Digging out

By: Allen Zeyher

If the number of new models introduced this year is an indication, the excavator segment of the construction equipment market is healthy. Many manufacturers have new products out—and in many cases smaller is better. There is an emphasis on zero-tail-swing models that can fit into confined spaces, including urban areas.

"They’re very popular in Asia and in Europe because of tight quarters," Wes Lee, director of marketing for heavy range products at Case Construction Equipment, told Roads & Bridges, "and we’re seeing demand for that in the inner cities, big cities where you have tight alleyways, street locations that require no overhang over the tail of the machine into the street."

"Excavators are very versatile, and we’re seeing them on different jobsites where loader backhoes used to do some of that work," added David Wolf, Case’s marketing manager for excavators and wheel loaders. "Some of that is being done now by excavators."

Evidence of the popularity of excavators was supplied by the fact that they were the most requested of all the items offered by Rentmaker, the Internet equipment rental service, in the first half of this year. Earthmoving and material handling equipment took the top five places in Rentmaker’s list of most requested items from January to June 2001.

At the top of Rentmaker’s hit list were crawler-mounted hydraulic excavators, representing almost 8% of the requests received for the company’s top 100 items. Next on the list were backhoes (7.1%), scissor lifts (6.7%), bulldozers (5.2%) and forklifts (5.1%).

Wolf said about 20% of Case’s excavators go to the rental market, and many of the excavators that go to Case dealers are rented out by the dealer before being sold.

The cost of diesel fuel has gone down from its peak of about $1.75 per gal in spring to about $1.55 per gal, but it is still considerably higher than the $1.10 or so of 12 months ago, according to the Case spokesmen. Fuel costs and tougher engine emission standards that take effect on Jan. 1, 2002, were part of the motivation for the latest line of Case excavators, which meet the Tier II emissions standards and include features to conserve fuel.

Case calls these new excavators "intelligent machines." The CX series includes four models—CX130, CX160, CX210 and CX240—ranging from 26,920 to 53,405 lb, from 110 to 163 hp and from 20 ft to 24 ft 3 in. in digging depth.

Case’s Pro Control System monitors and regulates the performance of the machine. In automatic work mode, an on-board computer selects the optimal operation mode by sensing load demands and automatically balancing power and speed for the greatest efficiency and economy.

"Because there’s a loss of what we call highly experienced operators in the industry and a proliferation of first-time operators, it allows the contractor to get a first-time operator, put him in the seat and say, ‘You’re going to work in auto mode on this job,’" said Lee. "That assures him that when he gets into a digging situation, he doesn’t have to go in and fiddle with the engine speed or mess with the hydraulics. It automatically thinks for itself and adjusts to the digging conditions."

If the operator runs into a stump or rock while digging a trench, the machine automatically boosts power to the boom and stick and works through the obstacle.

The hydraulic system in the CX series is loaded with pressure and flow sensors that send information to controllers that adjust flow and pressure to where it is needed. The machines also have self-diagnostic systems that the operator can monitor from the seat of the cab to help identify any problems that might arise.

Three manual work modes also are available. Heavy mode provides full engine power and force for heavy excavation. Standard mode provides 90% engine speed and pump torque for normal digging and loading operations. Light mode provides the best fuel economy with 85% engine speed and 70% torque for precision operations and lifting.

The Auto Power Boost feature available on the CX210 and CX240 instantly increases power by 10% in eight-second intervals when the Pro Control System detects resistance. A button on the control lever of the CX130 and CX160 models provides extra power.

A standard climate control system is just one of the comfort and functionality features in the cab of these units.

The 322 is the latest—and the smallest—of the D-Series compact excavators from Bobcat Co., West Fargo, N.D. The 15.7-hp machine features improved serviceability, an enhanced operator station and a simplified hydraulic system. It also has a hydraulically activated expandable undercarriage, giving the machine a traveling width of just under 39 in.

The 322 offers a bucket break-out force of 3,408 lb, a digging depth of 7 ft 2 in. and a dipper force of 1,971 lb. Engineers simplified the machine’s hydraulic circuit for improved hydraulic line routing, and new spool metering advancements increase work group function control.

To reach jobsites through narrow entries, the undercarriage of the 322 contracts from 53 in. down to 39 in. The tracks expand again at the digging site, providing enhanced lifting and trenching, especially when working over the side of the excavator.

The LX Series of excavators from LBX Co., Lexington, Ky., has what the company calls a revolutionary computer system. The Intelligent LX, or Inte-LX, computer control system monitors and regulates hydraulic output, pressures and engine performance for the maximum balance between speed, power and fuel efficiency needed to handle the job.

The newest and biggest in the line is the 330 LX, with an operating weight of 78,000 lb and a 247-hp engine. The 330 LX is equipped with a 21-ft 2-in. boom and a choice of three arm lengths: 8 ft 8 in., 10 ft 8 in. and 13 ft 3 in. It has a digging radius, depending on the arm, of up to 39 ft and a digging depth of up to 26 ft 8 in.

Auto-Mode is the most sophisticated of the five working modes available on the LX Series. Auto-Mode is activated from a switch on the control panel. Using actual working pressure readings, Inte-LX instantly changes modes assuring the best combination of speed and power while the operator can stay focused on the work at hand.

The other four operating modes are Heavy Mode for heavy excavation or extra power, Standard Mode for standard digging and loading operations reducing fuel consumption, Lift Mode for lifting and other operations that need fingertip accuracy and Allied Attachment Work Mode, which automatically adjusts engine speed and pump output to match attachments.

An on-board diagnostic system allows service personnel to quickly analyze up to 148 items in four categories: machine status, troubleshooting, history and systems configuration. Inte-LX also stores in memory the machine’s performance records, which can be downloaded to a personal computer.

Although the manufacturer is well-known for its large equipment, the latest line of excavators from Kobelco Construction Machinery America LLC, formerly known as Kobelco America Inc., Stafford, Texas, is a line of zero-tail-swing compact machines, ranging in weight from 3,240 to 10,428 lb. The SR-2 series includes five models (13SR, 25SR-2, 30SR-2, 35SR-2 and 45SR-2) with digging depths from 6 ft 11 in. to 11 ft 11 in. and bucket forces from 2,593 to 8,747 lb.

Single and bi-directional auxiliary hydraulic valves and piping are standard equipment and allow the use of attachments such as hammers and augers.

The center-swing feature helps in digging around obstacles and against walls. Rubber tracks minimize damage to paved sidewalks and driveways, as well as decreasing noise. Steel tracks are offered as optional equipment.

Increased horsepower and hydraulic flow are the selling points for the new 322C L hydraulic excavator from Caterpillar Inc., Peoria, Ill.

The C series of excavators also includes the 307C, 312C and 315C, all of which tout similar innovations.

The 322C L is powered by a Cat 3126 TA engine, which produces 165 net hp, about 8% more than the previous model, the 322B L. The machine weighs about 53,400 lb. The engine design reduces noise and vibration, according to the company, for improved operator comfort, and the automatic engine speed control maximizes fuel efficiency and minimizes sound. Engine emissions meet worldwide requirements.

The increased engine power allows increased hydraulic flow—7% more than the previous model—through the open-center, two-pump hydraulic system. Increased flow works with the hydraulic cross-sensing system to boost productivity through faster implement speeds and quicker, stronger pivot turns.

The machine has a maximum digging depth of 22 ft and a maximum reach at ground level of 32 ft 10 in.

Yanmar Diesel America Corp., Buffalo Grove, Ill., has introduced a series of excavators over the past year—all of them minis or compacts and all of them with zero tail swing for working in close quarters.

The ViO 40 mini excavator features left and right boom swing, which allows the unit to operate close to and travel parallel to walls or other structures. The machine has an operating weight of 9,600 lb. It is powered by a Yanmar 30.6-hp, three-cylinder diesel engine, with a three-pump hydraulic system, control pattern selector and standard dual auxiliary PTO for attachments.

Large dozing blades, combined with Yanmar’s VICTAS offset track design, provide extra stability without increasing track width. Features such as a recessed work light, Codura protected and concealed hydraulic hose lines and same-side engine servicing for routine engine care provide easier maintenance.

The PC228USLC-3 excavator has an operating weight of 51,765 lb but has a tight tail swing so it fits into small work spaces. The machine has a maximum road width of 13 ft 5 in., allowing it to work in one lane without having to close both sides of the road.

The 143-hp PC228USLC-3 was designed by Komatsu America International Co., Vernon Hills, Ill., with a more comfortable cab, increased power, easier maintenance and a longer undercarriage for greater flotation, lift capacity and stability.

Digging height is extended to 34 ft 11 in. and a bigger bucket brings capacity to 2 cu yd. An increased bucket digging force (31,085 lb) and arm crowd force (22,708 lb) add to the performance features.

A low-effort joystick reduces fatigue. Viscous damping mounts reduce noise to 70 dB.

The newest excavators from New Holland Construction, Carol Stream, Ill., are full-sized diggers. The EC350 crawler excavator has a 249-hp engine and a maximum digging depth of 24 ft 3 in. The EC240 has a 176-hp engine and a maximum digging depth of 22 ft 6 in.

The operating weight of these machines is 54,234 lb (EC240) and 77,382 lb (EC350). The standard arm is 9 ft 10 in. (EC 240) and 11 ft 10 in. (EC350). With the optional arm, the maximum digging depths are 24 ft 6 in. for the EC350 and 26 ft 7 in. for the EC240. Bucket sizes range from 0.75 to 1.9 cu yd (EC240) or from 1 to 2.6 cu yd (EC350).

Like all New Holland excavators, these machines feature an advanced three-pump hydraulic system designed to boost productivity. The three-pump hydraulic system produces faster, smoother work cycles, according to the company, as well as reduced fuel consumption and hydraulic oil heating.

The new mini excavator from Kubota Tractor Corp., Torrance, Calif., follows the trend of smaller, more maneuverable equipment. The KX41-2SV is equipped with a three-cylinder, 21.6-hp diesel engine. The machine has an operating weight of 3,710 lb.

The "V" in the name stands for variable-width track frame. With the switch of a lever, the operator can alter the track width from 51 in. to 39 in. without lifting the machine off the ground or dropping the dozer blade.

The standard bucket capacity is 1.34 cu ft with a maximum break-out force of 3,269 lb and a maximum digging depth of 7 ft 9 in. The boom swing speed is 8.7 rpm with a boom swing angle of 90û to the left and 50û to the right.

Without the need for the operator to select a work mode, the hydraulic system of the Gradall XL 3300 adjusts for light-duty work like grading and sloping in order to conserve fuel. The XL 3300 features the traditional benefits of the telescoping boom excavators from the Gradall Co., New Philadelphia, Ohio. The machine is able to work in low-overhead environments such as under bridges or tree limbs or in tunnels, while providing a good view. The telescoping boom has a 220û tilting action for efficient work in hard-to-reach places like on hillsides and on the sides and ceilings of tunnels.

A 148-hp turbocharged engine powers both the superstructure and the four-wheel-drive undercarriage of the XL 3300. The maximum digging depth is 19 ft 4 in. Boom radius at the ground is 28 ft 1 in. The rated boom force is 21,940 lb.

All of the full-sized excavators from Volvo Construction Equipment feature the company’s Advanced Control System, which balances engine horsepower and hydraulic pump output to increase productivity and fuel economy. The newest model from Asheville, N.C., the EC150, packs a 107-hp engine and an operating weight of 36,290 lb.

The EC150 fits into the smaller end of the line of eight Volvo excavators, which also includes the EC140, EC140LCM, EC210, EC240, EC290, EC360 and EC460.

The maximum digging reach of the EC150 with the standard 8-ft 6-in. arm is 29 ft 5 in. The maximum digging depth is 18 ft 11 in. The machine has a bucket break-out force of 20,930 lb in normal mode (22,890 lb in power boost mode) and an arm tear-out force of 16,500 lb in normal mode (18,030 lb in power boost mode).

The Automatic Sensing Work Mode offers a summation system that provides full use of the pump oil flow; a boom priority option that gives priority to the boom operation for fast raising when loading or deep excavating; an arm priority option that gives priority to the arm for faster cycle times in leveling and for increased bucket filling when digging; a swing priority operation for faster swing during simultaneous operations; and a regeneration option that enhances the cylinder life cycle to prevent cavitation and provides priority to other movements during simultaneous operations.

Gehl Co., West Bend, Wis., has a line of 13 compact excavators ranging from 3,600 to 25,000 lb. The latest also is the biggest. The GE1202 has a 25,000-lb operating weight and is powered by a 98-hp turbo diesel engine.

The hydraulic system on the GE1202 is continuously variable and regulated to provide the exact power needed for the conditions.

The boom on the GE1202 swings 80û to the left and 50û to the right. With a tail swing of only 5 ft 5 in., the machine can fit into small spaces.

The GE1202 has a maximum digging depth of 14 ft 8 in., a maximum dump height of 17 ft 9 in., a bucket dig force of 15,653 lb, a bucket capacity of 17 cu ft and a drawbar pull of 24,279 lb. Steel tracks are standard; rubber tracks are optional.

The Solar-V family of excavators from Daewoo Heavy Industries America Corp., Suwanee, Ga., has had a couple of additions in the past year. One of the newcomers is the S170LC-V. This "baby" has an operating weight of 37,919 lb, a 116-hp engine, 24-in. tracks and an 8 1/2-ft overall width.

The S170LC-V is designed as a mid-sized excavator for small contractors faced with a wide variety of tasks. The machine features benefits common to the Solar line, which include low fuel consumption and a 76 dBA rating.

The S170LC-V’s little brother is the new S130LC-V, with an operating weight of 30,200 lb and a 108-hp engine. The excavator is an upgrade of the previous model and now includes a dozer blade for backfilling.

The S130LC-V provides two pilot-pressure joysticks for ISO control. The cab features four-sided safety glass for a good all-around field of view.

For the biggest earthmoving jobs, the biggest of the excavators from John Deere Construction Equipment Co., Moline, Ill., provides smooth movement by keeping a constant balance between pressure and flow, according to the company. The engine and hydraulic management system in the 167,602-lb model 750 is called Powerwize and is powered by two variable-displacement axial-piston pumps.

The 750 is equipped with a six-cylinder, direct injection, turbocharged and aftercooled engine supplying 434 net hp. The machine has a maximum reach of 51 ft 6 in., a maximum digging depth of 34 ft 8 in. and 55,460 lb of lift capacity (over the front). The whole package sits on tracks 20 ft 10 in. long.

Booms and arms are of all-welded, box-section design.

Operators in the 750 can choose from two power modes that regulate engine speed. Standard mode offers fast cycle times for normal or average applications, delivering an efficient engine speed and 100% hydraulic pump output. Economy mode is designed for light-duty applications where productivity and fuel economy are a must.

The T-45S mini excavator from Thomas Equipment Ltd., Centreville, New Brunswick, Canada, delivers 4,509 lb of bucket break-out force and 2,589 lb of arm force in a package that weighs only 4,460 lb. The machine is powered by a 44.8-hp diesel engine and features a maximum digging depth of 13 ft 4.8 in. and a maximum dumping height of 13 ft 9 in.

The excavator’s drive system features a variable piston pump that automatically adjusts both hydraulic flow and pressure to match the load demand. The boom swings 80û left and 55û right.

The half-pitch rubber tracks on the T-45S are independently powered for high maneuverability. The machine features two hydraulic pilot-operated joystick controls, with fully adjustable arm rests. Either ISO or SAE control pattern is available.

The Lineman TMX is the world’s first towable mini excavator, according to the maker, Excavation Technology Inc., Wheaton, Ill. The machine has a built-in trailer and lock-out wheel hubs for a quick-on and quick-off hitch system. It eliminates the need for a trailer.

The Lineman TMX is equipped with a 20-hp gasoline or optional diesel engine. The machine produces 6,600 lb of digging force, with a maximum digging depth of 8 ft. It is propelled by an independent hydrostatic drive system and features low ground pressure and a zero turning radius.