Replica of a
Late Bronze Age Kiln
As part of the 2009 experimental projects to provide
first hand observation, a replica of a Late Bronze Age kiln was reconstructed
with the help and effort of team members. The project was inspired by
the exposure in 2004 of a variety of pyrotechnic installations in the
eastern part of the mound. Following 5 years of excavations, we can now
confirm that this part of the LBI city functioned as an industrial quarter
with some installations designated for the production of pottery, metal
and other materials. The 2008 magnetometry survey had already defined
a large number of anomalies (interpreted as pyrotechnological installations)
in the eastern side of the mound, suggesting a location for the craft
quarters of the site. This evidence coincides with the afternoon wind
direction in the Amuq valley which always blows from west to east, thus
preventing the poisonous effects of smoke from reaching the city.
The Kiln discovered during the 2004 excavation season.
A 1.5 m x 1.5 meter area was cleaned at the dig house near the 2008 experimental bread oven (tandir). A square space was dug to a 30 cm depth to allow 20 x 40 cm mud bricks to stand on their short sides. The ground level of the foundation trench was then coated with a mud and straw mixture. This layer provided insulation and functioned as mortar bedding for the mud bricks.
Fig 1: The foundation and the firing pit Fig 2: Covering the foundation with straw and mud mixture
Fig 3: Students preapering the mud brick foundation. Fig 4: The mud brick foundation.
The Upper Deck/ Floor
One of the most complicated tasks in building a kiln was the preparation of the upper clay stage that would be on top of the mud brick foundations. To enable the hot airflow from the lower deck to flow up into this platform stage, flues were made in the lower chamber. To seal the lower chamber and in order to create the upper stage, a decision was made to use a technique resembling slab construction. Each day only a portion of the floor was added in the horizontal space. For this type of construction, like in the bread oven, a special type of clay was necessary. East of the Alalakh mound, in the deep cut of a canal constructed to drain Lake Antioch, a strata of light colored soil provided good quality clay for constructing bread ovens. This clay was traditionally used by the villagers for making mud brick and pise structures. Last year, following the same tradition, our bread oven was constructed from the same source. Since this clay has enough strength and cohesion, we decided to use it for constructing the kiln stage. Carrying chunks from the canal in sand bags, the clay was afterward set in water tanks. The clay chunks were levigated with the aid of water and each day, an amount was taken out from the tanks for drying. The half dried clay was mixed with straw and the mixture was laid on top of the brick foundation. This slow process started by moving from the sides of the wall into the interior. It was very important for the clay to stick to the brick support and then move to other spots slowly where no brick support existed. Emulating the excavated 2004 examples, to enable the hot airflow to the upper deck, the upper stage itself was perforated for flue holes. Ten holes were made into the clay surface to provide an equal distribution of air flow without losing the carrying strength of the stage. Based on the coiling technique used, the approximate thickness of the stage surface varied from 2-4 cm at several spots.
Fig 5-6: The preaparation of the clay floor.
The archaeological record has limited information about the superstructure of the furnace. Therefore, a decision was made to raise the walls of the kiln by using a brick vaulting technique, called corbelling. The surrounding walls were elevated by 4 brick courses. Each new course of mud bricks were laid slightly inwards creating a corbelled arch formation. Each day only three courses were added to allow the mud and straw combination of mortar to dry. Any attempt to do more would have collapsed the entire structure since no wooden supports were used. Under the skeptical eyes of the many team members, the corbelled arch vault rose to the top and the central section was left open for the chimney. A door was located on the north side of the structure which could be sealed with mud bricks, and a mud and straw mixture in order to provide full insulation each time before the firing. 200 mud bricks were used for the construction of the walls.
Fig 7-8: Constructing the Walls.
While constructing the vault, we realized why the kiln did not operate during our first attempts. The error was in raising the walls of the installation at the same height as the firing pit. In order to make a more solid construction, we realized that it was at the expense of air circulation. The space created in the firing chamber made the hot air rise towards the ceiling of the firing chamber rather than flow into the underground channels of the lower chamber. This mistake was fixed by taking down the walls of the firing pit and creating a very low ceiling that will push the hot air into the channels in the lower chamber and then into the upper stage.
Fig 9: Firing the Kiln. Fig 10: The plastering of the outer surface.
Firing the Kiln
Several thermocouples were located inside the construction during the first firing attempt. One was attached to the wall face of the firing pit, two were located inside the lower chamber and two more were located on the upper stage. A separate one was attached to the chimney. As mentioned above, when thermocouples were placed, the standing walls of the firing pit were at the same height as the construction, approximately 1.50 m. When the heat approached 600 degrees in the firing pit, the lower and upper stage kept their stable temperature and did not reach higher then 34 degrees.
Fig 11-12: Ben Claasz Coockson working on the firing pit of the Kiln.
We corrected this error by taking the walls of the firing chamber to
the height of the floor level, so that the fire in the pit was forced
to run through the lower deck then to the upper stage floor and finally
to the chimney. Unfortunately, when this was done, the experiment was not
tested with thermocouples due to the absence of the Geologist member of
the team, Pinar Ertepinar Kaymakci. However, a trial to bake a figurine made
by our Registrar Ferhat Can showed that the kiln was functioning properly
except for the fact that it needed more channels to allow smoke to escape
for less oxidization. As the final step to insulate the kiln, the entire
structure was sealed by a mud and straw mixture by plastering the dome.
Special thanks to Hasan Ay, Sarah Hawley, Marjie Bush,
Nurettin Bataray, Aycan Ensan, Ferhat Can , Isa Okten, Sadik Isik, Gokhan
Maskar , Eda Atasever and Ben Claasz Coockson for their great efford on
the construction of the Kiln.
for more information