Going underground

Rob Smith – Senior Minerals Planner

A key challenge for the developer of the major new Woodsmith Mine, now being built in the National Park, is how to get the polyhalite mineral from the mine itself to a suitable location for further processing and export without causing unacceptable impact on the environment. Solving this problem was a critical step towards the eventual decision to grant planning permission. Although it forms only one element of what is a huge and complex construction project, digging the 23 mile (37km) mineral transport tunnel from the minehead south of Whitby to the processing site at Wilton on Teesside is a massive undertaking in its own right. Work on the tunneling is about to start.

It may not be widely known that there is a patron saint for mining, Saint Barbara.  This reflects the fact that mining has been, and to some extent remains, a risky business and it is perhaps not surprising that a degree of divine support is called upon to help look after those involved at the sharp end. Similarly, it is not unusual for mining machines themselves to be treated with a certain degree of reverence, like you would a ship, in order to help them on their way.  Within that context, Sirius Minerals recently held a naming ceremony and blessing for the first of three huge tunnel boring machines (TBMs) to be used to construct the required tunnel.

A cold, bright, breezy April day at Wilton saw an estimated 200 or so visitors and workers gather in a mass of high viz jackets to watch the ceremony.  Local schools had put forward a short list of names:  Persephone (Queen of the Underworld according to Greek mythology); Gertrude (for Gertrude Bell, the famous explorer with connections to Redcar) and Stella Rose (Stella to reflect the ‘bright star’ link with the Sirius name and Rose from Roseberry Topping, the prominent landmark near the Wilton end of the tunnel). An online poll of around 7,000 votes found in favour of Stella Rose and 8 year old local primary school pupil Warren Walls, along with the Leader of Redcar and Cleveland Borough Council, unveiled the name on the day.  A short blessing by a local Cannon followed, invoking the assistance of Saint Barbara in achieving a safe and successful outcome.

The front of Stella Rose the TBM. Copyright NYMNPA.

Whilst divine intervention is all well and good, the TBM is clearly also the product of great engineering talent and ingenuity.  Resembling a cross between a freight train and a pre-launch space rocket lying horizontally, it is more capsule than machine – a self-contained burrowing monster weighing 1,800 tonnes and 225 metres in length (that’s two full size football pitches end to end) including on-board canteen and washrooms!

Tunneling through the Redcar mudstone towards the Woodsmith Mine site will start in earnest over the next few weeks and will take two years or so to complete, as part of a giant subterranean relay along with the other two TBMs.

Looking along only part of the length of the TBM. Copyright NYMNPA.

Whilst there will always be differing views about the decision to grant permission for the mine development, the sheer scale and intensity of the construction effort, driven in part by the need to help conserve the environment of the National Park, is impressive to witness.

Warren Moor Mine: Part One – the Lime Mortar task

Eleanor Lees – Land of Iron Community Archaeology Intern

For five days back in August a group of very determined Land of Iron volunteers and staff, along with one local lime mortar expert descended on Warren Moor Mine in Little Kildale to begin conservation work on the winding engine bed. During the 144 years since the mine closure tree roots, vegetation, insects and the weather have slowly eroded the site of Warren Moor Mine which includes a winding engine bed. The stonework had very little remaining mortar, and so we took on the task to re-point in order to help protect this historic structure.

Follow this link for a 360 view of the site.

A (Very) Short History of Warren Moor Mine – the story of Warren Moor Mine starts in 1857 when the Bell Brothers of Middlesbrough surveyed the nature of the ironstone in this dale, once isolated but now connected by the new railway. Investigations on the main seam revealed that it was 5-6 ft. deep but split by a band of shale and also had low iron content; only just averaging out at 26% when other parts of the Cleveland area averaged at 30%. The Bell Brothers Ltd declined the mining lease offered by the Kildale estate (landowners) and for eight years Warren Moor remained undisturbed.

Then, despite the results of previous surveys, in 1865, under John Watson and his southern investors, work began on open drift mines into the top ‘dogger’ seam. Drift mining means digging into an edge from the side, horizontally, and is much easier and therefore cheaper than digging downwards. A year later Watson took out a 42 year lease and the ‘Warren Moor Mine’ (Company Ltd) was formed. Letters suggest that the first year of the lease resulted in profit. The ironstone extracted was calcined (roasted to remove impurities) on site and then transported by rail to the blast furnaces. Work began to sink two shafts to intercept the main seam at 220 ft., along with the construction of a steam boiler house and corresponding chimney, a winding engine and a steam powered pumping engine, all to enable deep mining. By 1868, most of the structures had been completed with the exception of the downcast shaft which had only been completed to a depth of 150 ft. but by that time the Warren Moor Mine Company Ltd were in financial trouble no doubt partly due to the poor quality of ironstone leaving the Warren Moor Mines. Kildale estate reclaimed the site and all its equipment.

Four years later in 1872, the Leven Vale Company Ltd took out a lease on the site, not put off by the previous company’s failure to make the site commercial. A row of stone cottages were built to house miners and their families, these cottages appear on historic maps labelled Leven Vale Cottages – in 1972 the cottages were demolished by volunteers from Kildale village and the stone was used in the Village Hall. Regardless of the initial investment into the site by the Leven Vale Company no progress was made with completing either the downcast shaft nor any other parts of the non working downcast mine. The company continued to use the drift mines to mine the top seam but in 1874 became insolvent just like its predecessor.

So after only nine years of operation the mines were abandoned for the next 105 years until 1979 when the archaeologist John Owen and his team excavated the site providing detailed diagrams and explanations for many of the mines remaining features (Owen’s report can be found here)

…And then along we came!

A view of Warren Moor Mine today, Copyright NYMNPA.

Of course we weren’t the first group to set foot on the site since then, but being in such a remote location it sometimes feels that way. Our task in August was to conserve and protect what was left of the winding engine bed and that involved re-mortaring. We started with a day of training and demonstration at Kildale Village Hall (built with the stones from the Leven Vale Cottages). Our expert, Nigel Copesy, explained the benefits of using a hot lime mortar mix over natural hydraulic limes (NHLs) or other cementitious materials, as well as explaining the science behind the mixing process and why that resulted in better effective porosity enabling buildings to shed water quicker resulting in less damp and decay. He also showed us different ways of creating a mix and some of the more extreme reactions of slaking quick lime.

Nigel Copsey demonstrating the reaction from mixing hot lime mortar. Copyright NYMNPA,

Over the next four days we undertook the actual task of re-pointing the engine bed. I think we were all surprised at the amount of mortar you could put into a joint before you would feel any resistance! We used three different types of mortar on the different areas of the engine bed in order to provide the best level of protection that we could.

The first mix that we made was used to point the sides of the stonework; it consisted of two different types of sand, brick dust, quick lime, a clay based pozzolanic additive and water. This created an exothermic reaction, where a decent amount of heat was given off but quickly cooled to useable temperatures.

The second mix is appropriately named an earth lime mortar and was used to fill the larger gaps on the top of the engine bed packed with some loose stones. To make this mix a slightly different technique was used. Using some excess soil from a previous archaeological test pit, we soaked it for a few hours before adding some quicklime to give it form. This soil contained high amounts of clay which is known to work well with quick lime. Earth mortars are more common than people realise. Many traditional buildings in the North York Moors and elsewhere have earth mortars at the core of the wall. They allow the building to breathe which can help prevent damp and create a healthy living space.

Our third and final mix was used on top of the earth lime mortar and had a very high pozzolanic value, making it more durable and less permeable. As the top of the engine bed will be most exposed to weathering, the mortar used had to almost repel any rain water. Although this type of mortar would not have been used in this location traditionally; it was thought necessary to adapt the mortar on this occasion to help protect this historic monument into the future, which is now far more exposed to the elements than it was when originally built.

Re-mortaring Warren Moor Mine engine bed - with the bottom of the chimney in the background. Copyright NYMNPA.Warren Moor Mine engine bed - with new lime mortar. Copyright NYMNPA.

The result of all five days of hard work is a winding engine bed that is infinitely more protected than it was at the beginning of the week. Conserving our industrial heritage is hugely important, especially with a site like Warren Moor which still provides a snapshot in time. The Land of Iron team would once again like to thank the amazing efforts of our volunteers, Kildale estate, and also Nigel Copsey for sharing his knowledge.

1865

Stephen Croft – TEL Programme Manager

2015 sees a number of notable 150th anniversaries in the story of ironstone and railways in the North York Moors. It turns out that 1865 was an important juncture in industrial development in this area when elements combined to boost the output and feed expansion.

1865 saw the opening of the ‘deviation’ line on the Whitby and Pickering Railway which eliminated the need for the mechanical incline at Beck Hole using winches, allowing the railway to become fully steam hauled. This 1865 re-route around Beck Hole and Goathland remains the line of the North Yorkshire Moors Railway today, one of the oldest railways in the world still running on (most of) its original route. It was at this time that today’s Goathland Station was built beside the water mill – it was originally called Goathland Mill station.

Railway bridge feature - end of a tie rod - NYMNPA

1865 witnessed the completion of the North Eastern Railway (NER) North Yorkshire and Cleveland branch which connected Grosmont with Middlesbrough and hence linked the Whitby and Pickering line into the growing rail network and connected product with market. This, too, is still running today – as the Esk Valley line.

Railway bridge - NYMNPA

1865 saw the opening of the extension which took the railway line around the head of Rosedale to reach the mines and calcining kilns (heating ironstone to extract the iron) on the east side of the valley. The original railway had opened 5 years earlier but this extension meant that both sides of the dale were connected and exploitation augmented. The Rosedale Railway was operational until after mining ceased in the dale in 1926 and for three years afterwards the valuable mineral rich waste from the calcining process was recovered from spoil heaps. The tracks were then lifted but the Rosedale Railway route remains open today for walkers, cyclists and horse riders to experience.

Railway bridge underside - NYMNPA

1865 is when the rail network built across the North York Moors which serviced the ironstone industry, was complete. Whether still running as a railway today or now dismantled, these railways shaped the landscape we know and brought transformation to what had previously been a remote and isolated rural area. The railways enabled easier and quicker movement – not only providing a relatively cheap method of transport for the heavy ironstone, but also making goods manufactured in the towns available to the local rural community and vice versa, stimulating the market. They also provided a passenger service – the world’s first cut price railway excursion ran from Grosmont as early as 1839.

Railway lines - NYMNPAUntil the arrival of these railways, heavy goods such as building stone were laboriously exported via packhorse or cart along poor roads down into Whitby on the North Sea coast from where it was loaded onto ships. The railways revolutionised the viability of quarries allowing high quality stone to be sent down the coast to London and beyond where it was particularly valued for its resistance to seawater for the construction of harbour works and river embankments. It was to export this stone that the Whitby and Pickering Railway was first built and it was during its construction that ironstone was discovered in substantial seams at Grosmont. That discovery changed the history of the North York Moors.

So for 150 years, it has been possible to travel across the North York Moors by rail. The abundance of ironstone found here in the mid-nineteenth century and the railways to carry it away cheaply led on to the development of industrial Teesside, a world centre for iron and steel and heavy engineering – Gladstone’s ‘Infant Hercules’ – steaming forward beyond the second industrial revolution into a new idealised industrial age.

http://commons.wikimedia.org/wiki/ - File:North_Eastern_Railway_map_(centre).jpg

This Exploited Land (TEL) is a Heritage Lottery Fund HLF Landscape Partnership Programme currently under development. It will tell the story of pioneering ironstone exploitation and iron making together with the early development of railways along the remote valleys of the North York Moors, as well as their forgotten communities.

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Looking forward

Geoff Taylor – Kirby, Great Broughton & Ingleby Greenhow Local History Group; and member of the This Exploited Land Executive Group

“As a volunteer supporter of the This Exploited Land (TEL) project from its early days there are some really positive potentials for our Partnership to build on. Whilst the public often view the North York Moors as a fairly static and unchanging landscape our role is to interpret and preserve some of the features which made it an area of rapid and dynamic progress during a period when Britain led the world in the making of iron and steel.

It took some courage to seize upon industrial archaeology as the basis for a Heritage Lottery Fund bid but our success at first try has given us great heart and our two person team of Stephen Croft and Louise Cooke have already generated great progress toward the stage 2 submission of our proposals by late 2015; the interval is as frustrating as it is necessary!

Looking across Rosedale

The ‘Rosedale railway’ line is walked by thousands each year as part of the ‘Coast to Coast’ walk. A brief diversion toward the Incline above Ingleby Greenhow or onto the giant flat contour loop in the direction of the Rosedale mines throws a whole new insight into the landscape and its past; the stone kilns must have appeared in thousands of photographs as a feature or stunning backdrop and yet the inevitable process of erosion and decay will take them and the story they represent from future generations unless we act to conserve these and similar features as we intend to do through TEL.

Rosedale East Kilns

Just as important is the task of reconnecting some of our local communities with their past; each of the stations on the Esk Valley line has its own story to tell and the challenge for us is to encourage and support the local population to research and share that story whilst it is still accessible. We hope to deliver heritage trails for each of our communities which once created can only serve to provide pride and a real sense of relevance and purpose from a different period of time.

Grosmont - junction of Esk Valley Line and NYM Railway

So much of Teesside and the North East of England’s heritage is based upon production – solid and tangible items like girders, ships, bridges and bolts – much of that has gone and we owe it to the people whose families played their part in that story and who still live in the area to preserve at least some elements for the generations yet to come. As part of the process we have the opportunity also to add significantly to the National Park’s current offering in terms of biodiversity – for industrial/post-industrial Teesside the North York Moors is still a green lung, a place to step back from the pressure of 21st century Britain.

Rosedale Bank Top KilnsFor young people, if TEL can achieve its aims some of our ‘pearls’ can become open air classrooms where the relatively straightforward technology of mining and engineering from that period can be displayed in ways which can be readily understood and these first principles once digested can lead children on to move to more complex and challenging processes.

The passage of the steam trains to and from the mines across the high moorland landscape must have been incredibly dramatic in the 19th century, the track bed was unfenced so that it must have been possible to stand within a few feet of one of these awesome transports throughout the year. We hope to recreate a little of that drama using virtual reality as part of our project so that anyone equipped with an Internet link can witness for themselves this aspect of our truly remarkable story.

Warren Moor Mine site

My own local history group based in Broughton, Kirby and Ingleby Greenhow linked up in partnership with the Rosedale History Society back in 2009 to support the work of Malcolm Bisby who had studied the Rosedale railway in great detail and to celebrate the 150th anniversary of its inception. That work proved to be one of the building blocks for the TEL project and we continue to strongly back the excellent National Park staff TEL Executive Group Meeetingwho will see the project through to completion. As our bid gathers substance and the detailed costings for conservation and interpretation come to hand we shall be able to publicise more of how the task is to tackled but we know we want to deliver to our visitors a really rich experience and with the team we have I am confident we can.”

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