Stacker

Its function is to pile bulk material such as limestone, ores, coal and cereals onto a stockpile.

A stacker can usually move in at least two directions: horizontally along the rail and vertically by luffing (raising and lowering) its boom.

Luffing of the boom minimises dust by reducing the distance that material such as coal needs to fall to the top of the stockpile.

Stacking in a single cone tends to cause size segregation, with coarser material moving out towards the base.

Modern machines are typically semi-automatic or fully automated, with parameters remotely set.