Old tech with a new twist.

Less than a kilometer south of Kharaba Tawus, at a lower elevation near the modern road, there are a series of mudbrick buildings standing in contrast to the modern cinder block constructions that make up the majority of structures on the western Erbil plain. We identified them a brick kilns where the ancient technology of handmade fired brickmaking was still practiced, but with a few modern twists. Seeing activity down at the kilns, one morning Mary, Rafeeq, and I took an hour away from the excavations to investigate and learn about this craft.

We met Qasim and his assistant at their brick kiln, There were in the final process of stacking the kiln with 40,000 sun-dried but not-yet-fired bricks, all made by hand in moulds and ready to be fired. The doorway underneath Qasim (dress in black) leads into the kiln interior but it is blocked with bricks. In fact, the entire structure they are standing on is filled with bricks. They were just putting on the last few rows. Over the following days they would cover all the top bricks with a thick layer of mud plaster, sealing the kiln. Qasim’s assistant has staged bricks next to him that he is handing up six or eight at time to Qasim. On the left are a pile of finished, baked bricks ready for use.

The bricks are made with clay dug up in a pit about a kilometer or so away from the kiln, mixed with straw brought in from the fields, and water. You can see that the recipe is pretty variable. The straw helps keep the bricks from cracking during firing and cooling. When they are fired, the straw has been burnt away, but leaves a negative impression on the clay. We see this tell-tale impression on bricks (both fired and sun-dried) dating all the way back to the Neolithic. Old tech!

Here are bricks that have been formed in rough wooden moulds and stacked to let them air and sun dry. Once thoroughly dried, they can be put in the kiln. Putting bricks that still have water in their cores into the kiln causes them to explode upon exposure to high heat. These bricks are laid out on a specially prepared surface made of animal dung and straw that can be pressed into a flat surface to which the bricks don’t stick when still wet. The small pile of material in the left background of this photo is actually a pile of straw ready for use in brick making.

So the bricks are made and dried. They are stacked in a vast organized heap filling the inside of the kiln, which is in essence a square room with brick walls covered in mudplaster. The kiln is sealed at the top. How does the firing work?

We went to a second nearby kiln that was empty to document the interior of the firing chamber. Below the kiln is a large open space, another entire room, that has a grill-like ceiling leading into the kiln. Here you can see the openings leading from this below-ground firing chamber into the kiln. The bricks were stacked over and on top of the grill openings with enough space between them to allow the passage of hot air between the bricks during firing. This is what Qasim’s kiln looks like when it’s empty.

Around the side of the kiln is a passage that leads down into the firing chamber, which has two parts. One is the room below the kiln with the grill-like ceiling. This subterranean room conducts the heat up into the kiln. The second part is where Rafeeq is heading in this photo. It is the room where the fire is set. The walls are charred from intense heat. The fire in this chamber will burn for three days, according to Qasim, driving all the remaining water out of the bricks and slightly fusing the clay-mud mixture into a durable, permanent brick.

This is where the technological twist comes in. In ancient times, the kiln would have been fired with wood, brush, or animal dung which had been prepared for use as fuel. The modern countryside is largely devoid of wood and while animal dung is still used for some domestic tasks, it has largely been replaced for use in brick making by an energy source plentiful in the region — petrol.

This picture might seem oddly out of place, but it is actually quite important. The modern brick kilns use old clothing to soak up the petrol for firing the kilns. For three days, that small chamber will, in essence, be fed gasoline-soaked rags to keep the fire burning hot and even enough to fire the stacked bricks. This process involves no advanced machinery to run; the skill of the brickmaker ensures that the bricks are fired long enough for them to be fully strengthened but not too long that they are ruined in the process. These kilns, like those in ancient times, could be overfired, ruining the bricks and the kiln itself, and creating a hard, spongy mass we call slag. Ruined bricks and pottery are called wasters and when we find wasters at an archaeological site, we know that the ancient inhabitants had used such kilns to make bricks, pottery, metals, or other materials requiring the controlled use of high heat.

We were told that the firing of Qasim’s brick kiln was going to happen in the next few days, so stay tuned to see how it all works out.