Gleaston Castle Geophysics Survey 2016

Name of walk Gleaston Castle Geophysics Survey 2016
Date of walk 2016-04-29

Gleaston Castle is a Scheduled Monument in the village of Gleaston, South Cumbria. A twenty minute drive from my home on Walney Island. Last week I joined the volunteers, students and professional archaeologists from the University of Central Lancashire (UCLan) in conducting an archaeological geophysical survey of the castle. The project was organised by Louise Martin, Cultural Heritage Officer for the Morecambe Bay Partnership. I had met Louise when I got involved in the archaeology documentary research training earlier this year. The owners of the castle site and Historic England have granted special permission for the community training sessions. The castle site is currently not accessible to members of the public given its ruinous and unstable condition. The Geophysical Survey training sessions have been arranged by the Morecambe Bay Partnership as part of its Heritage Lottery Funded Headlands to Headspace programme.  We will have an opportunity to learn the science behind a variety of geophysical survey techniques and their application to archaeology, eg Resistivity, Magnetometry, Ground Penetrating Radar, etc. as well as Laser Scanning. As a former science teacher how could I possibly resist?

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I took a few photos on the Friday before the survey. It was sunny and the weather for the next week was not looking brilliant! Gleaston Castle dates from the 14th century, but its history began back in the 13th century as construction may have begun as early as 1297. The castle, built mainly of limestone with some red sandstone features, consisted of four corner towers with curtain walls connecting each tower. It is likely that the interior of the curtain walls were lined with timber buildings such as barracks, stables and workshops. Today the castle is largely a ruin, however features in the south west and south east towers such as staircases, doorways and fireplaces are still there.

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In this photo is the north-west tower, this is the largest and most important tower and was used as the baronial residence. It consisted of a Great Hall with dungeons on either side and apartments above. The remaining walls are covered in ivy and are used as nest sites for birds.

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The south-western tower is the smallest in area, the highest, the oldest and also the best preserved of the four angle towers. It was used to house officers and constables of the manor and consists of a dungeon in the basement with accommodation for the officers above. Above this there are two more floors and battlements reached by a spiral staircase.

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The farm house was built in 1830.

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The south-eastern tower consisted of a two floor structure with battlements above and a basement below. A door on the first floor leads to the only example of a wall-walk in the castle. The function of this tower is unknown but it was probably used as a dwelling as there are latrines and two large fireplaces.

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Sun worshipers.

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The sheep will have to vacate their field for the duration of the survey. They look a bit miffed!

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Gleaston Watermill dates from 1774. The owners let us use their car park each day, and were very happy to arrange tours of the mill.

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Wooden gearing.

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The 18ft waterwheel.

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Next to the mill is Dusty Miller's Cafe. I grabbed a latte everyday for lunch.

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The cafe has a glass window view of the waterwheel.

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An old plan of the castle.

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Every morning we meet at Gleaston Village Hall before heading down to the Castle. (Photo Louise Martin)

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We gather in the grounds for morning briefing. We go through Health and Safety and get into groups.

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Dave Robinson from UCLan explains what he wants each group to do. (Photo Louise Martin)

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Unfortunately we are not allowed inside the two towers as some of the stones are in quite precarious positions, like in the photo above of the wall of the south-eastern tower.

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In the summer of 2015 Matthew Emmott was lucky enough to gain access and has given me permission to use a few of his internal tower photos. Matthew joined us on the Tuesday. (The link to his website 'Castles, Towers and Fortified Buildings of Cumbria' is given at the end of this post.) This is an interior view of the south-east tower.

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Stairway to the first floor of the south-east tower. (M. Emmott)

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Interior of the south-eastern tower. The many square holes in the walls are evidence that it was later adapted to be used as a dovecote. (M. Emmott)

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The south-west tower. The stone around the doors and windows is red sandstone. It is much easier to carve than limestone. The wall has many cracks, the biggest is on the far side.

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Stairway to the first floor of the south-western tower. (M. Emmott)

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Interior of the south-western tower. (M. Emmott)

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My team....Cameron, Connor, Arnold and John.

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View from the bottom of the inside of the north-western tower.

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Doorways, stairs and floor levels are visible.

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Some of the stone had been cannibalised in the making of the field walls. The evidence are the pieces of red sandstone which are not native to the geology of the surrounding fields.

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Dave gathers us in the top field. For the next five days we will be using the latest science instruments to gather data for the survey. But, to be a good archeologist you must first be skilled in gathering data by 'old school' methods. Dave tasks us with measuring our pace, so we can use this method to survey the whole site, its perimeter, buildings, slopes, dips and changing elevation levels without using any measuring devices. My pace is 0.77m.

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My group gets the south field area. View through a hole in the south west curtain wall.

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From this angle you can see how precarious the walls of the north-west tower are.

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Without the ivy holding it together it would probably fall over!

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Arnold's pace is 1.0m, so we task him with walking backwards and forwards so save us having to calculate distances. Connor's task is to draw a map to scale of our given area and show the slopes.

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Dr. Rick Peterson from UCLan and Susannah Bleakley from Morecambe Bay Partnership checking out the Total Station Theodolite.

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Dave Robinson from UCLan and Louise Martin, Cultural Heritage Officer with Morecambe Bay Partnership, who is co-ordinating this project.

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Day two sees the 'Dream Team', myself, John Cameron, Arnold and Connor doing resistivity.

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First we have to mark out grids. John's good at this!

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Claire Bedford from UCLan demonstrates the resistivity meter with help from Louise.

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Electrical current is passed through the ground at 0.5m intervals in a marked out survey grid. The two electodes just need to touch the ground to detect the electrical resistance of the soil. Pieces of copper or water offer low resistance, whereas stone, pottery or air offer high resistance. This means we can map out constructions under the surface such as walls or ditches that may be invisible at ground level. Evening Mail photographer, Lindsey Dickings in the background.

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We take turns using the meter. Cameron's go.

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Then mine, Cameron takes my photo, as does Lindsey to use for the piece in the Evening Mail.

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John's turn.

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Another group was doing magnetometry in a grid below the north-western tower.

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This is the technique of measuring and mapping patterns of magnetism in the soil. It is a good method for locating ditches, large pits, gullies and ridge and furrow type crop marks. It is not good for locating graves.

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The downside of using this technique is that your clothing must contain no metal. So no metal zips, glasses, shoe eyelets, bra fastenings! Easier said than done! Some people even discovered that their wellies contained metal.

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The group photo from Saturday's Evening Mail article. Michael Emmott, the provider of the internal tower photos, is in the middle with the cap. (Photo Lindsey Dickings)

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Day three was the day I was most looking forward to. Laser Scanning. I had seen TV programmes where it had been used to 3D map whole cave systems and also burial catacombs. We were going to use it to map out the remains of the north western tower. Today we were also joined by student, Danielle and by Stephe Cove. He is part of the Duddon Dig survey and excavations of Medieval Longhouses in the Duddon Valley which continues this summer. Dave takes us through the use of the laser scanner. We have three pages of A4 instructions!

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The reference spheres are already in place from the day before, so we put the laser scanner in its first position of the day

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We need to set the inclination and compass direction and then we are ready do our first scan.

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The scanner will scan a 20m radius for 360 degrees. Once 'start scan' is pressed you have just a few seconds to run like hell, and hide out of view of the scanner. The scan takes about nine minutes.

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Connor, Arnold and Stephe work their way through the on screen instructions.

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The weather is awful this morning. It is dark and very cold. Snow is coming!

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Our sketch map of the north-west tower building and surrounding field and its elevations. 'x' marks the sequential scanner placings and 's' the marker spheres.

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After completing several scans Dave took us on a tour of the outer walls of the castle, looking at the features and building phases with reference to some old artwork. In the 18th century the only way to record a ruined castle was to draw it. This engraving of Gleaston Castle is by the Buck brothers 1727.

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It was now snowing and freezing cold! We looked at how the later field boundary had been built in to the north-west tower wall.

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We located the now filled in arched gateway in the west wall on the right.

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A large crack in the south-western tower wall. The main thing we realised from our tour is that you cannot rely on art work for accuracy. The 1727 engraving took far too much artistic license, having buildings where there were none and changing things, like window position, to suit the picture.

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After lunch the weather improved and we continued with the scanning

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Two of the reference spheres on the right.

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The scanner's computer screen has frozen. After much gnashing of teeth, Clare comes over, turns the scanner off and reboots it. A method not far removed from the traditional 'giving it a good thump'!

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While hiding behind the north west tower wall (yes, the precarious one!) for another nine minute scan, John takes a photo of me and a view through the windows of the tower. A bit of art amongst the science!

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John and Andy at the end of the day.

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On day four it rained.....and rained.....

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We were doing magnetometry. As the forecast was due to get even worse we packed up not long after midday and headed back to Gleaston Village Hall.

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Dr. Rick Peterson and Clare Bedford set up equipment to look at the results gathered so far. (Photo Louise Martin)

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Rick goes through some of the data. (Photo Louise Martin)

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Lunch in the village hall.

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By the last day I was even on first name terms with the cattle. This is Doris, she's a dribbler. Every day we had to go through the cattle shed to access the site.

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The cows and their offspring chill-out in the straw.

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Today we were on the Total Station Theodolite. The total station is an electronic theodolite integrated with a laser distance meter to read slope distances from the instrument to a particular point. Our job was to accurately measure the position of castle walls, field walls and slope elevations at the site's southern end. Arnold and Cameron.

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All the resistivity meter and magnetometer results can then be overlaid over ours to get an overall view.

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The use of it reminds me of Bob Monkhouse's TV game show from the 60's and early 70's 'The Golden shot'. "Left a bit, up a bit, right a bit, fire!" I am made to feel very old as no one apart from Rick is old enough to remember it!

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The TST computes results and generates a map of the surveyed area on the screen.

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Connor holds the pole with a reflective central piece in the top. The pole also has a spirit level. It is difficult to keep it still in the wind.

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I have to aim at the centre of the reflective circle. Then fire the laser. This is good fun, and we collect hundreds of readings.

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We take our last few readings and call it a day!

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After five days the sheep will now get their field back.

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They seem very happy about that!

It was an excellent week! We had some blue skies, but at times we endured extreme cold, rain, hail, wind and snow. Despite that, I learned an awful lot from both the professionals, the students and even my fellow volunteers. Thanks to the UCLan team for their dedication and knowledge, especially Dave for his sense of humour, he deserves a ‘faction’ all to himself. Special thanks to Cameron, Connor, Arnold and Danielle for putting up with ‘the oldies’ (me and John) all week. Thanks to John (Grid Man) for his convivial company; what luck to have a surveyor on our team! Finally thanks to Louise for her organisation of the project and for going five days without a lunch break…..legend!

The link to ‘Castles, Towers and Fortified Buildings of Cumbria is :http://www.matthewpemmott.co.uk/2015/08/gleaston-castle-gleaston.html

For a 3D aerial view of the castle go to:http://www.morecambebay.org.uk/news/cutting-edge-technology-reveals-secrets-gleaston-castle

Jo.

 

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