Chimneys provide ventilation for hot flue gases and smokes. They are vertical structures such as, for example, GRES-2 Power Station Chimney, Ekibastuz (420m). Although many kind of industrial facilities have tall chimneys most of the chimneys with heights of 200 metres and more are part of thermal thermal power stations (especially coal-fired power stations). Only few smelters, steel mills, chemical factories and oil refineries use such tall chimneys.
|H < 45m||1 level of low intensity obstruction lights shall be used|
|45m < H < 105m||2 levels of obstruction lights shall be used: top level with medium intesity, intermediate with low intensity|
|105m < H < 210m||4 levels shall be used: top with medium intesity, 1stintermediate with low intensity, 2nd intermediate with medium intensity, lower level with low intensity|