Open Hearth While other rail producers used the Bessemer Process to create the steel in their rails, the Tennessee Coal, Iron and Railroad Company would become one of the first rail mills in the country to use the Open Hearth process for its steel rail production. Besides this unique steel making process for that time, the year 1907 would find TCI enlarging their rail mill to a capacity of 600,000 tons of rail a year which would put the South’s first and only rail mill as the third largest rail producer in the country at that time.
