Improvements to articulated dump trucks are addressing the needs of today’s job sites: tight working spaces, inexperienced operators, safety, and productivity.
In May 2018, Doosan Infracore North America introduced its updated DA30-5 articulated dump truck, rated in the 30-metric-ton size class.
The new version of the Doosan DA30-5 includes numerous updates to the truck's performance, operator comfort, controllability of the machine, ease of maintenance, and fuel efficiency.
The main priority of the updates to the DA30-5 ADT was to enhance the operator experience, notes Aaron Kleingartner, marketing manager.
“A big part of the enhanced operator experience are the updates to the truck’s front suspension,” he says. “The front suspension was updated to a hydro-gas, self-leveling system to provide superior performance and greater shock absorption. Combined, these suspension system features allow for better driving comfort, especially when the truck is being driven while empty on a construction job site or at a mining operation.”
Doosan has increased the number of gear ratios available in its ADT transmissions, designed to provide smoother and easier shifting for the operator. Also, enhancements to the truck’s hydraulic retarding braking efficiency allows the machine to slow itself in a more optional way as the truck transverses downhill, says Kleingartner.
From a technical standpoint, the truck’s hydro-gas cylinders are connected to pressure accumulators and the accumulators and hydraulic system replace the previous shock absorbers and a rubber spring, says Kleingartner.
“The suspension of the updated DA30-5 includes a self-leveling feature and the ability to change the characteristics by adjusting the pressure,” he adds.
The truck’s vehicle control unit updates were designed to include more robust hardware, better processors, and more input channels for customized functions or further technology developments.
Telematics has been a significant technology enhancement to articulated dump trucks, notes Kleingartner.
“Above and beyond the regular telematics reporting and engine and machine codes are load count and material weight moved throughout a given period,” he says. “Fleet managers can use this information to make sure operators are optimizing the use of the trucks. Trucks sitting idle are hampering revenue.
Komatsu America’s newest models are the HM300-5, a 324-net horsepower, 30.9-ton payload articulated truck and the HM400-5, a 466-net hp, 44.1-ton payload.
Frank Nyquist, product marketing manager, Komatsu America, points out that the capabilities of the ADTs include a dump body capacity of 22.4 cubic yards (SAE heaped 2:1) for the HM300-5 and 31.4 cubic yards (SAE heaped 2:1) for the HM400-5.
“Both trucks are all-wheel drive and are used in all types of earthmoving applications, most notably those without dedicated roads or roads that aren’t routinely maintained,” he says. “Depending on ground conditions, payload, and haul length, these trucks can traverse grades approaching 45%.”
Design priorities focus on maintaining the economy, longevity, and productivity of the previous generation machine while achieving Tier 4 Final emissions compliance, notes Nyquist.
“These machines often wind up in rental fleets, so lowering cost of ownership for the machine owner is paramount,” he says, pointing out that from the standpoint of the contractor who rents the equipment, uptime is critical.
A standard feature of both articulated trucks is KOMTRAX, Komatsu’s remote equipment monitoring and management system.
KOMTRAX is designed to allow owners and fleet managers access to machine performance data such as fuel consumption, utilization, and production with the metrics used to lower owning and operating cost.
“Maintenance reminders and error codes are also reported so machine health can be monitored remotely,” says Nyquist. “All of this data can be accessed via the web or smartphone app. KOMTRAX does not require a subscription and it is a no-cost feature.”
The payload meter is a standard feature that displays payload tonnage on the machine monitor so the truck operator is aware of the weight in the dump body. An external display lamp on the roof of the cab indicates to the loading tool operator when the payload has been reached. Payload data can be accessed via KOMTRAX as well as downloaded directly from the machine.
Another standard feature is the rearview camera and dedicated color monitor in the operator’s cab.
Among the improvements that have been made to automated braking and transmission efficiency is Komatsu’s traction control system (KTCS), which monitors wheel speeds and automatically engages and disengages wheel brakes individually, transferring power through the differential to the tire with the most traction.
“This system allows for maximum machine performance in soft and slippery ground conditions,” says Nyquist.
Selectable powertrain features allow the operator to choose the transmission starting gear (F1 or F2) to match job site conditions.
“The operator can also choose to lock the center differential so a 50/50 split of power flows to the front axle and rear axles,” says Nyquist.
Selectable working modes such as power and economy modes can be selected for maximum output in demanding applications and fuel savings when the terrain is not as challenging.
Caterpillar’s new ADT models include the 730 and the 730EJ, with a payload of 31 tons, the 735 with a payload of 35 tons, and the 740GC with a 40-ton payload.
Safety, comfort, ease of operation, storage, and visibility were the driving forces behind the design.
“With the new cab now being standard on all models except the 725, Caterpillar now has a common look and feel for many of the operating features,” says Scott Thomas, product application specialist for Caterpillar.
Assisted hoist, automatic retarding control, and stability assist come standard on the new models.
Thomas notes that the 735 is now being built on the medium truck platform and as a result has lost close to 14,000 pounds of empty weight, resulting in up to a 15% reduction in fuel consumption and up to an 18% increase in fuel efficiency.
The technology of Stability Assist is designed to prevent the truck from tipping over when hoisting and gives the operator an audible warning when they are on a side slope greater than 15%, says Thomas.
“Assisted Hoist when turned on will apply the wait brake, neutralize the transmission, elevate the engine rpm to 100% and hoist the bed,” says Thomas. “All the operator needs to do is flick the hoist switch. It has reduced the operator movements during the dump cycle by 66%.”
For automated braking and transmission efficiencies, ARC (Automatic Retarding Control) is now on the 730 as well as all of the larger trucks.
“The truck knows the grade, whether it has material in the bed, and the speed the truck is going,” says Thomas. “It will then determine the correct gear, downshift if needed, hold itself in the correct gear, apply the correct amount of retarding from off to low, medium, or high, and apply the brakes when needed to keep the truck from over-speeding.
Caterpillar’s new 740 GC expands the company’s articulated dump truck lineup, re-introducing the 40-ton (36.3 metric ton) size class to the Cat ADT range.
The new model is designed to incorporate the proven features and performance of models currently in the ADT lineup and includes new controls, transmission-protection features, hoist-assist system, advanced traction-control system, stability-assist system, and a fuel-saving ECO mode.
Additionally, the 740 GC also incorporates the latest automatic retarder-control system, designed to require no input from the operator. The new model also features a “wait-brake” which temporarily applies the service brakes during pauses in the work cycle for reducing operator effort and fatigue.
Also, a hill-start system automatically holds the machine on grades to enable the operator to move from the service brake to the throttle with no roll-back on slopes.
The 740 GC cab features the new external spinal-ROPS found on other Cat ADTs in the range. This cab incorporates a rear-quarter glass eliminating a structural pillar, designed for enhanced rear visibility.
A “wake-up” feature initiates machine displays when the door is opened. The door design is lighter and stronger than previous designs. It is designed to seal more effectively against dust infiltration. The overall cab design results in interior sound levels of 72 dBA.
Optional infrared glass is designed to reduce solar heating inside the cab. Left- and right-hand sliding windows feature increased ventilation while facilitating communication with workers and the loader operator.
An automatic climate-control HVAC system positions more vents above and behind the operator for increased heating and cooling efficiency. An optional heated/cooled seat provides added adjustments for operator comfort settings. The second seat with added cushioning now uses a flip-up/flip-down design, providing additional cab storage.
A lighting system controlled through a ground-level switch illuminates the cab’s entry steps and hitch area as part of the “wake-up” feature with optional long-range LED work lights designed to improve overall night visibility.
Optional integrated payload lights are designed to provide an external indication of payload levels for the loader operator or site supervisor to help ensure proper loading. Exterior features include a redesigned, flexible lower fender and a low-profile exhaust stack that need not be removed for transport.
The optional Cat Connect PAYLOAD technology is designed to calculate payload through sensors on the walking-beam suspension. It includes load-status lights at all four corners of the cab roof to ensure visibility to the loader operator from any angle.
Additionally, the standard Cat Detect/Stability-Assist system monitors the working angle of the tractor and body as well as the grade and cautions the operator if the machine is approaching a set threshold angle, stopping the dump process if continued action might potentially result in tipping.
The Cat Advanced Automatic Traction Control (AATC) system is designed to proactively apply differential locks to avoid wheel spin. A terrain-based, throttle-smoothing system prevents throttle input surges as the ADT travels over rough ground.
Controls for limiting machine speed, transmission gear-hold, and wait-brake applications are engaged using buttons on the combined transmission/hoist lever. A shift-protection system is designed to bring the truck to a safe stop if a directional shift is made while the truck is moving.
The combined shifting/hoisting lever also incorporates the parking brake position. In the unlikely event of primary and secondary service brake system failure, a red colored emergency-brake button located on the righthand side of the dashboard will apply the parking brake.
The 740 GC uses the Cat C15 ACERT engine available in configurations to meet emission standards of both highly regulated and less regulated countries. The transmission is the Cat CX38B.
The three new Cat articulated trucks—730, 730 EJ (Ejector), and 735—have been redesigned in such a way to enhance the performance of their C-Series predecessors—730C2, 730C2 EJ, and 735C—with new operator stations that include new controls, transmission-protection features, a new hoist-assist system, an advanced traction control system, a new stability-assist system, and an ECO operating mode.
The design of the 730 and 730 EJ is enhanced with automatic retarder control and a hill-start feature. The 735 retains these features from its C-Series predecessor and now incorporates a new Cat C13 ACERT engine, Cat CX31 transmission (also on the 730 and 730 EJ), and structural and dimensional modifications reducing the empty weight by 22%. The combined features offer a 19% fuel efficiency gain.
The cab’s new external spinal-ROPS design incorporates a rear-quarter glass eliminating a structural pillar in the C-Series design for enhanced rear visibility. It also includes the “wake-up” feature, lighter door design, and lower sound levels.
The models also feature the optional Cat Connect PAYLOAD technology, the standard Cat Detect/Stability-Assist system, the Cat Advanced Automatic Traction Control system and the terrain-based throttle-smoothing system.
Additional features include the transmission-and-hoist lever. New buttons in the combined transmission and hoist lever allow setting (limiting) machine speed and selecting the transmission-waiting brake.
The models also feature the shift-protection system and the new combined shifting/hoisting lever that incorporates a parking position as well as the tertiary brake switch.
The full range of articulated haulers available from Volvo Construction Equipment has grown over the last two years to include the launch of the world’s largest articulated hauler—the A60H and the updated G-Series—says Rob Palermo, Volvo Construction Equipment’s product manager for articulated haulers.
Volvo’s seven articulated haulers range from the A25G to the A60H. Updated features on the trucks are designed to make them safer and more efficient.
The newest addition to the line—the A45G articulated truck—can hold 45-ton payloads and is built on a dimensionally small, light, and agile platform, says Palermo.
New technologies including Hill Assist, On-Board Weighing, and a Dump Support System now come standard with the G-Series and the A60H. The updated G-Series platform is designed for optimal off-road capability.
“With hydro-mechanical steering, high ground clearance, Automatic Traction Control, and 100% differential locks, Volvo G-Series trucks can work in 4-by-6 and 6-by-6 drive combinations,” notes Palermo. “Fully hydraulic suspension on all wheels is offered on the A45G FS.”
On-Board weighing comes standard on the A35G, A40G, A45G, A45G FS, and A60H, and is an option for the A25G and A30G.
“The system is fully automatic, requiring no intervention from the operator," says Palermo. “Three indicator lights alert both the hauler operator and the excavator operator when a nominal load has been reached and can warn the operators of overloading. The hauling operator can also see the actual tonnage displayed in real time.”
Design priorities focus on safety, as well as increasing productivity and efficiency, he points out.
Palermo indicates there had been a demand from those in the field for equipment offering improved productivity while reducing cost per ton.
The G-Series was designed to offer end-users increased tonnage and lower fuel costs. The payload of the A25G, A30G, and A35G was increased by 1 ton.
The G-Series and A60H integrate a number of new technologies aimed at making it easier for operators to work safer and have more information during operation.
Hill Assist holds the hauler in place when driving on uphill slopes of 10% or greater without the need to engage the parking brake. The Dump Support allows operators to see the percentage side inclination of the truck and set parameters for safe dumping operations.
The first year after the purchase of a new articulated hauler comes with ActiveCare Direct at no extra cost, through which Volvo analysts and software at the Volvo Uptime Center monitor the equipment’s telematics and analyze the data, sending case alerts when action might be needed that provide probable causes and recommended solutions to prevent downtime, says Palermo.
ActiveCare Direct also includes monthly reports giving managers an overview of their fleet so they can flag areas for improvement or training needs among operators.
Dynamic Volvo Engine Brake (VEB) systems are among the array of improvements to the Volvo G-Series and the A60H. VEB is designed to improve brake life by reducing the need to use the brake and retarder pedal when going downhill.
The torque and shift points are now dynamically adjusted against the current load, incline, and rolling resistance.
The G-Series also comes standard with Dynamic Drive, designed to offer improved gear shifting strategy that takes into consideration both the payload and the gradient of the slope and a 3–10% fuel efficiency improvement depending on the model.
The machine can automatically detect when to choose a higher starting gear or when to shift up earlier, says Palermo, adding that if conditions require, the machine can even prolong the gear to ensure maximum rim-pull.
Bell Trucks America recently introduced the 20t 6x6 ADT B20E LGP (Low Ground Pressure), designed to address the needs of contractors operating machinery in locations where the ground is very soft and they need the lowest possible ground pressure to maintain production such as residential and golf course developments, notes Kevin O’Donnell, senior vice president, sales, Bell Trucks America.
O’Donnell adds that B20E LGP also is versatile as a rental machine and can be fitted with typical 20.5R25 earthmoving tires.
Another machine that had its genesis as a niche product but has increased in demand is the B30E 4x4, says O’Donnell.
“This two-axle machine still has an oscillation joint that keeps all of the wheels on the ground for the 4-by-4 drivetrain to do its job,” he adds. “The shorter truck gives improved maneuverability and turning circle, but the main benefit is the lack of tire scuff when cornering.”
O’Donnell points out that traditional three-axle ADTs cause a lot of wear on the rear tires when going around corners, which creates significant damage to the road.
“The 4 by 4 runs smoothly around corners without these two issues,” says O’Donnell. “The ground pressure under the rear tires is higher than a three-axle truck so it is not intended for soft underfoot conditions but rather harder roads, which are undulating and slippery when wet—the type of road one finds in a quarry.”
The Bell hydraulic braking system incorporates fully-enclosed dual circuit wet disc brakes. The system is virtually maintenance free and features a high flow circulating system with filtration and cooling.
Downhill braking is assisted by an engine Jake Brake coupled with automated brake retardation that can be set manually by the operator, notes O’Donnell.
“For example, when an operator goes over the crest of a hill and takes their foot off the accelerator at 22 kilometers per hour, then the truck will automatically vary retardation to maintain 22 kilometers per hour irrespective of the slope,” he adds. “If the operator brakes the truck to slow it down to 13 kilometers per hour and then takes their foot off the brake, then the truck will maintain the control speed to 13 kilometers per hour.”
For uphill safety, Bell’s Hill Assist feature is designed to prevent a truck from rolling backward if an operator takes their foot off the accelerator while driving up a hill, notes O’Donnell.
The service brakes on a Bell ADT are automatically applied to prevent this from happening, he adds.
“When the operator puts their foot back on the throttle, the brakes are released when enough torque has developed to allow smooth and safe pull-away,” says O’Donnell.
Noting that software control gives flexibility in adjusting how a function behaves, Bell has designed several features that enhance productivity, site and operator safety, and ease of operation.
Software features include I Tip for automated tipping, Tip Safe to prevent bin rollover, auto horn alerts, hill descent control, automatic traction control, and driver ID that allows the truck to be programmed with up to six different drivers, each starting the keyless truck with their own ID code that is recorded on the Bell telematics system, Fleetm@tic.
“The engine has a turbo spin down feature that when an operator pushes the shutdown button, the truck will continue to run and then shut down, allowing the turbo to slow down before the oil supply is cut off,” notes O’Donnell, adding the auto park brake is automatically applied when the truck is put into neutral.
Bell Telematics, the Bell Fleetm@tic telematic data standard on all Bell ADTs, is designed to make it easy for the operator to care for the machine by identifying operator training opportunities and improving additional operational efficiencies.
All Bell ADTs come standard with on-board-weighing so that production data includes all aspects that require this measurement such as total tons, cycle tons, tons per hour, fuel used per hour, and fuel per ton, says O’Donnell.
In 2017, John Deere released its 260E and 310E articulated dump trucks that rounded up the company’s lineup of five models. The models accommodate contractor’s desire for the productivity of 25- and 30-ton size class size equipment with maneuverability for tight job sites, notes Maryanne Graves, ADT product marketing manager for John Deere.
Given that inexperienced operators may most likely be placed in an ADT, John Deere designed automated features into the units, she says.
“We wanted to make sure those operators are able to maximize their productivity and efficiency without adding complexity to our trucks,” points out Graves. “Automating features like roll-over protection protects the operator and protects the truck from rolling the bin over by allowing the operator to set an incline at which if the truck is on an incline or grade steeper than that, it won’t allow that bin to go up in the air.”
An auto dump feature allows an operator to get the truck loaded, place it into high idle, engage the parking brake, and dump the load efficiently and quickly.
Many of John Deere’s automated features in the ADT lineup are designed to maximize productivity for inexperienced and experienced operators.
Productivity and safety are ADT design priorities, notes Graves.
Ground-level daily service that “keeps the operator’s feet on the ground while doing those daily checks” is another factor of emphasis in John Deere ADTs, says Graves.
“Operators can walk around the machine to do all of those daily maintenance items with their feet on the ground,” says Graves. “That’s a big advantage in keeping people efficient, productive, and keeping them safe.”
John Deere ADTs also feature a “hill hold” enabling the truck to stay in place if it’s stopped on a hill “which isn’t uncommon when they’re waiting to be loaded or on various job sites where there are multiple trucks,” says Graves.
The ADTs also feature an automatic differential lock that senses if a truck is flipping and it will engage the differential automatically.
“The auto differential lock, as well as our transmission retarder, takes the guesswork out for the operator,” says Graves, adding John Deere utilizes the transmission retarder instead of the service brakes to slow the machine.
While not specific to ADTs, John Deere’s telematics in its JDLink system and the company’s Machine Health Monitoring Center enables dealers and customers to manage fleets more efficiently by sending proactive notifications to “really get out in front of failures,” says Graves.
“It maximizes the time our products are up and running and pre-empting failures. It allows Deere to look at an aggregate level of what’s happening with machines in the field and if there are things we could proactively be doing to notify customers on changes to the machine or if they see failures are coming.”