Tag: Castle

How Civil Engineering Techniques Can Be Used To Help Inform Cultural Heritage Conservation

Post graduate student Tom Davies explains how he has taken some of the latest civil engineering techniques to help understand the condition of the stone work of old buildings, using Durham Castle as a case study.

Durham Castle was the building of interest for my master’s research project in 2023/4. Durham Castle has an incredible history, being founded in 1072 on the orders of William the Conqueror, to being the seat of the Prince Bishops, to now being part of a UNESCO World Heritage Site and University College for Durham University. The Castle’s rich history and architectural significance makes it preservation crucial, ensuring that its historic features are maintained for future generations.

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Copyright Tom Davies

My research was based on understanding how a section centred around and above the Norman Chapel, the oldest building in County Durham, behaves under ambient excitation. Every structure experiences ambient excitation under normal operating conditions, it is the study of how a structure moves due to natural stimuli such as how it reacts to windy conditions and how it responds to when people move through the structure. Within the section I investigated, the Norman Chapel was on the ground floor, the Senate Rooms on the first floor, and some of the rooms of the Norman Gallery were on the second floor, with the roof above. These spaces, along with their remarkable examples of Norman architecture, make the conservation of this part of the Castle especially vital. The first non-destructive in situ testing I conducted was ambient vibration testing. This involves using multiple accelerometers in orthogonal directions (at right angles, seen in Figure 2) to record how the structure responds to ambient excitation, in this case measurements were undertaken on a windy day. Every building vibrates naturally at its natural frequency, which is determined by the building materials and structural connections of the building among other conditions. The taller the building, the lower the natural frequency, as they are more flexible. The Castle section I looked at is 3 storeys high, so one would expect a higher natural frequency than that of a structure such as the main tower of Durham Cathedral, which is 66m tall. The recorded accelerations were converted into frequency measurements which revealed information about the natural frequencies. This conversion is important, as when plots are made, it is possible to see different modes of vibration.

Copyright Tom Davies

In order to characterise the masonry parameters that were used in the numerical model and subsequent simulations, another type of non-destructive in situ test was performed, sonic tests. Some tests were undertaken within the Norman Chapel, as this is the oldest part of the Castle, and its masonry has therefore been subject to the most deterioration of any internal section of the Castle due to its age. Additional tests on a masonry panel in a Gallery (corridor) just outside the Norman Chapel were conducted, this is because this Gallery is a very similar age to the masonry of the rooms above the Norman Chapel, from around the 1600s. From this, the different ages, and therefore state of deterioration, of the masonry within the Castle could be included.

Copyright Tom Davies

Sonic tests involve hitting the masonry, gently, with an instrumented hammer, shown in Figure 3,  and recording the time it took for the subsequent waveform to be registered on an oscilloscope (a machine that shows waves) connected to an accelerometer. Figure 3 shows how this process works, there are two types of waves: P and R waves. The main difference is one travels along the surface of the stone, and the other travels into the stone and reflects off the back of it and returns to the surface. I will focus on the P waves (their names are quite confusing, but it is interesting to know that you can obtain the desired outcome, here the determination of material properties, using either wave). From the recorded wave you can work out the speed of the wave, and using equations you can work out material properties. This is an incredibly important in defining the characteristics of the material within the numerical model. I constructed a finite element model and applied appropriate boundary conditions to represent the foundations of the building, as well as the connections between the section I was investigating and the rest of the Castle. I used the results of the sonic tests mentioned above to determine the masonry material parameters. From the numerical simulations, global frequencies were determined and compared to the results of the ambient vibration testing. global frequency, I mean results that represent the structure as a whole, rather than only a little part of it such as the tower you can see in Figure 4b, or an individual wall. The goal of the finite element model was for its results to be as close to the results of the ambient vibration testing as possible, as this would indicate the model was good at replicating the actual behaviour of the building.

Copyright Tom Davies

Looking forward, there is a plan to undertake a multi-year project to investigate Durham Castle on a much larger scale, building on the work I have done with the target of investigating the entire Castle. The most intriguing prospect is that when a full finite element model of the entirety of the Castle is built, simulations of different loading conditions can be investigated. This would allow different situations to be modelled and the results determined before any physical changes were done to the Castle.

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Newhouse Dig Diary – Day Five

In his final dig diary Dr Ryan Prescott updates us on the final day of the Newhouse excavation.

Day Five represented the final day of our excavations at Newhouse, and there was much still left to do before we wrapped up our work for the week.

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We had found it quite difficult since Monday to find the cut of the ditches from the natural, despite the clarity of their profile from outside of the trenches. While we had the JCB back on site, we thought it would be worthwhile to cut a little deeper into the ditch cuts on both Trench 1 and Trench 2 to determine more about them and their relationship to each other. Certainly, in Trench 1, we seem to have been able to find the extent of the cut and were able to record its measurements and draw sketches which will help us better interpret the nature of the earthworks as a whole. From this, it would appear that the mound was predominantly natural but had been reworked with an accompanying ditch cut around its perimeter.

Again, with the aid of our JCB, we set to work backfilling the two trenches and making sure that the site was returned as much to the state it had been in prior to our arrival. After the welfare unit had been collected, we packed up the car with our equipment, and ensured that the finds would be safely transported back to the office ready for the next phase of our project. We also had a visit from the farmer who was able to point out some other features on the broader site that he had been aware, including a much smaller mound to the north in the adjacent field which had existed until it had been ploughed out some years before.

Now that the fieldwork has been completed, we hope to bring you more information in the coming weeks about what we have found. We are hoping that the picture will become clearer in the post-excavation phase, but Newhouse has undoubtedly proven to be a site even more intriguing than we had first thought it to have been.

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Figure 1: Digging deeper into the ditch cut in Trench 1
Figure 2: The ditch profile in Trench 1
Figure 3: Trench 1 and Trench 2 were both backfilled before the end of the day

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Newhouse Dig Diary – Day Four

Dr Ryan Prescott updates us on what happened on day four of their dig

Today we have resumed our efforts in Trench 1.

The two features that garnered our attention in day three required more investigation, so we set to work to try and find the underlying cause of what was going on. We had managed to recover the pot from Trench 1 yesterday, and it remains safely packed for analysis but today we focused on the feature in the centre of the trench where the piece of leather had been found. At first, it seemed that the find had been sitting on a bed of charcoal. However, upon closer inspection (and much more digging!) it revealed to be a deposit of textile material which has remarkably survived and will provide a fantastic source of dating evidence, together with the pot. Small fragments of medieval pottery were also identified in both Trench 1 and Trench 2, as well as further pieces of flint and small animal bone.

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Figure 1: Textile remains recovered from Trench 1

Before the end of the day, we also had a visit from the Lincolnshire Historic Environment Record, as well as Peter Connelly from Humber Field Archaeology and showed our visitors what we had found so far. We have all been sharing our interpretations on what we believe may have happened at Newhouse and we have all agreed that the site is far more complex than anticipated. Previous research on the site had only acknowledged its medieval history, chiefly the construction of the abbey on the site of an ‘Anarchy’ period castle. However, it does seem that the mound may have had a much longer pedigree of human occupation which would have been an attractive prospect for Peter of Goxhill who was only too aware of the castles and monasteries which were being founded by nearby lords at Barrow and Barton upon Humber, and was keen to emulate their efforts. We are hoping that the picture will become clearer in the post-excavation phase, but Newhouse certainly has an important story to tell.

We have one more day to wrap up our work at Newhouse for this year, but we have much more work to do before we leave site, so it is shaping up to be a busy day.

Figure 2: Pottery from trench one

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Newhouse Dig Diary – Days Two and Three

Dr Ryan Prescott gives an update on what happened on days two and three.

Day Two

Day two of our investigations at Newhouse has seen us focus our efforts on Trench 2.

We spent the morning cleaning the trench and it became apparent that we were looking at two possible post holes nearer the eastern ditch of the earthwork. These were cleaned and carefully dug into before recording was then completed.

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On our first day we had unearthed a masonry slab and today we excavated around it to see if there were any other adjoining slabs. Unfortunately, it proved to have been an isolated example. It has been worked with a distinct curve, suggesting it may have been part of a doorway, likely part of the later abbey structures. Though it does not seem to have been in its original context. Nonetheless, it is a nice example which will help us date the activity on the site and build up a chronology. This is especially important as nothing from the abbey remains on the surface of the entirety of the field where we are based. This was one of the key aims of the project.

Figure 1: Two possible post holes in Trench 2
Figure 2: A masonry slab

Day Three

We are grateful to be finally benefiting from some much-needed sun. In good spirits, we returned on our third day to Trench 1 and were keen to see what the day would bring.

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Trench 1 was cleaned up and like in Trench 2, leaving it exposed over the past couple of days had really helped bring some features to light. After clearing a modern rubbish dump of bricks in the southern corner of the trench within the topsoil, we began working on a couple of areas of interest. Day one had revealed some pottery shards, and it became clear that there was more beneath the surface. After trowelling where the shards had been uncovered on Monday, we found the remains of a larger pot. Excitingly, the pot seems to be largely intact but appears to be older than the known history of the site. We also explored a potential feature in the centre of the trench where the soil appeared darker. After much digging, we discovered what appears to have been a small piece of leather, an incredible find. We recorded these two finds and importantly, safely transported them back to the site entrance before they are taken to Humberfield Archaeology for further analysis when the fieldwork has been completed.

Stay tuned to see us progress our work in Trench 1 on day 4 of our excavations at Newhouse.

Figure 3: The remains of a pot
Figure 4: A small piece of leather recovered from Trench 1

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Newhouse Dig Diary – Day One

Ryan Prescott gives an update on what happened on the first day of digging at Newhouse

The first day of our excavations at Newhouse has provided some promising results already. This week we are excavating two trenches across the earthwork identified last year from geophysical survey (please look at our aims for this year on the CST Blog).

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Trench 1 was swiftly opened with the aid of our JCB. It was hoped that this trench would help corroborate twelfth-century sources that a castle had existed prior to Newsham Abbey, founded here during ‘the Anarchy’. This trench was excavated diagonally from the west to the south-east of the earthwork in order to cut across two of its sides. However, we decided to extend our work in this trench with a perpendicular channel to the southern boundary. At a length of over 40m and 2m wide, the trench has yielded large quantities of flint, some of which appears to have been worked. We have also recovered evidence of burning and pottery finds which we will investigate further as the week progresses.

Figure 1: Trench 1 looking south.

To provide more comprehensive insight into the nature of this three-sided earthwork, Trench 2 was dug across the eastern side of the raised platform and extends from its middle into the ditch on this side at a length of around 25m, slightly longer than initially planned. At first, this trench appeared to show little of interest. Undeterred, we decided to dig deeper into the ditch, and much like in Trench 1, it is clear from this that the earthwork would have been higher than the remains which are left behind. We plan to dig deeper into this later in the week. We cleaned the rest of this trench and discovered a masonry slab, hoping to have a better view of any potential finds and features on our second day when we return to focus on this trench.

Figure 2: Trench 2 looking west with a view of the masonry slab found there.
Figure 3: The ditch being opened up in Trench 2 looking east

We are excited to see what the second day of the excavations reveals and will be posting updates as soon as we can.

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Newhouse Castle: excavation aims and objectives

Dr Ryan Prescott, project lead looks at what they hope to find at the excavations at Newhouse.

The reign of King Stephen, 1135 – 1154, commonly referred to as ‘the Anarchy,’ was marked by purported political turmoil and discord. Against this backdrop for the struggle for the throne, medieval chroniclers wrote of a surge in castle-building, seemingly in defiance of royal authority. While recent scholarship has since begun to reassess many aspects of Stephen’s reign, the archaeological dimension of these castles remains largely unexplored.

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With the support of the Castle Studies Group Small Projects Fund, a geophysical survey was carried out in the Spring of 2023 to investigate Newhouse Castle, known to have been built in North Lincolnshire amidst the conflict between King Stephen and the Empress Matilda. However, soon after its initial construction, contemporary sources indicate that the site of Peter of Goxhill’s castle was repurposed to establish a monastery, becoming England’s first Premonstratensian House, continuing to prosper until finally suppressed in 1536.

Figure 1: The results of geophysical survey conducted at Newhouse in 2023, funded by the Castle Studies Group.

On face value, the transient nature of the castle at Newhouse is typical of what we have come to recognise for ‘the Anarchy’ period, leaving much unknown about its characteristics, completion, or intended purpose. Through planned excavations made possible by a grant from the Castle Studies Trust, Dr Ryan Prescott and Humberfield Archaeology seek to achieve several key objectives in the summer of 2024:

  • Unearthing the Past: This phase of the project involves excavating the earthwork identified through geophysical survey. By examining the physical remnants of Newhouse, we hope to be able to provide evidence for its construction, size, and layout. This is a crucial step when profiling the site and attempting to determine the reasons why it was first built.
  • Dating Evidence: While historical documents offer some insights into Newhouse’s timeline, the lack of firm dating evidence leaves much to speculation. With two trial trenches planned across the monument, we aim to establish a more accurate chronology of the site, bridging the gap between written records and the physical evidence. This remains a key issue with all sites contemporary to ‘the Anarchy’ and where possible, we hope to be able to address this through the archaeological remains.
  • From Castle to Abbey: One of the most intriguing aspects of Newhouse is its rapid transition from a castle to an abbey. Through an examination of the archaeological evidence and various buried deposits present at the site, we hope to learn more about the structural changes which accompanied this transformation. Understanding how and why Newhouse evolved into Newsham Abbey is essential when interpreting the socio-political landscape of North Lincolnshire.
  • Contextual Analysis: Newhouse does not exist in isolation; it is part of a broader network of castles and religious foundations in North Lincolnshire and the Humber. By comparing Newhouse with nearby sites including the castles at Barrow upon Humber and Barton upon Humber, we aim to gain insights into the regional dynamics of lordly power during ‘the Anarchy’. How did these sites interact, compete, or cooperate in the midst of political instability? These are just some of the questions we hope to answer.
Figure 2: View of the earthwork at Newhouse looking south.

As we now enter the excavation phase at Newhouse, we will continue share our progress through blog posts, video updates, and our excavation findings when the work has been completed. We hope that our research at Newhouse will contribute to a deeper understanding of ‘the Anarchy’, and provide a much-needed local perspective into how lesser magnates, like Peter of Goxhill, expressed their wealth, power, and status through castle-building and religious patronage.

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Lowther Medieval Castle Week Four Dig Diary: Into the Labs

In Week Fourth and final week of the Lowther Medieval Castle and Village Project 2024, the team moved into the UCLan labs. This crucial phase allows us to draw together the evidence we’ve collected last year and this, from the recording of trenches to the analysis of soil samples.

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A major part of this process is the transfer of trench plans onto a Geographic Information System (GIS). During excavations, the dig team thoroughly recorded the contents of trenches in situ. This included the painstaking task of drawing the cobbled surfaces found inside the ringwork castle at 1:20 scale. Now, these hand drawings are transferred to the GIS and the outline of every cobblestone is traced digitally so that the archaeological contexts within the trenches be plotted with pinpoint accuracy.

Figure 1 Both last year and this, student archaeologists painstakingly recorded by hand the contents of all trenches
Figure 2 With hand drawings of trenches transferred to the project GIS, each component of the drawing needs to be traced digitally

Meanwhile, the team is also plotting onto the GIS hundreds of data points from around the ringwork castle taken using a Global Positioning System (GPS). This allows us to create a three-dimensional digital model of the ringwork castle, in order to investigate its form and plot the positioning and contents of trenches from this year and last, building up our picture of the castle, its features and finds.

Figure 3 Taking hundreds of data points via the GPS enables the team to construct a 3D digital model of the ringwork castle
Figure 4 Trenches from both phases of excavation can be plotted onto the 3D model of the ringwork castle using the GIS

While one cohort of student archaeologists has been busy in the computer labs, another has been hard at work processing soil samples. Throughout the excavation, the team has been collecting bulk soil samples of 40 litres from all trenches. These samples have now been processed using water flotation, in order to recover charred plant remains, as well as small bones and artefacts. This has so far yielded environmental evidence such as tiny snail shells, which can be analysed to reconstruct the surrounding environment at the time the ringwork castle was built.

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Figure 5 Dozens of soil samples have been processed using water flotation
Figure 6 Soil sample processing yields environmental evidence, such as tiny snail shells

Now that Phase Two investigations are drawing to a close, the team has also been able to take stock of the small finds garnered this year. As discussed in our last Dig Diary, this year’s finds have included cockle shells and gritty ware pottery, both of which will help us to date the castle and trace activity at Lowther in the Middle Ages. This builds on intriguing earlier finds this year of animal bones, including an articulated fetlock (discussed in our first Dig Diary this year). We can now add to this a bone bead, small but delicately carved, which looks to be dateable to the Middle Ages.

Figure 7 A small carved bone bead found during this year’s excavation

Work on analysing these finds – and the broader phase of analysis – is ongoing, and will be compiled into the project’s second interim report in due course.

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Berkeley Castle Donjon and Moat

Berkeley Castle Project Excavation Director Dr Stuart Prior takes a look at one of the many interesting discoveries made during the dig which is part of a new book looking at 15 years of excavation.

Between 2005 and 2019 the Berkeley Castle Project (BCP), conducted by University of Bristol, carried out excavations and survey work at Berkeley Castle, which have led to the publication of a new book. Excavations in 2015, of Trench 19, were able to gain insight into the early origins of the castle and the donjon that was constructed when the castle was built in stone by Robert FitzHarding in 1153–1154.

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It was originally believed that the first stone castle erected at Berkeley comprised a circular shell keep, but the BCP was able to shed new light on this aspect of the site’s past and its architectural evolution. In a Castle Studies Group Bulletin (CSG Bulletin 18, 2014), Neil Guy suggested that the castle may have had a square or rectangular donjon or keep that may have been modified as the basis for the Thorpe Tower by Thomas [III] Berkeley (1292–1361). Trench 19 was designed to look for evidence of the north-west corner and west wall of this postulated donjon. The argument here was that Thorpe Tower was not wholly created ‘as new’ in the 14th century but was instead a part-relic structure arising from a 1340s re-modelling of the 12th century castle. Namely, two corners and one side of a square donjon which abutted the north side of the ‘motte’, and for which the shell-keep encasing the motte was an inner (and elevated or upper) bailey.

Figure 1: Plan view of Trench 19 showing heavily robbed-out building foundations copyright Berkeley Castle Project

The archaeological remains observed in Trench 19 (Fig. 1) appear to demonstrate the presence of a heavily robbed-out building with structures of two later phases overlying it (Fig. 2). The orientation of the first structural phase (contexts 1912 and 1916) and the robber trench (context 1908) associated with it is in alignment with the south-facing elevation of Thorpe Tower. This orientation suggests that this first phase was associated with, and presumably connected to, Thorpe Tower. It is probable, therefore, that context 1912 represents a heavily robbed wall which is comparable, and most likely contemporary with, wall J3, identified by the 8th Earl, who was an amateur archaeologist, which extended from the northern elevation of Thorpe Tower (TBGAS, 1927, vol.49, 183-93 & 1938, vol.60, 308-39).

Figure 2 – Location of proposed donjon overlying plan of 8th Earl’s excavations. Copyright Berkeley Castle Project

It appears then that the shell-keep and Thorpe Tower are of a single phase, most likely dating to the mid-12th century. While there is no evidence currently that contexts 1912, 1916 and wall J3 are contemporary with this primary construction phase, it must be noted that the wall (1911) overlaid context 1912 and re-used some of its stone. Further to the evidence from Trench 19, the rear wall of this fortification can still be seen, incorporated into the castle’s later form (Figs. 3 & 4).

Figure 3 – 17th century painting by Dankerts showing original height of donjon along with remnant of projecting wall (heading north towards church).
Figure 4 – Aerial view of Berkeley showing reduced height of donjon; and with addition of 18th century laundry attached to north. Copyright Berkeley Castle Project

Accompanying the donjon, there are several medieval documents that record the cutting of moats around Berkeley Castle. In The Cartulary of St Augustine’s Abbey, Bristol, an entry made between 1171 and 1190 records a grant made by Maurice de Berkeley [I] to St Augustine’s of a rent of 5s from his mill below the castle, some tithes of pannage, and common pasture for a plough team ‘pro emendatione culpe mee de fossato quod feci de cimiterio de Berchel circa castellum meum’ (charter no. 78; Walker, 1998, 46–7), which roughly translated means ‘in recompense for my offence committed upon the cemetery of Berkeley in cutting a ditch around my castle’. This suggests that Maurice cut a moat around his castle, which encroached upon part of the cemetery, and he was subsequently fined for his actions. The grant is again confirmed sometime between 1190 and 1220 by Maurice’s son, Robert [II] (charter no. 119; ibid., 69–70).

During this period then, the castle comprised an ovoid shell-keep with adjacent forebuilding, the curtain wall of the inner ward and the Norman Great Hall, all wrapped around the skeleton of the earlier motte and bailey. Excavations carried out by the 8th Earl between 1917 and 1937 (TBGAS 1938, 321) demonstrated that the shell-keep was already adequately defended by a moat that ran around its base on the southwest, north-west and north-east sides – which may have encircled the earlier motte and bailey – and records show that Maurice [I] dug a deep moat around the south-east side of the castle, presumably to complete the defensive circuit, and diverted the Newport brook and others towards the castle to fill it.

More information on the Berkeley Castle Project (BCP), on the castle itself, and on the excavations and survey work conducted by University of Bristol can be found here: https://www.archaeopress.com/Archaeopress/Products/9781803275680

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Bibliography

Earl of Berkeley, 1927. Berkeley Castle. Transactions of the Bristol and Gloucestershire Archaeological Society

49, 183-193.

Earl of Berkeley, 1938. Excavations At Berkeley Castle. Transactions of the Bristol and Gloucestershire

Archaeological Society 60, 308-339.

Walker, D. 1998. The Cartulary of St Augustine Abbey, Bristol. Gloucester: Bristol and Gloucestershire Archaeological Society.

Medieval Climate Change at Caerlaverock – Fieldwork Week One

Project lead, Dr Richard Tipping, looks back at the first of the two weeks of fieldwork he and Dr Eileen Tisdall are undertaking to try establish whether climate change did impact the re-positioning of Caerlaverock Castle.

Well, somewhat later than planned or advertised, the first week of fieldwork at the old castle at Caerlaverock began on 3rd July. It has been dated by oak tree rings from the drawbridge across the moat to c. AD1229. The new castle, a couple of hundred metres away and upslope, began construction only 50 years later. Why the rebuild? This is the mystery.

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An image from a LiDAR survey, with the vegetation removed, showing the landscape and old coastline around the ‘old’ and ‘new’ castles at Caerlaverock

The natural environment played a role. Some archaeologists think the old castle started to fall apart because it was built on soft sediment, a deep clay-rich silt locally called ‘carse’. And sure enough, the new castle was built on the nearest outcrop of bedrock. But twenty years ago, a team of environmental archaeologists from the Universities of Stirling and Coventry found an additional reason for abandonment of the old castle. They found, in a wide ditch next to its moat, a thick layer of grey estuarine-marine mud penetrating the brown freshwater peat of the ditch. This suggested that very large storm surges impacted the environs of the old castle. Further work found very large gravel beach ridges, thrown up in these storms, stacked against the old shoreline.

That team included Dr Richard Tipping and Dr Eileen Tisdall from the University of Stirling. Now we are back to find more evidence and improve the dating of the sediments funded by the Castle Studies Trust, as Historic Environment Scotland, the custodians of both castles, seek to update what we know of Caerlaverock and improve the visitor experience.

Dr Tipping using the ‘simple’ corer to extract sediment cores

For a week, 3rd-10th July, Richard Tipping stuck tiny (2.5cm diameter) holes in sediments in the ditches and moat with a simple corer, a metre-long metal gutter with a handle on the end. Push it in, turn it around to cut out a sample and pull it out, together with a metre of sediment. Record the sediment and then repeat, usually in a straight line called a transect. He did this over 80 times in the week. Isn’t science exciting? It wasn’t too hard: the sediments in the ditches and moats are less than a metre thick before the ‘natural’, as archaeologists call it, the sterile silt of the ‘carse’. But because the sediments are so thin, and because we knew that they recorded a lot of environmental ‘events’ in a short period of time, logging the cores in detail took time. A challenge, too: there are only so many shades of grey or brown.

Dr Tipping logging the details of a sediment core

Coring started in the artificial ditch that runs parallel to the moat. This was where we first began, twenty years ago, to realise that something funny was going on; in fact, several funny things. Why, in the first place, dig a 60 m long, 3 m wide ditch alongside one side, and only one side, of the moat? Twenty years ago, radiocarbon dates on freshwater peat at the base of the ditch hinted that this ditch was actually earlier than the old castle, maybe 200 years earlier. We aim to clarify this. Coring found the same sediments we found last time, which is always reassuring. Peat at the base of the ditch was replaced by grey silt. This was sealed by more peat. There is more grey silt at the end of the ditch nearest the coast, although the upper layer penetrated the full 60 m length.

We could not understand, twenty years ago, the filling of the moat with sediment: too few boreholes, too far apart. This time, cores were spaced 1.5 to 3 m apart along a 40 m long line. Archaeologists generally excavate and record continuous sections. We can’t do this because the site is a Scheduled Monument, and besides, the sediment is under water (though this week mercifully dry underfoot), so we construct our section from transects of cores, ‘joining up the dots’ by correlation. For the first time we can show that the moat was probably affected by the same environmental impacts that hit the parallel ditch. This is only ‘probable’ because radiocarbon dating has yet to show the events are the same. But grey silt entered the moat from the coast, pushing up the moat, probably eroding earlier-formed peat but not penetrating the full length. At the end farthest from the coast, near the bridge, peat continued to form.

A line of flags showing the transect of boreholes in one arm of the moat, approaching the footbridge to the old Castle, itself precisely where the original drawbridge was.

Our cores also revealed two new aspects of moat construction. The first is that the constructors took a shortcut in making the moat. In two arms of the moat, they had incorporated natural stream channels in the moat, twice as deep as the rest of the moat. This was a way, of course, to ensure the moat was under water. But away from these channels, the ‘natural’ lay only 20-40 cm below the present sediment surface. If the water surface then was as it is now, the depth of water would have been barely above the knee. You might have waded to the castle rather than use the drawbridge.

Coring in parts of the moat also hit stone at shallow depths. The carse itself is stoneless, and so the stone was emplaced by people. Stabbing around with the corer revealed these stones to be large blocks. They are concentrated at one corner of the moat, nearest the coast. Maybe they were buttresses put in to strengthen the foundations of the castle, either as it started to subside, or maybe undermined by storm surges.

Now I’m thinking and planning the next part of the campaign, straightening my back, and hoping the insect bites subside: the joys of fieldwork. From 17th July we start again, for a week, away from the old castle and out onto the old beach ridges and the basins formed by them. In the early 2000s, tree-felling of Sitka spruce allowed us to see what we were doing. Now it’s a dense tangle of semi-natural oak woodland and not easy to move around in. Wish me luck!

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Name that castle – Castle Studies Trust quiz

Here are twenty images of castles either in the UK, Ireland or France. Can you name them all? No prizes except the honour of knowing your castles.

  1. Where is this iconic Norman keep?

2) Where is this mighty tower house?

3) Which “bawdy” castle is this?

4) This is the main entrance to the keep of which Welsh castle?

5) Where is this motte? The CST co-funded a geophysical survey of this War of Independence castle that transformed our understanding of its history.

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6) This is the courtyard of which English castle is this?

7) This is a pre First World War image of which castle? It’s not the name on the left of the image.

8) In which royal castle is this chapel?

9) At which royal castle can you find this motte?

10) Where is this royal favourite which was brought back to life with the help of CST funds?

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11) In which keep can you find this Great Hall?

12) Which castle is this prior to restoration?

13) The entrance to which castle is this?

14) Where can you find this gun tower?

15) Where is this castle, which the CST funded Dig It TV to produce a short video of?

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16) This is an old image of which Irish castle?

17) Which castle is this an entrance to?

18) In which castle can one find this chapel window?

19) Which castle is this prior to restoration?

20) The CST has funded two projects on this motte and bailey castle. Where is it?

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Answers will appear on this blog at some point week commencing 29 June.