Union Fighter at Gwynt-y-mor spells out future for Tiree if Argyll/Tiree Array proceeds

Union Fighter © Das Boot Andy Mahon

[Updated 23.40 below] The tug, Union Fighter – and no this is not an independence story - is working out of the Mersey, servicing the giant offshore wind farm, Gwynt-y-mor [Sea Wind], in construction in Liverpool Bay, off north Wales.

This is the largest offshore wind farm currently in construction in Europe, a €2billion project with 160 turbines, built by RWE npower renewables, funded by RWE Innogy [60%], in partnership with Stadtwerke München GmbH [30%], and Siemens AG [10%].

The first of the 160 Siemens 3.6MW turbines has been installed – in May this year, 2013. The farm’s installed capacity will be 576MW, using Siemens turbines and generators. It will be capable of generating enough energy to meet the average annual energy needs of around 400,000 homes; and is due to be fully operational by the end of 2014.

The interesting thing for Argyll and very particularly for Tiree, which is targeted for the much bigger – gigantic – Tiree Array [formally known as the Argyll Array] – is the insight from the Gwynt-y-mor operation into what the construction of such installations involves.

Tugs are compulsively interesting, their dogged strength, their multiple capability, the way they get down and dirty, with their shoulders to the most massive challenges, doing whatever needs to be done in nudging, shoving, pushing, pulling…

Union Fighter is a gem. Photographer Andy Mahon, who sent us the photographs of the two new Western Ferries boats, launched recently in a single week from their builders, Cammell Laird in Birkenhead, also sent us this shot of Union Fighter, and mentioned that she is shuttling endlessly in and out of the river to Gwynt-y-mor.

She was built in 2009, an offshore tug / anchor handler with a bollard pull of 90 tons ahead and 79 astern, a 125 sq m aft deck, a crane with a 12m outreach. She’s 40.65m length overall, with a moulded breadth [before you add on the buffers] of 12.7 m and a total power of 5,200 KW. She has accommodation for a crew of 10.

The Gwynt-y-mor operation

What she is doing at Gwynt-y-mor is shuttling out and in from Cammell Laird to the site, towing barges loaded with installation components, the monopile and transitions. Just now she’s working with barges UR3 and UR7.

Last year the barges were Vikingbarge 3 and 5, which Union Fighter also towed, along with sister tug, Union Diamond.

Out at Gwynt-y-mor, 8 miles offshore, there is a floating hotel, Wind Solution, for the installation crew. Then there are a host of small transfer vessels darting in and out of the river 24/7.

Ashore, on the Flintshire coast of North Wales, is the village of Mostyn which has become the turbine port for Gwynt-y-mor and will be the long term maintenance port for the wind farm.

£50 million has been invested in Mostyn, a modest enough sum which may indicate the limited durability of some of the huge storage structures now there. The port has a massive storage area to lay out the turbine towers, nacelles, blades and hubs for transportation to the farm. These arrive at Mostyn by RoRo ferry from Siemens base in Denmark and are transported locally out to Gwynt-y-mor.

Out at the farm, Sea Jack, a floating jack-up vessel, lifts the sections into place on the platforms already built.

There is an online RWE video  here, showing, amongst other things, the arrival of Sea Jack at the port of Mostyn.

The Tiree comparison

For Tiree, the issue is the relocation of the huge array which, at the moment starts only 5km offshore, on the very toes of the island’s beaches, wrapping itself aaround Tiree from the south east to the north west and occupying a sea area four and a half times the size of the island itself.

  • Where Gwynt-y-mor is eight miles offshore, the Tiree/Agyll Array starts only three miles offshore.
  • Where Gwynt-y-mor will have 160 3.6MW turbines, the Tiree/Argyll Array will have between 180 x 100MW turbines and 300 x 6mw turbines, at heights of between 146m to 202m. The Skerryvopre Light is 52m high.
  • Where Gwynt-y-mor will have a 567MW installed capacity, Tiree’s is to be over three times that, at 1,800 MW.

If the Tiree/Argyll Array was moved genuinely offshore – and deep water floating turbine technology is now developed in Norway with Hywind and Sway [the first installed in September 2009] – then Tiree would have the opportunity to consider the benefits from the project. As things stand now, benefits are substantially outweighed by negatives.

As it is currently planned, the array will bring a micro-climate which will alter the traditional weather patterns of Tiree. It will dwarf ‘the most beautiful lighthouse in the world’, the Skerryvore, even though a feeble and ineffectual concession saw a channel opened up in the turbine installations either side of the Skerryvore – which had been completely surrounded by the much taller turbine towers.  This channel is also a concession designed to interfere less with the movements of basking sharks, for which Tiree is a ‘hot spot’, visiting annually in large numbers as part of their breeding cycle.

When Alan Stevenson built the Skerryvore lighthouse – on a dangerous reef 12 miles SW of Tiree, he built the port of Hynish on the island as the base for the operations.

This has a stone harbour, now restored and in use by local and tourist boats, a signal tower, a barracks and other buildings,all stone built,  in two squares – the Upper Square and he Lower Square, all now also restored by The Hebridean Trust.

The planned wind farm will need its own port to service the construction base and to continue as the maintenance port. It will also need to build a very substantial sub-station on Tiree, to transfer the power from the offshore turbines to the sub-sea interconnectors to be laid and in to the national grid.

Where would these land-hungry installations go?

The reason for the location of Alan Stevenson’s Hynish in the south east of Tiree was shelter from the prevailing NW winds. That remains an issue for any harbour today, carrying the risk of loss of the valuable amenities of the island’s most fabulous beaches in the south east, home to boardsailors from all over the world.

A serious concern is that Marine Scotland’s Licensing and Consent [L&C]docudent, now in consultation, proposes that the Scottish Ministers will have the power to grant deemed planning permission, transferred from local authorities,  ‘for any terrestrial components of an offshore renewable generating station’.

Given the Scottish Government’s fairly unbridled gung-ho stance in driving through their wind agenda regardless, this is reason for alarm for the land based operation at Tiree, should this array go ahead.

The campaign organisation, No Tiree Array, has a 2013 Summer  Update on its website here – summing up the currnet position on a variety of interesting issues.


There is, of course, the thrill, the excitement of engineering, manufacture and construction, a world with which we have largely lost touch in our softer sevice-emphasised economy. Seeing tugs busying about, shrugging their shoulders at huge challemges is addictive. Watching the RWE video, linked above, who would not have wanted to have been in Mostyn when Sea Jack muscled her way in; or to have been on a boat at Gwynt-y-mor watching the erection of the first turbine tower?

It’s a question of balance and accommodation on both sides. If the SPR project off Tiree is not moved offshore it will face continuing, determined, sustained and very well informed opposition of the sort that has rightly seen it currently stalled. If it is moved offshore, there will still be very real issues about the location of the port and the substation, wiht more compromises to be made.

In the meantime, the fabulous tug, Union Fighter, will carry on shuttling supplies out to the more sheltered waters of Gwynt-y-mor.

As the first of Europe’s mega offshore installations, Gwynt-y-mor should  provide the evidence of experience that may help decisions to be taken on the viability of a very much bigger offhore wind farm out in the Atlantic, west of  Tiree.

Update 23.40 10th August: This map below, of the sea area Liverpool Bay / Irish Sea / SE of Isle of Man shows the sort of situation marine traffic in the area is facing with the number, scale and spread of offshore wind farms . During construction the volume of marine traffic to and from these sites is constant and substantial. The question of the carbon footprint laid down during these installations – with the amount of fossil fuel burned [often the particularly damaging bunker oil] – makes little sense in the pushing of wind energy by the green agenda.

Photograph of Union Fighter above © Andy Mahon [Das Boot], reproduced here with permission.

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5 Responses to Union Fighter at Gwynt-y-mor spells out future for Tiree if Argyll/Tiree Array proceeds

  1. You say, “the thrill, the excitement of engineering, manufacture and construction, a world with which we have largely lost touch in our softer sevice-emphasised economy.”

    While this may be somewhat true at the hands-on side it is not totally correct. Scots are still out there around the world engineering on all the major projects. Some of them quite young and very well educated.
    As long as we continue to train our youth in engineering we can easily adapt to any project, however gigantic.

    Workshop skills have changed with computerised machines capable of being developed to do the heavy fabrication and machining that we old hands were so proud of our ability to do manually to the highest standards.

    Engineering can be challenging, but it is a challenge that is relished by all well trained engineers and craftsmen.

    Like or Dislike: Thumb up 6 Thumb down 0

  2. You simply cannot compare the two projects.

    Engineering wise its a bit like comparing Connel Bridge with the new Forth crossing ( thanks for the edit as below)
    Environmentally it is akin to placing a single 40m turbine in a moorland to removing The Great Barrier Reef for road aggregate.

    I wish it was so simple that we could cover all the issues on one piece of A4…and thats without even getting into the pros/cons of Scotlands renewables policy.

    Footnote: last week it was reported that a school of “hundreds” of Basking Sharks were seen over a vast area of the proposed Array area ( Skerryvore reef area is not simply a hot spot for Scottish Basking sharks…it is the Atlantic hotspot for Basking Sharks)…

    Last winter hundreds of Great Northern Divers were seen in the array area…again the primary area of congregation for an internationaly endangered and protected species.

    This week we have recieved information on current trenching techology for sub sea cabeling…the tech isn’t yet available to deep trench bare gabbro/lewisian gneiss in an areas of tidal current of over 6knts and a winter swell of 20+m…we can’t even currently keep the sub-sea cable to Tiree servicable through a winter and its on the sheltered side of the isle !
    Options involve massive destruction of the seabed….the seabed bio-system in the area has not even yet been investigated.

    Interesting times…..

    Like or Dislike: Thumb up 1 Thumb down 2

  3. No Tiree Array(NTA) brief comment:-

    Port Development for operation and maintenance(O&M):- This may not necessarily be based on Tiree. The trajectory of O&M suggests not. Belfast looks an option for the O&M base. SPR has made a substantial investment in developing facilities at Belfast. Only one of the 4 options presented to Tiree in the 2012 Onshore Scenarios Mapping Exercise indicated a requirement for a meaningful Tiree port facility. To build a suitable facility could be disproportionate and dictate;-

    (1) a mother maintenance ship or rig, within the Array
    (2) a Belfast option.

    Deemed Consent. This is the elephant in the room. SPR has misrepresented the application of this legislation to the proposed Tiree Array with regard to any possible onshore converter station . NTA ,a few months ago ,asked Scottish Government (SG) for specific guidelines as to what it defined by ‘any terrestrial components of an offshore renewable generating station’. SG has not replied.

    A 3rd consenting lever by government, and local authorities,has recently emerged. A perceived national requirement,to achieve Government’s energy policy, may now pre-empt any objection to a specific development.

    Environmental Issues:- These are not restricted to birds or marine mammals. No one has yet clarified,with regard to the proposed Tiree Array,how the underwater engineering required for turbine foundations,and inter array cabling, can be achieved without significant seabed damage. This will create a massive marine environmental disaster. Hammering piles into Lewisien genies,for jacket foundations,is not an option. Drilling and explosives are not an option. Extensive, and significant rock cutting,including ts removal are required for gravity foundations. Cables require to be anchored. This demands extensive concrete carpeting. Dumping millions of tons of aggregate,the more usual technique,cannot,for technical and environmental reasons, be considered applicable for any proposed Tiree Array.

    No Tiree Array(NTA) will be making a substantial submission, in the Autumn to Marine Scotland on these environmental issues.

    Like or Dislike: Thumb up 2 Thumb down 0

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