A deeper dive into two newer machines that each play a key role in successful haul road management.
There are many elements to a great haul road management program, but one factor often taken for granted is the polish: grading and dust control. While the Komatsu GD955-7 and Caterpillar 789D autonomous water truck are both relative newcomers to the market, both have staying power as demand rises for these key fleet units.
Komatsu
The Komatsu GD955-7 motor grader was unveiled officially at MINExpo 2024 in Las Vegas, and introduced for the North American market in January 2025. Ideal for building and maintaining haul roads for truck fleets up to 100 tons, the machine has excellent maneuverability despite a large size and can execute tight U-turns on a standard haul road without the need to fully cut the wheel or course correct.
The long wheelbase and large, 27-degree articulation angle allow a tight turning radius and provide maneuverability for narrow haul road applications in confined spaces and around obstacles. It possesses 426 horsepower at 1,900 rpm (313 kW @ 1,900 rpm) and an operating weight of 104,323 pounds (47,320 kg). It is also worth noting that it has the same engine platform as the OEM’s HM400.
“Coming in at just over 104,000 pounds, this is a 50% increase in operating weight over the previous model,” said Sebastian Witkowski, product manager for Import Loading and Haulage.
“So that, coupled with the longer wheelbase extension, gives us the opportunity to achieve best in class blade downforce pressure just to penetrate the hard pack haul road surfaces and keep our haul roads clean.”
He added that one of the newest introductions for the grader has been a bearing-style drawbar circle, which eliminates the need to replace any wear parts or make any play adjustments or shim adjustments.
Then there’s a fingertip work equipment control.
“The concept behind this structure here is we’ve essentially taken the traditional antler rack configuration and brought it back down to the end of our armrests here just to maintain a more ergonomic feel and control,” Witkowski noted. “There’s a jog block that can be used to steer the front tires when low speed grading. We also have a steering wheel…for use for high speed roading that gives customers a little bit more feel and control.”
It has a number of additional advantages as well. These include up to a 33% increase in productivity with 18-foot moldboard (compared to its previous model); up to a 46% increase in productivity with 20-ft. moldboard (compared to the previous model); and up to a 21% reduction in total maintenance time with circle bearing system and auto-lubrication.
Finally, as it features a standard auto-lubrication system, the GD955-7 is engineered to help reduce planned and unplanned maintenance downtime while helping to extend life to overhaul.
“With significant increases in operating weight, blade downforce pressure and working travel speeds, this new size class motor grader will be a smart choice for increased efficiency on our customer’s mine sites,” said Joseph Sollitt, director of Mining Support Equipment.
Caterpillar
In March, Caterpillar confirmed its new Cat 789D Autonomous Water Truck for both dust and cost control via automated water delivery.
The announcement has come just months after the OEM’s announcement at MINExpo 2024 last September of its Water Delivery System 2.0 for higher water output – allowing trucks to run at higher speeds while delivering optimized output. Cat said its testing, completed at its Tucson Proving Ground in Arizona, found that 2.0 with a new water pump and hydraulic motor can offer a 25% increase in water output and 13% jump in water speed.
Cat officials said in the newest announcement of the AWT that the vehicle is fully integrating into the mine site’s Cat Command autonomous haulage fleet to control haul road dust. It will be the market’s first commercially available AWT built on the field-proven 789D mining truck chassis – integrating the truck, tank and Cat Water Delivery System (WDS) with the connection of its Cat MineStar technology.
Featuring Command for hauling, the new Cat 789D AWT offers the same potential for greater utilization than staffed equipment.
The fully autonomous truck reduces shift changes, meal breaks and other operational delays to improve efficiency. Complying with watering plans, the water truck seamlessly interacts with other autonomous equipment and integrates with customer mining processes and systems managed by Cat MineStar.
“The 789D is the largest Cat water truck product offering; it can accommodate up to 165,000 liter/43,588 gallons, depending on tank configuration,” said Corey Wurtzbacher, general manager and vice president, Technology and Global Sales Support.
“The AWT senses when the water tank is running low and can be programmed to integrate with the water refill station to fully automate the water refill process. The auto shutoff feature prevents tank overfilling.”
For dust control, Caterpillar said it responded to customer requirements by implementing a MineStar-integrated watering model based on many years of site watering studies and Cat WDS performance data.
“The model allows the truck to monitor traffic, weather and road conditions, prioritize what areas need watered, when the areas need watered, and how many passes it should take to apply the correct amount of water saturation, for the given conditions,” he added.
Mines can quickly switch the flexible 789D AWT from autonomous mode to staffed mode as necessary for tasks like front water cannon operation. The cannon has a capacity of distributing up to 2,839 l/min (759 gal./min) with a spray distance reaching 60 m (200 ft.). Even with staffed operation, Auto Mode water delivery automates the watering process to leverage variable water flow and automatic determination of the correct amount of water needed to control dust.
Cat Water Solutions integrates the 789D truck chassis with the proven Cat WDS and innovative MineStar technology. If the site is not yet ready for a fully autonomous water truck, MineStar has cloud-based solutions that will work in the interim and allow customers to utilize, track, and measure the productivity of the 789D before it is put into autonomous operation. Options include a basic or premium package; the former offers the location of the truck; water level; fuel level; watering mode; truck speed and refills; water dispersed; and truck utilization per shift.
When the site is ready for full autonomous mode, the water truck can be integrated into the MineStar ecosystem to work alongside the rest of the mining fleet.
This integrated autonomous water solution is fully supported by the Cat dealer and parts network and is also covered by a Caterpillar factory standard warranty. Retrofit kits are available for existing Cat 789D truck platforms in the field.