What is Trolley Assist?
Diesel Electric haul trucks utilize electric motors to provide tractive effort, or rimpull. The speed of the trucks, on grade, is limited by the quantity of electricity which the truck's diesel engine can generate. Trucks with trolley assist collect electricity from overhead conductors, so the speed of the truck on grade is no longer limited by the size of its engine - it is limited only by the capabilities of its motors and electrical drive system.
What are the Benefits of Trolley Assist?
Typical benefits include : Increased Productivity (due to increased speed on grade), Energy Cost Savings (by substituting cheaper electricity for expensive diesel), Extended Engine Overhaul Intervals (due to the reduced load factor), and sometimes there is even a significant Increase in Electric Wheelmotor Armature service life (due to reduced heating of the motors because less time is spent on grade).
Where has Trolley Been Successfully Applied?
Trolley assist has been operating successfully at numerous mines in Southern Africa for more nearly 20 years. In 1994 a trolley system was commissioned at the Barrick Goldstrike mine in Northeastern Nevada. Dave Hutnyak was Barrick's Project Manager for the design and installation of that system.
Are There any New Developments that Favor Trolley Assist?
Yes! The new Siemens AC drive is a natural candidate for trolley assist. This drive system has plenty of excess capacity, which makes it a "natural" for operating on trolley. The Euclid R280 and the Liebherr TI282 both are equipped with the Siemens AC drive system. Early in year 2000 the Euclid R280 AC truck was commissioned on a trolley at an ISCOR mine in South Africa - and now holds the distinction of being the "fastest trolley truck in the world".
How to Determine if Trolley is Suitable for a Particular Mine?
A detailed study needs to be performed to determine if the anticipated benefits of trolley will outweigh the probable costs. It is a common pitfall to underestimate the costs associated with trolley, and only concentrate on the benefits. Dave Hutnyak is experienced in various aspects of evaluating, designing, installing, commissioning and operating a trolley system. This experience allows him to evaluate the economics of trolley in a realistic, and very time-efficient manner. Since its establishment in 1998, Hutnyak Consulting has conducted numerous trolley studies for mining companies around the world. To learn more about Dave Hutnyak's experience with trolley assist click here
Want to Learn More about Trolley Assist?
Just click on these links to learn of trolley history, see photos, read technical papers and review presentations.