Caterpillar · 1998–present

Caterpillar 797B

The Caterpillar 797 is a series of off-highway, ultra class, two-axle, mechanical powertrain haul trucks developed and manufactured in the United States by Caterpillar Inc. specifically for high-production mining and heavy construction applications worldwide. In production since 1998, the 797 series represents Caterpillar’s largest, highest capacity haul trucks. The current, third-generation model, the 797F, offers one of the largest haul truck payload capacities in the world, up to 400 short tons (363 t) and has the highest payload capacity among mechanical drive haul trucks.

Text from Wikipedia (CC BY-SA 4.0).

Predecessor: Caterpillar 797 · Successor: Caterpillar 797F

All Caterpillar 797B data: UK builds, safety, recalls, model years →

Initial development

In 1997, Caterpillar decided to begin the development of a 360 short tons (327 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. 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.

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.

797B (2002–2009)

Caterpillar introduced the 797B in the spring of 2002, replacing the first-generation 797. The 797B's increased payload capacity of 345 t (380 short tons) is a 18.1 t (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 2,394 kW (3,211 hp) to net 2,513 kW (3,370 hp) enabling the 797B to achieve a 68 km/h (42 mph) top speed when transporting a 345 t (380 short tons) load, a 3.2 km/h (2 mph) increase over the first generation 797. The first 797B units entered service with customers in October 2002.

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. 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 (363 t). 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 (363 t) is a 20 short tons (18.1 t) increase over the 797B. Caterpillar replaced the gross 3,550 hp (2,647 kW) [net 3,370 hp (2,513 kW)] Cat 3524B EUI 24-cylinder diesel engine used in the 797B with the gross 4,000 hp (2,983 kW) [net 3,793 hp (2,828 kW)] Cat C175-20 ACERT 20-cylinder diesel engine, enabling the 797F to maintain the 42 mph (68 km/h) top speed of the 797B while transporting a heavier 400 short tons (363 t) payload.

Powertrain

The Caterpillar 797 series trucks employ mechanical drive powertrains 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 3,400 hp (2,535 kW) [net 3,211 hp (2,394 kW)] Cat 3524B HD EUI 24-cylinder, electronic unit injection, quad single-stage turbocharged, liquid aftercooled, four-stroke diesel engine powers the 797. 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). 797B engine. A gross 3,550 hp (2,647 kW) [net 3,370 hp (2,513 kW)], quad turbocharged Caterpillar 3524B engine powers the 797B. The power rating of the 3524B is valid up to an elevation of 8,500 ft (2,591 m) or 15,000 ft (4,572 m) with a high altitude arrangement. 797F engine. A gross 4,000 hp (2,983 kW) [net 3,793 hp (2,828 kW)] 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. The power rating of the C175-20 is valid up to an elevation of 7,000 ft (2,134 m) or up to 16,000 ft (4,877 m) with a high altitude arrangement. Transmission. The 797 series haul trucks are equipped with a rear-axle-mounted, computer-controlled, seven-speed planetary transmission with a separate lock-up torque converter. Both transmission and torque converter use a common powertrain oil.

Wheels and tires

Each 797 wheel is attached to the axle using 54 - 36 mm (1.4 in) nuts that are torqued to 2,300 lb⋅ft (3,118 N⋅m). A size 55/80R63 radial tire was developed by Michelin in conjunction with Caterpillar specifically for the first generation 797. The Caterpillar 797B and 797F run 4.028 m (13.22 ft) tall, 5,300 kg (11,680 lb) Michelin 59/80R63 XDR. Most first generation 797s have been retrofitted to use the 59/80R63 tires as well. Six tires are required per truck at a cost in 2009 of approximately US$42,500 per tire.

Sections adapted from Wikipedia (CC BY-SA 4.0); text is shortened. Read the full article for the complete history and citations.

Specifications

name: Caterpillar 797 Series
Manufacturer: Caterpillar Inc.
Production: September 22, 1998-present
Assembly: Decatur, Illinois
Class: Ultra class
Body style: Dump
Layout: Front engine, rear wheel drive
Transmission: Seven speed planetary gearset

Specification summary from Wikipedia (CC BY-SA 4.0). Check the linked sources for citations.

More photos

Caterpillar 797B — Lechhabmed · CC BY-SA 4.0 · source ↗

Sources

Wikidata — https://www.wikidata.org/wiki/Q5242824CC0 1.0 · retrieved 2026-10-01
Wikipedia — https://en.wikipedia.org/wiki/Caterpillar_797CC BY-SA 4.0 · Text © Wikipedia contributors; revision 1368989668 · retrieved 2026-10-01
Car Model Index — https://models.autoculturesociety.com/Compiled record. Sources that do not permit reuse are not copied; this index is credited instead.