Column Reconstruction



Background



Although the project of rebuilding one of the columns found in Abasseya Sector B was finally executed in the field season of 2015, the idea had been haunting us since 2012. In that season, a total of 63 column pieces, several of them with colored plaster, were identified. The decoration of the column drums consisted basically of red, yellowish and blueish diagonal stripes. Among the pieces found there was a column capital that preserved the original decoration pattern, a colored flower motive with a clear Egyptian inspiration.

The pictures were shared with the authorities of the National Corporation of Museums and Antiquities (NCAM) and immediately caught their attention due to the well preserved status of the decoration. Colored decoration, especially in columns is rare to find in the Meroitic archaeology due to the type of the pigments used, the quality of the construction material and the harsh preservation conditions.



The team agreed straight away that it was worth rebuilding one of these columns in order to show to the wider public a good representation of the Meroitic architecture and decoration found in Abasseya. Therefore, a proposal to rebuild the column either in Khartoum or Karima was presented to the NCAM. The permission to reconstruct the column in the Barkal museum at Karima was finally granted by the season of 2013. Although a small museum, we realized it was probably the most adequate place to keep a column from Abasseya. After all, this building complex was linked to the Barkal religious center.



Preparation tasks



According to how the pieces were scattered around the Abasseya B building, it was possible to partially determine which pieces corresponded to each of the columns. An archaeometric study of the pieces allowed us to understand the shape of the columns and determine their dimensions (height and width). Each column was formed by seven pieces: capital, astragalus, drums (four) and base.



In order to determine the current condition of the original sandstone rock used to fabricate the columns, a sample was taken to Barcelona’s UPC University for a petrological study. The density of the sample was measured and a compressive strength test was performed, showing the rock was capable of withstanding the load. The analysis also confirmed that the plaster covering the rock, aside of having a decorative function as a base for the colors, also gave structural integrity to the entire piece.



In the season of 2013 we proceeded to relocate the column pieces found until that date. For that purpose, a metal stretcher and some wooden pallets were manufactured. The pieces were moved to an open area within the fence of Sector B and arranged in lines, which grouped the components of each column. Four colored pieces identified for the column reconstruction, including the column capital, were moved to the storeroom of the Barkal museum. The other three were protected and left at the site.



In order to check that the lifting technique planned for the column drums was viable with the equipment available, a short test was performed. A sample column drum of cement was prepared with the average dimensions of the original ones. Different arrangements of slings were tried until an optimum length and lifting arrangement was established.



In order to maximize the effectiveness of time available for rebuilding the column, a dedicated trip to Khartoum was made two months ahead of the 2015 season, to get all the materials required. A crane design, prepared in advance, was given to a local metal workshop. Except for the lifting gear, the bolts and the shackles, the rest of the crane components (hook, travelling block, steel frame, reinforcement bars) and related equipment (scaffolding, trolley, wood and wire) were either bought or built in Khartoum.



As the crane had to be transported and assembled inside the museum of Karima, the crane design considered specific constraints on its dimensions and the ability to be easily transported and mounted. An assembly function test was performed in Khartoum to confirm the feasibility of assembling the crane in a confined space. Finally, a load test was performed to ensure it could handle the maximum weight of 600 Kgs.



Restoration work



The last step of the process, the reconstruction and restoration work of the column at the Barkal museum was performed during the 2015 season. The task began on February 9th and ended on February 24th and included five workers, two engineers and two restorers.

The crane pieces and all the assembling material were transported and installed inside the exhibition room No2 of the Barkal museum at Karima. The scaffolding was erected and used as a support to assemble the crane. Everything was placed in a way that would allow the easy movement of the pieces. The crane disassembling space requirements, after the column was rebuilt, had been considered when choosing the final position of the crane.



The seven column pieces used on the project were subjected to a diagnosis of its state of conservation.

The core sandstone was in good shape, but the main problem was the loss of the decoration layer, which was plaster with a polished finish. In some places it was detached from the sandstone, presenting bubbles, cracks and fissures. In other places it was already lost, leaving the edges unprotected and about to fall. It was needed to proceed with a direct protection using a lime and sand mortar – very similar to the composition of the original layer.

After an initial mechanical cleaning to remove sand remains and other surface accumulations, a natural lime-based mortar (PLM-A® CTS) was injected inside the gaps of the stone and between the fissures in order to consolidate them. Fixing the polychrome decoration was also required, since it was fragile and dusty. For this purpose, a consolidating chemical with a calcium hydroxide base dispersed in isopropyl alcohol (Nanorestore® CTS) was applied. Once the success of the consolidations applied was tested, each of the column elements was protected individually with geotextile, leaving them ready for moving and lifting them.

The colored capital was cased within a wood box stuffed with polystyrene. Two half-moon wood covers were installed at the bottom of the capital in order to allow setting it on top of the column, while easily removing the protection. Finally, the assembled box was wrapped and secured with metal wire for extra protection when turning around the capital to its final position.



All seven pieces were moved within the museum over wood pallets into the exhibition room No2 using a trolley. In order to circulate the trolley smoothly around the museum, different floor levels and obstacles had to be avoided. For this purpose, several ramps were fabricated and the obstacles were overcome successfully. The pieces were set in their assembly order next to the crane to optimize the reconstruction process. A cement pad of 90cm x 90cm x 10 cm was set as a base to avoid the original base block coming into direct contact with the museum floor.



The first step was to use the crane to turn the box containing the capital to its correct position. Then, it was set aside on an adapted wooden pallet. The base was picked up wrapping wide slings around it. Then, it was leveled on top of the cement pad by using a mortar of lime and sieved sand, similar to the original mortar used. The process continued in a similar way for the column drums. When the mortar was not enough to level up the piece, wooden wedges were used and then the gaps were filled up. Special care was given to align the color patterns of the drums. The capital was picked up with its protection box and it was leveled up in the same way. The alignment was done also by marking the start of the colored patterns in the neck of the capital. Once the capital was firm in its final position, the metal wire was cut, the bottom half-moon covers were disassembled and the box was lifted up. The final height of the column was 2.92 meters.



The next step was to carefully remove the crane and scaffolding out of the area. The crane was disassembled and the pieces were moved out of the museum. The restoration work was performed according the basic principle of archeological restoration: minimal intervention and maximum fidelity to the original piece.

The missing parts of the decoration supporting layer were restored using materials similar to the originals and of a reversible nature. A sifted-sand and lime-based mortar was applied where the plaster layer was missing. To obtain the desired consistency with the original decoration, on the restored plaster, light tones of natural pigments (Conscolor®) agglutinated with an acrylic emulsion (Primal SF-16®) were used.

Finally, the scaffolding was disassembled to be returned to Khartoum.



Conclusion and thanks



The column is now standing in a corner of the Barkal museum. The steady climatic conditions inside the exhibition room helps to protect it from the direct action of natural agents like the sunlight and wind. Next to the rebuilt column an explanatory sign has been placed. We want to thank all the people involved one way or another in this project. A special mention to Mr. Shihab El-Badawi and Mr. Alaeldin Sidahmed Alfadil for the great help given during all the phases of this project. A very big thanks to Mrs. Maria Eugenia Martinez for her constant support.​



Reconstructing the Past: Wahat Mission



Promotional video of the column reconstruction in the museum of Jebel Barkal during the Season 2015.





Wahat Projects



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