Lime binds Sunnambukulam on the banks of the Pulicat lake to a glorious past. Brave young men of the fishing hamlet 60 km north of Chennai take long, deep and dangerous dives and scoop out seashells from the lakebed to extract lime, a mineral used for construction at least from the Sangam age. The lime from here now breathes new life into heritage structures in Chennai and elsewhere in Tamil Nadu.
Reddiyars, as the mining community around the lake is known locally, were originally from Andhra Pradesh, just a few kilometres away, but, with the arrival of the British, moved closer to the sea for economic reasons. Several centuries ago, the community ventured into deep-water mining and set up more than 30 crusher units at Sunnambukulam and nearby villages such as Rasapapalayam, Chinna Kokkupalayam, Periya Kokkupalayam, Periya Kuppam and Kattur, where nearly 600 families live.
Divided into groups of five, the miners, mostly relatives and in their late 20s, enter the water. Each has his task cut out: one helms the sails of the boat and takes care of logistics; the “lucky” miner (one who has hit upon seashell repositories many times) divines within 5 km of the lake bund using a thin 15-foot iron rod. He plunges the rod into the 10-foot-deep water and if it hits any object, two miners dive to the lakebed to dig for seashells. Once the spot is identified and the mine dug, two teams of two miners each take over. One team collects seashells in a bamboo basket that can carry up to 20 kg. The other brings the basket to the surface. The seashells are cleaned to remove sand and clay before it is loaded on the boat, which can carry up to 20 tonnes. The work starts before sunrise and ends after sunset. On the shore, the seashells are dried for a few days before they are burnt with coal in an open furnace for 12 hours. Korrukkupet in north Chennai is the only other place where such crusher units function today. Sangam literature speaks of how lime mortar combined with jaggery and harde (Kaduka in Tamil and Malayalam) was used for construction purposes. Silappatikaram and Pattinappalai literature make frequent references to it, K. Sridharan, senior archaeologist and former Deputy Director of the Tamil Nadu State Archaeology Department, says. Thirumalai Nayakar Mahal and the Big Temple in Thanjavur are cited as stellar works made using lime mortar.