In July we attended the 6th International Congress on Construction History, hosted in Brussels, Belgium. The conference included participants with a wide range of interests in construction history and there was a strong showing of researchers investigating vault design and construction. This included colleagues from Spain and Germany, such as David Wendland and Marie Jose Ventas Sierra’s talk on the Hall of Arms vault in Albrechtsburg Meissen as well as Rocio Maira Vidal who discussed the abandonment of sexpartite vaults across Europe, including Lincoln Cathedral in England. It was a delight to meet Jacques Heyman, who wrote ‘The Stone Skeleton’, and gave a fascinating talk on the change of level in the fan vaults at Kings College, Cambridge.
At the congress we shared our initial investigations of the nave and choir vaults at Exeter cathedral, which we surveyed in 2016. We suggest that all the high vaults were laid out in two dimensions using a geometrical figure called the ‘starcut’, allowing the same proportions to be maintained throughout, despite different bay dimensions. The three-dimensional geometry of the vaults, however, presents significant variation between bays. These appear to correspond with the construction sequences proposed by previous scholarship. Nevertheless, the nature of the variations does not correspond fully with previous interpretations. We propose that two-centred arcs were found at Exeter earlier than generally recognised and in a different pattern of distribution than previously suggested.
David Wendland and his ‘Late Gothic Vaults’ team have produced a film exploring the vaults of St Anne Church in Annaberg-Buchholz, which feature complex double curvatures. Using total station surveying as well as original drawings, the team replicate the design process that medieval masons would have used via a plaster tracing floor, then experiment with stonework to create a replica of the final voussoirs. you can watch David’s film here:
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 CGD 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.
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?
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.