Basic Information

Name

Caterpiller 120M American 6x6 Motor Grader

Designation

Caterpillar 120M Grader

Alternate Designation

Caterpillar 120M Grader

Equipment Type

Motorcycle

Manufacturer

—

Date of Introduction

2019

Description

The Caterpillar 120M is a motor grader, used by the US military. The Caterpillar company does not manufacture any special military version of the 120M grader. However after some modifications, such as flat military paint, blackout lights, transport provisions, keyless ignition, and other, this road grading machine can be used for military roles. Though it is claimed that the militarized 120M grader has more reliable performance in extreme weather, mainly due to optional equipment. In 2011 it was announced that more than 1 000 of these motor graders will be delivered to the US Army, Navy and Marine Corps. Deliveries commenced in 2012. It replaced in service the old Caterpillar 130G grader, which has been in service for more than 30 years. The Caterpillar 120M grader has 3 axles. Graders delivered to the US military have an all-wheel drive system for improved mobility. Engine and cab are situated above the rear axles. There is a wide blade in between the 1st and 2nd axles. Actually the Caterpillar 120M grader has rather humble performance comparing with many other commercial graders. Still though it significantly outperforms the old Caterpillar 130G military grader. There is a 30 years difference in technology between these two machines. The 120M is fitted with modern grade control technologies for precise grading. It is also fitted with diagnostics equipment and is easier to maintain. The Caterpillar 120M is used to create a flat surface during the grading process. Graders create fine "finish grade", while the "rough grading" is performed by bulldozers, scrappers, or other engineering vehicles. The Caterpillar 120M is used for construction and maintenance of dirt and gravel roads. This machine is also used to prepare the base course to create a wide flat surface for paved roads. It can also produce inclined surface to give cant to roads, or produce drainage ditches. Additional front blade and rear ripper can be attached. This militarized grader can be used for construction of airfields, landing zones, defensive berms, anti-tank ditches and for other military earthmoving tasks. The operator has good visibility. Overall working environment of the operator is significantly better than on the previous 130G model. The new grader has joystick controls, air conditioned cab. Furthermore vibration levels inside the cab are much lower. An armored cab can be installed for operation in various hotspots. It provides protection for the operator against small arms fire, artillery shell splinters and various blasts. This grader carries no defensive armament, as it typically operates in rear areas. This construction machine is powered by a Caterpillar C6.6 diesel engine, developing 138-, 153- and 173 hp depending on optional equipment and grading mode. Number in the designation actually denotes a 6.6-liter displacement of the engine. There are 8 forward and 6 reverse gears. This machine has a 6x6 configuration with an all-wheel drive. The older Caterpillar 130G had 6x4 configuration. Unusual feature of this new machine is that it can make a faster turn by adjusting the outside front tire speed up to twice faster than the inside tire. This significantly reduces turning radius. Another unusual feature of the Caterpillar 120M is that this machine can disengage transmission form the rear axles. This feature was originally designed for precise grading. However this feature also allows the machine to return to base on its front wheels with various transmission problems. A number of options are available for these militarized graders. These include a cold starting kit (which allows to start the machine at -40°C), deep fording kit and some other. Optional equipment installed on these graders differs depending on the US military branch. For example US Navy machines have some optional equipment, that is not present on US Army machines. The Caterpillar C120M grader can be airlifted by a C-130 Hercules tactical transport aircraft with minimum of preparation.

Ground Specifications

Crew 1

Max Speed 45.0 km/h

System

Alternative Designation Caterpillar 120M Grader

Type Motor Grader

Crew 1 ea

In-Dash Instrument Cluster The instrument panel, with easy-to-read, high-visibility gauges and warning lamps, keeps the operator aware of critical system information.

Dimensions

Blade Base 8.3 ft (2.53 m)

Front Ground Clearance 1.9 ft (0.58 m)

Ground Clearance - Rear Axle 13.6 in (34.54 cm)

Height - Exhaust Stack 112.4 in (285.5 cm)

Height - Front Axle Center 22.5 in (57.15 cm)

Height - Top of Cab 10.8 ft (3.29 m)

Height - Top of Cylinders 113.7 in (288.8 cm)

Height to Top of Isomount Cab 10.8 ft (3.29 m)

Length - Between Tandem Axles 59.5 in (151.13 cm)

Length - Counterweight to Ripper 389.3 in (988.82 cm)

Length - Front Axle to Mid Tandem 232.8 in (591.31 cm)

Length - Front Axle to Moldboard 98.9 in (251.21 cm)

Length - Front Tire to Rear of Machine 334.1 in (848.61 cm)

Overall Length 27.9 ft (8.5 m)

Rear Ground Clearance 1.2 ft (0.37 m)

Wheelbase 19.4 ft (5.91 m)

Width Over Tires 8.2 ft (2.5 m)

Automotive

Engine Name Caterpillar C6.6 diesel

Engine Power 138 - 173 hp

Max Road Speed 45 km/h

Range INA

All Wheel Drive (AWD) System. The optional AWD system utilizes dedicated left and right pumps for precise hydraulic control. The infinitely variable pumps and motors maximize torque in each gear delivering the most power to the ground in the industry and increasing productivity in the most demanding applications.

Controls

Advanced Joystick Controls Two electro-hydraulic joysticks reduce hand and wrist movement as much as 78% compared to conventional lever controls for greatly enhanced operator efficiency. The intuitive pattern is easy to learn and provides the precise implement control you expect from Caterpillar.

Auxiliary Pod and Ripper Control The optional ripper control and auxiliary control pod are ergonomically positioned to allow simple, comfortable operation for the multiple hydraulic options.

Controls and Switches Reliable, longlife rocker switches are located on the right side cab post and front instrument cluster, within easy reach for the operator.

Intuitive Steering Control The 120M introduces a breakthrough in joystick steering control. This technology creates a direct relationship between the lean angle of the joystick and the turning angle of the steer tires.

Electronic Throttle Control Electronic Throttle Control (ETC) provides the operator with easy, precise, and consistent throttle operation. An automatic and manual mode on a single switch offers flexibility for different applications and operator preferences.

Left Joystick Functions The left joystick primarily controls the machine direction and speed. 1 – Steering: Lean joystick left and right 2 – Articulation: Twist joystick left and right 3 – Articulation Return to Center: Yellow thumb button 4 – Wheel Lean: Two black thumb buttons 5 – Direction: Index trigger shifts transmission to forward, neutral or reverse 6 – Gear Selection: Two yellow thumb buttons upshift and downshift 7 – Left moldboard lift cylinder: Push joystick to lower, pull joystick to raise 7 – Left moldboard lift cylinder float: Pushing joystick through detent engages float

Right Joystick Functions The right joystick primarily controls the Drawbar, Circle and Moldboard functions. 1 – Right moldboard lift cylinder: Push joystick to lower, pull joystick to raise 7 – Right moldboard lift cylinder float: Pushing joystick through detent engages float 2 – Moldboard slide: Lean joystick left and right 3 – Circle turn: Twist joystick left and right 4 – Moldboard tip: Thumb switch fore and aft 5 – Drawbar center shift: Thumb switch left and right 6 – Electronic Throttle Control: Trigger switch is resume and decrement 7 – Differential Lock/Unlock: Yellow button

Ripper Control Pod Infinitely variable roller switches control the rear ripper and/or front lift group (when equipped), for easy and comfortable control.

Programmable Auxiliary Hydraulic Pod. Four fingertip controls and a mini joystick maximize hydraulic control flexibility, accommodating up to six hydraulic circuits. Individual functions are easily programmable through Cat ET to meet the configuration you need. The optional auxiliary hydraulic pod is provided in addition to the ripper control pod when the machine is configured with three or more auxiliary functions.

Smooth Shifting Transmission The 120M combines several key innovations to ensure smooth, powerful shifts throughout the gear range.

Electronically Controlled Shifting The full Electronic Clutch Pressure Control (ECPC) system optimizes inching modulation and smooths shifting between all gears and directional changes. This provides outstanding control and also extends the life of the transmission by reducing stress on gears.

Controlled Throttle Shifting This standard feature helps to smooth directional and gear changes without use of the inching pedal.

Structure

Front Frame Structure The 120M front frame is a formed structural carbon steel tube. Advanced fabrication technology significantly reduces the number of weld joints, which more evenly distributes stress loads. The result is a robust machine that delivers the durability you expect from Caterpillar.

Rear Frame Structure. The box-sectioned hitch design helps resist torsion loads and ensure structural durability. The integrated bumper ties the rear frame together as a single, solid unit, so the frame can withstand heavy-duty applications such as ripping and winging snow.

Articulation Hitch A large tapered roller bearing at the lower pivot carries loads evenly and smoothly. This joint is sealed to prevent contamination in this critical area. A mechanical locking pin prevents frame articulation to help ensure safety when servicing or transporting the machine.

Circle Construction Our one-piece forged steel circle is built to stand up to high stress loads and provide structural durability. The front 240° of circle teeth are hardened to reduce wear and ensure component reliability.

Drawbar Construction The A-frame drawbar features a tubular design for high strength and optimum durability.

Aggressive Blade Angle With a long wheelbase the operator can obtain aggressive moldboard angles, so material rolls more freely along the length of the blade. This is particularly helpful when handling very dry materials or cohesive soils. Better material control gets the job done faster, requires less power and saves fuel.

Hydraulics

Advanced Electro-Hydraulic System. The 120M incorporates a state-of-the-art electro-hydraulic system. This technology is the foundation for revolutionary changes of the machine and implement controls. Advanced joystick controls provide unmatched controllability with precise, predictable hydraulic movements and the reliability you expect from Caterpillar.

Blade Float Blade float is built into the blade lift control valves and is optional for some auxiliary hydraulic functions. The blade float feature allows the blade to move freely under its own weight. By floating both cylinders, the blade can follow the contours of the road when removing snow. Floating only one cylinder permits the toe of the blade to follow a hard surface while the operator controls the slope with the other lift cylinder.

Independent Oil Supply Large, separate hydraulic oil supply prevents crosscontamination and provides proper oil cooling, which reduces heat build-up and extends component life.

Load Sensing Hydraulics (PPPC The time proven load-sensing system and the advanced Proportional Priority Pressure-Compensating (PPPC, or “triple-PC”) electro-hydraulic valves on the 120M are designed to provide superior implement control and enhanced machine performance in all applications. Continuous matching of hydraulic flow and pressure to power demands creates less heat and reduces power consumption.

Cat® XT™ Hose Caterpillar hose technology allows high pressures for maximum power and reduced downtime. Intelligent routing minimizes exposure to damage. Hose clips prevent hose rubbing and excessive vibration for lower owning and operating costs.

Balanced Flow Hydraulic flow is proportioned to ensure all implements operate simultaneously with little effect on the engine or implement speeds. If demand exceeds pump capacity, all cylinder velocities are reduced by the same ratio. The result is improved productivity in all applications.

Consistent and Predictable Movement PPPC valves have different flow rates for the head (red) and rod ends (blue) of the cylinder. This ensures consistent extension and retraction speeds for each cylinder, and gives the operator a consistent and predictable response every time an implement control is moved.

Image Sources

Notes https://catused.cat.com/en/construction/motor-graders/caterpillar-120-m/d6e89f61-66a2-482c-852d-5fa8670b76d2.html; ;