The methodology of calculating the productivity of an excavator emerged together with the first excavator machines. Essentially, excavator productivity is typically measured by the volume of loose or rock soils the machine can displace in a hour of continuous operation. In other words, the productivity of an excavator is determined by the volume of the soil it can dig up in a minute. The calculations for excavator productivity are straightforward and can be simply completed on a standard calculator.

Understand the formula for calculating excavator productivity. The formula is as follows:

Q = (60_q_z_n_kf) / kl,

where Q is the productivity of the excavator, q is the capacity of each rotor bucket in cubic feet, z is the number of buckets on the wheel and n is the speed of rotation of the rotor, measured in revolutions per minute. kf stands for the filling factor of a bucket while kl represents the soil-loosening factor.

Gather the data. Typically, you can get the date for the capacity of each rotor bucket in cubic feet, the number of buckets on the wheel and the speed of rotation of the rotor from the operator's manual of your excavator, supplied by its manufacturer. The filling factor of the bucket and the soil-loosening factor can be determined experimentally. The filling factor, ranging from 0 to 1, determines the degree of the excavator bucket's utilization. For example, whether it is half-full or three-quarters-full determines the excavator bucketâ€™s utilization. To determine the soil loosening factor, which is always greater than 1, calculate by how much the density of the soil in the ground is greater than the density of the excavated soil. For example, if the soil loosens by 10 percent, the soil-loosening factor is 1.1.

Use the formula from Step 1 to calculate excavator productivity. For instance, if the capacity of each rotor bucket is 10 cubic feet, the wheel has only one bucket, the rotor rotates at a speed of 5 rotations per minute, and the filling factor and the soil loosening factor are one, the productivity of the excavator stands at:

Q = (60_q_z_n_kf) / kl = (60_10_1_5_1) / 1 = 3,000 cubic feet per hour.

kf stands for the filling factor of a bucket while kl represents the soil-loosening factor.