India is experiencing a building boom to cope with its rapid urbanisation. Thousands of concrete-frame high-rise blocks with brick infill can be seen rising up around Delhi and Mumbai. Almost every one of the millions of bricks involved has been transported by donkey or mule during its production at a brick kiln.
So how does it work?
Around the kiln, brick-makers mix local clay with black ash, salt, rice bran and water. The mix is then left to dry to the right consistency. The mix is pressed into moulds with the kiln’s name embossed in it, and turned out to dry on the ground. As the sun’s heat hardens them, the bricks are built into progressively larger stacks. Each stack has a fixed number of bricks in it, allowing for easier counting by the kiln manager.
The brick makers also manage the building and firing of the kilns. All being well, a cycle of construction, firing with coal, and dismantling runs continuously throughout the six-month brick-making season from November to May.
The itinerant workers live in their social groups in temporary shelters around the kilns. The monsoon rains mark the end of the season, when most workers return to their villages – some of which might be hundreds of miles away.
Workers are paid according to results, and each workforce or social group gets on with its job with little or no supervision.
Once the bricks have hardened enough, a second workforce of donkey owners and donkeys transports the raw, unfired bricks to the kiln.
The drivers and their donkeys work mostly in the cool of the night, starting between 2am and 4am. The workers live alongside their animals in basic shelters made of unmortared bricks.
The brick makers and the donkey owners work together to build a quadrant of bricks part way round the central chimney of the kiln. About a hundred thousand bricks must be stacked in a precise pattern for each firing. Gaps are left between the bricks to allow for coal and the circulation of hot air and gasses.
During the firing the kiln is constantly monitored and topped up with coal through little inspection holes with metal lids on them. The brick makers wear wooden-soled shoes to protect their feet from the hot earth. Occasionally there are collapses which can pitch workers into the furnace below.
The big central chimney, the outer retaining walls, and a network of arched gas flues are the permanent part of the kiln. The bricks in various stages of production are like slices of pie around the chimney. While one section is firing, the next section is under construction with unfired bricks, and a third section of fired bricks is being dismantled. A fourth is left open to allow in the donkeys and workers that ferry the bricks from one area to the next. The process continues like a giant merry-go-round, 24 hours a day.
Finally, once the fired bricks have cooled, a third workforce dismantles the stack in a haze of dust and ash. They cart the bricks away and stack them up in huge walls around the kiln waiting for buyers to come and truck them away.