Steel Industry of ancient Lanka
Earliest evidence of steel making comes from Samanalawewa area in Sri Lanka where thousands of sites were found. (Ref. Juleff, 1996). These early furnaces were powered by Monsoon winds and has been dated to 300 B.C. using radiocarbon dating techniques.
In one of the most recent archaeological discoveries in Lanka, Steel Smelting Furnaces along with samples of steel, belonging to 200 BC, were discovered from a village in Hingurakgoda. They supported the previous discoveries made in Anuradapura, Sigiriya, Ala Kola Weva, Kuratiyaya, and Nikavatana.
This proved the Syrian records that once Sri Lankans had the world's best steel technology. These ancient Lankan furnaces might have produced the legendary Damascus swords. It was these steel that was exported to the middle east. There are records in Syria that the best steel they reeceived was from "Sivhala" (Lanka).
These furnaces had been built on locations where the wind crossed. Using this natural wind blowing and the manual blowing of wind, the soil with iron was heated up on wood pieces unti lthe temperature reached 1100-1200 centigrade. After several hours the steel was formed at the top while the rubbish ended up in the bottom. Then the steel pieces were washed in water. Sinhalese made one ton of pure best quality steel out of every 2 tons of soil. That was a remarkable feat.
One of these furnaces was in such an intact state, the archaeologists were able to actually use it. They used the natural monsoon winds to smelt the iron ore, freely found in the Samanalawewa area. They produced steel ingots in the same way it was produced for over 2,200 years by the lankan engineers of those times.
G. Juleff, "An ancient wind powered iron smeting technology in Sri Lanka", Nature 379 (3), 60-63 (January, 1996)
Nature 379, 60 - 63 (04 January 1996); doi:10.1038/379060a0
An ancient wind-powered iron smelting technology in Sri Lanka
Samanalawewa Archaeological Project, Archaeological Department of Sri Lanka, Sir Marcus Fernando Mawatha, Colombo 7, Sri Lanka and University College London, Institute of Archaeology, 31−34 Gordon Square, London WC1H 0PY, UK
BEFORE the development of the blast furnace, iron smelting was achieved by ore reduction at temperatures below the melting point of the metal, forming an agglomerated 'bloom' of low-carbon iron and slag. The forced-draught (bellows-operated) shaft furnace known from archaeological studies is usually regarded as the pinnacle of this early smelting technology1−3. Examples of natural-draught furnaces, in which gas buoyancy in a shaft of sufficient height induces a draught adequate to drive the smelting process4, are also known, but are generally regarded as disappointingly inefficient by comparison5. Here I report the discovery and excavation at Samanalawewa, Sri Lanka, of a previously unknown furnace type. The furnaces are all situated on the western margins of hills and ridges, where they are exposed to the strong monsoon winds. Field trials using replica furnaces confirm that this furnace type uses a wind-based air-supply principle that is distinct from either forced or natural draught, and show also that it is capable of producing high-carbon steel. This technology sustained a major industry in this area during the first millennium AD, and may have contributed to South Asia's early pre-eminence in steel production.
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