Haya preheated-air steelmaking
Acero de alto horno con aire precalentado (haya)
- Date
- c. 500 BCE-500 CE · confidence low
- Place
- Kemondo Bay, Kagera, Tanzania
- Credited to
- Haya people (ancestors), Lake Victoria region
- Field
- Matter & energy
⚠️ Disputed: the sources disagree.
What it is
Forced-draught furnaces with tuyeres inserted into the charge, preheating the air and reaching very high temperatures to produce carbon steel. Haya smiths reconstructed the process for archaeologists in 1976.
Schmidt and Avery (Science, 1978) argued that the preheating surpassed pre-industrial European furnaces; Rehder, Killick and others dispute the temperatures and the real importance of the preheating.
What it led to
- steel tools in the Great Lakes region
- a demonstration of sophisticated African ironworking
- experimental archaeology using traditional knowledge