Caterpillar expanded its Next Generation mini hydraulic excavator portfolio with the addition of six new models in the 7- to 10-ton category.
The lineup’s new models include the following:
- 307.5, a standard tail swing model with a fixed boom;
- 308 CR, a compact radius model with a swing boom;
- 308 CR VAB, featuring a variable angle (two-piece) swing boom;
- 309 CR, a new mini range model featuring a compact radius, swing boom and high flow auxiliary hydraulics;
- 309 CR VAB, which expands the 309 CR’s capability with a variable angle boom; and
- 310, which features a fixed boom, standard tail swing, and twin blade cylinders for handling heavy duty dozing chores.
The machines range in maximum operating weight from 18,152 to 22,447 pounds and in standard dig depths from 13 feet, 5 inches to 17 feet. Three models—307.5, 308 CR and 309 CR—are available with a long-stick option that increases dig depth by approximately 22 inches. The variable angle boom, available with the 308 CR VAB and 309 CR VAB, enhances digging capability in congested work areas.
Powering the 307.5 is the Cat C2.4 turbo diesel engine rated at 55.9 net hp; the five larger models use the Cat C3.3 diesel engine rated at 70.3 net hp. The machines also feature automatic two-speed travel and cruise control.
The new models include the Cat Stick-Steer system, which allows the operator to switch from conventional lever/foot-pedal steering controls to low-effort joystick control with the touch of a button.
The excavators are fitted with cabs, sealed and pressurized, featuring a redesigned heating, ventilating and air conditioning system. Suspension seats, with a retractable 3-inch-wide belt, come standard, and the operating consoles feature adjustable wrist rests. In-cab sound levels come in at 72 dB(A).
Controls include the Next Generation LCD monitor; a machine-security system with a numeric code; and a radio with Bluetooth capability. The large front window slides upward and stores overhead, and glass areas on the sides and rear of the cab, plus a skylight, provide all-around visibility. A rear camera is integrated into the monitor.
The cab includes protective structures—ROPS, TOPS and top guard. The controls are protected via a hydraulic lockout. Halogen boom lights help illuminate the work area, and optional LED lights, front and rear, further enhance visibility. The models also feature tie-down points on the track frames.
The mini excavators use a hydraulic system with an electronically controlled variable-displacement piston pump capable of oil flows up to 44 gpm in the 307.5 and 308 models and 62 gpm in the 309 and 310 models.
The standard auxiliary hydraulic system provides one-way, two-way and continuous flow. Manual and hydraulic couplers are available, as are a thumb-ready package and a certified lifting eye. Front-shovel operation, a capability that enhances precision when digging around utilities, can be accomplished with both pin-on and coupler-mounted buckets.
The 307.5, 308 CR, and 309 CR come equipped with a standard undercarriage length, while the 309 has the option for a long undercarriage. The 310 is available with a long undercarriage only, which is designed for added stability.
A dozer blade expands the machines’ capability and features ample travel, above and below grade, and has a float function.
Routine maintenance check points are accessible at ground level through the side doors, and the battery is maintenance-free. Side panels are flat and recessed to protect them from damage.
