The true all electric mine is not just about the LHDs and haul trucks, it has to include all the supporting underground equipment, from service vehicles to shotcreters, graders, scalers, cassette vehicles, scissor lifts and personnel carriers. The move to electrify these machines is being led by a group of innovative companies worldwide, one of which is North Bay, Ontario based Miller Technology, which has developed the STEV (subterranean electric vehicle), an innovative fully electric light utility automobile and the next generation in mining vehicles, specifically designed for the harsh environment and rigorous duty cycle required to operate in underground environments.
Product Research and Business Development Manager, Hugh McDermid told IM that this machine is just one part of the company’s electric program and that Miller also has a battery powered grader and conversion kit for Toyota Landcruisers used underground. And while Miller is Canada-based, the company sees the market as worldwide, with more stringent air quality regimes in the pipeline in Europe and Australia in particular.
The STEV features an industry first hybrid charging system which allows for both off-board DC fast charging and on-board AC opportunity charging. in addition, the vehicle also features a dynamic braking system that prevents unwanted accelerations and maximises range by converting excess kinetic energy in to electrical energy. STEV reduces an organisation’s carbon footprint, maximises energy efficiency and minimises operating costs.
McDermid states: “STEV provides consistent, intuitive and transparent operational feedback and a tuned suspension to create a more pleasurable driving experience. miners can develop respiratory-related disease or death due to exposure to diesel emissions in underground mines. To mitigate such danger mechanical ventilation must be provided, constituting a large portion of a mine’s operating budget. in response STEV offers health, environmental, and reliability benefits and makes positive financial sense.”
Miller Technology developed STEV over a 2.5-year period to meet the evolving needs of global mining operations while recognising the need to match or surpass the performance of traditional diesel equipment. High strength alloy steel construction maximises safety in roll over and falling objects situations and minimises overall weight. the vehicle is also equipped with a powerful mid-ship mounted motor with dual output flanges resulting in impressive full time 4-wheel drive.
McDermid adds: “Miller’s system vastly reduces the number of moving parts, maintenance costs, and downtime. battery modules used in the energy storage system have passed rigorous highway and marine testing standards to ensure the utmost safety. our modular arrangement makes it possible to adapt the platform to various usage cases. all major systems are equipped with a liquid loop that is primarily utilised for cooling but can be adapted to allow for heating in extremely low temperature environments.”
The STEV hybrid charging system allows both off-board CCS type 2 DC fast charging and optional on-board charging for opportunities anywhere in a mine. range is enhanced and maintenance costs reduced through an innovative dynamic braking system preventing unwanted acceleration and by converting excess kinetic energy in to electrical energy. STEV is easily configured in two or four door variants for transportation of personnel or various work truck builds such as a flat deck or scissor lift.
“STEV is quiet so a forward projected white noise pulse is used while driving to warn pedestrians. the cockpit is designed with touch screen interface capability with display units providing operating feedback in several ways. Miller is respected industry-wide as an innovative and resourceful designer and fabricator of cutting edge technologies and equipment. Solutions developed by Miller have positive and direct, real world, impacts for operators in the field. Through the development of equipment such as STEV, Miller is harnessing efficiencies to enhance the bottom line for operators, deliver environmentally friendly options for mining and tunnelling industries and maximise equipment value/investment for the end user.”