On Site Conservation: July 9-27, 2006
During the third week of our site conservation project (July 9-13), the work gained speed with the arrival of the remaining part of the team, including the new conservators from Ankara University Baskent Vocational School and the first of their four successive supervisors, Dr. Selçuk Sener. Together with Ebru Torun of K. U. Leuven and METU, they drafted a detailed plan of all activities for the remaining part of the campaign and prioritized the planned interventions, depending on the state of each building.
The conservation team's first major intervention involved checking the condition and temporarily (re-) conserving, where necessary, the mosaic floor exposed in the Basilica of St. Michael in 1999. Unfortunately, no sponsor has yet been found to provide the funding to conserve and expose this wonderful polychrome central mosaic floor. It measures 14.5 by 7.5 meters and is composed of several different bands surrounding a central labyrinth, and there is a similar carpet made of geometric patterns, 12 by 2 meters in size, which covers the northern aisle. This basilica, established in the courtyard of the former Bouleuterion, is one of the oldest well-preserved churches in Anatolia, dating to the early fifth century A.D. At the end of the 1999 campaign, the season's conservation team covered the mosaic with layers of geotextile, polyethylene sheet, sand, and pumice for protection.
In exposing the mosaic this season, first, the sand had to be removed carefully in order to open the surface. Five workmen continuously removed and filtered the sand of rougher particles, like stones and plant remains, so we could use it again later to cover the surface after treatment. When the mosaic floor was revealed, it was very carefully cleaned of dust and soil with brushes. Afterward, its current state was documented with digital pictures and drawings indicating the state of preservation. The purpose of re-exposing the mosaic floor was not active conservation, but it to provide a better cover for the coming years until a good sponsor is found and an extensive conservation project, which requires a roof that does not conflict with the old structures around it, is implemented. The mosaic floor was covered properly after the documentation. Layers of geotextile, sand, dry brick, and lime mortar were applied. Because of a lack of space in the Upper Agora to store the removed sand, only half of the mosaic was opened this past week, and the other half will be exposed next week.
Plaster patches found at the Macellum and in the West Portico of the Upper Agora were consolidated. One of the latter covered an inscription, recycled upside down into one of the arched rooms supporting St. Michael's Basilica. After carefully removing the wall plaster that partially covered it, the inscription was revealed to be a late antique board game, which we copied and photographed. Conservators also worked on the mosaic parts found during the excavation of the Domestic Area (see Domestic Area, July 16-27, 2006).
Meanwhile, the conservation team's four experienced builders, supervised by Göze Uner, continued to work on the West Portico of the Upper Agora. Cleaning and consolidating rubble walls by capping and pointing occupied most of their time. A new capping detail designed last year in the Domestic Area, where it produced excellent results (see On-site Conservation, June 25-July 6, 2006), was applied this year in the West Portico to better protect the walls.
Last year, Ebru Torun and the previous campaign's conservation architects designed an intervention documentation scheme. The implementation of this scheme began this week with the arrival of architect Aysem Kilinc from METU Ankara. Digital documentation of every intervention is shown through detailed photographs of both the current state of the walls and the intervention work.
||Left, the recycled game board in the West Portico, along the Upper Agora, with the wall plaster covering the older inscription. Right, the late antique game board after removing the wall plaster.
At the beginning of the fourth week (July 16-20), the conservation team of sivacilar (mortared brick masons), supervised by Göze Uner, continued consolidating the rubble stone and brick walls of the late Roman to early Byzantine subdivisions of the Upper Agora's West Portico. The Ankara conservators, directed by Selçuk Sener, focused further on conserving the mosaic floor of St. Michael's Basilica. In addition to its scheduled work, the team had to do many emergency protection interventions during the week.
In the West Portico, two of our experienced workmen built scaffolding in order to deal with a potentially dangerous wall in the northwest corner. After all security precautions were taken, Ebru Torun, Selçuk Sener, and Göze Uner had to decide the type of intervention to use on the unstable parts of the wall. Different types of capping and masonry repairs were examined and discussed. Eventually, based on photographs from the 2000 campaign that showed the wall in a better condition than it was presently, the wall was consolidated and repaired.
One of the most interesting parts of the West Portico is a room with an ancient water canal running through it, which in the course of the sixth century fed the large open-air water basin built against the West Portico. Proper preservation methods were discussed and work began by creating structural support for the north wall of the canal, which is arranged on a sloping terrain. Our building team continued capping and pointing the existing walls.
In the Basilica of St. Michael, formerly treated wall paintings were re-opened to check their state of preservation. The borders were consolidated, and hollow or detached parts were treated with injections. They were protected against severe weather conditions by geotextile, sand, and dry brick walls. The scaffolding on the west wall, which protected a large section of figural painted wall plaster, was removed, and better protection for the wide plaster surface was provided in the form of a timber frame and polyethylene sheet. In the western half of the basilica, the mosaic floor is still being re-opened by very cautiously removing the sand on top.
In the late Roman to early Byzantine Domestic Area palatial mansion, the curvilinear wall of the apse that was revealed in Room 52--above Room 46--had to be consolidated in the northeast corner of Room 46, before excavations could continue in that sector (see: Domestic Area, July 16-27, 2006). The gaps in the wall caused by collapse and mortar loss had produced severe structural damage, which needed to be fixed immediately. The Domestic Area supervisor Inge Uytterhoeven (K. U. Leuven), security manager Luk Karremans (K. U. Leuven), and the conservation team discussed all possible intervention methods. In the end, it was decided that temporary steel supports should be placed against the critical wall stones. Wooden buffers were placed where the steel bars touched the brittle wall, in order to protect the original material.
At the same time, immediate interventions were also required in the Odeion. In Corridor 2, the 2-meter-long lintel above the rectangular opening in the east wall (see: Odeion, July 16-27, 2007), which had several cracks, was found to be poorly supported. The team brainstormed again and decided on the best interventions to ensure the safety of both the structure and the people working in that area. After a proper timber support was installed, the conservation team filled in the cracks in the stones with a special mix of lime mortar, matching tinted pigment, and Primal Ac--an acrylic resin. Then, two builders cleaned the infill wall and consolidated its rubble stone masonry. Now, we must wait until Sunday for the mortar to dry and be stable before removing the supports.
Over the course of the week, the conservation team treated two walls in the Roman Baths (sectors 1 and 2). Temporary timber scaffoldings had to be installed before further excavations could be carried out in that part of the complex. Next week, the conservation team will probably work in the Roman Baths, consolidating the two walls of brick and mortared rubble. The plaster surface of a brick wall was also consolidated this week.
In the Macellum, the arcosolium (vaulted alcove) in Room 3, discovered last week, had plaster on all three walls and on the remains of the vault. Proper interventions were made for the protection of these walls as the excavations continued.
|Left to right: Repair of the water-supply system feeding the sixth-century water basin. The support below the northwest corner of room. The Corridor 2 door lintel's temporary support in the Odeion. The endangered brick and mortared-rubble wall in the southern spaces of the Roman Baths between RB 1 and RB 2.
During the fifth week of conservation, Hande Kokten replaced Selçuk Sener as head of the Ankara conservation team, which continued its scheduled work in the Upper Agora's West Portico and in the Basilica of St. Michael. In addition to these tasks, architectural interventions and fine conservation were required at different excavation sites, including the Odeion, the Macellum, the palatial mansion in the Domestic Area, and the Roman Baths.
In the West Portico, the workmen capped and pointed the walls with respect to the original masonry patterns. The floor of the room with the ancient water channel was re-opened for control. The terracotta pipes and different floor levels were cautiously cleaned and covered with geotextile, synthetic netting, and sand.
In the Basilica, consolidation work on the wall paintings continued. The west half of the mosaic floor was carefully, completely opened by trained conservators and was documented with damage analysis drawings and photographs. The mosaic was covered again for protection, in anticipation of the day it will be restored.
The wall that was repaired last week in the Odeion had fully dried and had gained enough strength for us to remove the supports, so that the infill could be pointed and the excavation could continue safely.
As excavation continued in the Domestic Area Room 46, the rubble infill over the collapsed tuff vault in the northeast corner was exposed. The conservation team, collaborating with the security manager Luc Karremans, used temporary steel supports to hold the unstable stones. However, stronger and more extensive support was required for the wall in order to continue the excavation in this important space of the villa. After on-site discussions, it was concluded that if the wall was to be kept intact, a durable masonry support holding the rubble infill needed to be constructed. One of the experienced builders of the conservation team started to work in this room under the supervision of architect Mehmet Koyuturk, who arrived this Monday to join the on-site team.
Also, fine conservators consolidated the plaster surfaces in the Roman Baths.
In the Macellum's Room 1, a structural problem was discovered in the southwest corner, caused by material and mortar loss. The conservators and archaeologists decided that since the room and the wall were very significant, a masonry repair should be built to keep the wall safe. Work started following the example of the existing structure and wall material, and digitally documenting every intervention completed. Two niches were restored in the corner. In addition to all of this, plaster consolidation work continued in Room 3.
The site conservation team plans to complete all tasks in the upper part of the town next week, after which the entire team will concentrate on the masonry problems in the Roman Baths and in the Lower Agora until the end of the campaign.
|Left to right: The nearly finished West Portico on the Upper Agora subdivided into smaller units, with the sixth century basin built to the left of it. Part of the uncovered mosaic floor in the western part of the church of St. Michael. Section of the newly exposed western part of the mosaic floor of the basilica. The outer door in Corridor 2 of the Odeion after the consolidation of its lintel and the repair of its late antique infill.