continuous concrete pours;
• Substation and Landfall component installation;
• oil filling of transformers at the Substation;
• jointing operations along the Onshore Export Cable Corridor; and
• testing and commissioning.

2.1.16                    Not all these activities will involve HGV movements or will generate only infrequent HGV movements. For example, oil filling of transformers at the Substation, which are of a different nature to the frequent HGV movements of primary consideration within this Outline CTMP.

2.1.17                    Up to an hour before and after the normal construction working hours, the following activities may be undertaken:

• arrival and departure of the workforce at the site and movement around the main Proposed Development that does not require the use of plant;
• site inspections and safety checks; and
• site housekeeping that does not require the use of plant.

2.1.18                    The hour before and after the normal construction working hours will not include HGV movements to or from the temporary construction compounds along the public road network, but contractors using light vehicles (cars and vans) can make use of the wider public road network outside of these hours to travel to or from the Proposed Development.

2.1.19                    At all times, no vehicles will be permitted to wait or queue on public roads while seeking access to the Proposed Development, no vehicles will be permitted to load/unload on public roads, and all vehicles must turn off engines while stationary after turning off the public road.

Reducing the Impact of Heavy Goods Vehicle Movements

2.1.20                  The load sizes of HGVs will typically be maximised and therefore vehicle usage typically minimised by contractors to reduce transportation costs. This will be encouraged by the Principal Contractor during construction of the Proposed Development. Where possible, site supervisors will be encouraged to re-use HGVs, such as using vehicles which have delivered material to remove excavated material if this needs to be removed from a site. Where practical, local suppliers will be used to reduce the distance travelled by HGVs.

2.1.21                    All HGVs transporting fine and loose material will be sheeted to avoid dust and the spillage of materials onto public roads. Furthermore, dampening of surfaces, such as the access track in locations where it is close to public roads, will be undertaken in dry weather where the movement of vehicles or delivery of loads may cause immoderate dust.

2.1.22                   Where there is a risk of mud from the construction works being transported onto the road network by HGVs, wheel cleaning facilities will be provided at each access along the road network such that HGVs do not deposit mud and dust onto the road network.

2.2Management of Abnormal Indivisible Loads

2.2.1                       The construction vehicles required to transport cable drums to the Onshore Export Cable Corridor and 400 kV Cable Corridor and transformers to the Substation site will be AILs on the road network in terms of both weight and size.

2.2.2                      The access routes to be used by AILs will be of a standard that safely accommodates the movement of these vehicles to ensure the insurance of the heavy haulage company is valid. Restrictions along the routes will be removed as required to accommodate the AILs which will travel under a controlled environment.

2.2.3                      Depending on the width, length or weight of the vehicle, different notice periods must be provided to road authorities, bridge authorities and the police. These can vary between two and five days. The below activities will need to be undertaken in accordance with the Road Vehicles (Authorisation of Special Types) Order 2003 (Special Types General Order):

• Before the start of a journey, notify in accordance with Schedule 5 the chief office of police for each area in which the vehicle or vehicle combination is to be used.
• Ensure that the vehicle or vehicle combination is used in accordance with the requirements of Schedule 5.
• Ensure that the vehicle or vehicle combination is accompanied during the journey by one or more attendants employed in accordance with Schedule 6.

2.2.4                     The number of AIL movements will be low and each load will be present on the road network for a short period of time. Standard measures, including traffic management measures, will be applied in terms of route, timing and method of delivery to minimise delays to other road users. The police would be notified of all AIL movements. In addition,  prior notification would be given to THC and stakeholders within the locality via methods such as local newspapers/radio so that other road users have advance notification and can avoid or re-time their journeys to negate impact.

2.2.5                      AILs would also be under escort, as directed by the local police authority or as voluntary provided by the heavy haulage contractor, with those delivering transformers being under police escort. Those escorts would not only control the AILs but would also interact with other road users to control, guide and protect them accordingly to safeguard their safe and expedient passage. This includes not just other vehicles but also non-motorised users and those who simply wish to watch/observe the movement of the AILs transporting the larger transformers from the roadside.

2.2.6                     The timing of AIL movements will be discussed with THC and Transport Scotland to minimise delay and risk to other road users. THC, Transport Scotland and the police will dictate the timing of AIL movements along the road network and this may be during night time periods.

2.3Management of Construction Staff Movements

Construction Workforce Routeing

2.3.1                       It is considered that construction staff to both the Substation and Landfall may route along the A9, A99 and A882 towards the relevant accesses.

2.3.2                      It is considered that construction staff to the Onshore Export Cable Corridor may route along the A9, A99 and A882 and then along the Bower Quarry access road, the B874 and the Gillock access road towards the temporary construction compound at what is proposed to be Access Point 14 as shown on Figure 2.2   Open ▸ .

Construction Workforce Travel

2.3.3                      There is value in managing and reducing the movement of construction workers across the road network. The final CTMP, developed prior to the commencement of construction activities, will set out the measures to be implemented to encourage construction workers to make use of sustainable modes of transport where possible and where appropriate, including those in the list below.

• Provide incentives to car share and information to facilitate car sharing to increase vehicle occupancy and reduce single occupancy car use.
• Provide measures to encourage walking and cycling where appropriate where these modes offer an opportunity for construction workers to access sites, including provision of temporary cycle parking at construction sites.
• Provide welfare facilities at the temporary construction compounds to reduce the need for construction workers to travel elsewhere during the day.

2.3.4                     An appropriate number of car parking spaces on and around construction sites will be provided to avoid car parking on verges and along public roads, to avoid vehicles idling and waiting for access and to deter construction workers from driving unnecessarily.

2.3.5                      The working hours of 07:00-19:00 seeks to avoid construction workers travelling during the road network peak hours and therefore reduce the impact on the road network.

2.4Site Accesses

2.4.1                       The Proposed Development includes 25 construction accesses along the PPP Application Boundary to the Substation, Onshore Export Cable Corridor, 400 kV Cable Corridor and Landfall.

2.4.2                     During construction of the Proposed Development, access to the Substation, Onshore Export Cable Corridor, 400 kV Cable Corridor and Landfall would be required for construction workforce traffic, as well as rigid and articulated HGVs and AILs to deliver items such as cable drums and transformers.

2.4.3                     Within the Onshore Export Cable Corridor and 400 kV Cable Corridor, internal access tracks (haul roads) would be provided to allow for the movement of construction vehicles and the installation of cable circuits.

2.4.4                     The design of the construction accesses would come forward as part of Matters Specified in Conditions (MSC) following PPP consent and would accommodate construction workforce traffic, as well as HGV and AIL movements. The final design of all construction accesses will be agreed with THC prior to the start of construction.

2.4.5                     The working areas will be designed to enable plant, materials and waste to be loaded/unloaded and to enable vehicles are able to enter and leave in a forward gear. No contractor or supplier will be permitted to wait or load/unload from the public road, unless under traffic management control during the formation of the accesses.

2.4.6                     Construction accesses will be provided with appropriate fencing so that work sites are secure. Construction accesses will be designed to eliminate the risk of vehicles queuing back onto the public road by providing sufficient length and width and will be appropriate for the types of vehicles anticipated to use the access. The above principles will apply to the site as well as any compounds.