Editor’s note: This article first appeared in the March/April 2014 edition of Grading and Excavation Contractor.
Rigid frame trucks are designed to haul large, abrasive, rocky materials on well maintained haul roads, says Scott Knoblauch, senior consultant with Caterpillar Inc. “Grades under 15% and long-haul road distances have minimal effect on rigid frame truck performance,” he says. “They also are designed to run well on long downhill grades, fully loaded where we can use the Automatic Retarding Control. Rigid frame trucks are ideal when operating in these types of conditions.”
Articulated trucks were designed to run in poorly maintained areas, areas with high rolling resistance and on multiple grades, Knoblauch says. With any application, haul road maintenance is a key to achieving maximum production, but articulated trucks are generally capable of handling harsh conditions.
Editor's note: This article first appeared in the March/April 2014 edition of Grading and Excavation Contractor. Rigid frame trucks are designed to haul large, abrasive, rocky materials on well maintained haul roads, says Scott Knoblauch, senior consultant with Caterpillar Inc. "Grades under 15% and long-haul road distances have minimal effect on rigid frame truck performance," he says. "They also are designed to run well on long downhill grades, fully loaded where we can use the Automatic Retarding Control. Rigid frame trucks are ideal when operating in these types of conditions." Articulated trucks were designed to run in poorly maintained areas, areas with high rolling resistance and on multiple grades, Knoblauch says. With any application, haul road maintenance is a key to achieving maximum production, but articulated trucks are generally capable of handling harsh conditions. [text_ad] Mark Oliver, product marketing manager with John Deere Construction and Forestry, says four factors are at play when deciding what type of truck to use: terrain, grade, volume, and distance. Terrain relates to overall job-site conditions, but especially to the haul road. Are the areas where the trucks are being loaded and unloaded well maintained with good underfoot conditions? Will the job site have the support equipment necessary to maintain haul roads? If not, articulated dump trucks are a great choice for the contractor. Compared to rigid frame dump trucks, articulated dump trucks (ADTs) can handle just about any terrain and do not require well-maintained haul roads. And if there are a lot of steep grades to maneuver, ADTs perform much better than rigid-frame trucks. When it comes to volume, most manufacturers' largest ADTs fall into the 40-ton size class (approximately 30 cubic yards) while rigid frame dump trucks are available with much larger capacities. Rigid frame dump trucks have the ability to haul more material per truck, but again the overall job conditions need to be considered before making the final decision of rigid frame versus articulated dump trucks. Distance is important because it relates to cycle times, says Oliver. If the distance is long and the haul roads are well maintained, rigid frame dump trucks generally have a higher top-end speed. If there is any part of the haul that is not maintained, again the rigid frame truck advantage quickly diminishes. Komatsu and Caterpillar manufacture articulated haulers and rigid-frame dump trucks alike. Komatsu articulated trucks are designed to haul between 30 and 44 US tons, whereas Komatsu mechanical rigid trucks are designed to haul between 35 and 150 US tons. If the ground conditions are hard and smooth, the contractor should consider rigid frame trucks. These firm ground conditions will allow the customers to have larger payloads and faster travel with rigid trucks, says Rob Warden, product manager for trucks and loaders with Komatsu America Corp. The Komatsu articulated trucks feature large payloads that were increased over the previous model. They feature low-height sideboards that allow for efficient side loading, and they easily match loading with 40-ton to 60-ton hydraulic excavators or large wheel loaders. The 324-horsepower HM300-3 features a 30-ton US payload capacity, and the 469-horsepower HM400-3 can haul 44.1 US tons. Komatsu designs and builds the engines for its articulated trucks. The engines are certified to pass EPA Tier 4 Interim and EU Stage 3B emissions rules. Both machines are equipped with selectable engine working modes to help tailor the machine performance to the application. Economy mode is best suited for work on flat ground, while the power mode is best suited for work in uphill loaded travel. Komatsu articulated trucks feature the new Komatsu Traction Control System (K-TCS), which automatically provides optimum traction when operating in soft ground conditions. As ground conditions worsen, speed sensors located on four wheels detect tire slippage, and automatic application of the inter-axle differential lock occurs. If tire slippage continues to be detected, four independent brakes can be applied to slipping wheels to regain traction. New From Caterpillar Caterpillar recently introduced its C Series of articulated dump trucks-725C, 730C, and 730C EJ (ejector)-featuring new engines with more power, advanced transmission control, enhanced operator amenities, new serviceability features, and, for the 730C and 730C EJ models, automatic traction control. The design of the new models centers largely on customer requests for increased productivity, lower operating costs, superior availability, long-term durability, added rim pull/retarding capability, ease of operation, high resale value, and maximum rental margins. The 725C has a rated payload capacity of 26 tons, and the 730C and 730C EJ models are rated at 31 tons. The 725C Cat C9 engine is rated at 314 net horsepower (234 kW), and the Cat C13 in the larger models has 367 net horsepower (274 kW). All three models are available in US EPA Tier 2/EU Stage II, Tier 3/Stage III, or Tier 4 Final/Stage IV configurations to meet worldwide emissions standards. A diesel particulate filter and selective-catalytic-reduction system provide exhaust aftertreatment for Tier 4 Final/Stage IV models. Compared with predecessor models, the 725C has a 4% gain in gross power and a 20% boost in gross torque; 730C and 730C EJ models have nearly 16% more gross power and more than a 30% gross torque improvement. The Cat 6F/1R power-shift transmission, which electronically modulates clutch engagement pressures for smooth, positive shifts, now also incorporates the Caterpillar Advanced Productivity Electronic Control Strategy (APECS). The APECS system improves acceleration, maintains torque converter lockup (and ground speed) during critical shifts, increases rim pull, provides automatic speed-holding, modifies shift points to match operating conditions (for increased fuel economy), and automatically reduces retarding forces on lesser grades in lower gears. The overall net benefits are optimum productivity and optimum control of the truck. For controlling speed on downhill grades, Caterpillar 730C models employ a new engine compression brake that provides 60% more retarding power than predecessor models. The 725C uses a fluid retarder with four operating modes. Both systems effectively manage speed and minimize service brake application for extended brake life. The new Cat 770G and 772G off-highway trucks have been designed with major advancements in emissions control technology, transmission and traction control systems; frame, drive train, and cooling system enhancements; added operator amenities; and serviceability improvements. Many of the outstanding features introduced on larger Cat G Series trucks are being incorporated on the new 770G and 772G models. With nominal rated payload capacities of 40 and 52 tons, respectively, the new trucks use Cat C15 and C18 engines, with net power ratings of 477 and 550 horsepower (356 and 410 kW). Available in Tier 2/Stage II, Tier 3/Stage III, and Tier 4 Final/Stage IV configurations, the engines can be programmed to achieve the customer's specific fuel economy goals. Two programmable modes are available: economy and adaptive economy. Economy mode lets the customer select a derate value between 0.5% and 15%. At the touch of a button, economy mode applies steady power deration across all portions of the haul cycle. With adaptive economy mode, the truck monitors power demand, delivering fuel savings when possible and horsepower when needed, to optimize fuel economy throughout the haul cycle. For further fuel savings, the new Auto Neutral Idle feature automatically places the transmission in neutral gear after the brake is applied for more than 15 seconds while in a forward gear. This reduces parasitic drive train loads and provides major fuel efficiency improvements. Once the operator removes his foot from the brake, the transmission re-engages. This is completely transparent to the operator. Also, a hydraulically driven, on-demand cooling fan reduces power draw on the engine by operating only when required and only at the speed required. John Deere's Artic Trucks John Deere offers five articulated dump trucks that range from 18 cubic yards to 33.4 cubic yards in capacity. Horsepower ratings range from 265 net horsepower on the 250D-II up to 481 net horsepower on the 460E. The E Series also includes the 370E with 422 net horsepower and the 410E with 443 net horsepower. John Deere features manual or auto differential lock control on the E-Series ADTs. The 250D-II and 300D-II have limited slip differentials on each axle with planetary, torque proportioning lockable interaxle lock. Deere's E-Series models have hydraulically actuated, wet disc brakes; the 250D-II and 300D-II have hydraulically actuated, dry disc brakes. E-Series models have rear-view cameras, and ground-level service access. All models have owner-enabled speed limits, owner-enabled dump body rollover protection, and secondary steering systems. Brian Bereika, ADT product specialist at Doosan, says the company's dump bodies can haul payloads of up to 50 tons, which puts the largest ADT about the same capacity as the smaller rigid frames. They have a maximum travel speed of around 35 mph and can handle a gradient of approximately 40%. Because they articulate, they have a smaller turning radius as a benefit. The horsepower ratings of both the DA30 and DA40 have been increased by 8% over Tier 3 models. The DA30 uses operator-engaged interaxle and rear differential locks. It has limited slip front and rear differentials. The DA40 uses operator engaged inter-axle lock with limited slip front and rear differentials. All differential locks can be engaged on the fly and they will also disengage at preset ground speed. Ejector bodies are available as custom order on both models, and the current DA40 has improved nitrogen gas/oil struts on the front suspension. A single rear axle on both models has unique gear-driven oil-bathed tandem housings that allow constant ground contact. Wet disc brakes are featured on all wheels of both models, not just front and center axle wheels. Both engine brake and transmission hydraulic retarder standard equipment Volvo's Articulated Haulers The F-Series articulated haulers from Volvo Construction Equipment not only meet the demanding standards set by the Tier 4 Interim (US) and Stage IIIB (Europe) emissions legislation, but also feature a package of improvements in functionality, design, and maintenance. The F-Series ranges from the 24-26.5 ton A25F up to the 43-ton A40F. Having developed the articulated hauler approach in the 1960s, Volvo says it is still the market leader. Central to the Volvo design is the articulated steering system, which gives operators good control of the machine through both its high steering force in tough off-road conditions (e.g., deep mud) and also its accurate, safe operation at high hauling speeds. The self-compensating hydromechanical system also affords exceptionally short turning circles. It is useful in confined loading and dumping areas and on tightly turning haul roads. Volvo says durability and strength are the hallmarks of all its haulers. Heavy-duty front and rear frames have been designed for severe off-road operation and long service life. The load body is also heavy duty, made from HB400 steel, and its design, high dump clearance, and tipping angle all promote good material ejection. A powerful, load sensing "closed center" hydraulic system and double acting, single-stage hoist cylinders raise the body even on steep downhill gradients. The system allows for precise, controllable dumping-shortening cycle times and aiding safety. The company says that a load-and-dump brake is applied by pressing a button in the cab to apply the service brakes and shift the transmission to neutral, further increasing safety and reducing operator fatigue. All machines also feature new dumping functions-detent body lowering and, notably, the adjustable tipping angle. Using the onboard Contronics system, operators can set the maximum tipping angle and, therefore, overall height of the body, ensuring safety when working under electrical wires, in tunnels or underground, for example. Freightliner Trucks With set-forward or setback front axles, a full range of severe duty vocational suspensions and a wide selection of efficient and powerful engines, Freightliner dump trucks are tough, reliable and enhance the bottom line, says Mary Aufdemberg, director of product marketing for Freightliner Trucks. The 122SD is the flagship vocational truck model from Freightliner. The 122SD is a heavy commercial truck that can haul anything from granite to logs to heavy equipment across the most challenging of terrains. Mack Trucks The Mack Granite truck comes in axle forward and axle back configurations and is powered by Mack MP7 and MP8 engines. The MP7 is an 11-liter engine rated at 325 to 405 horsepower and delivering 1,200 to 1,560 ft.-lb. of torque. The MP8 is a 13-liter engine rated from 415 to 505 horsepower and delivering 1,560 to 1,760 ft.-lb. of torque. Mack Granite models can be equipped with the Mack T300 series manual transmissions available in 8-, 9-, 10-, 13-, and 18-speed versions. Also available are Eaton Fuller manual transmissions and Allison automatic transmissions. The Granite is available as a single-steer axle, rated at 12,000 through 23,000 pounds, or is available with twin steer axles. The rear axle can be ordered in single drive rated at 23,000 to 30,000 pounds, a tandem rear axle rated from 38,000 pounds through 65,000 pounds with special options for 80,000 and 100,000 pounds, or a tri-drive combination rated up to 69,000 pounds. The suspensions offered are Mack Camelback, Mack Walking Beam, Mack AL Air Leaf, and the new Mack mRIDE spring suspension launched in March 2013. The Granite also can be ordered with suspensions from Hendrickson, Chalmers, and other suppliers, in both mechanical and air ride versions. Mack's mRIDE suspension is a high-articulation mechanical suspension design using spring leafs supported at each end by rubber shock towers. The suspension is then dampened at all four corners by shock absorbers and tied together with a six-rod system. Combined with Mack axles, the suspension delivers a lightweight, stable, and smooth ride with excellent ground clearance and more than 15 inches of articulation. The mRIDE is available in 40,000-pound, 46,000-pound, and 52,000-pound ratings, and is in production today. Mack axles come standard with Mack's patented inter-wheel power divider. Mack and vendor axles can be ordered with power divider inter-axle lockouts and driver-controlled differential locks. Bendix and Meritor ABS are available, and both can be specified to include auto traction control. An all-wheel drive version can also be special ordered from the factory. Navistar Last July, Navistar announced the launch of its heavy-duty International WorkStar vocational trucks powered by the company's 13-liter engine with selective catalytic reduction (SCR) emissions technology. The WorkStar is the fourth heavy-duty International truck model to transition to SCR technology since December 2012. The company's portfolio of SCR-based heavy-duty trucks also includes the International ProStar, International PayStar 5900 Set-Back Axle, and International 9900i-all available with the Cummins ISX15 engine. In addition, Navistar's proprietary 13-liter engine with SCR was launched in the ProStar in April and is now available in the WorkStar. The remaining lineup of International heavy-duty truck models will transition to SCR emissions technology in a phased launch in the coming weeks based on volume and customer demand. Navistar claims that the WorkStar is designed to take on the heaviest loads and the most rugged jobs. The heavy-duty WorkStar model includes two variations, 7600 SBA (46-inch set-back axle) and 7600 SFA (30-inch set-forward axle). Both models feature a 113-inch BBC (bumper to back-of-cab). Peterbilt's Construction Truck One of Peterbilt's newest vehicles is the vocational Model 567, introduced last March during the Mid-America Trucking Show in Louisville, KY. The Model 567 is now in full production, says Charles Cook, Peterbilt product marketing segment manager. This versatile truck and tractor can be configured to meet the full range of severe-service vocational customer needs, including dump, mixer, heavy haul, and refuse. This all-new model is available in both a 121- and 115-inch BBC and can be configured as a day cab or with one of three detachable sleepers: 44-, 70-, or 80-inch. Additionally, it can be spec'd with a wide range of heavy-duty components and axles, including single, tandem, tridem, and lift. The Model 567 is standard with the Paccar MX-13 Engine, available in ratings from 380 to 500 horsepower and 1,450 to 1,850 lb-ft of torque. Optional engine choices include the Cummins ISX12 and ISX15, the latter available up to 600 horsepower and 2,050 lb-ft torque. To match customer requirements, including ease of operation and fuel efficiency, a wide range of transmissions are available. The Model 567 can be spec'd with a manual 9-, 10-, 11-, 13-, or 18-speed Fuller, the Fuller automated UltraShift or the Allison automatic. The Model 567's steer axle is available rated up to 22,000 pounds. Rear drive axles are available rated up to 70,000 pounds. A broad range of rear suspensions are available, including Peterbilt's Air Leaf, FLEX Air, Low Air Leaf, and Air Trac; Reyco's 79KB, 102 and 102AR; Hendrickson's HMX and RT; Chalmers' 854; and Neway's ADZ. Front air-disc brakes are standard as is the Bendix Electronic Stability Control System with Automated Traction Control. In addition to greater straight-line braking control, these systems combine to provide added stability and traction by applying the brakes when excessive wheel slip or a critical stability threshold is detected. Other key features of the Model 567 include outstanding visibility and an operator environment that promotes comfort and productivity. The one-piece windshield and narrow, reinforced A-pillars allow for a panoramic view from the cab, enhancing safety on congested job sites. The quiet, ergonomic cab is a roomy 2.1 meters wide. The new gauge panel is easy to read, completely visible through the steering wheel, and provides critical and functional information to the driver. The Model 567 also features a 5-inch color driver information display that provides operators with a wide array of information, including an engine-RPM sweet-spot indicator to help drivers maximize fuel economy. A secondary panel can house up to six optional gauges or, when specified, Peterbilt's SmartNav audio and navigation system. Western Star Western Star will continue to offer its rugged 4900 model lineup in 2014 for dump applications, says Peter Schimunek, marketing segment manager, Western Star. Available in a set-back and set-forward configuration, the 4900 provides a powerful and versatile solution for demanding vocational jobs. With its bodybuilder-friendly design, the 4900 is designed to reduce installation time and extend the truck's longevity. It can also be spec'd with lightweight components for weight-sensitive applications. Combined with Western Star's hallmark roomy cab, ample storage space, plush seating the 4900 delivers the best in performance, durability, and comfort on-road and off-road for the toughest jobs. Kenworth's New T880 Vocational Truck "The T880 features a panoramic windshield for enhanced visibility, quiet cab with its triple-sealed and robust doors, five-piece hood for easier and faster repairs, air-assisted hydraulic clutch, complex reflector headlamps, excellent maneuverability, and new lightweight, factory-installed lift axles that vocational customers will especially appreciate," said Kevin Baney, Kenworth chief engineer. "On top of all that, we designed the T880 with distinctively sculpted lines that form an evolutionary, but uniquely Kenworth look." The new T880 is for vocational applications, including dump, mixer, refuse, and heavy haul. Its addition will complement Kenworth's current vocational lineup that includes the T800, T440, W900S, and C500. The Kenworth T880 is standard with the 12.9-liter Paccar MX-13 engine. With its high-end ratings of 500 horsepower and 1,850 lb-ft of torque, the Paccar MX-13 engine provides a lightweight, fuel-efficient engine option for vocational applications, including dumps and heavy-haul applications over 100,000 pounds. The T880 also is available with the Cummins ISX15 engine with up to 600 horsepower and 2,050 lb-ft of torque. The T880 uses Kenworth's 2.1-meter wide, stamped aluminum cab, which is robotically assembled. The cab has a comfortable 23 inches of room between the seats. The T880 offers the premium Diamond VIT and Vantage trim levels and two interior color options of sandstone tan and slate gray.
Mark Oliver, product marketing manager with John Deere Construction and Forestry, says four factors are at play when deciding what type of truck to use: terrain, grade, volume, and distance. Terrain relates to overall job-site conditions, but especially to the haul road. Are the areas where the trucks are being loaded and unloaded well maintained with good underfoot conditions? Will the job site have the support equipment necessary to maintain haul roads? If not, articulated dump trucks are a great choice for the contractor. Compared to rigid frame dump trucks, articulated dump trucks (ADTs) can handle just about any terrain and do not require well-maintained haul roads.
And if there are a lot of steep grades to maneuver, ADTs perform much better than rigid-frame trucks. When it comes to volume, most manufacturers’ largest ADTs fall into the 40-ton size class (approximately 30 cubic yards) while rigid frame dump trucks are available with much larger capacities. Rigid frame dump trucks have the ability to haul more material per truck, but again the overall job conditions need to be considered before making the final decision of rigid frame versus articulated dump trucks.
Distance is important because it relates to cycle times, says Oliver. If the distance is long and the haul roads are well maintained, rigid frame dump trucks generally have a higher top-end speed. If there is any part of the haul that is not maintained, again the rigid frame truck advantage quickly diminishes.
Komatsu and Caterpillar manufacture articulated haulers and rigid-frame dump trucks alike. Komatsu articulated trucks are designed to haul between 30 and 44 US tons, whereas Komatsu mechanical rigid trucks are designed to haul between 35 and 150 US tons. If the ground conditions are hard and smooth, the contractor should consider rigid frame trucks. These firm ground conditions will allow the customers to have larger payloads and faster travel with rigid trucks, says Rob Warden, product manager for trucks and loaders with Komatsu America Corp.
The Komatsu articulated trucks feature large payloads that were increased over the previous model. They feature low-height sideboards that allow for efficient side loading, and they easily match loading with 40-ton to 60-ton hydraulic excavators or large wheel loaders. The 324-horsepower HM300-3 features a 30-ton US payload capacity, and the 469-horsepower HM400-3 can haul 44.1 US tons.
Komatsu designs and builds the engines for its articulated trucks. The engines are certified to pass EPA Tier 4 Interim and EU Stage 3B emissions rules. Both machines are equipped with selectable engine working modes to help tailor the machine performance to the application. Economy mode is best suited for work on flat ground, while the power mode is best suited for work in uphill loaded travel.
Komatsu articulated trucks feature the new Komatsu Traction Control System (K-TCS), which automatically provides optimum traction when operating in soft ground conditions. As ground conditions worsen, speed sensors located on four wheels detect tire slippage, and automatic application of the inter-axle differential lock occurs. If tire slippage continues to be detected, four independent brakes can be applied to slipping wheels to regain traction.
New From Caterpillar
Caterpillar recently introduced its C Series of articulated dump trucks-725C, 730C, and 730C EJ (ejector)-featuring new engines with more power, advanced transmission control, enhanced operator amenities, new serviceability features, and, for the 730C and 730C EJ models, automatic traction control. The design of the new models centers largely on customer requests for increased productivity, lower operating costs, superior availability, long-term durability, added rim pull/retarding capability, ease of operation, high resale value, and maximum rental margins. The 725C has a rated payload capacity of 26 tons, and the 730C and 730C EJ models are rated at 31 tons.
The 725C Cat C9 engine is rated at 314 net horsepower (234 kW), and the Cat C13 in the larger models has 367 net horsepower (274 kW). All three models are available in US EPA Tier 2/EU Stage II, Tier 3/Stage III, or Tier 4 Final/Stage IV configurations to meet worldwide emissions standards. A diesel particulate filter and selective-catalytic-reduction system provide exhaust aftertreatment for Tier 4 Final/Stage IV models.
Compared with predecessor models, the 725C has a 4% gain in gross power and a 20% boost in gross torque; 730C and 730C EJ models have nearly 16% more gross power and more than a 30% gross torque improvement.
The Cat 6F/1R power-shift transmission, which electronically modulates clutch engagement pressures for smooth, positive shifts, now also incorporates the Caterpillar Advanced Productivity Electronic Control Strategy (APECS). The APECS system improves acceleration, maintains torque converter lockup (and ground speed) during critical shifts, increases rim pull, provides automatic speed-holding, modifies shift points to match operating conditions (for increased fuel economy), and automatically reduces retarding forces on lesser grades in lower gears. The overall net benefits are optimum productivity and optimum control of the truck.
For controlling speed on downhill grades, Caterpillar 730C models employ a new engine compression brake that provides 60% more retarding power than predecessor models. The 725C uses a fluid retarder with four operating modes. Both systems effectively manage speed and minimize service brake application for extended brake life.
The new Cat 770G and 772G off-highway trucks have been designed with major advancements in emissions control technology, transmission and traction control systems; frame, drive train, and cooling system enhancements; added operator amenities; and serviceability improvements. Many of the outstanding features introduced on larger Cat G Series trucks are being incorporated on the new 770G and 772G models. With nominal rated payload capacities of 40 and 52 tons, respectively, the new trucks use Cat C15 and C18 engines, with net power ratings of 477 and 550 horsepower (356 and 410 kW).
Available in Tier 2/Stage II, Tier 3/Stage III, and Tier 4 Final/Stage IV configurations, the engines can be programmed to achieve the customer’s specific fuel economy goals. Two programmable modes are available: economy and adaptive economy.
Economy mode lets the customer select a derate value between 0.5% and 15%. At the touch of a button, economy mode applies steady power deration across all portions of the haul cycle. With adaptive economy mode, the truck monitors power demand, delivering fuel savings when possible and horsepower when needed, to optimize fuel economy throughout the haul cycle.
For further fuel savings, the new Auto Neutral Idle feature automatically places the transmission in neutral gear after the brake is applied for more than 15 seconds while in a forward gear. This reduces parasitic drive train loads and provides major fuel efficiency improvements. Once the operator removes his foot from the brake, the transmission re-engages. This is completely transparent to the operator. Also, a hydraulically driven, on-demand cooling fan reduces power draw on the engine by operating only when required and only at the speed required.
John Deere’s Artic Trucks
John Deere offers five articulated dump trucks that range from 18 cubic yards to 33.4 cubic yards in capacity. Horsepower ratings range from 265 net horsepower on the 250D-II up to 481 net horsepower on the 460E. The E Series also includes the 370E with 422 net horsepower and the 410E with 443 net horsepower.
John Deere features manual or auto differential lock control on the E-Series ADTs. The 250D-II and 300D-II have limited slip differentials on each axle with planetary, torque proportioning lockable interaxle lock. Deere’s E-Series models have hydraulically actuated, wet disc brakes; the 250D-II and 300D-II have hydraulically actuated, dry disc brakes. E-Series models have rear-view cameras, and ground-level service access. All models have owner-enabled speed limits, owner-enabled dump body rollover protection, and secondary steering systems.
Brian Bereika, ADT product specialist at Doosan, says the company’s dump bodies can haul payloads of up to 50 tons, which puts the largest ADT about the same capacity as the smaller rigid frames. They have a maximum travel speed of around 35 mph and can handle a gradient of approximately 40%. Because they articulate, they have a smaller turning radius as a benefit.
The horsepower ratings of both the DA30 and DA40 have been increased by 8% over Tier 3 models. The DA30 uses operator-engaged interaxle and rear differential locks. It has limited slip front and rear differentials. The DA40 uses operator engaged inter-axle lock with limited slip front and rear differentials. All differential locks can be engaged on the fly and they will also disengage at preset ground speed.
Ejector bodies are available as custom order on both models, and the current DA40 has improved nitrogen gas/oil struts on the front suspension. A single rear axle on both models has unique gear-driven oil-bathed tandem housings that allow constant ground contact.
Wet disc brakes are featured on all wheels of both models, not just front and center axle wheels. Both engine brake and transmission hydraulic retarder standard equipment
Volvo’s Articulated Haulers
The F-Series articulated haulers from Volvo Construction Equipment not only meet the demanding standards set by the Tier 4 Interim (US) and Stage IIIB (Europe) emissions legislation, but also feature a package of improvements in functionality, design, and maintenance. The F-Series ranges from the 24-26.5 ton A25F up to the 43-ton A40F.
Having developed the articulated hauler approach in the 1960s, Volvo says it is still the market leader. Central to the Volvo design is the articulated steering system, which gives operators good control of the machine through both its high steering force in tough off-road conditions (e.g., deep mud) and also its accurate, safe operation at high hauling speeds. The self-compensating hydromechanical system also affords exceptionally short turning circles. It is useful in confined loading and dumping areas and on tightly turning haul roads.
Volvo says durability and strength are the hallmarks of all its haulers. Heavy-duty front and rear frames have been designed for severe off-road operation and long service life. The load body is also heavy duty, made from HB400 steel, and its design, high dump clearance, and tipping angle all promote good material ejection. A powerful, load sensing “closed center” hydraulic system and double acting, single-stage hoist cylinders raise the body even on steep downhill gradients. The system allows for precise, controllable dumping-shortening cycle times and aiding safety.
The company says that a load-and-dump brake is applied by pressing a button in the cab to apply the service brakes and shift the transmission to neutral, further increasing safety and reducing operator fatigue. All machines also feature new dumping functions-detent body lowering and, notably, the adjustable tipping angle. Using the onboard Contronics system, operators can set the maximum tipping angle and, therefore, overall height of the body, ensuring safety when working under electrical wires, in tunnels or underground, for example.
Freightliner Trucks
With set-forward or setback front axles, a full range of severe duty vocational suspensions and a wide selection of efficient and powerful engines, Freightliner dump trucks are tough, reliable and enhance the bottom line, says Mary Aufdemberg, director of product marketing for Freightliner Trucks.
The 122SD is the flagship vocational truck model from Freightliner. The 122SD is a heavy commercial truck that can haul anything from granite to logs to heavy equipment across the most challenging of terrains.
Mack Trucks
The Mack Granite truck comes in axle forward and axle back configurations and is powered by Mack MP7 and MP8 engines. The MP7 is an 11-liter engine rated at 325 to 405 horsepower and delivering 1,200 to 1,560 ft.-lb. of torque. The MP8 is a 13-liter engine rated from 415 to 505 horsepower and delivering 1,560 to 1,760 ft.-lb. of torque.
Mack Granite models can be equipped with the Mack T300 series manual transmissions available in 8-, 9-, 10-, 13-, and 18-speed versions. Also available are Eaton Fuller manual transmissions and Allison automatic transmissions.
The Granite is available as a single-steer axle, rated at 12,000 through 23,000 pounds, or is available with twin steer axles. The rear axle can be ordered in single drive rated at 23,000 to 30,000 pounds, a tandem rear axle rated from 38,000 pounds through 65,000 pounds with special options for 80,000 and 100,000 pounds, or a tri-drive combination rated up to 69,000 pounds. The suspensions offered are Mack Camelback, Mack Walking Beam, Mack AL Air Leaf, and the new Mack mRIDE spring suspension launched in March 2013. The Granite also can be ordered with suspensions from Hendrickson, Chalmers, and other suppliers, in both mechanical and air ride versions.
Mack’s mRIDE suspension is a high-articulation mechanical suspension design using spring leafs supported at each end by rubber shock towers. The suspension is then dampened at all four corners by shock absorbers and tied together with a six-rod system. Combined with Mack axles, the suspension delivers a lightweight, stable, and smooth ride with excellent ground clearance and more than 15 inches of articulation. The mRIDE is available in 40,000-pound, 46,000-pound, and 52,000-pound ratings, and is in production today.
Mack axles come standard with Mack’s patented inter-wheel power divider. Mack and vendor axles can be ordered with power divider inter-axle lockouts and driver-controlled differential locks. Bendix and Meritor ABS are available, and both can be specified to include auto traction control. An all-wheel drive version can also be special ordered from the factory.
Navistar
Last July, Navistar announced the launch of its heavy-duty International WorkStar vocational trucks powered by the company’s 13-liter engine with selective catalytic reduction (SCR) emissions technology. The WorkStar is the fourth heavy-duty International truck model to transition to SCR technology since December 2012.
The company’s portfolio of SCR-based heavy-duty trucks also includes the International ProStar, International PayStar 5900 Set-Back Axle, and International 9900i-all available with the Cummins ISX15 engine. In addition, Navistar’s proprietary 13-liter engine with SCR was launched in the ProStar in April and is now available in the WorkStar. The remaining lineup of International heavy-duty truck models will transition to SCR emissions technology in a phased launch in the coming weeks based on volume and customer demand.
Navistar claims that the WorkStar is designed to take on the heaviest loads and the most rugged jobs. The heavy-duty WorkStar model includes two variations, 7600 SBA (46-inch set-back axle) and 7600 SFA (30-inch set-forward axle). Both models feature a 113-inch BBC (bumper to back-of-cab).
Peterbilt’s Construction Truck
One of Peterbilt’s newest vehicles is the vocational Model 567, introduced last March during the Mid-America Trucking Show in Louisville, KY. The Model 567 is now in full production, says Charles Cook, Peterbilt product marketing segment manager. This versatile truck and tractor can be configured to meet the full range of severe-service vocational customer needs, including dump, mixer, heavy haul, and refuse. This all-new model is available in both a 121- and 115-inch BBC and can be configured as a day cab or with one of three detachable sleepers: 44-, 70-, or 80-inch. Additionally, it can be spec’d with a wide range of heavy-duty components and axles, including single, tandem, tridem, and lift.
The Model 567 is standard with the Paccar MX-13 Engine, available in ratings from 380 to 500 horsepower and 1,450 to 1,850 lb-ft of torque. Optional engine choices include the Cummins ISX12 and ISX15, the latter available up to 600 horsepower and 2,050 lb-ft torque. To match customer requirements, including ease of operation and fuel efficiency, a wide range of transmissions are available. The Model 567 can be spec’d with a manual 9-, 10-, 11-, 13-, or 18-speed Fuller, the Fuller automated UltraShift or the Allison automatic.
The Model 567’s steer axle is available rated up to 22,000 pounds. Rear drive axles are available rated up to 70,000 pounds. A broad range of rear suspensions are available, including Peterbilt’s Air Leaf, FLEX Air, Low Air Leaf, and Air Trac; Reyco’s 79KB, 102 and 102AR; Hendrickson’s HMX and RT; Chalmers’ 854; and Neway’s ADZ.
Front air-disc brakes are standard as is the Bendix Electronic Stability Control System with Automated Traction Control. In addition to greater straight-line braking control, these systems combine to provide added stability and traction by applying the brakes when excessive wheel slip or a critical stability threshold is detected.
Other key features of the Model 567 include outstanding visibility and an operator environment that promotes comfort and productivity. The one-piece windshield and narrow, reinforced A-pillars allow for a panoramic view from the cab, enhancing safety on congested job sites. The quiet, ergonomic cab is a roomy 2.1 meters wide. The new gauge panel is easy to read, completely visible through the steering wheel, and provides critical and functional information to the driver. The Model 567 also features a 5-inch color driver information display that provides operators with a wide array of information, including an engine-RPM sweet-spot indicator to help drivers maximize fuel economy. A secondary panel can house up to six optional gauges or, when specified, Peterbilt’s SmartNav audio and navigation system.
Western Star
Western Star will continue to offer its rugged 4900 model lineup in 2014 for dump applications, says Peter Schimunek, marketing segment manager, Western Star. Available in a set-back and set-forward configuration, the 4900 provides a powerful and versatile solution for demanding vocational jobs.
With its bodybuilder-friendly design, the 4900 is designed to reduce installation time and extend the truck’s longevity. It can also be spec’d with lightweight components for weight-sensitive applications.
Combined with Western Star’s hallmark roomy cab, ample storage space, plush seating the 4900 delivers the best in performance, durability, and comfort on-road and off-road for the toughest jobs.
Kenworth’s New T880 Vocational Truck
“The T880 features a panoramic windshield for enhanced visibility, quiet cab with its triple-sealed and robust doors, five-piece hood for easier and faster repairs, air-assisted hydraulic clutch, complex reflector headlamps, excellent maneuverability, and new lightweight, factory-installed lift axles that vocational customers will especially appreciate,” said Kevin Baney, Kenworth chief engineer. “On top of all that, we designed the T880 with distinctively sculpted lines that form an evolutionary, but uniquely Kenworth look.”
The new T880 is for vocational applications, including dump, mixer, refuse, and heavy haul. Its addition will complement Kenworth’s current vocational lineup that includes the T800, T440, W900S, and C500.
The Kenworth T880 is standard with the 12.9-liter Paccar MX-13 engine. With its high-end ratings of 500 horsepower and 1,850 lb-ft of torque, the Paccar MX-13 engine provides a lightweight, fuel-efficient engine option for vocational applications, including dumps and heavy-haul applications over 100,000 pounds. The T880 also is available with the Cummins ISX15 engine with up to 600 horsepower and 2,050 lb-ft of torque.
The T880 uses Kenworth’s 2.1-meter wide, stamped aluminum cab, which is robotically assembled. The cab has a comfortable 23 inches of room between the seats. The T880 offers the premium Diamond VIT and Vantage trim levels and two interior color options of sandstone tan and slate gray.
