Grading and Excavation Contractor | SKID-STEER PRODUCTIVITY PLUS

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	Photo: Bobcat

More powerful than its predecessors, today’s machine offers a bigger and beefier productivity package.

By Carol Wasson


	Understanding Skid-Steer Specs

At the end of a shift, it’s all about productivity. Is more time spent in the skid-steer seat or in the maintenance shed? How many different jobs can be tackled with the same unit? Is that equipment investment delivering a payback each and every day? Today, people want to get more, more, and still more from their machines. Skid-steer manufacturers have answered demand with new plus-sized productivity packages. A bigger, beefier skid-steer breed features increased lift capacity and lift height, higher hydraulic horsepower capacity, greater breakout force, more operator comfort amenities, better visibility and ease of operation, and minimized maintenance requirements. In the mid- to full-size skid-steer arena (versus the mini models), less is definitely not more.

When Size Matters More
Not to say that bigger is always better—skid-steer selection should always be based on the given application—one shouldn’t oversize or undersize. There is an option suitable for everyone.

Skid-steers in the 1,751- to 2,200-pound class currently comprise the largest selling segment—an upgrade in size preference from the most popular 1,600-pound class of a decade ago. Machines in the 2,201- to 2,701-pound rated operating load class are the second-largest grouping of skid-steers on the job site.

With that said, it follows suit that Bobcat Co. has recently introduced its largest skid-steer loader yet—the S330, which delivers a 3,300-pound rated operating capacity. The company says that an increase in demand for larger skid-steer loaders with a lift capacity of more than 3,000 pounds prompted it to offer customers more options. With a 10-foot, 10-inch lift height, the vertical-lift-path S330 is targeted for applications such as nurseries, supply centers, turf and sod contractors, and demolition and residential contractors.

Another plus-size factor regarding the Bobcat S330 is a bigger 85-horsepower (hp) diesel engine for increased pushing power and drive torque when digging. It also improves performance in high-flow attachment applications by providing more support for the machine’s hydraulic horsepower.

Photo: Bobcat

Joystick controls allow for speed and horsepower management.

Photo: John Deere

When skid-steer shopping, base your selection on the given application.

Higher-Flow Hydraulics
More than 70% of mid-range skid-steer models feature optional high-flow hydraulic pumps, most of which boost flow by 50% or more over standard flow rates. Generally, standard flow hydraulic pressures range from 16 to 25 gallons per minute (gpm), while high-flow hydraulic pressures range from 26 to 40 gpm. According to www.Spec-Check.com, hydraulic horsepower with standard pumps runs the gamut from 23 to 43 hp, and high-flow options take the maximum up over 78 hydraulic horsepower.

With high-flow hydraulics, machines become powerful loading units, as well as more versatile tool carriers—with the ability to operate larger, and more specialized attachments such as cold planers, hammers, breakers, large augers and trenchers, rock and concrete saws, and more. With high-flow hydraulics, attachment possibilities are almost limitless. Note that if a machine has less flow than an attachment requires, this may cause costly damage to mechanical or structural parts of the skid-steer or the attachment.

The Caterpillar 248B skid-steer loader, with a rated operating capacity of 2,000 pounds, is offered with the high-flow XPS hydraulic system as a standard feature. It uses a variable-displacement piston pump to provide hydraulic flow and pressure up to 33 gpm and 4,060 psi when running high-flow work tools. Its load-sensing system can provide high hydraulic power whether the engine is at low or at high idle, says the company.

As an example, the Lakes Highway District of Northern Idaho purchased the Cat 248B equipped with seven work tools—pallet forks, utility grapple forks, a cold planer, a material handling arm, an auger, a general-purpose bucket, and a pickup broom—all driven by high-flow hydraulics. This allows the crew to multitask and eliminates the need to have several machines and several operators on the job site.

Big on Loading
Vertical lift is all about loading, say manufacturers. It gives greater forward reach and height, delivering optimum truck loading ability since the bucket is about 3 feet in front of the skid-steer’s front tires. Alternatively, radial-lift arms are more suitable in digging applications.

Lift height is usually measured as the “height to hinge pin,” meaning the pivot point between the arms of the loader and the bucket. Smaller models range from 8 feet, while larger models may exceed 10 feet.

Many of today’s current skid-steer models offer increased vertical lift. For example, the recently introduced Gehl 7810E (rated load capacity of 3,850 pounds) features a lift height of nearly 12 feet, the highest in the industry, says the company. Gehl engineers describe the model as having “true vertical-lift linkage,” which provides consistent forward reach throughout the entire life cycle. The machine is suitable for applications ranging from breaking, hauling, and grinding concrete to digging, moving materials, and loading trucks.

With a 2,000-pound operating capacity, a 10-foot lift height, and 29 inches of forward reach, the New Holland L175 skid-steer loader features a 60-hp turbocharged engine and the company’s patented Super Boom vertical-lift linkage. The latter is said to offer the following advantages: It lifts the load up and away for maximum reach at maximum height, keeps the bucket level for less spillback even with a full load, and features a low center of gravity that reduces tipping and increases lift capacity.

Photo: John Deere

High-flow hydraulics provide extra power for carrying and operating specialized attachments.

Creature Comforts
Directly linked to productivity is cab comfort and ease of operation, which allows operators to work longer hours without fatigue. That is the key driver of sales, say manufacturers. Amenities may include deluxe suspension seats, cooled glove boxes for lunch storage, plush arm rests, silencing insulation, power outlets and heating and air conditioning, plus almost any other luxury option within one’s budget. More importantly, some manufacturers are even designing elements that give operators a choice.

The Volvo B-Series skid-steer loaders are said to be the only models in the industry to offer operators a choice (depending on preference or application) of popular foot and hand mechanical controls or the comfort and efficiency of hand-operated pilot controls. Both control systems were designed with the assistance of skid-steer loader operators in multiple competitive field evaluations to achieve the highest level of operator comfort, performance, and productivity, reports Volvo. A new seat bar provides an ergonomic armrest and control lever positions fall naturally to hand, creating improved efficiency and reducing fatigue. New joystick handles for both the mechanical and pilot control systems incorporate the standard auxiliary hydraulics functions.

Late in 2006, Bobcat Co. added selectable joystick controls (SJC) to their S130 and T140 loaders. Operators can have drive and hydraulic controls at their hands and receive the advantages of having speed and horsepower management.

For operators accustomed to different styles of loaders, the SJC option allows them to choose between “ISO” and conventional skid-steer “H” control patterns. This makes the loaders more user-friendly, and operators can choose the driving style they prefer.

Bobcat says it’s the only manufacturer that offers SJC that is electrically switchable from the cab. When the SJC switch is in the ISO position, the left joystick operates the drive functions, and the right joystick controls the lift and tilt functions. In the H position, the left joystick controls the left wheels and lift arm functions, while the right joystick controls the right wheels and the attachment tilt functions.

SJC can be extremely beneficial in minimizing operator fatigue because operators will be more comfortable using their preferred control pattern. The option also features horsepower management to maximize pushing and digging power and hand engine speed controls with an accelerator foot pedal.

With speed management, operators can simply “dial in” their required travel speed in small increments from 0 to 7 miles per hour, while maintaining driveline torque and full hydraulic power.

Bobcat representatives say that speed management is extremely useful to customers such as landscapers and asphalt contractors who run certain attachments at a slower travel speed for an extended time.

For example, landscapers can use the feature when operating box blades, landplanes, trenchers, or vibratory rollers for several hours to prepare the soil. In asphalt construction, the feature is ideal for operating attachments like planers and wheel saws, which are often run at slow speeds for top attachment performance.

Photo: Bobcat

Skid-Steer loader lift height ranges from 8 to more than 10 feet.

Maintenance Ease
If an operator has easy access to maintenance, important routine maintenance tasks are more likely to be done. As such, manufacturers are lengthening service intervals in some cases, and are making access to service points easier and more localized. Many manufacturers build the skid-steer’s cab to roll either forward or backward for ease of maintenance or repair.

On the Volvo B-Series skid-steer loaders, lubrication is required only once each week rather than daily.

The lockable rear door opens wide for ease of engine compartment access where daily checks like engine oil, hydraulic oil, and engine coolant can be done quickly.

Regular maintenance is also enhanced with the fuel filter and water separator remotely mounted inside the rear door.

There is improved air cleaner and tilt-out oil cooler access to allow complete accessibility for cleaning.

Caterpillar has also designed service ease into its B-Series skid-steer loaders. The rear service door opens 90 degrees for easy access to both sides of the in-line-mounted engine. The machine is configured for straightforward access to the oil filter and air cleaner as well as fluid level checkpoints. The cooling fan and air-conditioning compressor are hydraulically driven to eliminate the maintenance required by belt drives. Extended life coolant and 250-hour engine oil change intervals further reduce maintenance.

Productivity Is Key
Most will agree that productivity is the key factor in determining one’s return on an equipment investment. By selecting the right model for the job, productivity and profitability are sure to follow. Examine skid-steer specifications closely. Consult with your equipment dealer or compare models at Web sites such as www.buyerszone.com or www.Spec-Check.com, each of which shares a wealth of information.

No matter what model you examine, you’re likely to uncover numerous features and benefits on the productivity plus side.

Construction writer Carol Wasson owns JCL Marketing & Communications Inc.

GEC - May 2007

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