Author Archives: conservation

Visit to the secret part of Canterbury Cathedral, by Zoi Kokkoni

That Canterbury Cathedral constitutes a fine example of Gothic and Romanesque architecture is widely known. What few people know is that this same building has been restored and partly rebuilt countless times, and, as a result, exemplifies various attitudes to conservation. In our last visit to this monument, we were accompanied by the head of Stone Conservation at the Cathedral, Ms. Heather Newton. Ms. Newton gave us a rare opportunity to explore “the unseen world” of the roof and the tallest tower, Bell Harry. The roof, mostly dating back to the Tudor period, has been divided to several rooms for fire protection. Its beams have been restored numerous times following the rotting of the original timbers. Circulation inside the roof was through a series of timber corridors, which offered access to the ceiling without loading the nave vaults below them.

The most challenging part of our visit was the ascent to the top of Bell Harry, the tower over the crossing. On the base of the tower, we found a sophisticated crack monitoring gauge and a humidity meter that records the micro-climate of the cathedral’s interior. After hundreds of steps, we reached a room where we found the pulley mechanism for the lifting of building materials. On the top of the tower, apart from the old bell mechanism, there is a microscopic meteorological station which is linked to a central computer inside the Cathedral. The highest point of the cathedral is exposed to the weather, and this has caused the decay of the limestone there. Unfortunately, as Ms. Newton explained,this decay seems to have been accelerated by “plastic repairs” carried out in the 1930s. These involved the use of cement mortar to fill cracks and to recapture the lost profiles of stone elements. This hard, impermeable mortar prevents the “breathing” of the wall and the evaporation of moisture. Trapped in the core of the wall, moisture accelerates stone decay caused by frost weathering and the crystallization of salts.

Zoi Kokkoni

View of the Roof of the Chancel of Canterbury Cathedral from the top of the tower over the crossing.

View of the Roof of the Chancel of Canterbury Cathedral from the top of the tower over the crossing.

Heather Newton, Head of Stone Conservation of Canterbury Cathedral (left) and students of the MSc programme in Architectural conservation on the top of "Bell Harry", the central tower of Canterbury Cathedral.

Heather Newton, Head of Stone Conservation of Canterbury Cathedral (left) and students of the MSc programme in Architectural conservation on the top of “Bell Harry”, the central tower of Canterbury Cathedral.

Basilica B at Philippi: retracing the phases of an incomplete monument

In the context of the event ‘Archaeology at Kent in 2014’, Dr Nikos Karydis presented the case study of Basilica ‘B’ in Philippi, an archaeological site in Northern Greece near Amphipoli. Apparently, Philippi was a strategic location in the Early Christian Period, when the city’s powerful Christian community decided to erect four churches. Chief among them were the timber-roofed Basilica ‘A’, and Basilica ‘B’, which was a domed basilica, a rare type in the region. The latter occupied three Roman urban blocks, which previously included the Palestra and a commercial building of the Roman Period.
Paul Lemerle, the archaeologist who surveyed the site, proved that Basilica ‘B’ was never completed. The reasons were neither the incapacity of the workmanship, nor the lack of materials. The research of Dr Karydis revealed the most reasonable cause of the collapse of the vaulting. It was shown that the building was constructed on the foundations of a previous building. Now, this earlier building was to echo the plan of the Basilica ‘A’, nearby. Hence, the building was initially conceived as a timber-roof basilica, but, at some point after the foundations were laid, the design changed. The new design abandoned the timber roof in favour of a vaulted ceiling. It therefore demanded large piers to support the vaults, and an alignment between the piers to form square bays. This could not be easily combined with the use of the existing  foundations (which were too weak and lacked the necessary geometry). The load-bearing structure that was eventually built was a compromise, and failed to counteract the thrusts of the wide vaults. Soon after these were erected the church collapsed. The mission of altering the church was condemned from the outset, and proved to be catastrophic for this major monument.

Zoi Kokkoni, 2014

46 N screen and Pier 1 from E

David Watkin Presents his Work on the Roman Forum, by Zoi Kokkoni

On Monday, we attended a lecture on the Roman Forum by Professor David Watkin, one of the most important historians of our times. The “Foro Romano”, visited by millions every year, has had a fascinating and vivid building history from Antiquity to the Present. During this period, the forum was repeatedly modified, and as a result, distinguishing the dates of its buildings is not always easy. Temples that seem to be ancient were in fact erected just eighty years ago. For instance, the Temple of Vesta, in its present form, dates back to the 1930s (Watkin David, The Roman Forum, p.16).

Examining views of the forum, including the famous ones engraved by Piranesi, Watkin revealed the Roman monuments in all their grace and splendour, and traced their development from the Early Cristian Times to the Baroque period. The way in which churches were integrated into old roman edifices was absolutely astonishing. On the other hand, the Nineteenth Century idealized the “magnificent Roman ruins” at the expense of more recent buildings.

After a visit to the Forum it is easy to feel disorientated as you are trying to resolve a puzzle of multiple building phases that make the monuments comparable to palimpsests. Despite the archaeologists’ recent interventions to the site (considered to be “clumsy” by Watkin), the Roman Forum remains an ideal site to study Rome’s history and architecture as well as the development of conservation philosophy.

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Zoi Kokkoni 11/2014

The MSc in Architectural Conservation Begins!

The new MSc in Architectural Conservation has started with a site visit to the historic centre of Canterbury, followed by lectures and seminars on Conservation Philosophy and Policy. The lecturers in the first term include Dr. Manolo Guerci, Dr Nikolaos Karydis, and Dr Timothy Brittain-Catlin. We have also enjoyed three guest lectures by Martin McKay, Conservation Officer, Medway City Council, who illustrated his lectures with many interesting examples from Medway. We very much look forward to the lectures of Prof. David Watkin and Nick Dermott (Conservation Officer, Margate Council) next week.