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British Art Studies Article

Our article investigating the creativity and imagination used to design the choir aisles at Wells cathedral has now been published in ‘British Art Studies’.  This article is free to view here.


This paper explores the topics of creativity and imagination in relation to the design and construction of the lierne vaults in the presbytery aisles of Wells Cathedral, erected around 1330. It explores the potential of digital scanning and analysis for forensic investigation of the structure in order to identify the processes involved. Four different processes were employed and we compare those used in the three eastern bays of the north and south aisles. These are shown to share characteristics with the retrochoir but to involve different approaches to 3-D projection and stone-cutting. We conclude that the basic geometry of the vaults was defined in advance of construction, using full-scale drawings worked out on a tracing floor. In both sets of vaults the 3-D geometry continued as a sequence of steps and was derived from measurements ascertained from existing elements (including the drawings) but was not consistent across the two aisles. The processes reveal different priorities, whether for level ridges (north aisle), different choices in terms of rib radii or apex heights, and different sequences of design steps. This demonstrates the potential for experimentation at every stage of construction.

Buchanan, A., & Webb, N. (2017). ‘Creativity in Three Dimensions: An Investigation of the Presbytery Aisles of Wells Cathedral’, British Art Studies, Issue 6.

Scanning at Tewkesbury and Gloucester

In July 2017, we travelled to Tewkesbury Abbey and Gloucester Cathedral to create digital surveys of their respective vaults. First, we surveyed the abbey at Tewkesbury using our standard methods of laser scanning and photogrammetry, with the additional method of total station for the choir vaults. Total station surveying enables us to manually capture specific points of the vault ribs, as opposed to laser scanning which captures all points. Searching for specific points to document using total station is very labour intensive, particularly when trying to capture the vaults above. Based on advice from our friend David Wendland, who is carrying out exciting research on vaults in continental Europe, we worked in a pair with one of us roughly locating points using the total station’s laser, and the other laying on the floor looking up at the vaults through a pair of binoculars to locate the precise point that needed to be documented. This was a particularly long and arduous task over a day and a half, however, the resulting points mean we can very quickly and efficiently use the specific points documented to trace the vault rib geometries. Laser scanning, on the other hand, is much more time consuming in locating the required points amongst many million others to trace them. Both methods create accurate results and therefore having two sets of data ensures an even higher level of confidence in our methodology and findings. Once we completed our surveying, we backed up our data and travelled to Gloucester Cathedral to start the second phase of our field trip. We also found time in between to visit Pershore Abbey, where we already have access to a laser scan survey to investigate the vault geometries there. This scan data was very generously given to us to use by the abbey to use for our research, and we hope to be able to show are results of this in the next year. The Pershore Abbey laser scanning was particularly high in its quality, surveyed by CDG Ltd.

At Gloucester we continued with our primary method of laser scanning to survey the majority of the cathedral’s vaults, with particular attention given to the west end, transepts, crossing, choir and presbytery vault bays. Whilst at Gloucester, we were able to use our scan data to assist the cathedral architects in the installation of a new disabled platform to the east end as part of HLF funded Project Pilgrim, by linking scans from the crypt to those above to build up a very detailed picture of how the spaces connect, which was previously not accurate enough. This demonstrates how our survey data can be used by other stakeholders for mutual gain.

We are very grateful for the Liverpool School of Architecture’s David Foster Wicks endowment fund, which funded the field work and has enabled us to continue developing our research for Tracing the Past.

Courtauld Institute Parish Church Conference

On Friday 2 June, we’ll be sharing our latest research on St Mary’s church, Nantwich on the first day of a conference at the Courtauld Institute entitled Towards an Art History of the Parish Church. Further details of the programme and how to book are available here.

Our session will be chaired by Prof Paul Binski, who has recently published an article in the Journal of the British Archaeological Association on a miniature vault at St Andrew’s church at Irnham in Lincolnshire, which he identifies as a copy of the high vault of Wells Cathedral (also dedicated to St Andrew). Also on the programme are Andrew Budge, who spoke at our ‘Modelling Medieval Vaults’ conference in 2016; Jon Cannon, who has published on Bristol Cathedral, which has wonderful lierne vaults, and Prof Sandy Heslop, who organized the ‘Invention and Imagination’ conference at the British Museum in 2014, at which we first presented our project. It will be very exciting to find out about so much new research being undertaken on the parish church and to be able to demonstrate what our methods can add to this discussion.

4th Annual Construction History Conference

On Saturday 8th April, we presented a paper to the 4th Annual Conference of the Construction History Society, which took place in the congenial surroundings of Queens’ College, Cambridge. Robert Willis argued that Queens’ was a perfect example of a medieval college, although we were meeting in the more modern buildings on the other side of the Cam, reached by the famous ‘Mathematical Bridge’, designed by James Essex, who also worked on the lantern of Ely Cathedral which we scanned last year. The medieval fabric of Queens’ includes a beautiful example of a lierne vault in its gate-house – perhaps a future scanning project?

Our paper ‘Tracing Tiercerons: an evaluation of the significant properties of thirteenth and fourteenth-century tierceron vaults in England’, is available here:

It was good to catch up with old friends, including Santiago Huerta, and to hear the latest news from our friend David Wendland’s project ‘Design Principles in Late-Gothic Vault Construction’ ). On this occasion, Dr Wendland presented with his collaborator Frédéric Degenève, one of the stonemasons working at Strasbourg Cathedral. Their paper ‘How to order fitting components for looping ribs: Design procedures for the stone members of complex Late Gothic vaults’ was a fascinating reconstruction of the methods used to prepare the voussoirs and bosses required by geometrically complex vaults such as the ‘Hall of Arms’ in the Albrechtsburg Meissen, built in 1521 by Jakob Heilmann. Wendland’s digital analysis of such vaults has demonstrated that all the ribs are formed using circular arcs in three dimensions. In this paper, he provided a convincing explanation of how the essential information could be transferred from the tracing floor to the block of stone using copper templates, ‘baivels’ (or square edges) and a rod to record key dimensions. The proposed method has been tested by and found to meet all the stonemason’s requirements, without any need for stereometric projections.

It was also useful to have the opportunity to meet and discuss our project with others who have also used digital recording methods, including Elizabeth Shotton, from Trinity College, Dublin, who shared her Irish Research Council funded project Minor Harbours, which has used digital methods to identify and analyse changes to the smaller Irish harbours over time.

The full conference programme is available here: and proceedings are available in print from the Construction History Society.

DAACH Article

Our article investigating the use of digital techniques to analyse the choir aisles at Wells cathedral has now been published in ‘Digital Applications in Archaeology and Cultural Heritage’. This article is free to view until 7th May 2017 through the following link:


Architectural historians have identified Wells cathedral as a key monument in the transition between high and late Gothic, a move in part characterised by the rejection of simple quadripartite or tierceron rib vaults for more complex vaults. Here we will show how digital methods are used to reopen questions of design and construction first posed in 1841 by pioneer architectural historian Robert Willis. Digital laser scanning documents vaults accurately, thereby establishing their geometries to a high degree of certainty and, at Wells, highlighting differences between the choir aisle bays which have previously been treated as a single design. Significantly, we will show how digital techniques can be used to investigate these differences further, using point cloud data as a starting point for analysis rather than an end point. Thus we will demonstrate how modern technologies have the potential to reignite historic debates and transform scholarly enquiries.

Webb, N., & Buchanan, A. (2017). ‘Tracing the past: A digital analysis of Wells cathedral choir aisle vaults’, Digit. Appl. Archaeol. Cult. Herit., 4, March 2017, pp. 19–27.

Review of Modelling Medieval Vaults

We are delighted that our symposium ‘Modelling Medieval Vaults’ was reviewed in the first issue of The Construction Historian (the magazine of the Construction History Society). With the kind permission of the author and editor (David Yeomans), it is reproduced here.

‘The life of a Gothic vault begins with a design, which exists as plan. This has then to be projected into three dimensions, not just to determine the overall geometry but also to enable individual stones of the ribs to be cut to shape so that they fit together. Once assembled the structure of the vault has to be stable and so must transmit the thrusts safely to the supporting walls and buttresses. They will then move in resisting the thrusts and so cracks will develop in the vault ribs and in the vault surfaces that they support, cracks that might seem to be signs of failure but which will have been there for hundreds of years. Sometimes, of course, the building might be destroyed and the vaults will then only survive as rubble, but rubble that might contain clues to the original form of the vault. Each of these stages provides material for different kinds of scholarship and all were represented in this one-day symposium.

There were speakers to cover every stage of the process. Those dealing with design aspects showed clearly the difference between approaches to architectural history and construction history. The former sometimes seemed to involve a special language. I simply cannot imagine what ‘visual space perception in micro and macro cosmological dimensions” could possibly mean, but perhaps it lost something in translation. It was a phrase used by Thomas Bauer in reference to vaulting in Prague with curved non structural ribs, typical of late vaulting in other Northern European countries. I am not sure about their designers ‘contributing to a new space discourse’. The idea that masons devised the elaborate, non-structural pattern of ribs that we were shown to compete with flat decorative ceilings that were coming into fashion seems simple and convincing.

My doubts are how well we can see into the minds of medieval designers. What we do know is that the designers of the more elaborate rib patterns were playing with geometry and that given an accurate survey of the rib pattern it is possible to reconstruct the geometrical process that was used. While Bauer demonstrated the very complex geometry of the vaults in Prague our hosts demonstrated it for the much simpler geometry used in the aisles of the choir at Wells. There vaulting with slight differences in the plans also had differences in section, some being flatter than others. Thus we saw how accurate survey methods now possible might show subtleties that had previously been unrecognized.

Once the geometry had been decided it needed to be marked out on the tracing floor. There is some evidence in the form of putlog holes in the walls that there was a scaffold immediately below the vault, which might have been used as a tracing floor. The masons could then have used plumb lines to the drawing immediately below the vault itself to mark up the stones, much as carpenters use plumb lines to scribe timbers to fit.

Of course the vault has to stand once built although there is often movement over time. Santiago Huerta delighted everyone with a model arch, which demonstrated the formation of cracks within both the ribs and the surfaces of vaults that result from the inevitable movement of supporting walls and buttresses. But while he described the attempts from the eighteenth century onward to understand the behaviour of medieval vaults there was no discussion of how they might have been structurally designed at the time. One speaker’s assertion that the columns of Mallorca cathedral could be as slender as they as because of loading built above the vault ribs simply raises more questions than it answered.

Perhaps the most surprising thing for the outsider was the way in which archaeologists may be able to reconstruct the appearance of collapsed vaults based on material in the rubble. In vaulting with intricate patterns of ribs, stones forming the connections indicate the directions of the connecting ribs and may make it possible to determine the overall pattern.

Much of all this new work on vaulting depends upon modern surveying methods: the use of photogrammetry and laser scanning. One paper compared the use of these two techniques while others described the process of making use of the data from laser scans. Different software packages appear to offer different advantages, or are it disadvantages. RHINO is not it seems a huge horned herbivore but just one of the packages available. There was much discussion of these systems and it was clear that the specialists in these aids needed to be brought in to help the communities of archaeologists or historians.

The last talk addressed what we normally think of as a model because Benjamin Ibarra-Sevilla had used digital printing to construct physical models of the vaults of the churches in Mexico that he had studied. Because the ribs of these are made of separate components they need to be held in pace while being assembled. The students helping with this process were able to gain an appreciation of the delicate balance of forces involved. It seems that what can be learnt about medieval vaults and what can be learnt from tem is far from exhausted. It also seems that from archaeologists to computer specialists there is something in medieval vaulting for everyone.

For anyone wishing to know more about the work being done by The Liverpool School of Architecture on vaulting see There is also to be a two-day event at Cambridge to look at the work of Robert Willis at’

We shall be presenting more about our work in a paper at the next conference of the Construction History Society in April 2017. Further details are available here:

Digital Past 2017

This week Nick presented at Digital Past 2017 in Newport, Wales. The paper focussed on the digital surveying and subsequent analysis of the fourteenth century medieval vaults  in the chancel and north transept of Nantwich St Mary’s Church, Cheshire. This produced two distinct discussions; the first investigating the chancel, which offered an opportunity to hypothesise the medieval design process of the in-situ vaults using reverse engineering. The second, the north transept, contains an incomplete (or possibly destroyed) vault and therefore a series of simulations were developed to postulate the design process, and how the vaults may have looked if completed. 3D digital models of the postulated designs for the north transept can be found on the Nantwich vaults page.

The conference presented numerous exciting and innovative digital heritage projects in Wales and beyond, such as Nick Hannon’s investigations into the Antonine Wall, as well as the Welsh Chapels project which is using games engines as a way of educating the public about heritage.

eCAADe 2016 – Tracing the Past presentation

At eCAADe 2016 (Education and research in Computer Aided Architectural Design in Europe) in Oulu, Finland, Nick presented a paper co-authored with Alex and JR discussing the advantages of different digital surveying methods for the project. The paper can be found via CUMINCAD here.

A contextualised digital heritage workshop led by Danilo Di Mascio was also organised, with help from Anetta Kepczynska-Walczak and myself, the details of which can be found here. We were very grateful for the support given by the University of Oulu, and were encouraged by the discussions held with participants, which provided an enjoyable couple of days leading up to the main conference. We hope to run the workshop again at eCAADe 2017 in Rome!



Tracing the Past was inspired by the work of Robert Willis (1800-1875), a famous Cambridge polymath. He was Jacksonian Professor of Natural and Experimental Philosophy and taught engineering in the early years of that subject.

Willis’s research and teaching was spread over a wide range of
subjects. Our particular interest is in his pioneering study of medieval vaulting, presented as a lecture to the Royal Institute of British Architects in 1841 and published in the first volume of their Proceedings in 1842. Willis proposed a number of hypotheses about the design of medieval vaults which he hoped contemporary architects would be able to test. However the difficulties of gathering suitable data were huge and it’s only now, with the introduction of laser scanning that his ideas can be more fully explored, through projects such as ours.

On 16-17 September 2016, both Nick and Alex will be giving papers in the Robert Willis: Technology, Science and Architecture symposium taking place at Willis’s own college, Gonville and Caius College, Cambridge. Alex will be speaking on Willis’s networks of knowledge and Nick will be presenting a digital update of Willis’s 1842 paper, for which the digital content can be found here. Other speakers will also be discussing Willis’s work on vaults, including Prof Santiago Huerta, Javier Giron, Martin Bressani (speaking on Willis and Viollet-le-Duc) and Antonio Becchi. The full programme is available here: willis-program-a4

The Symposium website includes a digital library of Willis’s publications, making it an incredibly useful resource for those sharing his interests. The Symposium proceedings will be published – further details available soon.




We’re off to Ely!

Ely Cathedral Presbytery
Ely Cathedral Presbytery

We already reported that the Society of Antiquaries of London have very generously funded a trip to Ely Cathedral, where we shall be scanning the vaults in the Presbytery, the Lady Chapel, the Octagon and Prior Crauden’s Chapel. We’ve now got permission from the Cathedral authorities to go ahead and we’ll be at the Cathedral on 13-14 September. As well as laser scanning, we’re going to be experimenting with total station.

The Lady Chapel was started in 1321 but attention moved when the crossing collapsed, in 1322, and the whole area had to be rebuilt. We know the vaults of the Presbytery were complete by 1337, when there were payments for painting them. Thus the work is exactly the same date as the vaults at Wells.

So far we’ve only scanned vaults in the west of England, so this will be our first opportunity to scan vaults in East Anglia, where design principles and construction methods might be very different. The Ely designs are associated with William Hurley, the King’s master carpenter, who designed the wooden vaults of the Octagon and William Ramsey, later the chief surveyor of the King’s works in the Tower of London and other castles south of the Trent, to whom the later parts of the design have been attributed on stylistic grounds.  The Ramsey family of masons were closely associated with the Royal Works and with East Anglian architecture, including the cloister of Norwich Cathedral, which also has lierne vaults showing a variety of rib curvatures, as in the aisles of Wells.

The vaults of Prior Crauden’s Chapel are of interest to us because they are not medieval but were reconstructed by Robert Willis in the 1840s. They were thus an opportunity for him to put into practice the ideas he had explored in his 1841 lecture ‘On the Vaults of the Middle Ages’.