| Ashkelon |
| Tel Ashkelon |
| The “Wall of Columns” in the Tel Ashkelon National Park |
| Implemented by: |
Fuad Abu-Taa'
Yoram Sa'ad
Eng. Ofer Cohen
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The “Wall of Columns”, on the beach at the edge of Tel Ashkelon, is a remnant of the fortifications from the Crusader period. This name stuck due to the granite columns incorporated in it. Such secondary use of columns from earlier periods was meant to strengthen the element from a constructive standpoint and is known from other Crusader complexes such as in Old ‘Akko and Caesarea. Another technological feature in the “Wall of Columns” is the layered construction simulating stone courses which it is done using semi-hewn stones and fieldstones. The mortar utilized in the construction contains large amounts of ash that is readily apparent. The use of ash was meant to absorb moisture and maintain the flexibility of the mortar in the wall.
The “Wall of Columns” was treated in 2008, was severely damaged in the winter of 2010 and was rehabilitated in 2013.
Because of its proximity to the water line the wall is exposed to waves, winds, winter storms and salt. These led to weathering and destructive processes and severe degradation of the construction materials. With increased erosion over the years the stability of the columns protruding from the surface of the wall was undermined to the extent that it endangered passers-by on the beach.
In 2008, the Ashkelon Economic Company commissioned the Israel Antiquities Authority Conservation Administration to carry out conservation measures and remove the danger there. The engineer Ofer Cohen planned the details of the treatment and the late David Katz, a marine engineer, designed the treatment of the section of beach in front of the wall. The actual implementation was conducted by conservators Tsagai Asmain and Eyal Kaho, with professional guidance provided by the author. The staff of the national park assisted in storing the equipment and supplying electricity and water. The conservation project at the time had two main objectives: to provide constructive support to the protruding columns and create a protective layer in front of the wall. The project lasted about six months and included four main components:
1. “Lining” a section of the beach with boulders (wrapped in geotechnical cloth) in order to prevent the erosion of sand from the wall foundations.
2. Exposing the original foundation in the front of the wall, in order to rebuild the wall according to its ancient line and on an existing foundation.
3. The construction of a debesh wall in front and support of the protruding columns: build a debesh wall c. 0.5 m thick a distance of 1 m from the existing wall, while ensuring the appearance of stone courses resembles the original construction; casting debesh between the new wall and the existing wall.
4. Stabilizing the upper part of the original wall: remove the vegetation from the top of the wall, point up the joints with mortar, stabilize the upper part of the wall and seal the top of the wall.
The intervention stressed the use of materials that are identical to the original ones, kurkar and a lime-based mortar mixture like the original mortars, as well as ensuring the construction was done in layers that reflect the existing original building technology.
The protective layer (the debesh wall) that was built in front of the “Wall of Columns” was damaged in the winter storms of 2010. The power of the waves that directly struck the protective layer caused damage resulting in a breakdown in the northern part of the construction and in water penetrating beneath the wall, which breached a hole in the center of the wall that undermined its stability. In addition, the following damage was identified: mortar was crumbling as a result of the action of the salts, the protective wall was partially detached from the original wall and the mortar that was placed between the remains of the original wall and the new protective layer had been washed away.
In 2013 a conservation team from the Conservation Administration headed by Fu’ad Abu Ta‘a took steps aimed at rehabilitating and stabilizing the debesh wall. The rehabilitation work included the following measures:
1. Rebuilding the wall sections that fell apart.
2. Renovating the mortar that had crumbled due to the weather damage and action of the salts.
3. Pointing up the joints with mortar and injecting mortar into the spaces between the protective wall and the original wall.
The rescue action in 2013 was made possible thanks to the Milestones Program of the Heritage Department in the Prime Minister’s Office.
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August 2015
To view the figures, click on the figure caption
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