Week 9 (9 - 15 August)

One word will sum up week 9 on site. Rain!

A view of the waterlogged site and trench covers

Rain forced us to close the site to the public for three days; rain brought down the cover on Trench 3; rain caused a section to collapse in Trench 5; rain filled up every pit and cut feature on site and threatened to turn the excavation into a quagmire. Things are now drying out, however, and the site is fully up and running again. Only three weeks to go - can we get back on schedule?

Trench 3

The new Trench 3 shelter takes shape

The collapsed shelter over (sorry, in) Trench 3

Little happened in this trench as staff and placements battled to sorted out the cover and get the rainwater out of the trench. In the brief time available it was possible to examine further the construction of the ramparts. An interesting situation is developing in the north-west corner of the trench where it appears that part of the rampart might have slumped into an underlying feature. This will not be understood until excavation has continued into these lower levels. Natural still has not been reached in the bottom of the large pier base pit - which is now full of water.....

Trench 4

The cover in Trench 4 was the only one which managed to stay in place during the downpour, allowing work there to continue. As the 16th century deposits resulting from the demolition of the medieval hospital were cleared away, evidence for the construction cut of the medieval stone-lined drain was encountered. This drain, some 800 years after its construction, coped with the deluge from the heavens much better than its 20th century equivalents, cheerfully carrying the water away from the sites as it was intended to do by the monks who built it!

A domed bone object, perhaps a counter, from Trench 4 (14mm diameter)

Trench 5

Here too the rain stopped play for a period as sections began to collapse and the covers could not cope. Nonetheless more wall plaster is still coming out of the trench. YAT conservator Erica Paterson and conservation student Karl Knauer were called onto site urgently to 'lift' a number of large fragments of painted Roman wall plaster. Fragments of painted and plain plaster were found jumbled together, many lying face down or on their sides The diggers described the plaster as being so fragile it was 'like digestive biscuits' and had obviously suffered cracking and breakage when dumped, not helped by the wet weather on site had made the porous material even softer and more difficult to handle.

Conservators lifting wall plaster from Trench 5

Two large fragments of plaster approximately 30 x 40 cm were uncovered face down in the trench and the aim was to lift them intact so that any surviving painted design could be saved for full study. Because of their fragile and fragmented state the conservators applied strips of - bandage impregnated with plaster - similar to that used in hospital for setting broken limbs. Once set, this created a rigid cast around the plaster fragments. Thin metal baking sheets proved useful in separating the plaster from the underlying soil. These were pushed horizontally underneath the layers of plaster and then the whole block of soil and plaster was lifted onto wooden boards. Once back in the laboratory the supported fragments could be turned over and the slow and painstaking process of removing soil to reveal the hidden painted surfaces could begin. Conservation placement student Karl Knauer from the Winterthur/University of Delaware M.S. Program in Art Conservation in the U.S. learned the art of on-site lifting from lab staff and is now continuing work on the plaster as one of his special projects.

Karl explains the process…..

A fragment of wall plaster undergoing conservation

"As the plaster pieces were face-down in the trench, turning the "block lifts" over was naturally the first step in cleaning them. The soil (which had been below the painted surface prior to turning the plaster over) was removed methodically with palette knives, scalpels and brushes. Slowly, the painting became evident - and a large section of red border design was uncovered. An exciting orange-coloured area of the plaster revealed itself, as well - indicating that the design motif may have combinations of geometric and curvilinear patterns in a variety of colours. It will certainly be interesting to see if these pieces can come together and give a more complete picture of how the mural would originally have appeared!"

The next step will be to consolidate the crumbly and fragmented plaster with an appropriate synthetic resin, then to provide suitable packaging so the pieces can be stored safely yet be easily accessible for viewing.

Bizarrely, wall plaster appears to be in the fortress rampart as well as within the Multangular Tower. This would indeed be strange and the picture will become clearer once further work has been done.

The backfill of the 1920's trench has now been completely removed. Beneath this an area of mortared rubble confirmed that we had located the position of another column in the medieval hospital, which clearly did extend right up to the Multangular Tower.

A detail of Trench 5 showing another layer of wall plaster fragments (top), the rubbly fill of a modern trench (bottom left) and the mortared rubble foundations for a medieval column (bottom right).

Trench 6

Work continues in Miller's trench to get to the timber piles but, as everywhere, the rain sodden ground is making progress difficult. In the eastern part of the trench, initial examination of the layers below the modern turf shows that, so far, they are all 20th century.

Removing modern deposits in Trench 6. The water filled cut (background) is the Miller trench (partially excavated).