Tag Archives: AHRC

Back to Wells

Last week (11-14th October) we returned to Wells, revisiting our earlier scans and taking the opportunity to scan new areas. In particular, we have been privileged to be allowed to record the ‘tracing floor’, an extraordinarily rare survival of the ‘drawing office’ where the master mason worked out designs full scale by inscribing them on a plaster floor. The tracing floor at Wells is above the north porch of the nave, accessible from the triforium gallery via a spiral staircase in the north transept. Because the surviving examples are in fairly inaccessible places, it is believed that such spaces were probably used for design rather than for cutting stones, however it could be that more accessible multifunctional spaces may not have survived and that the ones we know about were exceptional. There is a larger and more famous example of a tracing floor above the north transept at York Minster, but the Wells example is of particular interest to us because it has been suggested (Pacey) that one area corresponds to the vaults of the cloister.

In recording the tracing floor we have decided to experiment with three different methods. Firstly, we have used photogrammetry, a method we have tested elsewhere, which is based on taking multiple photographs and stitching them together digitally to create an image without the distortion of perspective. We have also scanned the area using our laser scanner on its highest settings, to see how much detail it can record. Finally, we have used an innovative method called ‘RTI’ (Reflectance Transform Imaging). Like photogrammetry, this involves taking multiple images, however, reflective spheres are added to the scene and photographs are taken at intervals around the target’s hemisphere using a flash gun which is set at the same distance from the target in all images. These images are then processed using CHI software, which allows us to re-light the tracing floor from any angle and potentially reveals surface detials that have not previously been seen by eye. Our technicians, Sarah Duffy and JR Peterson, are experts in the use of this method and initial results look very promising in terms of picking up very fine levels of detail. However the method has disadvantages in that it can only currently be used successfully on small areas, which need to have a wide margin around them and which cannot yet be ‘stitched together’ to create a single image. We cannot therefore use RTI on the whole floor, except in individual sections towards the centre of the space. We have therefore sampled two areas that offer potentially interesting data: one which appears to show the springing off a vault and another which has some very fine details not recorded in previous surveys.

We have also taken the opportunity to take laser scans in colour, rather than the black and white we previously used, and to scan some areas we originally omitted, including the chapter house and the cloister. It has also been very helpful to re-examine areas where our data was of insufficiently high quality to answer more archaeological questions. We are very grateful to Jez Fry, the cathedral’s Clerk of Works, for granting us access and facilitating our studies at this most beautiful and fascinating building.

 

Scanning at Norwich Cathedral

This week we have been scanning at Norwich cathedral. This is the biggest site we’ve tackled to date – the whole Norman cathedral was covered with lierne vaults in the 15th century and there is also a tierceron vaulted cloister and a 14th-century lierne vault in the so-called Ethelbert Gate into the cathedral precinct.

Like other sites we have previously scanned, including Gloucester cathedral and Tewkesbury abbey, Norwich cathedral remains largely a Romanesque building, originally built as a visible symbol of the Norman Conquest of 1066. The elevations display the massive piers and round-headed arches typical of Romanesque architecture. Although undoubtedly impressive, this style would have looked very old-fashioned by the 14th century, so when the central spire blew down in 1362, damaging the east end of the building, the monks might have seen this as a good opportunity to update their church. The presbytery clerestory (top storey of windows) was rebuilt with Perpendicular tracery and, in the fifteenth century, the whole building was vaulted. The Norman walls had not been intended to carry stone vaults, so we will be interested to explore what effects these might have had on the existing fabric. Moreover, in reverse, the existing bay dimensions would have placed specific requirements on the 15th-century designers, inevitably affecting their artistic freedom.

We selected Norwich as one of our case studies for a number of reasons. Firstly, Professor Robert Willis noted that the cloister vaults showed a number of different 3D forms, despite all following the same 2D plan. Such situations – which we knew existed at Wells cathedral and have also found at Exeter – provide very interesting data for our analysis, revealing the sophistication of medieval design processes. We are therefore very much looking forward to interrogating our scan data once it has been processed. It may also provide further clues for understanding the sequencing of the cloister – the dates at which the different parts were erected – which has long been an interesting puzzle for archaeologists.

In addition, Norwich will provide an interesting comparison with Ely cathedral, as we know from documentary evidence that the same named masons worked on both sites. Members of the Ramsey family worked at Ely and Norwich in the early fourteenth century (as well as at St Stephen’s Chapel in the Palace of Westminster, whose surviving undercroft we have also scanned). Our data may help to identify whether the Ramseys and their teams used the same design methods at different sites and whether their approach was different from our other West Country vaults.

Finally, it has been argued by Frank Woodman that the vault of the Ely Lady Chapel is not 14th-century, as had always been assumed, but dates from the 15th century. He used the high vault at Norwich as a comparison for dating purposes, therefore it will be interesting to see whether laser scan data can be used to support or disprove his theory. The Norwich cathedral lierne vaults are the latest in date that we have scanned and we will be looking to see whether methods had remained constant from the 14th century or whether familiarity with the techniques had enabled improvements.

We are very grateful to all the staff at the cathedral, especially Roland Harris, the Cathedral Archaeologist, for facilitating our visit and making us feel welcome in this beautiful building.

Scanning at Westminster Abbey and the crypt of St Stephen’s Chapel

In January 2019, we travelled to London to undertake a digital survey of the medieval vaults of Westminster Abbey and the Victorian reconstructed vaults of the undercroft of the destroyed St Stephen’s Chapel beneath the Palace of Westminster using funding from the AHRC.

Westminster Abbey, perhaps the best known church in the UK, offers a number of valuable opportunities to the project. Whilst most of the hundreds of thousands of visitors each year pay homage to Britain’s illustrious dead buried there, architectural historians continue to argue over whether the nation’s mausoleum owes more to France than to England. Our research will enable us to compare Westminster’s vaulting with other sites both in the UK and in France to explore the ‘Frenchness’ of its design. Furthermore, the chapter house and cloister vaults have previously been identified as having unusual 3D geometries, so we will use our digital data to investigate this. As a royal project, Westminster is also unusually well documented in the records of the King’s Works, throwing further light on the building sequence, the identity of the designers and details of construction methods. From such records, we know that the medieval masons plotted their designs on a full size ‘tracing floor’, from which moulds were cut for the individual blocks of stone and the wooden formwork by which the ribs were supported during construction.

St Mary Undercroft, formerly the crypt of St Stephen’s Chapel in the Palace of Westminster and now the place of worship for the Houses of Parliament, is another well-documented royal work, started by Edward I. Its vaults take an innovatory ‘lierne’ form, with extra decorative ribs which have been claimed as the earliest liernes in England. Although now largely a Victorian reconstruction following the great fire of 1837 which destroyed most of the medieval palace, measurements were taken from the medieval vaults prior to demolition. Our digital survey will be used to compare the measurements of the demolished medieval design with the current Victorian reconstruction and possibly identify elements of original medieval fabric lurking beneath the Byzantine-style paintwork.

The two surveys add to a growing list of case study buildings that will be individually analysed, as well as offering comparisons between sites. We are currently making good progress with analysis at Exeter, Ely and Wells cathedrals, and will begin investigations using the Westminster Abbey and St Stephen’s Chapel data later this year.

Join our team!

We are seeking to appoint a Postdoctoral Research Associate and a Research Technician on a fixed term contract to be part of our exciting AHRC funded project titled ‘Tracing the past: analysing the design and construction of English medieval vaults using digital techniques.’ Further details of the posts can be found via the links below:

Postdoctoral Research Associate (18 months full-time)
https://www.jobs.ac.uk/job/BNR596/postdoctoral-research-associate-grade-7

Research Technician (6 months full-time or 12 months part-time)
https://www.jobs.ac.uk/job/BNR738/research-technician-grade-6-full-or-part-time

For queries, please email Dr Nick Webb – njwebb@liverpool.ac.uk

AHRC Research Grant Success

Through the Arts and Humanities Research Council’s Early Career Research Grant scheme, we have secured funding to develop the project further. Using the grant, we will scan vaults at five further sites, bring in an additional researcher and technician, archive our data digitally and make it available publicly, create a travelling exhibition with associated outreach events at key sites, support the publication of a book, as well as enabling a second symposium on vaults with research and industry partners.

We will continue to use digital technologies to identify and explore the geometries of medieval vaults at key sites in England, enabling new readings of gothic design and construction. The grant will focus on the design process of masons and clients, particularly how practical 2D geometries are projected into 3D, as well as issues of construction such as stone-cutting, installing scaffolding and formwork, structural issues and site management. We will also investigate factors leading to innovation in vault design, when and where these occurred, as well as the transfer of ideas in the above areas across sites of vaulting locally, nationally and internationally.

The AHRC funded project ‘Tracing the past: analysing the design and construction of English medieval vaults using digital techniques’ will commence in September 2018 lasting until February 2021.