IMTO – ITALIAN MISSION TO OMAN University of Pisa

PRELIMINARY REPORT (FEBRUARY-MARCH 2008)

ITALIAN MISSION TO OMAN Salut 2008 In February-March 2008 a short programme was conducted at Salut to help determine future goals and strategies. The programme comprised four main aspects which can be defined as: Excavation Conservation Restoration Presentation Excavation was restricted to the large scale removal of collapsed deposits from outside the main wall on the east side of the site, including the tower/bastion that projects onto the adjacent plain, and the subsequent up-dating of the general architectural plan. In addition to this, the spoil from previous excavations was removed so has to re-establish the original profile of the site when viewed from a distance. Conservation was focussed on an assessment of the state of preservation of mud-brick structures and a number of trial tests to find a suitable way to preserve the original mud-brick surfaces and to prevent further decay. Restoration was focused on ways to maintain pre-existing structures and an initial rebuilding of parts of the main masonry wall which surrounds the site. The first of these activities entailed the installation of an efficient drainage system in part of the site, and the second involved the partial reconstruction of the upper part of the tower/bastion. Presentation of the site to the general public requires the formulation of a strategic plan containing suggestions for access routes, parking and visitor facilities and the identification of key points of historical interest. This needs be done in a way that reveals all that is important and interesting about the site whilst at the same time having minimal environmental impact on the surrounding historical and natural landscapes.

EXCAVATION Excavation was restricted to the removal of collapsed masonry on the east side of the site so as to reveal as much as possible of the outer perimeter wall. The removal of the deposits was aided by the use of a bulldozer where this was considered to be appropriate. There is a thick deposit of collapsed stone around most of the outside of the perimeter wall and this contains both Islamic and Iron Age pottery. That said, the amount of Iron Age pottery is quite considerable and is probably due to active erosion on the top of the site and its being washed down the slope. Below approximately 1.5 metres the nature of the collapsed deposits changes and contains noticeably more silt and fewer voids between the fallen stones. At this level a number of terrace walls are evident. It remains to be seen whether these date from the Iron Age or the later Islamic occupation of the site. At the bottom of the slope, where the Iron Age wall forms a corner with the tower/bastion, there are clear foundations and part of a standing wall that will require proper excavation. The removal of the collapsed deposits, as described above, has further revealed the plan of a large section of the Iron Age perimeter wall. The revealing of this wall also creates a better profile of the site when viewed from a distance. This perspective has also been improved greatly by the removal of the large spoil heap which had formed at the south east corner of the site. In other areas of the site spoil heaps and piles of stones have been removed to make way for further excavation at a later date.

Fig.1 General view of Salut before work started (February 2008).

Fig.2 General view of Salut at the end of work (March 2008).

Fig.3 Detail of perimeter wall during the early stages of removing collapsed masonry.

Fig.4 General view of the outline of the perimeter wall.

Fig.5 View of the East side of the tower/bastion at an early stage of clearing.

Fig.6 View of the East side of the tower/bastion after clearing.

Fig.7 Profile of the outer perimeter wall.

Fig.8 Detail of perimeter wall and adjacent terrace walls.

CONSERVATION REPORT Antonella Sechi, conservator, Desenzano del Garda, Italy Conservation status assessment From the 25th of February to the 4th of March the basement area comprising rooms 1a-d, 2a and 3a was the main focus of a conservation status assessment and systematic tests to determine appropriate ways to consolidate and restore the mud-brick fabric of the building. A few days were spent compiling photographic documentation and the graphic mapping of rooms 1a-d and 2a (in cooperation with Stefano Bizzarri, architect). General remarks Mud-brick is a very fragile material, perishable and very sensitive to both sun and rain, and many deterioration features resulting from exposure to atomospherical agents were quickly identified. All the mud-brick walls in the basement area are affected by widespread micro-cracks and by loss of cohesion of the constituent materials. Several walls exhibit wide longitudinal cracks and in some cases the fracture permeates the entire wall. The mud-bricks are characterized by two kinds of erosion. In most cases it is a result of wind action and affects a relatively small depth of the wall surface. Other cases of erosion are the result of rain water which has a more localized but deeper effect, penetrating upto 30cm into the surface of the wall. Portions of some walls that were rebuilt in the past, and the lower parts of some mud-brick walls indicate widespread, random alveolar erosion (i.e. holes formed by insects). Due to these factors, lack of choesion and detached pieces of mud-brick are characteristic of almost all of the walls. The results Several tests of chemical consolidation using selected products were untertaken. The best results were achieved with an acrylic resin (Acrylic 33), especially in cases of adhesion defect or detachment. A water solution of the product was applied in several proportions (5 to 20%) according to the damage, trough infiltration. To avoid washing out the clay content and in order get better consolidation, it is important to proceed quickly on specific areas. Lower concentrations of Acrylic 33 have been sprayed with satisfactory results. For dechoesion and micro-cracks, ethyl silicate solvent (RC70), applied for imbibition by the use of a small brush, seem to give the best result. A small trial of replastering cracks and fractures, using local mud, also gave satisfactory results. The eventual shrinkage, which occurred only in a few cases, could be avoided by adding a small amount of straw to the mud mixture. Wider cavities can be filled with materials similar to the original – mud-brick, mud and gravel. The use of new mud plaster is most probably the best way to preserve extensive areas of exposed mud-bricks as found on the platform area. In the case of extensive mud-brick pavements erosion is still a factor, but the dangers of structural collapse are not as great as in the case of free standing walls like those found in the basement area. An important point, however, is that any new mud-

plaster should be visibly distinct from the older mud-bricks. This can be achieved by adding a quantity of straw to the new mud plaster and this will serve as a binding agent as well as making it easily distinguishable. Comments It must be stressed just how important it is to protect the basement area from the action of atmospheric agents. The mud-bricks of the pavement and walls must be the focus of a rigorous programme of conservation and maintenance. Mud-brick walls will otherwise suffer wash-out and erosion, especially by the direct action of rain. Similarly, cracking and fragmentation will be caused by the thermal gradient and UV radiation, even after consolidation. A permanent covering of the basement area is necessary for the conservation of its whole structure and as a protection against rain, wind and direct UV radiation.

Fig.1 Exemple of crumbling.

Fig.2 Exemple of fracture.

Fig.3 Exemple of washing out by water.

Fig.4 Exemple of detachment.

Fig.5 Exemple of wind erosion.

Fig.6 Consolidation by permeation (seepage).

Fig.7 Stucco work.

Fig.8 Consolidation by imbibition.

ENGINEERING TECHNICAL REPORT 2008A Eng. Chiara Cei, Prof. Eng. Mauro Sassu, Department of Structural Engineering, University of Pisa

Introduction. The restoration work which formed part of the archaeological campaign at the site of Salut, undertaken from 8th of February to 6th of March 2008, was focused on two main objectives:

1) installation of a drainage system in the basement area to help preserve the mud brick structures;

2) consolidation and restoration of the stone masonry wall which surrounds the entire site.

The installation in the basement area of a drainage system. The basement is a mud-brick area on the north-western side of the site, paved with large mud-bricks and enclosed by mud-brick walls. During periods of short but heavy rainfall, it had been noticed that the water cannot find a way out from the enclosed area, thus creating a pool of water and the subsequent deep erosion of the mud structures. In order to avoid the possible total destruction caused by the accumulated water, it was decided to modify a very small portion of three walls in order to create an appropriate and efficient drainage system. The main phases in the installation of the water drain can be listed as follows:

1) Identification of the water flow and retention area, and consideration the inclination of the pavement in order to determine the strategic points for draining holes.

2) Careful opening of a small “pilot hole” using a steel rod and small hammer. 3) Enlarging of the pilot holes in order to put in place a Φ 40 mm plastic pipe. 4) Fixing of the plastic pipe by the friction created between appropriately shaped small stones

placed against the surrounding masonry. 5) The pipes were then cut in order to avoid the direct flow of the water against the wall

surfaces and consequent erosion. 6) A small-mesh inox net was placed over the upper part of the pipe to prevent blockage

caused by stones or other debris. 7) The inox net was fixed in place using small stones. This creates a second filter for small

particles and prevents the erosion of the adjacent part of the wall caused by the mechanical action of the water flow.

Following the method outlined above, two drainage holes were created in M9 for the draining of room 1b and room 1c, and a third pipe was installed in M6 for draining of room 3a. This should ensure efficient drainage of the entire basement area.

Drainage pipe in M6

Drainage pipes in M9

Internal view of the drain system

Restoration of the tower, a part of the stone masonry wall - M36. As part of the SL08A mission the restoration of the eastern face of M36, a circular tower on the north-eastern side of the site, was initiated. Given the restraints imposed by time and other factors (e.g. need to train workmen, procurement of materials etc.) , this part of the external wall was chosen for trial restoration because it will provide the most impact and immediate impression of the outward appearance the site after a relatively short period of concentrated effort. The type and methods of intervention, chosen in respect of scientific and archaeological needs, together with structural considerations, follow UNESCO – ICOMOS general principles and issues.

A general description of the work.

Work on the north-western part of M36 started on February the 12th with the cleaning of the chosen section of wall and the removal of the upper part of the internal fill adjacent to the inner wall-face. The latter involved the removal of the earthen fill to a depth of approximately 80 cm from the inner wall-face, so as to have enough space for the reconstruction phase. When necessary, as in the case of very poor cohesion and other critical situations, a wider part of the filling material was removed. A few stones which showed evidence of outwards rotation or an unsafe position were removed from the upper course of original masonry and stored nearby for future reuse. The reconstruction of the wall then started with the placing of a layer of geotextile to divide the original masonry from the new. The old and new masonry can be easily distinguished in outward appearance and, therefore, the geotextile was been placed just inside the outer wall-face, keeping its scientific function as separator but without affecting the aesthetical appearance of the wall.

Local stone blocks, taken from the excavated collapsed deposits accumulated against the outer wall, have been laid in courses using the dry stone technique. For each restored part of the tower, blocks of similar shape and size to those in the adjacent still remaining wall were chosen and arranged in a way that provides continuity in the wall texture and an harmonious aesthetic appearance. When necessary, large stone blocks have been reduced and worked by hand, using an hammer and chisel, in order to get a regular shape that gives stability to the masonry as a whole. Small stones and chippings have been placed in the space that remains between the outer wall and the earthen filling. This prevents clay particles from penetrating the joints between stone blocks which in turn causes a reduction of friction and potential weakening and collapse of the outer wall. It is also an appropriate means of drainage which helps to decrease water pressure against the wall in times of rain. Small flat stones have been placed also in the gaps between stones to get a forced embedding of blocks and improved friction. The filling of the gaps provides also a more even transmission of vertical loads and stress through the masonry and thus avoiding shear cracks. On the 23rd of February, after topographic survey and necessary documentation, the dismantling phase and cleaning of the north-eastern part of the tower was begun. Work on this part of the tower have been undertaken using the same techniques as described above. After the decided height and number of new courses had been reached (determined according to time and workmen skills etc), a capping of small and medium sized flat stones set in a mud and lime plaster, was applied to the top of the restored wall. For the binding material/plaster, local soil coming from excavation debris was used with a small percentage of lime added as a stabilizer. This capping layer should further help to prevent rain from penetrating the inner wall and also protects previously exposed areas of original wall fill from further erosion. This new surface has been applied following the pre-existing silhouette of the earthen filling and thus preserves the impression and integrity of the original.

The tower before restoration, viewed from the front.

The tower before restoration viewed from the eastern side

The tower after restoration viewed from the western side

The tower after restoration viewed from the frontal - eastern side

ARCHITECTURAL REPORT 2008A Arch. Stefano Bizzarri, Firenze, Italy The aims relating to the presentation of the site included the estimation of the site’s tourist potential and the facilities that need be put in place to bring this to fruition. Essential things to consider include: 1) Accessibility: access roads parking area reception area pedestrian pathways

specific places of interest integration in the wider landscape

2) Information: on-site information – un-obtrusive information panels and sign posts on-site information – printed material/ brochures off-site information – advertising etc. Accessibility Considering the site and its position in relation to the track that leads from the main Jabrin-Bisya road it is considered essential that any new initiatives to enhance tourist potential should be carefully integrated in the landscape; new roads should intrude as little as possible and where possible existing structures and buildings should be used in place of constructing entirely new ones. To facilitate tourist access to the site a new track should be established that approaches the site first from the east, so as to afford a good view of the site and then turns right towards the proposed parking and reception area. In this area there currently exists a derelict mud-brick house. This should be restored as a reception building, for which its size and position is highly suited. The fact that the suggested parking and reception area would be hidden from view provides a perfect solution for integrating the parking area into the landscape in such a way that it will be invisible from the summit of the archaeological site. In constructing the new access track, the use of asphalt should be avoided at all costs. Far more preferable and in harmony with the landscape would be a compacted earthen surface laid on top of a substantial hardcore foundation with provisions for adequate drainage. The restored mud-brick house would house the guards, and tourist information employees. After leaving the reception area, tourists would be guided towards two pathways. One pathway will provide a route around the base of the entire site. The other path will follow the already well established path to the summit of the archaeological site where specific places of interest will be indicated along with appropriate information. Direct access to the excavated areas will have to be restricted and designated viewing places established.

Information The main source of on-site information should be a brochure made available to all visitors in different languages. The brochure will contain a map showing the way around the site and specific places of interest. It will also contain information about the excavations and a selection of the objects found in the excavations should be included in the illustrations. The provision and training of guides to welcome visitors to the site and possibly provide guided tours should be considered. Off-site information should include targeted advertising in the local press and international tourist literature. Other ways of delivering more information about the site could include a dedicated website with more detailed information about the site, current excavations and major discoveries. Links to other nearby sites, places of interest, hotels and other tourist facilities should also be provided. A site logo should also be designed for potential brand utilization.