|
Excavating contractor
Frank Parker is big on small equipment. In addition to a Case 580
Super L backhoe, he owns four compact excavators (a Takeuchi TB145,
two Kubota KX101, and a Kubota KX008) and two compact loaders -
a Kubota R520 wheel loader and a Bobcat 773 skid-steer loader. For
good reason: His company, All Terrain Backhoe Services Inc. in San
Jose, CA, focuses on a specific part of the market. "We want the
jobs that contractors with the big equipment can't get into and
that the guy with one machine or limited labor can't handle efficiently,"
Parker explains.
His
company serves the area between San Francisco and Monterey, where
high-priced real estate continues to shrink the amount of available
space for digging, moving, and loading dirt and other materials.
His range of equipment provides the versatility he needs to stay
profitable.
"Job sites are really getting compact with more structures
per acre," he notes. "With the diversity of our compact equipment,
we can do the tight-access work where we can't use our backhoe.
Our customers know we can get the job done."
 |
The company started 16
years ago with a tractor-loader backhoe and began adding compact
excavators seven years later. The first compact wheel loader was
purchased four years ago, followed the next year by the first skid-steer
loader. The loaders complement the backhoe and excavators, improving
productivity and bringing in more business. The wheel loader and
skid-steer machines are used for placing dirt and sand, backfilling
trenches, loading trucks, and cleaning up construction debris. "We
didn't do this type of work before," he states. "We also use the
loaders with the excavators. For example, if we use one of the excavators
to cut out a bank, we'll use the loaders to move and load the dirt.
The loaders have helped our business grow, which was the main reason
for buying them. But they have also freed up our backhoe to do what
it does best - high production work, like digging footings and trenches
in wide-open areas."
In
addition to moving construction materials, the 49-hp wheel loader
(Kubota R520), which has a 9-ft., 9.2-in. lift height, also is used
for loading into end dumps and trailers. The 46-hp skid-steer loader,
with a rated operating capacity of 1,750 lb., hauls dirt out of
areas too small for the wheel loader. The skid-steer loader stockpiles
materials, which the wheel loader then dumps into the trucks.
The loaders and other compact equipment often work simultaneously
on the same job to save as much time and labor as possible. "Each
machine has an operator," Parker explains. ""Sometimes every machine
is working on a project. On one sidewalk installation job, one of
the compact excavators was used to demolish concrete and the skid-steer
loader hauled the debris away for the wheel loader to put into a
truck. The wheel loader was also used to feed base rock to the skid-steer
loader, which spread it for the new sidewalk. Another time, one
of the excavators dug a footing inside a high school and the skid-steer
loader carried the spoil outside. We wouldn't be able to do this
kind of work without our compact equipment."
A Versatile Range of Choices
Parker's experiences illustrate the moneymaking value
of compact loaders and other small equipment, both in their own
right and in supporting larger machines. The undisputed king of
the compact loaders is the skid-steer loader, which pioneered the
concept of small, agile, multipurpose machines more than 40 years
ago. Since then, the role of compact loaders in the grading and
excavating industry has increased steadily as manufacturers have
refined existing technology while inventing new ways to tackle work
in confined spaces. In addition to developing downsized versions
of track loaders and articulated wheel loaders, they've created
new concepts for compact machines. Despite their different capabilities,
the various types of compact loaders share at least one common trait:
the ability to use different attachments, such as a bucket, an auger,
and a breaker. That multitask capability adds to their versatility
and value on a construction site.
With the ability to turn 360º within their own length,
skid-steer loaders excel in jobs that require maneuvering quickly
in tight spaces. They offer the widest choice in size and performance
capabilities, ranging from the most compact units that can slip
through a gate or doorway to 5-ton machines with rated operating
capacities of more than 3,000 lb. In general, skid-steer loaders
are priced lower than other types of similar-size compact loaders.
"The market for skid-steer loaders has matured in the
past 10 years," observes George Mac Intyre, marketing manager for
Case Construction Equipment. "However, they will continue to be
popular because they can handle so many different types of work,
from home building and highway construction to industrial and agricultural
applications."
Track loaders represent the fastest-growing segment of
the compact loader market. In addition to the agility of a skid-steer
loader, they offer added benefits. Equipped with rubber tracks,
they can work in soft or muddy conditions that would stop a loader
with wheels and cause less disturbance of turf and other sensitive
surfaces. Manufacturers see a bright future for these workhorses.
"Many contractors are just starting to realize what compact track
loaders are capable of doing," notes Dan Rafferty, product sales
manager for Takeuchi loaders and compact excavators.
Four-wheel-drive compact wheel loaders, typically under
100 hp with bucket capacities of less than 1 yd.3, offer
a tight turning radius, better visibility, and smooth turning for
less tire wear, surface disruption, and spillage of material than
a skid-steer loader. "Customers want more skid-steer loader-type
features, so we've added more powerful hydraulics, hydraulically
operated quick couplers, along with more choices in comfort, model
size, tire options, and the like," states Keith Rohrbacker, product
manager for Kubota Construction Equipment wheel loaders and compact
excavators.
The oscillating frame of an articulated wheel loader
provides a more stable platform when working on rough or uneven
terrain than does a rigid-frame skid-steer or track loader. Also,
unlike those two types of loaders, a compact wheel loader can tackle
work from both ends. Attachments, such as an auger, a breaker, or
other skid-steer loader tool, can be mounted on the front, while
a backhoe or tractor implement, such as a box blade, can be hooked
onto the rear.
Here's a look at some of the recent improvements in these
machines' ability to do more work in less time while offering more
operator comfort and convenience.
New Designs
A Two-in-One Loader
Last year Bobcat introduced
the world's first loader to offer a choice of skid steering, for
tight turns, and all-wheel steering, for smooth turns, at the flip
of a switch. In all-wheel steer, the four independently controlled,
steerable axles coordinate angling of the wheels to roll through
a turn. In skid-steer mode, the axles remain perpendicular to the
frame. The two wheels on one side of the loader work independently
of each other. Measured from the outside bucket corner, this allows
the model A300, the larger of the two models, to turn in a 23-ft.-diameter
circle. By rotating wheel direction on one side counter to the rotation
direction on the other side, this machine can turn 360º within its
own length of 14 ft., 4 in. The models provide operating capacities
of 2,200 or 3,000 lb.
"The machine is designed for contractors who work on
both rough and finished grades and want to maximize productivity
in either case," states Mike Fitzgerald, Bobcat loader product representative.
"It reduces, if not eliminates, the need to repair marks left by
skid-steer turning and extends the life of tires when operating
on asphalt or other hard pavement."
All-Wheel-Steer
Loader
This past summer Gehl introduced a new line of all-wheel-steer
loaders, in which the wheels turn up to 40º right or left to produce
a tight turning circle. Curb-to-curb turning radius is about 50%
shorter than a comparably sized articulated loader. But that's not
the only benefit, points out Tom Eggers, product development manager
for Gehl Company.
"With articulated loaders, the load center moves from
side to side as the machine turns," he explains. "This reduces the
total weight of the load you can carry and remain stable when turning
on a grade. However, four-wheel steering keeps the load centered
as you turn. Consequently, an all-wheel-steer loader can carry more
payload per pound of machine than an articulated loader without
tipping. Eliminating articulated steering also provides room for
a bigger cab and right and left entry and exit."
Three models have conventional loader booms, and three
offer a telescopic boom with maximum dumping heights of 13 ft.,
1.5 in. to 14 ft., 8 in. and a dumping reach of 3 ft., 11 in. to
6 ft. The turning radius, between walls, for the models ranges from
11 ft., 10 in. to 15 ft., 2 in.
These loaders can employ attachments typically used with
compact wheel loaders as well as those designed for skid-steer loaders,
Eggers reports. "Combining a telescopic boom and a short turning
radius expands the versatility of these loaders beyond conventional
wheel loader applications. A landscape contractor could save time
using the telescopic boom on one of these all-wheel-steer machines
to load balled and burlapped trees on a semi-truck from just one
side. You could also use it to reach out with a tree spade to avoid
possible damage to nearby trees or structures."
Lower-Priced Compact
Track Loaders
Until recently, the increased traction, flotation, and
lower ground pressure of compact track loaders, compared to skid-steer
loaders, came at a cost - a higher price tag. At least one manufacturer
is changing that, however. In addition to four other models, including
the largest - a 105-hp unit - ASV now offers two models, a 31.5-hp and
a 50-hp machine, priced under $30,000.
"In the past, if you wanted a compact track loader equivalent
in power to a $25,000 skid-steer loader, you'd spend about another
$15,000 to buy it," relates Brad Lemke, the company's new product
development manager. "These two loaders are more affordable options.
Performance
Improvements
As skid-steer loaders
have proven their ability to save time and labor in grading and
excavating jobs, contractors are challenging them to work harder.
Manufacturers are responding with brawnier machines.
More Lifting Power
"At one time, models with operating capacities of about
1,500 pounds were our best sellers," recalls Lance Schulz, Bobcat
loader product representative. "Now sales of units with rated operating
capacities of about 2,000 pounds or more are beginning to overtake
the smaller machines, and that trend will probably continue."
The maximum rated operating capacity offered by most
manufacturers is around 3,000-3,500 lb. While not necessary for
typical grading and excavating work, say the experts, that extra
power comes in handy for heavy lifting jobs, such as handling pallets
of sod or concrete blocks.
The type of lift path also affects lifting power. At
one time, the lift path of most loaders, when viewed from the side,
described a fixed-radius arc. These machines have been popular for
digging applications. More and more manufacturers are offering models
with a vertical lift path, however. These machines are better for
lift-and-carry chores, notes Erick Kohout, product manager for New
Holland Construction.
"We're seeing a shift to a lot more vertical lift models,"
he observes. "The boom geometry keeps the machine's center of gravity
relatively low for more stability. This type of lift path also provides
more reach at the top. That makes it easier to dump into the center
of trucks or raise loads to scaffolding. The increased cost of the
boom design is offset by the fact that this type of machine doesn't
require as much horsepower as a radial lift loader to lift a given
weight."
More Engine Power
After a point, of course, improving the productivity
of a machine by make it bigger defeats the very trait that makes
these machines so useful - their small size. So manufacturers are
building more work capacity into a compact frame. One way is by
increasing horsepower without increasing engine size. For example,
all the models in the Case XT line of skid-steer loaders are equipped
with the same basic diesel engine. However, the rating of these
models varies from 60 to 85 hp.
"Our engines have a range of horsepower where they work
most effectively," states Mac Intyre. "We rate an engine within
that span to get the power we want for a given model. That power
is properly matched to the specific components, like axles and drive
motors, in a particular machine."
This also helps hold the line on dealer and equipment
owner costs by minimizing the number of different service and maintenance
items they need to stock, such as oil or air filters, he adds.
More Hydraulic Power
The higher-performance attachments developed in the past
few years also have increased the need for more hydraulic flows
and pressure to operate them at peak efficiency. At the same time,
more powerful hydraulics produce faster cycle times for more productivity.
In general, high-flow loaders provide hydraulic flows of about 30
gal./min.
"Compact loaders are becoming portable power units for
use with a wide array of attachments in situations where you can't
use large hydraulic tools," says Kohout. "The new hydraulic systems
are designed to accommodate higher flows."
Manufacturers are boosting hydraulic flows by adding
pumps and increasing pressures. However, both must be matched correctly,
cautions Schulz. "You can have high hydraulic flow or high pressure,
but you can't have both. Depending on the machine, a combination
of a 30-gallons-per-minute pump and a pressure of 3,000 psi could
produce more hydraulic power than a 35-gallons-per-minute pump and
2,000 psi."
More Efficient Travel
and Working Speeds
Many of the larger skid-steer loaders now are equipped
with two-speed-drive systems with high-range speeds of 12 mph or
more. That boosts productivity by saving time traveling between
work sites.
Another new development found on Bobcat all-wheel-steer
loaders is an inching control. It enables an operator to maneuver
slowly and precisely, without sacrificing torque. This allows hydraulics
and attachments to operate at full engine speed for top performance,
while the machine creeps along or travels no faster than 4 mph.
Kubota offers a similar feature, called a travel-speed-limiter
switch, on its compact wheel loaders. These machines are also equipped
with a load-sensing transmission that automatically changes from
a high-travel-speed/low-engine-torque operation to low-speed/high-torque
mode.
"When you engage the bucket in a pile of dirt and press
the accelerator, engine power is directed from travel to torque
for maximum breakout force and lifting capacity," Kubota's Rohrbacker
explains. "Once the bucket is in travel position and you step on
the accelerator, the transmission provides power for maneuvering
and carrying the load. When you're ready to dump the load into a
truck, the machine responds to the accelerator by using engine power
to operate the boom and bucket tilt quickly to begin another work
cycle."
More Sophisticated
Attachments
In addition to expanding the different types of tools
available for grading and excavating work, manufacturers are improving
the quality of the work these attachments can do. For example, equipped
with laser systems, compact loaders can use a box blade or a grader
attachment to grade with an accuracy of +0.25 in. A device
that mounts between the loader and the attachment makes it possible
to rotate hydraulically each side of the tool up or down 15º from
center as you work. Using it with a bucket, for example, you can
cut a level path out of a side hill, dig a drainage ditch with the
corner of the bucket, or keep a load level on uneven terrain.
Attachments also are becoming more sophisticated in terms
of the type of work they do. For example, Case recently introduced
an attachment to speed up installation of silt fence. It features
a vibratory plow and a spindle that holds the silt fence fabric.
As the machine travels in reverse, this tool pulls the fabric into
a slot created by the plow, burying material up to 12 in. deep.
Then stakes are driven in by hand and the fabric is attached to
the stakes, completing the installation.
More Durable Tires
Although skid steering is the key to skid-steer loaders
being able to turn completely around within their own length, it's
also tough on tires. Recently Michelin introduced the first radial
tire for skid-steer loaders. The company reports that the XZSL Stabil'X,
a steel-belted radial tire, has a 30% longer life than a bias-ply
tire. A steel casing and special rubber compounds increase resistance
to cuts and abrasions for fewer flats and longer tread life. Other
features include improved traction, handling, and ride and an aggressive,
nondirectional tread pattern that leaves fewer marks on concrete
and pavement, the company reports.
Comfort
Features
Cab Amenities
Manufacturers continue
to improve comfort for operators of compact loaders with such features
as quieter cabs, more head and leg room, easier entry and exit,
better placement of controls and gauges, and improved visibility
to the side, front, and rear corners of the machines. Many models
include such options as fully adjustable suspension seats that adjust
to the operator's weight and enclosed cabs with heating and air
conditioning.
Low-Effort
Controls
Reducing operator fatigue also can improve productivity.
One of the biggest advances in this area has been development of
the latest generation of joystick controls. It's the same technology
used to control large excavator and other big construction equipment.
These joysticks replace conventional levers - which use
cables and mechanical linkages to control hydrostatic pumps - with
a much more reliable and much easier to operate hydraulic control
system. The left joystick controls steering direction and travel
speed, while the right joystick controls boom lift and attachment
tilt functions.
"Some
of the earlier servo-assist hydraulic controls were very jumpy,"
recalls Rafferty. "There was a momentary delay between the time
you pushed a lever and the machine responded. With the latest pilot
controls, however, response is immediate and very smooth and precise.
Instead of working your arms and shoulders all day when operating
a skid-steer, you use small wrist movements to get very fine control
responses. You don't end up fatigued at the end of the day."
Convenience
Features
Manufacturers also are improving productivity of compact-loader
operators and owners by reducing the time and effort required to
operate, service, and maintain the machines.
Easier Tool
Changes
Changing from one attachment to another is one example.
After sitting in the sun on a hot day, the oil in a hydraulic line
can expand and build up enough pressure that it's very difficult,
if not impossible, to disconnect an auxiliary hydraulic from an
attachment without first turning a key, pushing a button, or unscrewing
the line and dealing with dripping oil. At least one manufacturer
(Bobcat) has developed an easier solution to that problem - a pressure-relief
quick coupler. Before disconnecting a hydraulic line from an attachment,
you press the hose forward for a few seconds. This allows some of
the hydraulic fluid to drain into the reservoir, leaving a void
at the coupler end of the line and making it easy to reconnect the
hose.
Several manufacturers offer an increasingly popular option
that allows you to switch from one attachment to another without
leaving the cab. Pressing a switch inside the cab activates a hydraulic
cylinder that opens and closes the pins that secure the attachment
to the loader. However, hydraulically driven attachments, such as
augers, still require you to connect and disconnect hydraulic lines
by hand.
Easier Speed
Control
In addition to the conventional throttle for setting
a specific engine speed, several models of compact loaders include
a convenient accelerator pedal. It allows you to adjust engine speed
easily between slower rpms, saving fuel or reducing noise, and higher
rpms when more power or speed is needed.
Time-Saving
Service and Maintenance
Servicing and maintaining compact loaders has never been
easier thanks to such features as flip-type cabs that provide quick
access to hydraulic and hydrostatic systems; wide, swing-open tail
gates to check fluid levels and change filters; and more zerk fittings
to reduce maintenance needs.
Several Case skid-steer loader models have optional jump-start
terminals at the rear of the machines to save the time involved
in bringing an engine back to life if the battery dies and to jump-start
other equipment on the job site. It also includes a switch for disconnecting
the battery as extra protection against theft or vandalism.
State-of-the-art instrument panels provide electronic
monitoring and diagnosing of engine and machine operation, complete
with computer screens and keyless-start security systems. The instrument
cluster on New Holland skid-steer loaders, for instance, monitors
14 different functions, from air filters to engine hours, and even
includes a low-fuel alarm.
More Handy
Touches
Other convenience items offered as options on some makes
include a dome light, a power socket that accommodates a cell phone,
and an AM/FM stereo radio.
These are just some of the ways manufacturers are improving
the ability of compact loaders to make grading and excavating work
in confined areas easier, more comfortable, and more profitable.
If the past is any indication of the future, the performance and
value of these machines will continue to improve.
Greg Northcutt is a frequent contributor to Grading
& Excavation Contractor.
GEC
- May/June 2003
|
