Caterpillar 797B
Encyclopedia
The Caterpillar 797 is a series of off-highway
Highway
A highway is any public road. In American English, the term is common and almost always designates major roads. In British English, the term designates any road open to the public. Any interconnected set of highways can be variously referred to as a "highway system", a "highway network", or a...

, ultra class, two-axle
Axle
An axle is a central shaft for a rotating wheel or gear. On wheeled vehicles, the axle may be fixed to the wheels, rotating with them, or fixed to its surroundings, with the wheels rotating around the axle. In the former case, bearings or bushings are provided at the mounting points where the axle...

, mechanical powertrain
Powertrain
In a motor vehicle, the term powertrain or powerplant refers to the group of components that generate power and deliver it to the road surface, water, or air. This includes the engine, transmission, drive shafts, differentials, and the final drive...

 haul trucks developed and manufactured in the United States by Caterpillar Inc.
Caterpillar Inc.
Caterpillar Inc. , also known as "CAT", designs, manufactures, markets and sells machinery and engines and sells financial products and insurance to customers via a worldwide dealer network. Caterpillar is the world's largest manufacturer of construction and mining equipment, diesel and natural gas...

 specifically for high production mining
Mining
Mining is the extraction of valuable minerals or other geological materials from the earth, from an ore body, vein or seam. The term also includes the removal of soil. Materials recovered by mining include base metals, precious metals, iron, uranium, coal, diamonds, limestone, oil shale, rock...

 and heavy-duty construction
Construction
In the fields of architecture and civil engineering, construction is a process that consists of the building or assembling of infrastructure. Far from being a single activity, large scale construction is a feat of human multitasking...

 applications world-wide
World
World is a common name for the whole of human civilization, specifically human experience, history, or the human condition in general, worldwide, i.e. anywhere on Earth....

. In production since 1998, the 797 series represents Caterpillar’s largest, highest capacity haul trucks. The current, third-generation model, the 797F
Caterpillar 797F
The Caterpillar 797F is an off-highway, ultra class, two-axle, mechanical powertrain haul truck developed and manufactured by Caterpillar Inc. in the United States specifically for high production mining and heavy-duty construction applications worldwide...

, offers one of the largest haul truck payload
Cargo
Cargo is goods or produce transported, generally for commercial gain, by ship, aircraft, train, van or truck. In modern times, containers are used in most intermodal long-haul cargo transport.-Marine:...

 capacities in the world, up to 400 ST (362.9 t) and is the world's largest, highest payload capacity, mechanical drive haul truck.

Initial development

In 1997, Caterpillar decided to begin development of a 360 ST (326.6 t) 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. Engineer
Engineer
An engineer is a professional practitioner of engineering, concerned with applying scientific knowledge, mathematics and ingenuity to develop solutions for technical problems. Engineers design materials, structures, machines and systems while considering the limitations imposed by practicality,...

s at Caterpillar's Mining & Construction Equipment Division in Decatur, Illinois
Decatur, Illinois
Decatur is the largest city and the county seat of Macon County in the U.S. state of Illinois. The city, sometimes called "the Soybean Capital of the World", was founded in 1823 and is located along the Sangamon River and Lake Decatur in Central Illinois. In 2000 the city population was 81,500,...

 created a new design for the 797 using computer-aided design
Computer-aided design
Computer-aided design , also known as computer-aided design and drafting , is the use of computer technology for the process of design and design-documentation. Computer Aided Drafting describes the process of drafting with a computer...

 technology. This was the first time CAD tools had been used extensively to design a Caterpillar truck.

797 (1998 - 2002)

Caterpillar first unveiled a completed 797 on September 29, 1998 at the Decatur, Illinois assembly plant.

Testing

The first two 797's produced were transported to Caterpillar's Arizona
Arizona
Arizona ; is a state located in the southwestern region of the United States. It is also part of the western United States and the mountain west. The capital and largest city is Phoenix...

 proving grounds for testing. In the second quarter of 1999, the third and fourth 797's produced were the first to be placed in service with a customer at the Bingham Canyon Mine
Bingham Canyon Mine
The Bingham Canyon Mine, also known as the Kennecott Copper Mine, is an open-pit mining operation extracting a large porphyry copper deposit southwest of Salt Lake City, Utah, USA, in the Oquirrh Mountains. It is the deepest open-pit mine in the world. The mine is owned by Rio Tinto Group, an...

 in Utah
Utah
Utah is a state in the Western United States. It was the 45th state to join the Union, on January 4, 1896. Approximately 80% of Utah's 2,763,885 people live along the Wasatch Front, centering on Salt Lake City. This leaves vast expanses of the state nearly uninhabited, making the population the...

. Caterpillar put 18 additional 797's into service with mine operators world-wide as production development units.

Full worldwide marketing

Caterpillar began marketing the 797 in North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

 in 2000, with full world-wide marketing
Marketing
Marketing is the process used to determine what products or services may be of interest to customers, and the strategy to use in sales, communications and business development. It generates the strategy that underlies sales techniques, business communication, and business developments...

 following in 2001.

797B (2002 - 2009)

Caterpillar introduced the 797B in spring of 2002, replacing the first-generation 797. Caterpillar increased the power output of the Cat 3524B engine to cope with the 797B's higher payload capacity of up to 380 ST (344.7 t), a 20 ST (18.1 t) improvement over the 797. The first 797B units entered service with customers in October, 2002.

797F (2009 - Present)

Caterpillar introduced the latest 797 in the series, the 797F, at MINExpo International
MinExpo International
MinExpo International is a trade show sponsored by the National Mining Association. The show exhibits the latest mining and minerals processing technologies, and state-of-the-art machinery and equipment for the coal, metal and nonmetal mining processing industries...

 in September, 2008. When Caterpillar began full production of the 797F in late 2009, the 797F replaced the 797B.

The 797F comes equipped with a new, more powerful and more efficient Cat C175-20 engine and an increased payload capacity of up to 400 ST (362.9 t).

Powertrain

The Caterpillar 797 series trucks employ mechanical
Machine
A machine manages power to accomplish a task, examples include, a mechanical system, a computing system, an electronic system, and a molecular machine. In common usage, the meaning is that of a device having parts that perform or assist in performing any type of work...

 drive powertrain
Powertrain
In a motor vehicle, the term powertrain or powerplant refers to the group of components that generate power and deliver it to the road surface, water, or air. This includes the engine, transmission, drive shafts, differentials, and the final drive...

s in contrast to the diesel-electric powertrains of similar haul trucks offered by competitors. 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.

797 engine

A gross 3400 HP [net 3211 HP] Cat 3524B HD EUI 24-cylinder
Cylinder (engine)
A cylinder is the central working part of a reciprocating engine or pump, the space in which a piston travels. Multiple cylinders are commonly arranged side by side in a bank, or engine block, which is typically cast from aluminum or cast iron before receiving precision machine work...

, high displacement
Engine displacement
Engine displacement is the volume swept by all the pistons inside the cylinders of an internal combustion engine in a single movement from top dead centre to bottom dead centre . It is commonly specified in cubic centimeters , litres , or cubic inches...

, electronic
Electronics
Electronics is the branch of science, engineering and technology that deals with electrical circuits involving active electrical components such as vacuum tubes, transistors, diodes and integrated circuits, and associated passive interconnection technologies...

 unit injection
Unit Injector
Unit Injector is an integrated direct fuel injection system for diesel engines, combining the injector nozzle and the injection pump in a single component...

, quad single-stage turbocharged
Turbocharger
A turbocharger, or turbo , from the Greek "τύρβη" is a centrifugal compressor powered by a turbine that is driven by an engine's exhaust gases. Its benefit lies with the compressor increasing the mass of air entering the engine , thereby resulting in greater performance...

, aftercooled
Intercooler
An intercooler , or charge air cooler, is an air-to-air or air-to-liquid heat exchange device used on turbocharged and supercharged internal combustion engines to improve their volumetric efficiency by increasing intake air charge density through nearly isobaric cooling, which removes...

, four-stroke diesel
Diesel engine
A diesel engine is an internal combustion engine that uses the heat of compression to initiate ignition to burn the fuel, which is injected into the combustion chamber...

 engine
Internal combustion engine
The internal combustion engine is an engine in which the combustion of a fuel occurs with an oxidizer in a combustion chamber. In an internal combustion engine, the expansion of the high-temperature and high -pressure gases produced by combustion apply direct force to some component of the engine...

 powers the 797. The Cat 3524B HD engine is a tandem unit consisting of two 12-cylinder Cat 3512B HD engine blocks
Cylinder block
A cylinder block is an integrated structure comprising the cylinder of a reciprocating engine and often some or all of their associated surrounding structures...

 coupled to operate as a single engine.

797B engine

A gross 3550 HP [net 3370 HP], twin turbocharged version of the Cat 3524B engine powers the 797B. The power rating of the 3524B is valid up to an elevation
Elevation
The elevation of a geographic location is its height above a fixed reference point, most commonly a reference geoid, a mathematical model of the Earth's sea level as an equipotential gravitational surface ....

 of 8500 ft (2,590.8 m) or 15000 ft (4,572 m) with a high altitude
Altitude
Altitude or height is defined based on the context in which it is used . As a general definition, altitude is a distance measurement, usually in the vertical or "up" direction, between a reference datum and a point or object. The reference datum also often varies according to the context...

 arrangement.

797F engine

A gross 4000 HP [net 3793 HP] Cat C175-20 ACERT single block, 20-cylinder, electronic common rail
Common rail
Common rail direct fuel injection is a modern variant of direct fuel injection system for petrol and diesel engines.On diesel engines, it features a high-pressure fuel rail feeding individual solenoid valves, as opposed to low-pressure fuel pump feeding unit injectors...

 injection, quad turbocharged, air-to-air aftercooled, four-stroke diesel engine powers the 797F. The power rating of the C175-20 is valid up to an elevation of 7000 ft (2,133.6 m) or up to 16000 ft (4,876.8 m) with a high altitude arrangement.

Transmission

The 797 series haul trucks are equipped with a rear axle
Axle
An axle is a central shaft for a rotating wheel or gear. On wheeled vehicles, the axle may be fixed to the wheels, rotating with them, or fixed to its surroundings, with the wheels rotating around the axle. In the former case, bearings or bushings are provided at the mounting points where the axle...

 mounted, computer
Computer
A computer is a programmable machine designed to sequentially and automatically carry out a sequence of arithmetic or logical operations. The particular sequence of operations can be changed readily, allowing the computer to solve more than one kind of problem...

 controlled, seven speed planetary transmission
Transmission (mechanics)
A machine consists of a power source and a power transmission system, which provides controlled application of the power. Merriam-Webster defines transmission as: an assembly of parts including the speed-changing gears and the propeller shaft by which the power is transmitted from an engine to a...

 with an integral lock-up torque converter
Torque converter
In modern usage, a torque converter is generally a type of hydrodynamic fluid coupling that is used to transfer rotating power from a prime mover, such as an internal combustion engine or electric motor, to a rotating driven load...

.

Wheels and tires

Each 797 wheel is attached to the axle using 47 nuts that are torqued to 2300 ft-lb (3,118.3 N·m). A size 55/80R63 radial tire
Radial tire
A radial tire is a particular design of automotive tire . In this design, the cord plies are arranged at 90 degrees to the direction of travel, or radially ....

 was developed by Michelin in conjunction with Caterpillar specifically for the first generation 797. The Caterpillar 797B and 797F run on the largest tire
Tire
A tire or tyre is a ring-shaped covering that fits around a wheel rim to protect it and enable better vehicle performance by providing a flexible cushion that absorbs shock while keeping the wheel in close contact with the ground...

 in the world, the 4.028 m (13.2 ft) tall, 5300 kg (11,684.5 lb) Michelin
Michelin
Michelin is a tyre manufacturer based in Clermont-Ferrand in the Auvergne région of France. It is one of the two largest tyre manufacturers in the world along with Bridgestone. In addition to the Michelin brand, it also owns the BFGoodrich, Kleber, Riken, Kormoran and Uniroyal tyre brands...

 59/80R63 XDR. Six tires are required per truck at a cost in 2009 of approximately USD $42,500 per tire.

Manufacturing and assembly

Major components of the 797 are manufactured and assembled at six Caterpillar or supplier facilities located throughout North America, then shipped to the customer site for final assembly by Caterpillar technicians.

The engine is manufactured by Caterpillar in Lafayette, Indiana
Lafayette, Indiana
Lafayette is a city in and the county seat of Tippecanoe County, Indiana, United States, northwest of Indianapolis. As of the 2010 census, the city had a total population of 67,140. West Lafayette, on the other side of the Wabash River, is home to Purdue University, which has a large impact on...

 and is then shipped to Caterpillar's Decatur, Illinois assembly plant.

The tires are manufactured by Michelin North America at the US7 Earthmover Manufacturing plant in Lexington, South Carolina
Lexington, South Carolina
Lexington is a town in and the county seat of Lexington County, South Carolina, United States. The population was 17,870 at the 2010 census.-Geography:Lexington is located at ....

 and are shipped to the customer site.

The driver's cab
Cabin (truck)
The cab of a truck is an enclosed space in a truck where the driver is seated. The word originated as a short form of cabriolet, not cabin. Some may refer to the tractor unit of a semi-trailer truck as a cab, but this is not the subject of this article...

 is manufactured by Bergstrom Climate Control Systems' Contract Assembly division in Joliet, Illinois
Joliet, Illinois
Joliet is a city in Will and Kendall Counties in the U.S. state of Illinois, located southwest of Chicago. It is the county seat of Will County. As of the 2010 census, the city was the fourth-most populated in Illinois, with a population of 147,433. It continues to be Illinois' fastest growing...

. Each cab is assembled by one person and requires forty hours to complete. The cab is shipped to the customer site.

The dump body
Body-on-frame
Body-on-frame is an automobile construction method. Mounting a separate body to a rigid frame that supports the drivetrain was the original method of building automobiles, and its use continues to this day. The original frames were made of wood , but steel ladder frames became common in the 1930s...

 is composed of five components: the floor, the two sides, the front wall and the canopy. The dump body is 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
Frame (vehicle)
A frame is the main structure of the chassis of a motor vehicle. All other components fasten to it; a term for this is design is body-on-frame construction.In 1920, every motor vehicle other than a few cars based on motorcycles had a frame...

 is created from nine individual metal casting
Casting
In metalworking, casting involves pouring liquid metal into a mold, which contains a hollow cavity of the desired shape, and then allowing it to cool and solidify. The solidified part is also known as a casting, which is ejected or broken out of the mold to complete the process...

s manufactured by Amite Foundry and Machine Inc. in Amite City, Louisiana
Amite City, Louisiana
Amite City is a town in and the parish seat of Tangipahoa Parish, Louisiana, United States. The population was 4,110 at the 2000 census. It is part of the Hammond Micropolitan Statistical Area.-Geography:Amite City is located at ....

. The smallest casting weighs 500 lbs and the largest casting weighs 12000 lbs. The rough castings are shipped to the Caterpillar Decatur, Illinois assembly plant.

At Caterpillar's Decatur, Illinois assembly plant, the frame is assembled and the powertrain is installed and tested.

The nine castings that compose the frame are machined
Machining
Conventional machining is a form of subtractive manufacturing, in which a collection of material-working processes utilizing power-driven machine tools, such as saws, lathes, milling machines, and drill presses, are used with a sharp cutting tool to physical remove material to achieve a desired...

 to provide clean welding
Welding
Welding is a fabrication or sculptural process that joins materials, usually metals or thermoplastics, by causing coalescence. This is often done by melting the workpieces and adding a filler material to form a pool of molten material that cools to become a strong joint, with pressure sometimes...

 surfaces. The castings are placed in a jig
Jig (tool)
In metalworking and woodworking, a jig is a type of tool used to control the location and/or motion of another tool. A jig's primary purpose is to provide repeatability, accuracy, and interchangeability in the manufacturing of products. A jig is often confused with a fixture; a fixture holds the...

 and are initially joined by human welders. The frame is moved to a second welding station for further welding by robots
Industrial robot
An industrial robot is defined by ISO as an automatically controlled, reprogrammable, multipurpose manipulator programmable in three or more axes...

. The third and final welding stage is completed by human welders. To ensure quality, welds are tested using an ultrasonic
Ultrasound
Ultrasound is cyclic sound pressure with a frequency greater than the upper limit of human hearing. Ultrasound is thus not separated from "normal" sound based on differences in physical properties, only the fact that humans cannot hear it. Although this limit varies from person to person, it is...

 flaw detector. In total, 275 lbs of welding wire is used to join the individual castings into a monolithic frame.

After the frame assembly is completed, production workers attach hydraulic
Hydraulic machinery
Hydraulic machines are machinery and tools that use liquid fluid power to do simple work. Heavy equipment is a common example.In this type of machine, hydraulic fluid is transmitted throughout the machine to various hydraulic motors and hydraulic cylinders and which becomes pressurised according to...

 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.

Transportation

The engine, frame, axles and differential requires six to seven semi-trailer truck
Semi-trailer truck
A semi-trailer truck, also known as a semi, tractor-trailer, or articulated truck or articulated lorry, is an articulated vehicle consisting of a towing engine , and a semi-trailer A semi-trailer truck, also known as a semi, tractor-trailer, or (in the United Kingdom and Ireland) articulated 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 can not be driven on public roads due to its exceptional size and weight. Moving a 797 requires dis-assembly, loading on to 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, seven days per week for 20 days in addition to the time required to assemble and weld the dump body.

Cost

Although the price varies based on individual customer specifications, each 797 costs approximately USD $5,000,000.

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.

Competition

The Liebherr T 282 B
Liebherr T 282B
The Liebherr T 282B is an off-highway, ultra class, rigid frame, two-axle, diesel/electric, AC powertrain haul truck designed and manufactured by the Liebherr Mining Equipment Co. in Newport News, Virginia, USA...

 and Bucyrus MT6300AC
Bucyrus MT6300AC
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...

 both match the Caterpillar 797F's 400 ST (362.9 t) payload capacity, but employ diesel/electric powertrains in contrast to the 797F's diesel-powered, mechanical powertrain. Depending on customer requirements, lower payload capacity 360 ST (326.6 t) products such as the Komatsu 960E-1 may also place competitive pressure on sales of the 797F.

Comparison chart

Caterpillar 797 Series Comparison Chart
797 797B 797F
Introduction to Service 1999 2002 2008
Nominal Payload Capacity 360 ST (326.6 t) 380 ST (344.7 t) 400 ST (362.9 t)
Engine Power 3211 HP net 3370 HP net (SAE J1349) 3793 HP net (SAE J1349)
Engine Model 3524B High Displacement EUI Cat 3524B High Displacement EUI Cat C175-20 ACERT
Engine Arrangement V-12 x 2 V-12 x 2 V-20
Top Speed (Loaded) 40 mph (64.4 km/h) 42 mph (67.6 km/h) 42 mph (67.6 km/h)
Gross Machine Operating Weight 1230000 lb (557,918.6 kg) 1375000 lb (623,689.5 kg) 1375000 lb (623,689.5 kg)
Overall Height to Top of ROPS (Empty) 23 in 8 in (7.21 m) 24 in 11 in (7.59 m) 24 in 5 in (7.44 m)
Overall Height (Body Raised) 49 in 3 in (15.01 m) 50 in 2 in (15.29 m) 51 in 6 in (15.7 m)
Overall Length 47 in 7 in (14.5 m) 47 in 5 in (14.45 m) 49 in 6 in (15.09 m)
Overall Tire Width 30 in 0 in (9.14 m) 32 in 0 in (9.75 m) 31 in 3 in (9.53 m)
Fuel Capacity 1000 US gal (3,785.4 l) 1800 US gal (6,813.7 l) 1000 US gal (3,785.4 l)

See also

  • Bucyrus MT6300AC
    Bucyrus MT6300AC
    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...

  • Komatsu 960E-1
    Komatsu 960E-1
    The Komatsu 960E-1 is an off-highway, ultra-class, rigid-frame, two-axle, diesel/AC electric powertrain haul truck designed and manufactured by Komatsu America Corp. in Peoria, Illinois, United States. The 960E-1 is Komatsu's largest, highest capacity haul truck, offering a payload capacity of up to...

  • Liebherr T 282B
    Liebherr T 282B
    The Liebherr T 282B is an off-highway, ultra class, rigid frame, two-axle, diesel/electric, AC powertrain haul truck designed and manufactured by the Liebherr Mining Equipment Co. in Newport News, Virginia, USA...

  • Belaz 75600
    Belaz 75600
    Belaz 75600 SpecificationsMaximum payload: Engine: Cummins QSK 78-C V18Engine rated output: @ 1900 RPMMaximum torque: @ 1500 RPM Weight: Weight loaded: Length: Width: Height: Speed: Bed volume: struck heaped...

  • Terex 33-19 "Titan"
    Terex 33-19 "Titan"
    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...

  • Haul truck

External links

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