Caterpillar debuted the 308CR fixed-boom mini excavator at this year’s World of Concrete in Las Vegas, replacing its 307.5 with more hydraulic power and efficiency.
As the latest addition to Cat’s 8-metric-class lineup, the 308CR brings a new compact-radius design with 67% less overhang when using the 550-pound counterweight and 61% less with the 1,100-pound counterweight.
Equipment World
Under the hood, a 69-horsepower Cat C2.8 Turbo (similar to Cat's larger mini excavators) is equipped with auto idle, auto engine shutdown and a variable displacement pump for hydraulics. The 308CR’s operating weight comes in at 18,659 pounds.
Caterpillar increased digging depth to 15 feet 5 inches and maximum reach to 22 feet 8 inch in the long-stick configuration. Minimum-maximum configuration lift capacities have also increased when operating over the front with blade down and over the side.
Greg Worley, market professional at Caterpillar, says the 308CR meshes well with the growing trend of urban redevelopment.
"We're doing more and more brownfield development," Worley says. "Basically, we're going back in redeveloping or filling in the spaces in urbanized areas; [there's] less green construction going on nowadays."
"So when you go into these urbanized areas, you need as much power performance and capability in the machine's smallest package possible," he continues. "So that's why moving from a standard tail swing machine in the 8-ton platform with a fixed boom to that compact radius is important as we get more done in these smaller, tighter environments."
Excavator Highlights
Equipment World
Compared to the 307.5, other upgrades on the 308CR include increased track width of 7 feet 7 inches and increased undercarriage length of 9 feet 5 inches.
In the sealed and pressurized cab, operators will find:
- Next-gen monitor with customizable preferences.
- Standard Cat stick steer with button activated switching from lever and paddle to joystick control.
- Fluorescent seatbelt. (A seatbelt reminder system is optional.)
- Cruise control options.
- Improved air conditioning.
- Adjustable wrist rests.
- Suspension seat.
The 308CR features ground-level routine check points with grouped service points, a back-up camera, side camera and work lights.
Available track options on the 308CR include rubber belt, steel track and steel track with rubber pad.
Operators won’t have to update their work tool lineup, as the 308CR offers the same pin sizing as the 307.5. The excavator’s load sensing hydraulics, with the variable displacement piston pump, offer 44 gallons per minute of oil flow. The primary auxiliary circuit pumps 35 gallons per minute, and the second auxiliary circuit's maximum flow comes in at 9 gallons per minute.
Multiple Tech Options
Contractors can choose between two software packages from the factory, which can also be added as a field upgrade kit:
- Cat Indicate — Adds visual and audible indicators for determining bucket placement relative to target grade and can be programed to a flat grade or slope. It's best suited for tasks like footings, septic systems, foundations and slope work.
- Cat E-Fence — Restrains the 308CR’s motion to preset E-Ceiling and E-Floor boundaries when working in tight spaces, including beneath power lines, ceilings and trees and above fiberoptic cables and utilities. An E-Wall setting can also confine range of motion in front of the 308CR.
Additional technology options for the 308CR include the Laser Catcher for creating a consistent reference point across the jobsite, the aftermarket Cat Grade automatics for setting digging and leveling parameters for simple and complex designs, and Cat Grade 3D for achieving real-time kinematic positioning guidance on complex jobs.
Caterpillar 308CR Mini Excavator Specs:
- Operating weight: 18,659 pounds
- Engine: Cat C2.8 Turbo
- Horsepower: 69
- Tail swing: 56 inches (551-pound counterweight), 58 inches (1,103-pound counterweight), or 51 inches (no counterweight)
- Overall width: 91 inches
- Lift capacity: 3,186 pounds (14.8-feet lift point height, long stick, over front)
- Max reach: 22 feet 8 inch
- Max dig depth: 13 feet 7 inches (standard stick), 15 feet 5 inches (long stick)
- Digging force: 9,285 pound-feet (standard stick), 8,250 pound-feet (long stick)
