IM 2018 July 18 | Page 28

MINING ENGINES engines, however. A fleet of 140 240 ton class Komatsu 830 haul trucks operates at Vale’s Carajas iron ore mine in Brazil. In 2016, two of Vale’s Komatsu 830E truck engines approached their maximum number of operating hours before overhaul. The risk of a breakdown was growing every day. Both Komatsu 830E trucks were powered by an MTU competitor’s engine. Always on and with lower maintenance costs,” says Etrusco. “The biggest advantage is lower fuel consumption. With the new engines, the trucks are close to 10% more fuel-efficient. For an operation of such a large scale, those savings are going to really add up.” “The second repowered truck started operating on December 15, and after 135 days of continuous activity, our engine completed exactly 3,000 hours. These numbers gave us a daily average of 22.2 hours a day, which is an extraordinary fleet availability,” says Etrusco. Two more repowers with MTU engines were then scheduled in 2017. the lookout for a better way, As well as being cleaner, the Tier 4 MTU engine generation for mine vehicles uses far less fuel than older engines total emissions generated during the mining process. For example, if vehicles repowered with clean engines output fewer emissions, the mine may be allowed to operate more vehicles. That means clean engines not only improve profitability, they also boost productivity. Repowering existing haul trucks has yet another benefit. It means the new engines can be operated to match their ideal performance curve. For example, a truck used to haul copper- or gold-bearing ores from a mine has a significantly higher load factor than a coal-mining truck. Operating all haul trucks with the same engine model at the same rated power (as often happens) is uneconomical. Repowering provides the chance to match the engine perfectly to its application, achieving even further fuel savings. “Several mine operators seized the chance to test the new MTU engines before the official sales kick-off. Four years ago, for example, MTU replaced the 16V Series 4000 Tier 1 engine in a Komatsu 930 haul truck with a modern Tier 4 engine in the same series. The mine operator ran the tests to find out more about the latest Tier 4 engine technology before the new emissions regulations kicked in. The aim was to accurately gauge how the new units would influence mine operation and maintenance processes. The MTU engineers involved used the opportunity to get a more accurate picture of the performance capabilities of their Tier 4 technology in a tough mining environment.” Instead of using a 16- cylinder engine, they fitted a 12-cylinder Series 4000 unit – and the move proved successful. The Type 12V 4000 Tier 4 engine delivere