Author: Bernadette Ballantyne
Partner: WSP
Along the west coast of Scotland lies a chain of island communities where fishing and farming have been a way of life for thousands of years. From the islands of Lewis and Harris in the northern Outer Hebrides, to Jura and Islay in the Inner Hebrides further south, this network of over 136 islands has a rich and vibrant history.
Stone-age structures tell us that settlers inhabited these islands thousands of years ago as the climate became mild enough to sustain ancient peoples. In the centuries that followed Celts, Picts, Vikings, Clansmen and British armies fought to control the islands leaving a legacy of languages, structures and settlements.
By the late 18th century thousands of inhabitants had made these islands their home, but the turbulent times were not over. The Highland Clearances, collapse of the Scottish kelp market and a devastating potato famine led to economic migration. People fled to Australia, Canada and the US seeking new opportunities. Populations on the islands dwindled from thousands, to hundreds, and some islands were abandoned altogether.
Crucial connectivity
Yet those who stayed persisted in finding inventive ways to sustain themselves, and today crofting or small-scale food production remains a way of life for many in the Hebrides.
Of course the arrival of new transport and power connections over the past few decades has opened up new opportunities for residents who were no longer forced into burning peat for heat and growing or catching their own food. But in securing the future of these islands through providing reliable electricity, teams from Scottish and Southern Electricity Networks are looking to the past to ensure that the rich history is not lost. “We serve 59 Scottish islands connecting some of the UK’s most remote communities to vital electricity supplies, to provide heating and lighting and electricity for cooking,” says Katy Urquart from Scottish and Southern Electricity Networks Distribution. As subsea projects environmental manager Katy has to make sure that all of the environmental consents are in place for the 280 miles (450km) of cables linking Scottish islands to the electricity system.
This includes the Isle of Coll. Coll is one of the smaller islands of the Inner Hebrides at just 13 miles long and 4 miles (6.4km) wide and is served by a single 11KV subsea electricity cable. “When you look at the demographics of the people that live on Coll, and some of the surrounding islands, like Tiree, Iona and Mull, there are probably only about 153 properties,” explains Katy emphasising the importance of power provision. “And the population themselves, about a third of that population are over the age of 65.”
This is something that SSEN is very aware of in terms of the vulnerability of its customers to any disruption in supply and why it has kept a very close eye on the condition of the cables. Coll’s first connection was put in place in 1987 running from the neighbouring Island of Mull under the sea to the Bay of Sorisdale on Coll.
Rocky conditions
Despite the idyllic surroundings this passage is not easy. The cable sits on a rocky seabed, in very deep water affected by strong currents, and these conditions led to multiple faults developing in the cable which were picked up by SSEN’s inspection regime. After just 14 years it had to be replaced. This was in 2001. This new cable was monitored closely over the next 20 years using remotely operated undersea inspection tools and in November 2018 the team realised that the cable had been damaged once again.”We did find that there was areas on the outer side of the cable that had been exposed to wear and tear. And that it’s kind of reached a point where we need to change the cable before it gets to the point where it may fault,” says Katy.
If it should fault there could be a disruption in the energy to the islands. “The last thing we want is for any of our consumers to be without power,” say Katy. SSEN also prides itself on protecting the environment, and the heritage of the places where its teams work. Katy described the ways in which the company would protect and monitor basking sharks, minke whales, barnacle geese and other bird species as part of the project.
There is a lot of evidence documented in the local archives. “On the Isle of Coll is a lot of history, there is a lot of architecture, and we’re very fortunate that a lot of this information has been bookmarked, if you like.”
Leaving a lasting legacy
Historic features have been recorded into public archives, but there is only so much that we can be learned from physical archaeology, what SSEN think is missing is an oral history recorded by residents. “We want to engage with the customers to help leave a lasting legacy. We wanted to create a programme that will not only benefit the community for generations to come, but that will unite current generations and celebrating their historic and proud Island traditions.”
Archaeologist Kevin Mooney is Principal Heritage Consultant for WSP. WSP is conducting archaeological and environmental assessments for SSEN on range of power projects around these island communities including Coll and Mull. “The northern portion of Coll is an emotive landscape with very few inhabitants in it and dispersed isolated communities,” he says. “Their cable landfall or the shore-end was in the Bay of Sorisdale at the north end of Coll. And there is a small crofting community which is situated around the Bay.”
Finding out more about this is more critical than ever before as the crofting way of life becomes less common. Kevin explains that crofting is a traditional social system in Scotland, which is defined by small scale food production, characterised by its common working in community townships surrounded by original individual crofts. “The actual crofting lifestyle survives around arable vegetable production. Generally it’s poorer quality hill ground is used for common grazing for cattle and sheep,” he says.
Archeologic ingenuity
Much of the archaeological remains that the team discovered as part of the cable replacement project speak to the sustainable and unique way of life in this part of the world. In prehistory, the inhabitants of Coll, six or seven thousand years ago were harvesting and processing the readily available natural resources. The small amount of subsequent development in the area increases the survival rate for archaeology and the remains of byers, kelp kilns and boat nausts are well preserved. Boat nausts are small stone coves for boats sitting in the sand dunes above the bay providing temporary shelter or storage.
“We identified on the survey, which were absent from the historic environment record, a number of small Cairns located on kind of peaks across the assessment area.”
Cairns are small wayfaring piles of stones that are grassed over. “They potentially allowed the inhabitants of the area and the crofting community to navigate their way, either by land throughout the landscape and find a way to a rich fishing area or an area of peak or a turf cutting,” says Kevin. Or they could have allowed people from fishing boats along the bay to navigate along the coastline, and work out and triangulate where exactly they were.
Kevin is clearly impressed the ingenuity of Coll’s ancestors and preserving this is the objective of the oral history project which will form an audio library of local experience. Like everyone else the team has been delayed by the impact of the COVID19 pandemic, and the recordings will only begin once it is safe to do so, but that this experience too will be captured. “We are mindful that we now live in, in a completely different time to where we were a couple of years ago with the effects of the Covid 19 pandemic,” says Katy. “And that in itself is a great thing to capture in terms of how that’s affected the way of life. They would have had a lot of tourism that’s kind of halted that process. And it be interesting to understand from the residents of the communities, how are they coping with a change in the world as is.”
Substation replacement challenge
Another island community that has experienced major change, during the Covid19 pandemic and over the centuries before it is the Isle of Lewis in the Outer Hebrides. In fact it is the most northern of all of the Western Isles and boasts a population of around
18,500 people.
“Traditionally, the Isle of Lewis was supplied by a diesel power station at battery point, which was originally opened in the 1950s. And that is what supplied the electricity for the island up until 1991,” says Simon Hall consents and environment manager for Scottish and Southern Electricity Networks Transmission. He explains that in 1991, just over 30 years ago, a mainland electricity link was established which ran from the town of Fort Augustus which sits at the south end of Scotland’s famous Loch Ness over to Broadford, a village on the Isle of Skye. A cable then ran from Broadford to Ardmore, where two 33 kilovolt subsea cables were installed. They then run from Harris, a neighbouring island north of Skye via a 132 kilovolt overhead line up to Stornoway and then it is transformed down to a distribution network level and sent out across the islands to power people’s homes and businesses.
The system is maintained vigilantly. “There are three main substations on the islands and the transformers of two of those – Harris and Ardmore were replaced about five years ago as they come to the end of their life,” says Simon. “Stornoway managed to carry on for another couple of years, and that was then required to be replaced in 2018/2019 as part of the project that we are talking about today.”
Preserving historic peatland
Stornoway needs a new substation to maintain supplies to what is the biggest community in the Western Isles. The original substation has been in operation for 30 years and as an outdoor transformer it is exposed to all the weather and elements that the Western Isles can bring. Replacement isn’t as simple as removing the old substation and installing the new one. This would leave the island without power, so SSEN had to be creative with its plans for replacement. In simple terms it had to build a new one next door to the existing substation and only when it was completely finished switch all of the cable connections over to the new unit.
This created another unavoidable challenge for the team. A challenge that had been gathering for hundreds, if not thousands of years – the presence of a lot of very good quality and ancient peatland habitat. Restoration and protection of peatland is a priority for the Scottish government as it seeks to reduce its carbon footprint, because peatland is a great source of carbon sink. “So the first thing was to identify where we were going to put the new part of the substation. And then secondly, we then had to look at how to minimise the amount of peat that we actually disturbed even further,” says Simon.
Although the site of the existing substation was already fixed the team were able to orientate the new substation location in a way that minimised the amount of peat that was disturbed and made sure that the deepest layers were not affected. “We managed to reduce the amount of peat that we were likely to be disturb from about 10,000 cubic metres down to 4,000 cubic metres. And this was achieved primarily by looking at the size and orientation of the compound that would be required to be built for the contractors,” explains Simon.
At the same time Simon knew that the area had a lot to offer in terms of historic artefacts so they brought in archeologist Kevin Mooney again. “Interestingly, to the south of the site there was archaeological remains encountered underneath peat,” he explains. “There was a prehistoric funerary monument, a stone circle, which was found during peak cutting in the early 1800s, which was completely obscured by around two metres of peat. And so the potential existed for further archaeological remains across the site. We introduced a phased approach of archaeological monitoring during the construction of a substation.”
The next step was to work out what to do with the peat. Historically peatlands all across Scotland and Britain have been subject to peat cutting over many centuries, where the peat is cut out and dried for use as fuel to heat people’s homes. “There are several of these areas, and they are sort of prime candidates for peat restoration schemes where we can actually help to restore the original peatlands,” says Simon.
Working with The Scottish Environmental Protection Agency, SSENT identified several peat cut areas just to the south of the site, within about half a mile that were suitable for the replacement of the peat that we were going to excavate into these previously cut holes. Site drains were then blocked which would then retain moisture and help the peat to remain wet and regenerate. “Now, interestingly enough on consultation with the Western Isles Council archaeologist we discussed options to enhance and benefit their historic environment record,” says Kevin. “ And during we identified that there had been very little radiocarbon dating done of peat deposits across the aisle of Lewis.”
SSENT then agreed to fund a paleo environmental survey which involved drilling a core down through the peat to ascertain its age at various depths generating a stratigraphic sequence that basically gives an environmental baseline. This is particularly accurate thanks to the unusually low deposition rate of around one millimetre per year, which suggests that Stornoway must have been subject to periods of very slow or even no sedimentation. “And it suggests that most of the Holocene record was preserved in situ in this particular area, giving up a perfect, perfect snapshot of the environment on the Western Isles,” says Kevin.
A snapshot that will be used by the local University of the Highlands and Islands. “Ultimately the results of the work that we have done will be deposited in historic environment record allowing for advancement and further research, utilising the results of what we’ve found in Stornoway to incorporate further detail into what we describe as the future research agenda,” says Kevin.
