Project News North Wales Connection - connecting new low carbon energy in North Wales June 2016 Plans for underground connection at Menai Strait take shape Overhead line routes nearest to Gaerwen, Llanddaniel Fab and Bangor not being taken forward Up to 5km to go underground Sealing end compound search areas reduced in size to keep equipment further from coast and AONB Connection will go under the Menai Strait – more information on how and where More detailed information on the whole connection and consultation before the end of the year At our last consultation, we told you we where we make the crossing, the We’ve reduced the sizes of the would be putting the connection for equipment we need and where it could remaining sealing end compound Wylfa Newydd underground at the go. This includes equipment for sealing search areas – where we will go Menai Strait. Our work to do this has end compounds – where we connect underground – to keep our equipment been making good progress so we can overhead and underground sections. further from the coast and Area of now give you more details. Outstanding Natural Beauty (AONB). We are now clearer about how we will This means the connection will be Your feedback from the last consultation cross the Menai Strait. underground for up to 5km clearly showed that the area around the Menai Strait is special and should be On Anglesey, the 5D route, part of We have identified four areas where we preserved. You told us that the the 5A route and south sealing end could go underneath the Menai Strait landscape and environment is valued by compound search area, closest to and two technologies we could use residents and visitors. Gaerwen and Llanddaniel Fab are not being taken forward. People had Our teams have been looking carefully at concerns about pylons in a new area Find out more the geology of the Strait, communities – we’ve assessed this and think and heritage in the area, as well as the other routes will have less impact on Q&A on back page wildlife and marine environment. And views, cultural heritage and places of Map inside: they’ve been talking to specialist historic interest – Routes not organisations, including Bangor taken forward In Gwynedd, the 5H route and north University about this important work. – Size of sealing sealing end compound search area end search We’ve also been doing a lot of work to near Bangor are also not being taken areas reduced solve the complex engineering challenges forward. We think the other routes we – Proposed of going underneath the Menai Strait. This are looking at will have fewer effects crossing areas has a big influence on exactly how and on communities and the landscape 1 Project News – North Wales Connection Project The challenge of crossing the Menai Strait One of the big questions people have asked is exactly how we’ll cross the Menai Strait. It’s something we’ve been working hard to establish and now have a much clearer understanding of how best to do this. The unique and special features on You have told us how important all the coast and in the Strait itself these features are and we have make approaching and crossing the focused on keeping the effects of our Menai Strait a challenge. work on them as low as we can. We’ve considered the many Meeting all of these requirements, communities, properties and while also meeting strict technical businesses and we’ve thought needs to make sure the connection is More information online about the views to and from these safe and reliable, is a big engineering challenge that we’ve been working There are valued heritage features hard to solve. Pictures and diagrams of such as the Vaynol Estate, The underground connections Marquess of Anglesey’s Column We have two technologies we could More information on all of and Plas Newydd, which are also use to go under the Strait – horizontal the technologies we’ve important to tourism directional drilling (HDD) or tunnelling. considered to cross the We’ve ruled out other technologies we Menai Strait There are physical challenges don’t think are suitable. such as the tide and the geology News and updates Our decision on which technology to on either side of, and underneath, use will mainly be driven by how best Interactive maps the Strait we have to consider to meet the technical and engineering Fact sheets on our work challenges in this area. And there are the iconic views www.northwalesconnection.com along the Strait and to the We will be back to talk to you later in surrounding landscape which are the year so you can tell us what you important to residents and visitors think of our proposals in this area, as well as the rest of the connection. 2 For more information, please visit www.northwalesconnection.com We have two technologies we could use to go under the Strait – horizontal directional drilling (HDD) or tunnelling. HDD (Horizontal directional drilling) Anglesey Menai Strait Gwynedd Overhead Sealing end Underground Launch/ HDD drill Launch/ Underground Sealing end Overhead line compound connects cable reception pit for reception pit cable compound connects line overhead line to HDD drill for HDD drill overhead line to underground cable underground cable Tunnelling Anglesey Menai Strait Gwynedd Overhead Sealing end Underground Tunnel head Tunnel Tunnel head Underground Sealing end Overhead line compound connects cable house house cable compound connects line overhead line to overhead line to underground cable underground cable Sealing end compounds Horizontal directional drilling (HDD) Tunnelling Connect overhead line with Launch pit receives HDD drill – Tunnel starts at tunnel head house underground cable pit approx 150m by 100m – head house approx 16m in Typically about one acre in size Launch pit / reception pit located diameter and 7m high Contain equipment up to 20m high close to the shore Vertical shaft 15m internal diameter and approx 100m deep from head Sealing end required at each Steerable drill is used to create a house to crossing depth beneath end of underground cable (one in hole beneath the seabed from the Strait Anglesey, one in Gwynedd) launch pit to reception pit Each hole is lined using cable Tunnel boring machine creates tunnel Underground cables ducts – long welded sections of Permanent shaft provides access Four trenches each approx plastic pipe for drilling equipment, cable 1.5m wide x 1.5m deep Electricity cables then pulled installation and ongoing maintenance Each trench would contain through ducts three cables 14 drills required in total – 12 for Shaft and head house required at each end of tunnel Temporary road required for length electricity cables and two for of underground section during communication lines which monitor One tunnel required – approx 5m construction cable performance in diameter Continuous working width of up to 65m What happens next? The engineering requirements of going under the Menai Strait best to meet these engineering challenges. We will present are being reviewed as part of our work currently. Our proposals these proposals at the end of the year for consultation and on sealing end compound sites, the technology we will use and will be asking people for their comments then. We hope you where we go underneath the Menai Strait will be based on how continue to take part in developing our work. 3 Project News – North Wales Connection Project Your questions answered Q Why can’t you put all of We’ll be consulting on detailed Q When will you have more the second connection for proposals at the end of the year and detail on the proposals at Wylfa Newydd underground? will provide more details then. the Menai Strait? A We know many people and A We expect to have more Isle of Anglesey Council want Q Surely the costs of putting information at the end of the us to put the additional connection the connection underground year. We have lots of useful underground in all areas as well as are fair when you consider the feedback from our consultation last the Menai Strait. Compared to effects there could be on year, which we’re continuing to pylons, underground cables are Anglesey and Gwynedd? consider and have lots of information very expensive – several times from our studies in and around the more expensive per kilometre. The A We know that many people Menai Strait. The engineering UK government makes sure our have concerns about the requirements of going under the proposals offer value for money potential effects of pylons on the Menai Strait are being reviewed as because everything we spend is local area and particularly on part of our work currently. Our passed on to all of us through our tourism. We have considered effects proposals on sealing end compound energy bills. Underground on the local economy at every stage sites, the technology we will use and construction is also very invasive. of our work. where we go underneath the Menai Strait will be based on how best to It requires a continuous working We’re going under the ground at meet these engineering challenges. width up to 65m, which can have the Menai Strait which means no significant effects on ecology, additional pylons near to the coast archaeology and agricultural and AONB. It also helps avoid effects When are you next practices when compared to on popular tourist attractions Q overhead lines. This must also be consulting on your proposals including Plas Newydd and The around the Menai Strait? considered. Vaynol Estate, places you said are For these reasons, we do not highly valued. A Our next consultation will be at think the right option is putting the the end of the year when we Tourism is one of the reasons we will have more detail on sealing end entire connection underground.