The Scoop on Excavators

Dec. 28, 2000
Value is important to a consumer. Getting the most from your dollar has influenced people's buying habits on a wide range of purchases, whether it be peanut butter or a new car. The same goes for construction equipment. Getting the most out of one's machines is a driving factor in the market. This is one reason the skid-steer, a machine noted for its versatility, is growing in popularity in the construction field. Another versatile machine helping a contractor's money go further is the hydraulic excavator.

Versatility means the machine must be able to handle a multitude of tasks.

Value is important to a consumer. Getting the most from your dollar has influenced people's buying habits on a wide range of purchases, whether it be peanut butter or a new car. The same goes for construction equipment. Getting the most out of one's machines is a driving factor in the market. This is one reason the skid-steer, a machine noted for its versatility, is growing in popularity in the construction field. Another versatile machine helping a contractor's money go further is the hydraulic excavator.

Versatility means the machine must be able to handle a multitude of tasks. The more jobs one machine can do the less number of specialized pieces of equipment needed by the contractor.

The basic nature of an excavator makes it versatile, thus increasing its productivity. Mike Murphy, product manager, hydraulic excavators for Komatsu explains, "The excavator arm is designed in the analogy of the human arm. The upper arm is the boom, the fore arm is the stick, and the hand is the bucket. Because the excavator can swing 360 deg plus the fact it has the capability, like a human arm, of reaching out, and positioning far, close, deep, shallow, increases versatility. The positioning ability makes it cheaper to operate."

Attachments are the key element in an excavator's arsenal of versatility. "Customers demand machines with flexibility and versatility which can easily accept a wide range of hydraulic attachments, meeting a variety of applications. Today's customer considers excavators to be less of a bucket machine and more of a hydraulic tool carrier," says John Walker, sales support consultant for the North American commercial division, Caterpillar Inc.

"More and more excavators are using attachments. In the last few years we have seen an explosion in the number of attachments people are putting on excavators. As a result customers are demanding that manufacturers provide auxiliary circuits for those attachments," says Clark Johnson, manager product planning for excavators and motor graders, John Deere.

"A greater variety of attachment offerings and improved coupling systems have been key to increased excavator versatility," says Terry Dolan, marketing manager, excavators, wheel loaders and crawlers, Case Corp.

Hydraulics make the use of a variety of attachments possible. Murphy explains, "Hydraulic systems, and the computers which control these systems are the excavator's soul and brain. The engine is the heart."

In addition to hydraulics, electronics also are important in improving the capability of the machine, and this is one area where excavator advances are taking place. "Most advances taking place involve the electronic control of machine systems. Electronics allow the machine to be tailored to the specific job at hand by adjusting the engine rpm and the flow of the hydraulic system. Electronics are making the machine easier to operate," says Murphy.

But the use of electronics should not make the excavator over complicated and difficult to use. Johnson explains, "We see electronics as something the customer should not notice. We don't want to make them complicated in terms of the operator using the machine. We want to use a lot of electronics to make it simpler and more comfortable for the operator."

Electronics are responsible for improved productivity and operating costs. "The use of electronics and electronic controls allows operators the benefit of selecting machine performance perimeters through the selection of a few well placed buttons on an instrument panel. Operators can select and influence engine and hydraulic power, hydraulic flow priorities, engine speed and travel speed. The result is better performance and productivity while maximizing fuel efficiency," states Walker.

"Instead of putting a lot more horsepower in the machine to do the job, you can get by with the same horsepower and a good computer system. The fuel economy will improve and the machine will be easier to operate," adds John Hahn, director of sales and marketing, Fiatallis.

"Advanced electronic systems, like those found in our 90B Series, provide superior fuel economy and faster, more accurate diagnostics. Improved fuel economy is achieved through the help of a computer, which controls engine rpm and hydraulic pump flow. This allows the engine to operate at the most efficient rpm range without sacrificing performance," says Dolan.

Improving the performance of the machines has made them easier to operate. Hahn comments, "The ease of operation will take some skill away from the operator. You can now take an operator with less skill and make him very productive. You can put just about anybody on the machine and they'll do a good job."

"Electronics are making the machine easier to operate. A lot of the systems remove operator decisions," adds Murphy.

"Electronics also improves troubleshooting by providing on-board diagnostics and major systems overrides. The result is maximum up-time and improved productivity," says Walker.

"We offer diagnostics with trouble data memory. When a malfunction occurs the diagnostics will remember it for 1,000 hours. The technician can read out what went wrong and when. On board diagnostics lets the operator or technician monitor the machine to let them know what's wrong," adds Murphy.

Operator comfort

Designing a machine that is user-friendly is becoming increasingly important. When it is easier for the operator to do his job, production and quality of the work should improve. "More than ever before, the operator-friendly systems have become a priority in the development of new high-performance construction equipment," said Keith Rohrbacker, product manager, Kubota Tractor Corp.

Providing optimum operator comfort is proving to be another area important to excavator design. Getting the most out of the operator and the machine is the objective of good excavator design. Hahn explains, "Making the controls easier and less fatiguing to operate; making arm rests more adjustable so the operator can get comfortable; all this makes him more productive."

In general the construction industry is tough and dirty. One way to attract qualified people to the job is to provide them with a comfortable working environment. "One reason for making the operator's environment better and more comfortable is to attract good people. And the more comfortable they are the more productive they will be," says Murphy.

"More comfortable seats, better heating and air conditioning; anything that makes the operator more comfortable, makes his job easier to do. If the operator is more comfortable he becomes more productive. If he's more comfortable, he likes your machine better than the competition's," adds Johnson.

"Operator comfort is crucial to overall job performance. Quiet, comfortable, well appointed cabs with maximum visibility result in a better performing team of man and machine," states Walker.

Rohrbacker adds, "We view the machine and operator as a unit. The Kubota philosophy calls for the design of equipment which is capable of doing the job, but not at the cost of environmental impact or operator fatigue or stress."

Dolan sums it up, "At most productive job sites, operators are working at least eight to 10 hours per day, and for that reason, operator comfort is extremely important."

What an excavator can do

An excavator can offer a lot to a road or bridge builder. An excavator is a common sight on highway jobs--loading, grading or spreading material, but its use among bridge builders is increasing. "More and more bridge builders have to tear down an old bridge before they build a new one. This is where excavators are being used more, because there are attachments available that make the machine very efficient at the job of demolishing a bridge," states Murphy.

John Walker gives another reason why the machines are so popular with road and bridge builders. "Excavators can lower a customers cost per yard of material moved while providing highway and bridge builders the versatility to easily add an assortment of hydraulic-mechanical attachments to meet varying application requirements."

Dolan sums up, "An excavator can offer the highway or bridge builder a good rate of return because of the machine's versatility. The machine can be used for demolition when equipped with hammers and shears; trenching when equipped with buckets to match the job; and for setting pipe with its craning capability.

"And those are some of the more traditional uses. We see contractors using cold planers on excavators to resurface overhead bridges. We see others using excavators to work the entire demolition cycle, from hammering out decks and roadbeds to rebar separation and recycling preparation to loading. An operator can also move from one type of work to another very quickly with the use of a quick coupler to disconnect from a bucket to various attachments."

Here's just a few of the excavators available today.


Case offers its 90B Series of excavators, six models ranging from 28,000 to 99,950 lb of operating weight. Horsepower specs range from 100 hp to 300 hp and dig depth covers 18 ft 2 in. for the 9010B and continues deeper to a depth of 27 ft 7 in. for the 9060B. According to Terry Dolan, product manager, excavators, "With our 90B Series, we've retained the features operators liked best about the 90 Series and added things like one-touch power boost, arm anti-drift valves and an automotive-style operator's environment to enable operators to be even more productive in more applications."


The company has been upgrading its 300 line of excavators. Its 320B L and 322 B L replace the 320 and 322. In addition the 311B and 312B replace the 311 ad 312. These two new excavators improve operator controllability, while cab changes enhance operator comfort. "Cat excavator cabs are fully pressurized and filtered to keep dust out, and a climate-control air conditioning system is standard," says John Walker.

The 79-hp 311B and the 84-hp 312B weigh in at 25,320 lb and 26,640 lb respectively. Both models come with options that include a blade for backfilling and leveling, a 12-volt 5-amp power supply for cellular phones and radios and an air conditioner. Replacing the 235C is the 345B L, a 290-hp machine featuring an operating weight of 99,600 lb, and a maximum depth of 27 ft 4 in.


Daewoo Machinery Corp., Carlstadt, N.J., has introduced the new Solar Series 330-III and the 450-III excavators. Both models feature an ergonomically designed cab, with shock-free independence, all-round visibility, improved heating/air conditioning, multi-adjustable seat, and a low noise level. With 53,792 lb of breakout force, the 450-III has a digging reach of 40 ft 1 in. and a digging depth of 26 ft. The 330-III has a breakout force of 46,077 lb with a reach of 36 ft 9 in. and a depth of 24 ft 11 in. Both feature the company's electronic power optimizing system (EPOS III) with three power modes and four work modes.


Gradall approaches earth moving with a unique excavator design--a telescopic boom. The company's XL 4000 Series provides a boom reach of 30 ft 6 in. and can telescope, raise, lower, dig, swing and tilt 220 deg. With options the boom tilt can be increased to 360 deg. With boom extensions and a Telestick attachment, reach can be increased to over 45 ft. The XL 5000 Series can reach up to 34 ft with a boom tilt of 240 deg. As with the 4000 series, tilt can be raised to 360 deg and the Telestick pushes the reach to over 50 ft. Six-, 8- or 12-ft boom extensions also are available.

Both series come with an optional wheeled undercarriage to ease travel to job sites. The undercarriage is powered by a Cummins 6CT8.3 engine, and features power steering, six-wheel air brakes and a split air system incorporating separate circuits for service and emergency braking.


Hitachi Construction Machinery has introduced the Super EX1100-3, an upgrade of its EX1100. Some updated features include a strengthened frame and front, an emissions standard which meets current EPA regulations, and safety standards which conform to the European Norm.

The new model is powered by a Cummins QSK 19-C with turbocharger and after cooler. The cab has been redesigned to increase operator comfort and reduce fatigue. Controls, monitor and switches are ergonomically shaped, and a double slide mechanism allows the seat and levers to slide together or separately for customization.


Hyundai Construction Equipment has introduced a new excavator, the R180LC-3. "The R180LC-3 hydraulic excavator has been under development for the past year and when we announced it to our dealer network, it quickly became our most requested machine," says Randy Schlossin, marketing manager.

The machine is powered by a 126-hp Cummins 6BT5.9-C engine, has an operating weight of 39,240 lb and a bucket capacity ranging from 0.59 to 1.35 cu yd. Its digging depth is 20.6 ft and has a maximum reach at ground level of 29.4 ft.

John Deere

The 120 is John Deere's latest offering in its excavator line. It has an operating weight of 27,200 lb, 28 ft 3 in. of reach, 19 ft 6 in. of depth and a lift capacity of 5,725 lb. It is powered by a Powertech 4-cylinder, 90-hp Deere engine that complies with the new EPA emission standards. According to the company the user-friendly system actually feels when the arm meets with heavy resistance and automatically increases engine rpm by 6%. When the dig cycle is complete the system saves fuel by returning to the original setting. Three power modes are available to regulate engine rpm, and operators can select from four work modes. Other new excavator models include the 230 LC and 270 LC, which replace the 790E LC and 792D LC, respectively.


The PC128UU has been designed to operate in extremely tight working conditions. Its features include a zero tail swing design, offset boom, over-center boom design and electronic control system for the boom's height setting, offset positioning and digging depths. The company's newest machine is an addition to its family of Avance excavators, the PC150-6. The 38,800-lb, 105-hp machine has an ergonomic cab design and five working modes. The machine is available with either a standard length undercarriage, which increases mobility, or a long undercarriage to enhance application versatility.


Kubota Tractor Corp. introduces a new generation of compact excavators--the KX-2 Series. The line is powered by low-emission E-TVCS 3- and 4-cylinder diesel engines and range in output from 21.6 hp to 42.6 hp. Digging depth ranges from 7 ft to just over 11 ft 8 in.


The company has introduced a new addition to its Quantum Series--the 1600Q. The new machine is 14,990 lb with a bucket capacity of .24 cu yd to .45 cu yd., and is powered by an Isuzu 4JB1, turbocharged, 4-cylinder diesel, which produces 54 hp. Its small design allows it to work in tight corners and high traffic areas. It's redesigned cab features, among other things, a reclining, sliding, fully suspended seat, heater with three-speed fan, an AM/FM radio, a pop-up skylight and two safety control lockouts.


Tomen America Inc., Norcross, Ga. are distributing Nagano Industry Co., Nagano, Japan, compact excavators. The Highland Series is made up of six models that range in weigh from 3,366 lb to 10,054 lb, with a maximum cutting depth of 86.6 in. to 141.1 in. Engine power ranges from 18 hp to 43 hp.