Stefanutti Stock’ most recent victory in its engineering endeavours to improve environmental performance and operational efficiencies, has seen it extend the filtration service life on its fleet of Komatsu HD 465 rigid dump trucks, from 500 hours to 1000 hours. This followed the completion of an onboard engine filtration study, that complemented the optimised oil drain intervals achieved in 2017.

In 2017 Stefanutti Stocks became the first company in South Africa to carry out an optimum oil drain interval (ODI) field study, with the aim of increasing the oil drain intervals its HD 465 rigid dump truck fleet. The ODI study followed a performance monitoring protocol, provided by ExxonMobil and Bureau Veritas . Data was gathered via regular used-oil analysis  the performance of the vehicles was carefully monitored; and the oil drainage interval was successfully increased from 250 to 1 000 operating hours. This not only resulted in a saving (direct and indirect) of R4,7-million, it also paved the way for Stefanutti Stocks to be able to conduct its filtration study, with enough data points to minimise all potential risks.

The combined optimum oil drain interval study and contamination control study was conducted on the same Stefanutti Stocks Komatsu fleet, and was supported by AGL Centlube, ExxonMobil, Bureau Veritas and Cummins Filtration Services. The aim was to achieve increased engine filtration component effectiveness and to extend replacement intervals from 500hrs to 1000hrs, thereby syncing with the oil drain intervals.

The Stefanutti Stocks engineering team, together with Cummins Filtration Services, fitted a filtration system, with data logger and pressure transducers across the air filter, oil filter and fuel filters. The filter media assessment provided conclusive results indicating that the fuel cleanliness, engine air filtration and engine oil filtration were fit-for-purpose for up to 1 183 hours.

The oil analysis conducted throughout the filtration study indicated that the lubricant used (Mobil Delvac MX 15W40) offered superior viscosity and Total Base Number (TBN) retention, as well as soot handling capability, making it fit-for-use for up to 1 183 hours. This translated into a safety market of approximately 20% beyond the targeted 1 000-hour intervals.

A further innovation included the mounting of an external air restriction indicator that would switch from green, to orange, to red, to indicate when the air filtration service is due.

The filter package extension study yielded following outcomes:

  • Safety: Exposure reduction of 950 hours;
  • Environmental care: Environmental improvement of 23,199 litres, an outcome from the oil extension; and
  • Revenue improvement of R 1,597,404 as a result of a reduction in filtration cost.

Jerome Christian, the engineering manager for Stefanutti Stocks Construction and Mining, as well as the project champion for this field study concluded that while oil and filters are not high cost items, the productivity lost while vehicles are serviced, is substantial. He stated that the above outcomes do not reflect these indirect savings. Furthermore, as the combined optimum oil drain interval study and contamination control study took place in real life, operational conditions (and not within a controlled laboratory environment) the results and outcomes are perhaps even more relevant to the business.