Boost your productivity with Trolley Assist
Efficiency on top
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This is trolley assist. Normally, speed on grade is limited by diesel engine horsepower. If a truck could get more power by connecting to an overhead electric line while going uphill, it could climb faster. The engine would be idling and fuel consumption would be reduced by 95%. Noise and emissions would diminish, and productivity and engine lifetime would rise significantly.
Without a doubt, trolley operation takes some getting used to. But in mines with longer uphill hauls the economics can be particularly attractive – and trolley operation can become an invaluable supplement to the overall mine plan, achieving payback within a few years.
Higher speeds, shorter cycle times, leaner fleets
The Siemens AC drive can produce up to 5,200 HP when operated with an overhead trolley line. This can double the speed on grade and significantly reduce truck cycle times. For example, if the cycle time is reduced by 20%, 32 trucks on trolley produce the same as 40 trucks on diesel.
"Taking the line" and other technicalities
In contrast to trucks with DC drive, trucks with Siemens AC drive can connect to trolley at any speed, independent of the trolley line voltage. In addition, trucks can operate at existing line voltages of 1400V–1600V DC or on new, more efficient, high-voltage lines with 2600V. Trucks can even operate in mines with mixed systems, automatically detecting the line voltage. When the truck "takes the line," it automatically switches to either high-voltage Direct Trolley operation or low-voltage Diesel Boost Trolley operation.
Reduced operating and maintenance costs
Loaded travel on uphill grades typically accounts for 70–80% of a truck’s total fuel consumption. Depending on the relative cost of electric energy, this can translate into very attractive savings in operating costs. In addition, with engine operating and maintenance costs tied directly to fuel consumption, trolley assist further lowers your cost per ton because the time between engine overhauls may double or more.
One-Stop Trolley Shopping – from Siemens
Siemens can perform a site-specific evaluation – including haul profile data, cycle times, production requirements and energy prices – and create a cost-benefit analysis for possible trolley scenarios in your mine. Experience has shown that the higher productivity and the reductions in energy and maintenance costs lead to an attractive IRR and payback time of 1 to 3 years. In addition, we can supply all trolley equipment and services – on the truck as well as in the mine. That includes pantographs, overhead lines, substations, and line position sensors – together with financing, maintenance, and service support.
Trolley Assist: We do the math for you.
How quickly is the investment paid back? Our experience has shown that the higher productivity and the reductions in energy and maintenance costs lead to payback time of 1 to 3 years.
We consider site-specific variables to determine the economic feasibility of trolley assist. We will conduct your site-specific evaluation – including haul profile data, cycle times, production requirements and energy prices – and create a customized cost-benefit analysis for possible trolley scenarios in your mine.