After the crane system lifts the waste from the waste bunker and drops it to the feed chute, in the lower part of the chute, a hydraulic piston pushes the waste onto the combustion grate. It is important that waste in the chute is always at an optimal level and uniformly distributed. This prevents air from leaking into the furnace and ensures a constant supply of fuel for combustion. For that reason the minimum level in the feed chute has to be monitored and the resulting data displayed to the crane operator.