Cat D-Series Mini Hydraulic Excavators Boast Higher Bucket, Traction Forces

Tue July 15, 2008 - National Edition
Construction Equipment Guide

Three D-Series mini hydraulic excavators join the Caterpillar line. The 307D is a direct replacement for the 307C. The 308D CR, a compact radius machine that works productively in tight spaces, replaces the 308C CR. A new model, the 308D CR SB, combines the compact radius design with a swing boom for even more versatility.

The D-Series mini excavators retain the best features of the C-Series models while incorporating many improvements that increase productivity and reduce operating costs. The new mini excavators outperform their predecessors with 22 percent higher bucket forces and 10 percent higher stick forces, according to the manufacturer.

Lift capacity has been increased with the addition of a larger counterweight and a 15 percent increase in traction forces improves dozing and turning performance.

Each machine is powered by a new turbocharged Mitsubishi 4M40 TL engine, rated at 54 net hp (40 kW). The engine meets Interim Tier IV emissions regulations.

Improvements to the cab, plus a new rubber undercarriage option, standard high-pressure auxiliary hydraulics and standard thumb-ready sticks, make the D-Series models ideal for a variety of general construction jobs.

Comfortable and Quiet

The D-Series mini excavators share a common operator’s station with larger Cat excavators. The cab is quiet, roomy and well-ventilated with plenty of legroom. It offers all-around visibility and a clear view to the work area.

An air suspension seat is available for maximum comfort, and easy-to-use joystick controls are integrated with the seat and armrests to reduce fatigue. To improve communication between the operator and the machine, a new color monitor displays information in text, rather than codes. It can deliver messages in 27 languages to accommodate a diverse workforce.

One Machine, Many Jobs

The 307D, 308D CR and 308D CR SB are designed to do more jobs in more places. All models accommodate a complete range of work tools.

A standard combined function high-pressure auxiliary hydraulic circuit and standard thumb-ready sticks ensure the excavators are ready for any job. A standard Cat Tool Control System lets the operator pre-set flows and pressures for up to 10 work tools using the in-cab monitor. The tools can then be used at the touch of a button, without resetting the hydraulic system.

While a large work tool selection makes these machines excel at many jobs, their size also contributes to their versatility. The two compact radius models work where full sized units cannot go, and the addition of a swing boom to the 308D CR SB enables it to work more productively alongside buildings, fences and other obstructions, according to the manufacturer.

Lower Owning and Operating Costs

Many features make the D-Series models economical to own and operate. An economy mode reduces fuel consumption in light-duty applications, while maintaining high bucket forces and lift capacity. A boom and stick regeneration circuit saves energy during boom-down and stick-in operations, increasing efficiency and lowering operating costs. Grease lubricated track offers long wear life at lower total cost and easy-access service points and extended maintenance intervals increase uptime and drive down operating costs.

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