Understanding today’s cost pressures, OEMs look at different ways to improve fleets
By Steve Fiscor, Editor-in-Chief
The factories that churned out haul trucks at record levels a few years ago have slowed considerably with the downturn in coal and metals markets. Understanding that many mine operators are opting to squeeze more hours from their haul trucks before making replacement purchases, original equipment manufacturers (OEMs) are looking at different ways to help them improve performance and lower their cost per ton.
“We know that our mining customers are under tremendous cost pressure,” said Sudhanshu Singh, who has been the Caterpillar product line manager for large mining trucks since early 2013. “We have been focusing our continuous improvement efforts on existing assets to improve the cost per ton. One major push is to leverage the company’s technology R&D to deliver higher value with autonomous mining, data analytics and retrofit kits.”
Seeing a similar situation, Brian Mace, manager of Hitachi’s mining applications group, agreed and explained that many miners are grasping for tools to make operations more efficient. “
There is only so much that can be done with the actual equipment,” Mace said. “It’s also important to understand how it’s used and whether the mining operation has been designed to get the most out of the equipment.” Earlier this summer, Hitachi announced two new AC-drive trucks and the company is also looking at how to improve the performance of existing fleets.
Several new mines have announced productivity improvements through the use of autonomous operations. Most of these breakthroughs are taking place at iron ore mining operations in Western Australia that were designed specifically to take advantage of these techniques. The pit layout lends itself well to autonomous mining, and the remote locations and the expenses related to manpower necessitated a change. Whether mature mines can make the leap to autonomous mining is debatable, but they can certainly capitalize on the systems they have in place.
CAT OFFERS MORE OPTIONS
When Cat entered the mining truck market in the 1980s, the industry was dominated by electric-drive trucks. They introduced the 150-ton-capacity model 785 mechanical-drive haul truck and reshaped the mining business. “We have the very first 785, which we produced in 1984, in front of the truck plant in Decatur, Illinois,” Singh said. “It’s a testimony to the legacy that Cat has created in the industry with improved cost per ton, serviceability and reliability. Two of every three mining-class trucks sold in the last three years has been a Cat truck, and we take our leadership positon very seriously.”
Rio Tinto was the first to adopt autonomous truck haulage as part of its Mine of the Future Program at its iron ore mining operations in the Pilbara. While Cat was not involved with that program, its autonomous truck system is now being used by two different mining companies, also operating in Western Australia. One company recently reported a 38% productivity improvement with its fleet of Cat 793F autonomous trucks.
“The same company also reported a 13% productivity improvement with its conventional 793 trucks — achieved by working with Caterpillar and the regional Cat dealer to institute best practices,” Singh said. “The strength of the Cat dealer network helps us share best practices to help customers lower their cost per ton.”
Cat continues to invest in technology. In March, the company entered into a technology and predictive analytics agreement with Uptake, which provides dynamic analytics and insight platforms for a wide array of industries. Cat led the industry with its introduction of the Vehicle Information Management System (VIMS), which tracks fuel efficiency, idle times, location and other valuable data, Singh explained. “We have a really good platform that provides mine operators with actionable information to help drive costs down,” Singh said.
This relationship with Uptake will combine Cat’s product engineering and design expertise with Uptake’s software, application and data analytics expertise. As a result, Cat believes it will be able to transform the huge amount of incoming data it sees into useful information that it can feed back to the mines for on-the-spot decisions and planning purposes to further reduce owning and operating costs. Lowering the cost per ton through productivity is arguably more important now than ever before in the U.S. coalfields.
After the Bucyrus acquisition in 2011, Caterpillar identified an opportunity to provide an option for customers who sought 320-ton-capacity trucks.
“We still believe that, in many applications, the 250-ton-capacity Cat 793 truck still delivers the best cost per ton, but some customers have asked for a 320-ton option,” Singh said.
Singh worked with Unit Rig, which was acquired by Bucyrus when it bought the Terex mining business in 2010. When Cat acquired Bucyrus in 2011, he transitioned from Milwaukee to Decatur. In 2012, Cat launched the 320-ton Unit Rig MT5300. “We have been testing it since early 2013,” Singh said. “We have demonstrated a very competitive cost per ton in studies at two different mine sites.”
Cat will commercially launch the 5300 in 2016 as the 794 AC. The new Cat nomenclature identifies the truck as sized between the 793 and the 795. “We are launching it in a controlled way at targeted sites as a 320-ton Cat 794 AC mining truck,” Singh said.
The new truck is Caterpillar designed and fully integrated in the company’s manufacturing and product support system. The truck is manufactured in Decatur, where all Cat large mining trucks are built.
“It has passed through the same quality and testing procedures as the other Cat trucks in Decatur,” Singh said.
In a lot of ways the new truck’s design is similar to that of the 345-ton Cat 795F. “This gives the customer more confidence in the power train and engine performance,” Singh said. “The 795 electric-drive power train now has more than 2.5 million hours. The individual highest hours for the 795 is more than 35,000 hours. We are pleased with the feedback we are getting from miners. Some 795’s have achieved more than 8,000 hours operating time in a single calendar year. The 794 leverages all of the positive benefits of the 795 has brought into the Cat network.”
Cat has made a significant investment to give customers more options in the 320-ton size class.
For those miners looking to improve existing fleets, Cat is now providing retrofit kits for some technologies and improvements found on the newer trucks, such as extended brake-life materials, LED light kits and several safety features including one for working at height. “The working-at-height retrofit kits allow the miners to install tie off points on the truck,” Singh said.
“These tie-off points have become especially popular with mechanics working on the 400-ton Cat 797s in Canada.”
An improved fuel map feature for haul trucks lets miners use the engine and power train software to determine optimum fuel consumption in a given haul cycle. “We have been able to work with miners to improve fuel consumption by 6% to 12%,” Singh said. “Fuel represents 30% to 60% of mining costs for open-pit mines.” Cat is also investing in LNG technology for haul trucks. The company said it has successfully demonstrated the benefits they were targeting on a prototype at its proving grounds in Tucson, Arizona.
FULLY INTEGRATED HITACHI TECHNOLOGY
During the summer, Hitachi also added electric drive options for its haul truck customer with two new models, the 200-ton EH3500AC-3 and the 240-ton EH4000AC-3. Both trucks are equipped with an advanced AC-drive system that was developed by Hitachi. The company said it coupled the AC-drive system, which has a high load-responsive IGBT inverter, with drive-control software to better control travel motor speed and torque. Whether taking off from a standstill, ascending grades or performing steering maneuvers, Hitachi claims the system delivers an optimal, individual amount of power to each of the travel motors for smooth operation.
The Hitachi drive control system aims to achieve higher drive control performance by reducing tire slippage on acceleration and tire lockup during braking and preventing chassis oscillation in a front-rear direction and tire skid while steering. Consequently, the trucks boast strong and steady travel performance that ensures more stable haul cycle times, which will contribute to higher productivity, according to the company.
“This is a fully integrated truck from the drive to the frame,” Mace said. “We do not need to rely on another company’s technology. The slippage control on these AC-3 units prevents over-steering or drifting. The drive controls the pitch eliminating that rebounding effect from an oscillating chassis. The anti-skid feature prevents over-steering on turns.”
These two new AC-3 models also feature electric brakes that are activated during downhill driving. Since these trucks do not require the use of mechanical brakes during normal driving, not only is deceleration smoother, but maintenance for the mechanical brakes is required less frequently.
“Both of these size classes — 200 tons and 240 tons — are quite popular with coal operators,” Mace said. “For the EH3500AC-3, we were able to increase the capacity to get to the 200-ton nominal payload class. The previous model was a little smaller. We had a couple of these trucks operating at central Appalachian operations. We also have several AC trucks working in Colombia.”
Hitachi has not overlooked safety. At MINExpo 2012, the company introduced the SkyAngle feature that gives the operator 360° vision around the truck. “We are currently working on an object-detection feature that will be integrated into that system,” Mace said. Hitachi is also working on a collision-avoidance system that will be incorporated into its autonomous haulage system (AHS).
The research and development work related to its AHS is one of the exciting areas for Mace at Hitachi. “The AHS or any type of technology related to mine fleet management systems is where most of the interest lies these days,” Mace said. “A lot of miners are looking for tools and technology to make them more efficient. We are looking at several options to assist them as far as mine design and pit layout.”
While he doesn’t work with the group directly, Mace mentioned that Hitachi engineers are working with Wenco to improve scheduling systems. “Many of these systems were geared toward larger operations and we’re hoping to scale that down for smaller operators,” Mace said.
Mace also said that Hitachi is looking to incorporate some of the popular technology from its smaller trucks into the larger trucks . As an example, he referred to maintenance access points where Hitachi has moved from vertical ladders to stairways with open access. “The cabs are being redesigned with LCD monitors replacing the traditional gauges and dials,” Mace said. Looking toward the future, Mace said Hitachi will connect both mechanical- and electric-drive trucks to Hitachi’s global eService.