Such terms as "theoretical output", "effective output", "daily output" and "average output" are generally quoted without appropriate and realistic consideration of the particular mining conditions and the time factor. The output for the equipment is often estimated too optimistically. This applies especially to new equipment.
Information published on the subject matter is often vague and inaccurate.
Theoretical output calculations for bucket wheel excavators (BWEs), based on well established formulae, are of course necessary and are of value in determining the average output of the equipment. Such calculations have however, no resemblance to actual "real life" operating factors.
In the following an analysis of the output, operating factors and availability of 40 bucket wheel excavators is presented without priority to size and location of the machines.