Trucking Factors is a collective term used in the mining industry to describe the various elements that are related to the use and deployment of trucks. Ultimately, cost-per-tonne hauled is the key factor that affects bottom-line profitability. It is influenced by numerous sub-factors that can be tracked independently.
That said, the primary factor that influences and determines cost-per-tonne hauled is the actual measured volume of material loaded into a truck bin compared to the truck’s nominal payload capacity, as specified by the manufacturer. Capacity utilisation has a direct relationship to operating costs, with underutilised trucks increasing operating costs and cost-per-tonne hauled.
From our experience, some mines use the nominal payload capacity as a measure of all loads, whilst others might use an estimated average underload factor (e.g. 5%) to measure and account for material being shifted by their trucks. Whilst these are both simple systems to apply they don’t provide an accurate measurement of actual material shifted, delivered to the mill or to the stockpile. In both cases accuracy can be substantially compromised, making reporting and planning challenging.
Let’s consider an example of a mine with five 60T trucks each running 10 loads per shift, 3 shifts per day. Total material shifted at nominal capacity is 9,000T per day (3.285mT per annum). If you apply a conservative average underload factor of 5% to the 60T capacity, you get an average payload of 57T per truck. This would result in 3.121mT actually shifted annually, a significant reduction from nominal (-164,000T), adding up to nearly 2,900 extra trips each year.