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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Commemorating Bedford Castle on the 800th anniversary of the great siege of 1224

On Saturday, 24 August, the Higgins Museum in Bedford hosts an event to mark eight centuries since the town’s castle was subject to an 8-week long siege by the army of the teenage King Henry III (booking details at the end). Dr Peter Purton, FSA, outlines what happened in the siege.

Not much remains now of Bedford Castle – just a degraded and much altered mound near the river Great Ouse in the town centre and a few excavated fragments of stone buildings, making it hard to visualise that it was once a large stone-built fortress with a moat, barbican, two wards and a stone tower on top of the motte which marked the original castle built after the Norman Conquest. A display board nearby reconstructs its possible appearance in 1224.

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Image of display board showing how Bedford might have looked in 1224

 In that year, Henry III was assembling an army which was to be transported to France in an attempt to recover Poitou, part of the once extensive Angevin empire. This plan unravelled with the rebellion of Fawkes de Breauté. Fawkes had been one of the captains of King John, Henry’s father, and had become rich and powerful. He had been granted Bedford castle and we are told that he had strengthened the fortifications to make it “impregnable”. Rebelling against the crown, he prudently left the country while leaving Bedford in the hands of his brother, who in arresting the justices sent there by the king made it inevitable that he would face royal retribution: this was a direct insult to royal authority and following years of civil war and rebellion following John’s reign, there was no possibility that it could be ignored. The royal army, assembling conveniently nearby at Northampton, was diverted to Bedford. What happened next was recorded in several contemporary chronicles while royal expenditure was detailed in surviving accounts, a combination of evidence which is rare enough and which allows an unusually detailed reconstruction of the siege.

The royal army deployed seven stone-throwing engines (mangonels and petraries) and built two siege towers but the garrison resisted stoutly and inflicted heavy casualties on the attackers. Eventually the barbican and outer ward were breached and captured by royal soldiers then miners, summoned from the Forest of Dean, brought down the wall of the inner bailey and did the same with the tower on the motte, to which the defenders had withdrawn. The prisoners were set free and the entire garrison was hanged as punishment for their rebellion. The castle was then demolished.  A period of instability in England was thereby ended, but so too was English rule in Poitou, the French capturing La Rochelle at the same time as Bedford was being besieged.

These events were therefore of international as well as national significance, and through archaeology, it is possible to now know much more about Bedford castle. All these themes will be discussed at the conference on 24 August, the speakers are Professor David Carpenter, expert and author specialising in this period, Dr James Petre who has written about Bedford, Ben Murtagh who has been exploring Bedford Castle, Jeremy Oetgen (Albion Archaeology) who will update us on a long history of archaeology on the site, and the author of this blog who will place the siege in the context of contemporary siege warfare.

Anyone interested in attending can find all the details and book a ticket at the museum website: www.thehigginsbedford.org.uk. Tickets cost £15 and advance booking is encouraged.

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Higham Ferrers – a Royal Town

Project lead, Steve Parry, looks at what he and the team from MoLA and the Higham Ferrers Archaeology and Research Society hope to achieve during their geophysical survey of the once royal castle of Higham Ferrers starting on Monday 15 July 2024.

Walking through the streets of Higham Ferrers you’d be forgiven for thinking that you are looking at a pretty but provincial town.  However, documentary records reveal that Higham Ferrers once played a role on the national stage. During the Middle Ages it had a substantial stone-built castle which served as the headquarters of the extensive Northamptonshire landholdings of the Duchy of Lancaster and from 1399, became a possession of the Crown.  This castle, which was also the manor, would have been the focal point of the medieval town along with other fine nearby buildings including the Church of St Mary, the School House, the Bede House or hospital and the College founded by Henry Chichele, Archbishop of Canterbury before 1425. While these other buildings have survived to the present day the castle fell into disuse and was demolished in the early sixteenth century, with Henry VIII granting building materials from the site for the rebuilding of Kimbolton Castle. John Norden’s map of 1591 shows the site of the castle (‘b’) as broken masonry and uneven ground adjacent to the church, and all that now remains are a ruined dovecote, fishponds, and rabbit warren.

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A detail of John Norden’s Map of Higham Ferrers 1591

Thanks to a generous grant from the Castle Studies Trust, Museum of London Archaeology (MOLA), will work with Finham Heritage and members of the Higham Ferrers Archaeology and Research Society (HiFARS) to reveal Higham Ferrers’ royal connections through a series of geophysical surveys. We will use a magnetometer to identify any substantial ditches around the castle, as well as the buried remains of internal features such as robbed-out walls, hearths, and pits.  Alongside this, the team will use ground penetrating radar to locate the principal buildings of the castle confirming (or denying!) what our documentary sources tell us – that this substantial medieval building included a hall, chapel, tower house, King’s and Queen’s Chambers, not forgetting three substantial gates. Finally, a resistivity survey will be undertaken, with the particular support of HiFARS members, to provide further detailed information on any buried wall foundations or other structural remains.  The surveys will be undertaken in the various plots shown in this photograph from the 1980s extending from the church (top centre) to the small wood (bottom left-hand corner).

Aerial photograph of Higham Ferrers NCC9668_004
Reproduced by permission of Northamptonshire HER

Together with the documentary sources, the geophysical surveys will, we hope, shed light on the evolution of the site by:

  • Seeking evidence of a late Saxon and early medieval manor pre-dating the construction of the castle.
  • Testing the widespread assumption that a motte and bailey castle was built by William Peveril, who held the manor in 1086.
  • Attempting to map the layout of the late medieval stone castle.

The findings of the surveys will be considered alongside those of limited excavations in 1992, to see how the castle and its associated buildings fit within the development of Higham Ferrers from a Saxon administrative centre to medieval market town. The results and conclusions will be shared via a public lecture and published as a report on the Castle Studies Trust website.

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The Fourth Crusade: new evidence challenges long-held opinions

The final results are in and Dr Andrew Blackler, project lead for the Dating of the Towers of Chalkida, Greece, reveals the surprising findings of the project we funded in 2022 to try and date the hundreds of towers in the region.

In the autumn of 1204 forces of the Fourth Crusade, fresh from their capture of Constantinople, annexed central Greece. Studies have been undertaken of the major fortifications they constructed, but little is known about the hundreds of towers, which are today a ubiquitous reminder to the modern tourist of the medieval period in the region.

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The traditional interpretation is that they were built by the incoming westerners- the minor nobility – as part of a process of colonisation, to display and impose their power over the local Greek population. Yet, since no scientific study has ever been undertaken, we could not even be sure when they were built, and therefore why they were constructed or by whom – until now.

Figure 1: Map of Central Greece with Survey area on the island of Evia (Euboea)
 and the towers sampled (inset)

Following a two-year research program, funded by the Castle Studies Trust and led by Andrew Blackler, a member of the five-year ‘Hinterland of Medieval Chalkida’ survey, surviving towers in central Greece have now been dated using modern laboratory techniques. In October 2022 a team, including technical staff from the Institute of Nanoscience and Nanotechnology ‘Demokritos’ in Athens and from the Ephorate of Antiquities in Chalkida, took samples of wood and mortar from seven surviving towers on the island of Evia (Euboea). This is the second largest in Greece and runs two hundred kilometres down its eastern seaboard. The island, just seventy kilometres north of Athens, is separated from the mainland by a narrow strait only thirty-nine metres wide, the tidal flows of which even Aristotle failed to solve! Chalkida, its capital, became the Venetian administrative centre (as Negroponte) of its Aegean possessions in 1390 and, following its capture by the Ottomans in 1470, their capital of Central Greece for 350 years until the formation of the modern Greek state.

Figure 2. The ruins of a typical tower (Mistros)image description

All of the towers (walls about 8 x 8 metres and height up to 18 metres) were in an advanced stage of collapse. Samples were taken of the wood inserted to provide internal lateral structural integrity to their walls, and of the mortar used to bind their rough stonework. This ensured that these materials were not part of a more recent repair or renovation, which would have been the case for beams used to support the multiple floors of the towers, but part of the original construction phase. The ten timber samples obtained were then subjected to a process of radiocarbon (14C) dating, whilst the mortar was analysed using optical and scanning electron microscopy (SEM) and other techniques (pXRF and XRD) at the Demokritos laboratory.

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The results have been exceptional. Six towers from different topographic locations (coastal, floodplain, mountain areas) have been dated with 95% certainty to a period between 1270 and 1434. Unfortunately, the accuracy for most samples was only approximately +/- fifty years due to fluctuations in the cosmic concentration of 14C in the earth’s atmosphere caused by solar activity during the fourteenth century: there were therefore two possible dating ranges identified. Two samples were of sufficient quality that, using what is known as ‘wiggle’ analysis, more accurate dating was obtained.

Figure 3. An example of one sample showing the wiggle in the calibration curve, that causes widening of the calibrated ages and splitting of the ranges.

The analysis of the mortar samples also demonstrated that two towers had two phases of construction. It is difficult to know whether this was a deliberate action or simply a reconstruction due to the collapse of the upper levels, given that the region is subject to frequent seismic activity. More importantly, since we could not identify any timber samples for one tower, it was possible to show that the chemical composition of this tower’s mortar was similar to two other towers in its immediate vicinity and thus was possibly also constructed in the fourteenth century.

The general conclusion, therefore, is that all the towers studied were probably built at least a century, or five generations, after the annexation of the region by western forces, and no towers were built immediately after the Crusaders took control. The ’colonial’ interpretation of their role is thus overturned or, at the least, requires reconsideration. Rather, their construction appears to have been a reaction by landowners to increasing instability in the region following invasion of the island by Byzantine forces in the 1270’s, the threat of attack by the mercenary Catalan Company who took control of Thebes and Athens in 1311, and a growing fear of seaborne assault by Turkish corsairs in the fourteenth century.

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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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