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UG LOAD AND HAUL_proof 25/05/2016 09:25 Page 9 UG LOAD AND HAUL with highest power per weight ratio, tractive effort and breakout force and superb ergonomics and visibility we can reach substantial productivity gains. Further variants of the machine are in development including the hard rock version with a high reach z-link for truck loading.” GHH also sees big potential in the electric version of the 21 t machine, the LF-21HE, for both potash room and pillar production as well as block caving and stoping. GHH has already has about sixty Tier 4 interim and Final (about 50/50) engines in operation. The design challenge is especially the large aftertreatment system (SCR including urea tanks). “Although we have fitted these systems to both SLP and standard LHDs we have always managed to keep the original profile. The Tier 4 Final engines that we have in operation are extremely reliable and we are getting very good results. On all of our new developments we design directly for Tier 4 and downgrade the engines if required (such as for less regulated markets). Regarding maintenance there is some extra training required but no complications have been found so far. For our clients, the new engine generation makes a substantial difference for ventilation and thus cost. Therefore, increased complexity is not a real issue.” On technology, Riedel concludes: “Besides factors such as safety, ergonomics and cost per tonne our main focus is differentiation through high quality customised solutions. However, in a direct benchmark we seek differentiation through robustness (plain-tech) and additionally performance by means of our hydrostatic drivetrains. Although new electric drives are coming up in our industry the benefit of hydrostatics are proven in maintainability even in remote areas. The hydrostatic drive drastically reduces the operating cost by reducing fuel consumption, tyre wear, brake wear, etc.” Besides its home market in Germany the largest GHH fleets are running in South Africa and Zimbabwe. Besides Africa, GHH Fahrzeuge says it is developing markets in North and South America as well as Asia. The most important GHH range in terms of sales is between 7 and 14 t LHD and it will remain that way. However, besides Australia (where large LHDs are common) demand for larger machines is growing in other markets as well in order to increase productivity. GE Mining The GE underground hard rock program accelerated when the GE-Fairchild LHD-5-LB model was tested at the IAMGOLD Westwood gold mine. The model was a part of a GE FastWorks program, designed to quickly secure customer feedback on performance and tbased on the overall need for a battery propelled LHD in 34 International Mining | JUNE 2016 the market. As such, it was essentially an upgraded coal scoop without all the necessary features required for a hard rock LHD. Sid Gaitonde, Senior Product Manager, underground propulsion at GE Mining states: “The trial was so successful with positive reviews from IAMGOLD and other customers that GE developed a true battery propelled LHD for UG hard rock – the 7T BLHD.” The features of the 7T LHD that are different from the 5T model include the increased capacity to 7T (3.1 m3 bucket); and a new state-of-the-art GE Invertex Drive System allowing for ergonomic and intuitive operator controls, optimised battery endurance for longer shifts and automation readiness. A new operator display provides a full visual indication of critical vehicle system status, as well as more intuitive and faster trouble shooting. It is also multi-language compatible. It has a Quick Battery Change System for maximum availability, and improved overall vehicle speed increasing productivity with better control for downhill grades; and blended braking for better regenerative charging and reduced brake wear. It also has a higher bucket lift height to clear most truck beds up to 25 t. GE conducted an in-depth study on the available technologies including hybrid and fuel cells that are or will be available in the near future and matched them against mining customer needs. “Based on that research, GE has selected on our 7T LHD, battery-electric with exchange, as the system that best meets our customers' needs and is flexible enough to adapt to their operation as their mining plans change.” The company cites several advantages to using battery over diesel machines including safety, with diesel particulates underground a significant and serious health concern. “Our goal is to eliminate underground diesel particulate. If we can eliminate diesel particulate, it takes a known carcinogen out of the air, making it safer for the workers. Underground diesel equipment has a high noise level, one of the major reasons for early onset of deafness among underground The features of the GE 7T LHD that are different from the previous 5T model include the increased capacity to 7T (3.1 m3 bucket); and a new state-of-the-art GE Invertex Drive System all owing for ergonomic and intuitive operator controls, optimised battery endurance for longer shifts and automation readiness miners. Battery LHDs resolve a lot of these issues as they generate no diesel particulates and generate far less noise than diesel counterparts.” GE also argues that underground ventilation systems account for the single largest underground mine expense (up to 40% of total running costs) according to the Centre for Excellence in Mining Innovation. “Most global underground mines have a typical ventilation rate of 100-125 cubic feet per minute for every installed horsepower, as largely mandated by legislature. Reducing the ventilation requirement provides mine operators with options of reducing ventilation power costs or using that same ventilation to mine more locations simultaneously. That increases their operational efficiency and maximises production objectives.” The electric propulsion system has fewer moving parts than a diesel engine. It also does not burn fuel or require constant maintenance (such as filter and engine oil changes). “The battery LHD increases the time between two service intervals and reduces the duration of each interval, increasing valuable working time and machine availability.” Electric motors are particularly good in certain applications versus internal combustion engines due to their torque curve as demonstrated on locomotives and surface haul trucks. This allows the battery LHD to load in shorter periods and get a better speed on grade vs diesel LHDs. This reduces overall cycle time and improves productivity. Finally, reduced ventilation and cooling requirements saves mines from adding or upgrading their ventilation and cooling infrastructure, thanks to the elimination of diesel particulates. “It also allows the mine to develop