The Caterpillar 797 is a series of off-highway, ultra class, two-axle, mechanical powertrainhaul trucks developed and manufactured in the United States by Caterpillar Inc. specifically for high-production mining and heavy construction applications worldwide.[1] In production since 1998, the 797 series represents Caterpillar’s largest, highest capacity haul trucks.[2] The current, third-generation model, the 797F, offers one of the largest haul truck payload capacities in the world, up to 400 short tons (363t) and has the highest payload capacity among mechanical drive haul trucks.[3]
In 1997, Caterpillar decided to begin the development of a 360 short tons (327t) payload capacity haul truck to meet the demand from large-scale mine operators wanting to reduce operating costs at mines using 80 to 90 short tons (73 to 82 t) per pass shovels.[4]Engineers at Caterpillar's Mining & Construction Equipment Division in Decatur, Illinois, created a new design for the 797 using computer-aided design technology. This was the first time CAD tools had been used extensively to design a Caterpillar truck.[4]
797 (1998–2002)
Caterpillar first unveiled a completed 797 on September 29, 1998, at its assembly plant in Decatur, Illinois. The first two 797s produced were transported to Caterpillar's Arizona proving grounds for testing. In the second quarter of 1999, the third and fourth 797s produced were the first to be placed in service with a customer at the Bingham Canyon Mine in Utah. Caterpillar put 18 additional 797s into service with mine operators worldwide, as production development units.
Caterpillar began marketing the 797 in North America in 2000, with full worldwide marketing following in 2001. The first generation serial number prefix is 5YW.[4]
797B (2002–2009)
Caterpillar introduced the 797B in the spring of 2002, replacing the first-generation 797. The 797B's increased payload capacity of 345t (380 short tons) is a 18.1t (20 short tons) increase over the first generation 797. Caterpillar increased the power output of the Cat 3524B EUI 24-cylinder diesel engine used in the 797 from net 2,394kW (3,211hp) to net 2,513kW (3,370hp) enabling the 797B to achieve a 68km/h (42mph) top speed when transporting a 345t (380 short tons) load, a 3.2km/h (2mph) increase over the first generation 797.[5]
The first 797B units entered service with customers in October 2002.[6]
797F (2009–present)
Caterpillar introduced the 797F to the public at MINExpo International in September, 2008. The 797F replaced its predecessor model, the 797B, when the 797F entered full production in late 2009.[7][8] Prior to the introduction of the Caterpillar 797F and the Bucyrus MT6300AC at MINExpo International in September, 2008, the Liebherr T 282B, introduced in 2004, was the only haul truck with a payload capacity of 400 short tons (363t).
Compared to the 797B, the 797F has a higher payload capacity and a more powerful, more efficient engine. These changes allowed Caterpillar to meet mine operator's needs to increase operational efficiency and reduce costs by increasing the amount of material hauled per trip.
The 797F's increased payload capacity of 400 short tons (363t) is a 20 short tons (18.1t) increase over the 797B.[3]
Caterpillar replaced the gross 3,550hp (2,647kW) [net 3,370hp (2,513kW)] Cat 3524B EUI 24-cylinderdiesel engine used in the 797B with the gross 4,000hp (2,983kW) [net 3,793hp (2,828kW)] Cat C175-20 ACERT 20-cylinder diesel engine, enabling the 797F to maintain the 42mph (68km/h) top speed of the 797B while transporting a heavier 400 short tons (363t) payload.[9]
Powertrain
The Caterpillar 797 series trucks employ mechanical drive powertrains in contrast to the diesel-electric powertrains of similar haul trucks offered by competitors.[4] During initial development in 1997, a diesel-electric powertrain was considered for the 797, but this powertrain configuration was not developed because Caterpillar considered a mechanical drive powertrain more appropriate for market conditions at that time.[10]
797 engine
A gross 3,400hp (2,535kW) [net 3,211hp (2,394kW)] Cat 3524B HD EUI 24-cylinder, electronicunit injection, quad single-stage turbocharged, liquid aftercooled, four-strokedieselengine powers the 797.[11][12] The Cat 3524B HD engine is a tandem unit consisting of two 12-cylinder Cat 3512B HD engine blocks coupled to operate as a single engine with a combined displacement of 106 liters (6468 cubic inches).[13]
797B engine
A gross 3,550hp (2,647kW) [net 3,370hp (2,513kW)], quad turbocharged Caterpillar 3524B engine powers the 797B.[5] The power rating of the 3524B is valid up to an elevation of 8,500ft (2,591m) or 15,000ft (4,572m) with a high altitude arrangement.[5]
797F engine
A gross 4,000hp (2,983kW) [net 3,793hp (2,828kW)] Cat C175-20 ACERT single block, 20-cylinder, electronic common rail injection, quad turbocharged, air-to-air aftercooled, four-stroke diesel engine powers the 797F.[9] The power rating of the C175-20 is valid up to an elevation of 7,000ft (2,134m) or up to 16,000ft (4,877m) with a high altitude arrangement.[14]
Transmission
The 797 series haul trucks are equipped with a rear-axle-mounted, computer-controlled, seven-speed planetarytransmission with a separate lock-up torque converter. Both transmission and torque converter use a common powertrain oil.[5]
Wheels and tires
Each 797 wheel is attached to the axle using 54 - 36mm (1.4in) nuts that are torqued to 2,300lb⋅ft (3,118N⋅m).[15] A size 55/80R63 radial tire was developed by Michelin in conjunction with Caterpillar specifically for the first generation 797.[16] The Caterpillar 797B and 797F run 4.028m (13.22ft) tall, 5,300kg (11,680lb)Michelin 59/80R63 XDR. Most first generation 797s have been retrofitted to use the 59/80R63 tires as well.[17] Six tires are required per truck at a cost in 2009 of approximately US$42,500 per tire.[18]
Manufacturing and assembly
CAT 797 haul truck at the North Antelope Rochelle opencut coal mine.
Major components of the 797 are manufactured and assembled at seven Caterpillar or supplier facilities located throughout North America, then shipped to the customer site for final assembly by Caterpillar technicians.
The tires are manufactured by Michelin North America at the US7 Earthmover Manufacturing plant in Lexington, South Carolina, and are shipped to the customer site.
The driver's cab is manufactured by Bergstrom Climate Control Systems' Contract Assembly division in Joliet, Illinois. Each cab is assembled by one person and requires forty hours to complete. The cab is shipped to the customer site.
The dump body is composed of five components: the floor, the two sides, the front wall and the canopy. The dump body is manufactured at Caterpillar Mexico in Monterrey, Mexico, as well as at least to a limited degree by WesTech of Casper, Wyoming in the western United States and shipped in component form to the customer site where it is assembled and welded into a monolithic structure before being joined to the frame during final assembly.
The frame is created from nine individual metal castings manufactured by Harrison Steel Castings Co., in Attica, Indiana and by Amite Foundry and Machine, Inc., in Amite City, Louisiana. The smallest casting weighs 500lb (230kg) and the largest casting weighs 12,000lb (5,400kg). The rough castings are shipped to the Caterpillar Decatur, Illinois, assembly plant.
At Caterpillar's assembly plant in Decatur, Illinois, the frame is assembled and the powertrain is installed and tested.
The nine castings that compose the frame are machined to provide clean welding surfaces. The castings are placed in a jig, and are initially joined by human welders. The frame is moved to a second welding station for further welding by robots. The third and final welding stage is completed by human welders. To ensure quality, welds are tested using an ultrasonic flaw detector. In total, 275lb (125kg) of welding wire is used to join the individual castings into a monolithic frame.
After the frame assembly is completed, production workers attach hydraulic lines and electrical wiring to the frame before installing the engine and rear axle. The frame/powertrain assembly is tested and then partially disassembled to facilitate shipping from Caterpillar's Decatur, Illinois assembly plant to the customer site.[15]
Transportation
The engine, frame, axles and differential requires six to seven semi-trailer truck loads, the cab requires one semi-trailer load, the six tires require two semi-trailer loads and the dump body requires four semi-trailer loads. In total, one 797 requires 12 to 13 semi-trailer truck loads that originate at various manufacturing facilities and deliver to the customer site. If a 797 must be moved from one job site to another for any reason, it cannot be driven on public roads due to its exceptional size and weight. Moving a 797 requires dis-assembly, loading onto semi-trailer trucks, transport and re-assembly at the new location.
Final assembly
Final assembly of the 797 is completed by Caterpillar field mechanics at or near the customer site. Before the dump body can be joined to the frame, the dump body components must be assembled and welded together by a dedicated team, requiring seven to ten days per dump body. Final assembly of one 797 requires a team of seven mechanics working in three shifts around the clock, for 20 days, in addition to the time required to assemble and weld the dump body.[15]
Cost
Although the price varies based on individual customer specifications, each 797 costs approximately US$5,000,000.[15] Other prices have been listed at US$3,400,000.[20]
Service life
All major components of the 797 can be serviced or replaced during the useful life of the truck, except for the frame. The overall service life of the truck is therefore dependent upon the durability of the frame which Caterpillar estimates to have a twenty-year service life.[15]
Competition
The Liebherr T 282 B and Bucyrus MT6300AC, as well as Caterpillar's own 798AC, match the Caterpillar 797F's 400 short tons (363t) payload capacity, but employ diesel/electric powertrains in contrast to the 797F's diesel-powered, mechanical powertrain. Both fall short of the BelAZ 75710's 500 short ton capacity, the largest of any haul truck in the world, which also employs a diesel/electric powertrain. Depending on customer requirements, lower payload capacity 360 short tons (327t) products such as the Komatsu 960E-1 and Belaz 75600 may also place competitive pressure on sales of the 797F.
The Heavy Expanded Mobility Tactical Truck (HEMTT) is an eight-wheel drive, diesel-powered, 10-short-ton (9,100 kg) tactical truck. The M977 HEMTT first entered service in 1982 with the United States Army as a replacement for the M520 Goer, and since that date has remained in production for the U.S. Army and other nations. By Q2 2021, around 35,800 HEMTTs in various configurations had been produced by Oshkosh Defense through new-build contracts and around 14,000 of these had been re-manufactured. Current variants have the A4 suffix.
A V20 engine is a twenty-cylinder piston engine where two banks of ten cylinders are arranged in a V configuration around a common crankshaft. Large diesel V20 engines have been used in diesel locomotives, haul trucks, electric generators and marine applications.
A dump truck, known also as a dumping truck, dump trailer, dumper trailer, dump lorry or dumper lorry or a dumper for short, is used for transporting materials for construction as well as coal. A typical dump truck is equipped with an open-box bed, which is hinged at the rear and equipped with hydraulic rams to lift the front, allowing the material in the bed to be deposited ("dumped") on the ground behind the truck at the site of delivery. In the UK, Australia, South Africa and India the term applies to off-road construction plants only and the road vehicle is known as a tip lorry, tipper lorry, tipper truck, tip truck, tip trailer or tipper trailer or simply a tipper.
The Liebherr T 282 series are off-highway, ultra class, rigid frame, two axle, diesel-electric, AC powertrain haul trucks designed and manufactured in the United States by Liebherr Mining Equipment Co.
The P&H L-2350 Wheel Loader is a loader used for surface mining. It is manufactured by Komatsu Limited. It holds the Guinness World Record for Biggest Earth Mover. Designed to center-load haul trucks with capacities of up to 360 tonnes, the L-2350 provides an operating payload of 73 tonnes, a 7.03 metres (23.1 ft) lift height, and an 3.5 metres (11.5 ft) reach.
The Mitsubishi Fuso Canter is a line of light-duty commercial vehicles manufactured by Mitsubishi Fuso Truck and Bus Corporation, part of Daimler Truck, subsidiary of Mercedes-Benz Group. The Canter is manufactured since 1963, now in its eighth generation. The Canter is named after the English word describing the gait of a horse, emphasising the 'thoroughbred' nature of Mitsubishi trucks.
The Euclid Company of Ohio was a manufacturer which specialized in heavy equipment for earthmoving, particularly dump trucks, loaders and wheel tractor-scrapers. It operated in the US from the 1920s to the 1950s, when it was purchased by General Motors. The firm was later bought by Hitachi Construction Machinery.
The Komatsu 930E is an off-highway, ultra class, rigid frame, two-axle, diesel/AC electric powertrain haul truck designed and manufactured by Komatsu in Peoria, Illinois, United States. Although the 930E is neither Komatsu's largest nor highest payload capacity haul truck, Komatsu considers the 930E to be the flagship of their haul truck product line.
The Komatsu 830E is an ultra class haul truck used in open pit mining designed and built in Peoria, Illinois by Komatsu America Corporation, whose parent company is the Japanese held company Komatsu Ltd.
Haul trucks are off-road, heavy-duty dump trucks specifically engineered for use in high-production mining and exceptionally demanding construction environments. Most are dual axle; at least two examples of tri-axles were made in the 1970s. Haul trucks are denominated by their payload capacity, by weight.
The DAC 120 DE is a diesel-electric haul truck manufactured between 1988 and 1990 by Steagul Roșu Brașov Romania and by Mecanica Mârşa Works.
The Caterpillar 777 is a 100-ton haul truck, typically used in open pit mining, manufactured by Caterpillar Inc.
The M1120 HEMTT LHS is a M977 Heavy Expanded Mobility Tactical Truck with a load handling system in place of a flat bed/cargo body. The HEMTT is an eight-wheel drive, diesel-powered, tactical truck used by the US military and others. The HEMTT is manufactured by Oshkosh Defense and entered Army service in 1982, with the M1120 variant first produced in 1999.
P&H Mining Equipment sells drilling and material handling machinery under the "P&H" trademark. The firm is an operating subsidiary of Joy Global Inc. In 2017 Joy Global Inc. was acquired by Komatsu Limited of Tokyo, Japan, and is now known as Komatsu Mining Corporation and operates as a subsidiary of Komatsu.
The Bucyrus MT6300AC is an off-highway, ultra class, two-axle, diesel/AC electric powertrain haul truck designed and manufactured by Bucyrus International Inc. in the United States. The MT6300AC is Bucyrus' largest, highest payload capacity haul truck, offering one of the largest haul truck payload capacities in the world, up to 400 short tons (363 t). The closest analogs are Liebherr T 282B, Caterpillar 797F, which can carry the same weight, and BelAZ 75710 with 450 tons payload capacity.
The Komatsu 960E-1 (960E) is an off-highway, ultra-class, rigid-frame, two-axle, diesel/AC electric powertrain haul truck designed and manufactured by Komatsu in Peoria, Illinois, United States. The 960E-1 has been Komatsu's largest, highest capacity haul truck, offering a payload capacity of up to 360 short tons (327 t). The 960-E1 is the first generation of the 960E series of haul trucks and is alternately referred to by Komatsu specifically as the 960E-1 or generally as the 960E.
The Terex 33-19 "Titan" was a prototype off-highway, ultra class, rigid frame, three-axle, diesel/AC electric powertrain haul truck designed by the Terex Division of General Motors and assembled at General Motors Diesel Division's London, ON, Canada assembly plant in 1973. Only one 33-19 was ever produced and it was the largest, highest capacity haul truck in the world for 25 years. After 13 years in service, the 33-19 was restored and is now preserved on static display as a tourist attraction in Sparwood, BC, Canada.
Unit Rig was a manufacturer of haul trucks, sold under the brand name Lectra Haul.
The BelAZ 75710 is an ultra class haul truck manufactured in Belarus by BelAZ. As of 2013, it was the world's largest, highest payload capacity haul truck.
The Caterpillar C32 is a V12 diesel engine made by Caterpillar Inc. The engine displacement is 32.1 liters. The cylinder size is 5.71 inches x 6.38 inches bore/stroke. The engine can produce up to 1900 horsepower at 2300 rpm. The peak torque of 5532 lb-ft occurs at an engine speed of 1300 to 1800 RPM. The engine weighs over three tons at 6780 pounds. The C32 is used in CAT equipment including the 777G mining truck and the D11T bulldozer. It is also sold for use in rail and marine applications, and for other industrial applications such as crushers, pumps, and drills.
References
↑ "Off-Highway Trucks from Caterpillar". Caterpillar Website. Caterpillar Inc. Archived from the original on 2009-09-24. Retrieved 2009-10-21. Developed specifically for high production mining and heavy-duty construction applications...
1 2 3 4 Mercer, Mike (June 1999). "A look at Cat's new 797 haul truck - Caterpillar Inc". Diesel Progress North American Edition. CBS Interactive Inc. p.1. Retrieved 2009-10-27. Caterpillar designed the truck in response to mining companies seeking a means to reduce cost per ton...
1 2 "Caterpillar 797F Mining Truck Product Brochure AEHQ6039"(PDF). Caterpillar Website. Caterpillar Inc. September 2009. p.3. Archived from the original(PDF) on 2009-10-21. Retrieved 2009-10-28. Gross Power - SAE J1995 2983 kW 4,000 hp....The Cat C175-20 quad turbocharged and air-to-air aftercooled diesel engine...is a 20 cylinder, single block, four stroke design...
↑ Orlemann, Eric C. (2002). "Chapter 2 - The World's Largest Mechanical Drive Truck - 797 Haul Truck". In Kris Palmer (ed.). Colossal Caterpillar: The Ultimate Earthmover. United States of America: MBI Publishing. p.44. ISBN0-7603-0874-8. Retrieved 2009-10-27.
↑ Mercer, Mike (March 1999). "New era of mine haul truck giants". Diesel Progress North American Edition. CBS Interactive Inc. p.3. Retrieved 2009-12-10. ...diesel engine, which features electronic unit injection, an ADEM II electronic controller, aftercooling and four single-stage turbochargers.
↑ "Caterpillar 797F Mining Truck Product Brochure (AEHQ6039)"(PDF). Caterpillar Website. Caterpillar Inc. September 2009. p.14. Archived from the original(PDF) on 2009-10-21. Retrieved 2009-10-28. No low altitude arrangement (LAA) engine derating required up to 2134m (7,000 ft) altitude. No high altitude arrangement (HAA) engine derating required up to 4877 m (16,000 ft) altitude.
↑ Mercer, Mike (June 1999). "A look at Cat's new 797 haul truck - Caterpillar Inc". Diesel Progress North American Edition. CBS Interactive Inc. p.2. Retrieved 2009-10-27. This new tire was developed in conjunction with Caterpillar for this application.
↑ "Michelin Factbook - 2007 Edition". Michelin Corporate Website. Manufacture Française des Pneumatiques Michelin. 2007. p.15. Archived from the original(Shockwave Flash Presentation) on 2011-09-26. Retrieved 2009-10-27. 59/80 R 63 Michelin XDR Diameter: 4,028 meters...Weight: 5,300 kg...
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