The Scoop on Excavators

Hydraulics, electronics, and a variety of attachments have combined to make the hydraulic excavator more than just a dirt mover.

David Banasiak / December 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. 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

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

"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."

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

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."

just a few of the excavators available today.


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."


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.


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


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


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.


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.


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.

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