The Caterpillar 797B is one of the most iconic and powerful off-highway haul trucks ever produced for large-scale mining operations. Introduced as the second generation of Cat’s 797 series, the 797B was engineered to move massive quantities of ore, overburden, and rock with exceptional reliability and productivity.
With a payload capacity of 380 short tons (345 metric tonnes) and powered by the massive Cat 3524B high-horsepower diesel engine, the 797B delivers the high torque, traction, and durability required for the world’s toughest open-pit mines.
Engine Details
| Number of Cylinders |
24 (2x 12) |
| Engine Make |
Caterpillar |
| Engine Model |
Cat 3524B HD EUI (2x Cat 3512B HD) |
| Displacement |
7143 cu in (117.1 L) |
| Bore |
6.7 in (170 mm) |
| Stroke |
8.5 in (215 mm) |
| Gross Power |
3550 hp (2648 kw) |
| Net Power |
3370 hp (2513 kw) |
| Power Measured @ |
1750 rpm |
| Torque Rise |
22% |
| Fuel System |
EUI (Electronic Unit Injection) |
| Air Cleaner |
Dry-type air cleaners and pre-cleaner |
| Aspiration |
2x Twin turbocharged and aftercooled |
| Emission Standards |
US EPA Tier 1 + EU Stage I |
Caterpillar 797B Fuel Consumption
| Operating Condition |
Estimated Fuel Consumption |
Notes / Context |
| Light load / empty return / low grade |
31-53 gal (120-200 L/h) |
Minimal load, low hydraulics & braking demand |
| Moderate load / mixed cycle (haul + return) |
53–79 gal (200–300 L/h) |
Typical loading / dumping cycles under moderate load |
| Full load / tough terrain / heavy haul + incline |
79–119 gal (300–450 L/h) |
Heavy duty cycle, steep grade, frequent braking |
Dimensions
| Height to Top of ROPS (Full) |
250 in (6351 mm) |
| Height to Top of ROPS (Empty) |
258 in (6549 mm) |
| Overall Body Length |
569 in (14483 mm) |
| Inside Body Length |
391 in (9941 mm) |
| Overall Length |
572 in (14530 mm) |
| Wheelbase |
283 in (7200 mm) |
| Rear Axle to Tail |
158 in (4016 mm) |
| Ground Clearance (Full) |
34 in (869 mm) |
| Ground Clearance (Empty) |
42 in (1059 mm) |
| Dump Clearance |
74 in (1885 mm) |
| Loading Height (Empty) |
278 in (7083 mm) |
| Inside Body Depth (Max) |
132 in (3350 mm) |
| Overall Height (Body Raised) |
602 in (15292 mm) |
| Operating Width |
360 in (9154 mm) |
| Centerline Front Tire Width |
256 in (6512 mm) |
| Engine Guard Clearance (Full) |
36 in (919 mm) |
| Engine Guard Clearance (Empty) |
44 in (1122 mm) |
| Outside Body Width |
336 in (8524 mm) |
| Inside Body Width |
315 in (8000 mm) |
| Front Canopy Height |
299 in (7584 mm) |
| Rear Axle Clearance (Full) |
37 in (951 mm) |
| Rear Axle Clearance (Empty) |
41 in (1046 mm) |
| Centerline Rear Dual Tire Width |
245 in (6233 mm) |
| Overall Tire Width (Full) |
384 in (9761 mm) |
Dump System
| Payload Capacity |
837,757 lb (380000 kg) |
| Capacity, Struck |
246-290 yd3 (188-213 m3) |
| Capacity, Heaped (SAE 2:1) |
314-350 yd3 (240-267 m3) |
| Body Weight Range |
84,000 - 140,000 lb (38000 - 63000 kg) |
| Body Raise Time (High Idle) |
25 sec |
| Body Lower Time (High Idle) |
18.5 sec |
| Body Power Down (High Idle) |
17.3 sec |
| Body Raise Time (Low Idle) |
25 sec |
| Body Lower Time (Low Idle) |
18.5 sec |
| Body Power Down (Low Idle) |
18.1 sec |
Flat Floor Body or Mine Specific Design (MSD) Body
Weight Distributions
| Caterpillar 797B |
Empty |
Loaded |
| Front Axle |
43.5% |
33.3% |
| Rear Axle |
56.5% |
66.7% |
| Total Weight |
537,243 lb (243690 kg) |
1,375,000 lb (623690 kg) |
Operational Specs
| Nominal Payload Capacity (NRP) |
837,757 lb (380000 kg) |
| Body Weight (BW) |
84,000 - 140,000 lb (38000 - 63000 kg) |
| Chassis Weight (CW) |
473,600 lb (214820 kg) |
| Gross Machine Operating Weight |
1,375,000 lb (623690 kg) |
| Operating Voltage |
24 V |
| Alternator |
2x 75 amps |
| Battery |
2x 12 V, 93 Ah |
| Starter |
24 V |
| Steering Angle |
39° |
| Front Turning Radius |
130.9 ft (39.9 m) |
| Tire Size |
59/80R63 |
| Rims |
Center Mounted Rims (6) (44 x 63) (Used for 59/80R63 Tires) |
| Operator Seat |
Air Suspension Trainer Seat |
| Passenger / Trainer Seat |
Air Suspension with Storage Compartments |
| Noise Level (Interior) |
76 dB(A) |
| HVAC |
Heating/Air Conditioning (Electronically controlled 4-speed fan and 11 vents deliver temperature controlled air circulation |
| Display Option |
VIMS features a high resolution display and easy-to-use operator input keypad for vital machine status information |
| Cab Safety |
ROPS / FOPS |
Transmission
| Type |
Cat 7-speed automatic planetary powershift transmission, electronically controlled |
| Number of Gears |
7F / 1 R |
| Max Forward Speed |
42 mph (67.6 km/h) |
| Max Reverse Speed |
8 mph (12.9 km/h) |
| Torque Converter |
Lock-up torque converter. Engages at approximately 4 mph (6 km/h) |
| Service Brakes |
Forced oil-cooled/variable capacity disc brakes with electro-hydraulic controls. Sealed and individually serviceable |
| Parking Brake |
Spring-applied, hydraulically released; toggle switch activated. Uses same disc brakes as service brakes |
| Secondary Brakes |
Spring-applied, hydraulically released |
| Front Brake Surface Area |
20500 in2 (132258 cm2) |
| Rear Brake Surface Area |
30750 in2 (198387 cm2) |
| Retarder |
Automatic Retarder Control standard. Applied to all wheels (40/60 split, front and rear). Hand operated lever provides modulated engagement of service brakes for retarding |
| Brake System Standards |
J-ISO 3450 JAN88, ISO 3450 (1996) |
Final Drives
| Type |
Double reduction, planetary with full floating axles |
| Rear Axle |
Four-bar linkage connects the rear axle to the frame with maintenance free pins |
| Differential Ratio |
1.265:1 |
| Planetary Ratio |
16.67:1 |
| Total Reduction Ratio |
21.09:1 |
| Suspension System |
Uses oil-over-nitrogen struts to dissipate haul road and loading impacts |
| Suspension Cylinders |
Four independent self-contained, oil pneumatic, variable rebound suspension cylinders are designed to absorb shocks in the most severe applications |
Hydraulic System
| Relief Valve Setting (Raise) |
3450 psi (23787 kPa) |
| Pump Flow (High Idle) |
323 gal/min (1225 L/min) |
| Pump Flow (Low Idle) |
290 gal/min (1099 L/min) |
| Hydraulic Cylinders |
Twin, two-stage hydraulic cylinders, mounted outside main frame |
Service Refill Capacities
| Fuel Tank Capacity |
1800 gal (6814 L) |
| Cooling System Capacity |
315 gal (1194 L) |
| Engine Oil Capacity (w/ filter) |
110 gal (417 L) |
| Torque Converter/Transmission System (Includes Sump) |
166 gal (629 L) |
| Torque Converter / Transmission Sump |
50 gal (190 L) |
| Differentials Capacity |
185 gal (701 L) |
| Final Drives Capacity (Each) |
49 gal (185 L) |
| Front Wheel Capacity (Each) |
16 gal (61 L) |
| Steering System Capacity (w/ tank) |
114 gal (432 L) |
| Steering Hydraulic Tank Capacity |
62 gal (235 L) |
| Brake/Hoist Hydraulic System Capacity (w/ tank) |
486 gal (1842 L) |
| Brake/Hoist Hydraulic Tank Capacity |
263 gal (996 L) |
Building on the success of the original 797, the 797B introduced refinements in powertrain performance, structural strength, braking capacity, and electronic controls. Its advanced mechanical drive system favored for ultra class haul fleets ensures consistent performance on steep grades, predictable handling in extreme environments, and simplified maintenance for mine operators. Designed for long duty cycles and harsh conditions, the Caterpillar 797B remains a benchmark for ultra-class haul truck productivity, longevity, and total cost of ownership.
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