August 2008: Cover Story

Equipment Evolution
Small Loaders and Excavators Adapt to Utility Applications
By Jason Morgan

When it comes to categorizing the various species of machines, the subgenus of compact equipment is a growing family, migrating more and more into the utility business. Skid steers, track loaders, mini excavators and compact utility loaders are all new breeds of equipment that continue to enter new markets based on their adaptable and flexible nature.

While large equipment has a long heritage in many North American habitats (markets ranging from commercial to agriculture), in the 1950s new machines started exhibiting new traits — their stature shrank to fit tighter work areas and they evolved this ability to transform into multiple application machines, using attachment systems (from digging to loading to sweeping to breaking and adaptation onward).

This new, small machine subgenus grew. Sometimes certain machines worked in symbiosis. Compact equipment, like the skid steer and compact excavator, were able to inhabit the tight quarters of residential construction and utility work. With the compact excavator’s ability to quickly excavate a trench and the skid steer’s power of material mobility, the two machines began to inhabit the same work space — creating a community with an emphasis on results.

“The skid steer and compact excavator make the perfect tag team,” says Dan Rafferty, Compact Excavator Specialist for Volvo Construction Equipment. “It comes down to getting the best bang for your buck. Those two machines can tackle large tasks and get into smaller places than a traditional larger excavator and wheel loader. And with the cost of fuel, you’re only going to get X amount of dollars for a job. If you are spending three-fourths of that to do the job, you have to figure something else out, not to mention the attachments that make these machines so versatile.”

These small machines utilize innovative hydraulic systems to run multiple attachments ­— from hydraulic breakers and grapple buckets to hydraulic thumbs and four-way dozer blades. Skid steers and mini excavators can do more than just the dig, load and carry applications. Mini excavators can easily trench a utility project, place a small diameter pipe into that trench and then dozer and compact for restoration. It’s a do-it-all utility machine and most species of compact machines exhibit those same versatile traits.

Small Species Loaders

The skid steer climbed out of the equipment melting pot of the 1950s, when two brothers Louis and Cyril Keller were tasked with the challenge of creating a machine that would be able to clean out a client’s turkey barns. Versatility in a small package was the goal, and the brothers ended up developing the first generation of what would become the skid steer loader.

Skid steers have adapted to more than just material moving. A trencher can also be very useful and efficient, allowing you to trench in a straight line and make it right the first time.

The design was crude by today’s standards — the three-wheeled, self-propelled loader was powered by a 6.6-hp Kohler engine. Not yet a skid steer, the loader moved on two drive wheels in the front and a small caster wheel in the back. It wasn’t until four years later that the Melroe Mfg. Co., which is now Bobcat, unleashed the first four-wheel skid steer. It didn’t see fantastic sales the first couple of years, but through constant feature evolution, it found its way into the farming and load-and-carry markets.

Today, the skid steer industry is big business, as the small loaders are still in demand, despite the current economic uncertainty. Last year, the industry moved 53,000 units, according to Jim Hughes Marketing Manager for Case Construction Equipment, from manufacturers like John Deere, Caterpillar, Volvo, Case, Bobcat, Mustang, New Holland and Gehl. While that’s about a 10 percent loss from prior years, it’s still doing better than the construction industry, which is down about 30 percent overall, according to Rafferty.

“Skid steers going into utility work tends to be about 10 percent, depending on how those numbers are reported,” Rafferty explains. “While it’s still a niche market, it’s continuing to grow. Given the market slowdown, the skid steer market hasn’t reacted the same, possibly due to utility work. There are still water lines that need to be fixed and other utility line maintenance.”

Traditional skid steers still come in a variety of sizes, but there are also a few evolutionary differences. For example, skid steer loaders can either use lift arms with radial lift or vertical lift designs. Radial lift arms are connected to the machine with a single pin on each side, which allows the bucket to follow an arc as it rises.

On a radial lift, the bucket sits close to the machine when it is in the down position to make the machine more stable and compact when moving loads around. As the bucket is raised, it moves away from the machine and then straight up. This gives the machine extra reach, making it easier to dump a load into the middle of a pickup truck or place a pallet into a deep shelf.

On the other hand, vertical lift machines are better suited for loading and pallet work. While both types can be utilized for any application, life cycle and productivity determine which unit is a better match for the job and the contractor.

Variation in operator controls is another sub-species difference. Most skid steers are controlled by either single- or two-lever steering. The single lever system is best suited for pilot control systems and allows the operator to split the control of the machine into their right and left hands. All travel is accomplished by the left lever while the right lever controls the lift and tilt. With two-lever steering, the left travel and lift is accomplished by the left lever and travel and bucket are controlled by the right lever. In the last few years, joystick controls have been integrated into the operator controls, providing more intuitive operation.

On a utility jobsite, the skid steer can usually be found moving materials — but it’s not limited to just bucket work. Though moving pliable material such as dirt, sand and gravel is commonplace for skid steers, there are many attachments that lend themselves to carrying pipes, pallets and other utility-oriented materials.

“Lift booms would be the most efficient attachment to use for moving utility-type materials,” says Hughes. “However, you’ll see pipe transported with pallet forks or using a bucket by curling the bucket and placing the pipe in the cradle between the bucket and the loader arms. You’ll also see pallet forks and buckets with chains wrapped around the teeth used to move manholes and trench shoring materials.”

With rated operating capacities ranging from 700 to 3,300 lbs, small skid steers are no jobsite lightweights. But when you charge them with carrying an awkward or odd load — be sure to think about safety.

Mechanic mutations have allowed the skid steer to survive in the harshest of climates, especially today’s economic environment. Last year, the industry moved 53,000 units, according to Jim Hughes Marketing Manager for Case Construction Equipment.

“Safety is the most critical factor when moving material around on a jobsite. Balance and stability are critical,” Hughes continues. “You need to make sure that you have the material you are carrying securely fastened to the skid steer. You also need to make sure that the load is balanced. The last thing that you want is to have the load shift and spill or worse — tip the machine over. You want to carry the load low for optimal balance.”

“The safest place to be is in the skid steer, so the operator will want to look out for his or her coworkers,” Rafferty adds. “And with some loads that stick out past the forks or machine width, remember that you aren’t alone out there and you can use other people on the jobsite to help you get around corners or through trees or wherever you
need to go.”

Seasoned loader operators will know that with different materials come different operational nuances. A skid steer isn’t the smoothest moving machine on the jobsite, so when you travel the load could bounce or shift. Exceeding the tipping load only complicates matters — creating an unstable situation that could cause the load to shift or the machine to tip. So make sure you take that five seconds of prep time instead of taking five minutes to clean up the mess later.

To maximize its productivity in its natural habitat, the skid steer developed a universal attachment plate that allows contractors to swap attachments at the drop of a pin — a connecting pin to be exact. There are even breeds of skid steers that offer a hydraulic coupler as an option, allowing contractors to change attachments without having to leave the cab for optimal productivity.

“Many other work tools can be used in utility-focused applications,” says Pierre-Laurent Verdon, Caterpillar Skid Steer and Multi Terrain Loader Industry Manager. “I believe another key utilization of a skid steer would be digging.
A general purpose or a multi-purpose bucket can be used for digging, loading and dumping. A trencher [attachment] can also be very useful and efficient, allowing you to trench in a straight line and make it right the first time. And a utility broom can help you pick up material on the ground in a very quick manner.”

When connecting attachments to the skid steer, you’ll want to keep your machine’s auxiliary hydraulic flow in mind before plunking down the cash for a trencher or hydraulic breaker — two examples of high-demand hydraulic attachments. Typically today’s skid steers will provide the power needed, but high-flow hydraulic systems are available for those who feel the need for hydraulic speed.

Digging Darwinism

Genetic adaptations and inherent trait selection don’t happen overnight. It takes some machines longer than others to find the right blend of mechanical mutation to produce a new species of machine. While the small loader was well into its development in the 1970s, the mini excavator was just starting to make its debut into the equipment world.

The mini digger, typically characterized by its dig depth between 5 and 20 ft and tracked undercarriage, was first found in Japanese and European lands. But it wasn’t until nearly a decade later that the mini excavator migrated to U.S. markets. Since then, the market has been growing steadily. But with the drop off in residential construction, the mini excavator industry is starting to level out.

To get closer to objects and perform more specialized tasks, the mini excavator evolved into short swing radius and zero tail swing machines. In this confi guration, the excavator house stays within the tracks of the undercarriage when swinging the boom.

“The mini ex market is down, down, down,” says Rafferty. “Last year for June the industry did 3,000 [units]. This year, we’re down to 2,100. It’s a little bit of a shock. The mini ex market was one of the fastest growing markets and it reached its pinnacle. Now it’s dropping off. But utility work is keeping it up. That’s why we’re only down 28 percent as an industry and not 40 or even 50 percent. There’s always a need for new power lines and other utility work.”

“About 20,000 units are sold in the mini ex market,” adds Darren Wilson, MHE Industry Manager, North America — Caterpillar Inc. (NACD). “For utility markets it varies based on reporting because there’s no specific utility category. It’s lumped into residential, commercial and so on, but I’d estimate that a quarter of the mini excavators sold do some utility work.”

Electrical and plumbing are the most common utility applications. Many of these applications don’t require contractors to dig deeper than 4 to 7 ft, perfectly in range for a mini excavator. But it’s their compact size that gives them the edge over other digging machines.

To squeeze itself onto tighter jobsites, the mini excavator evolved into short swing radius and zero tail swing machines. In this configuration, the excavator cab stays within the tracks of the undercarriage when swinging the cab. That means that these machines can work right up against houses or buildings and on sidewalks and roads without the fear of the operator banging the rear of the machine into an object. For even closer-quarters snaking, retractable undercarriages are also an option on some machines — allowing the excavator to constrict the undercarriage to get through backyard fences and tight squeezes.

“Utility contractors like these machines for the relatively low ground pressure they provide, and the fact that they can trench quickly in a small space,” says Mark Wall, Product Marketing Manager, Excavators for John Deere Construction and Forestry. “In addition, tracked compact excavators with low ground pressure can be moved easily from house to house. Because of their reduced weight, they can be transported without the operator needing a commercial driver’s license, by putting it up on a trailer. So the compact machines provide great maneuverability and flexibility.”

In addition to trenching, these short, long-armed machines are often used to place small diameter pipe. There are typically two methods for pipe placement — through slings rigged to the excavator or utilizing a hydraulic thumb. If you don’t have a thumb attached to your machine, the sling method would be the most likely option.

“Most guys use a dual strap with two eyes,” explains Wilson. “They run the strap from the mini ex to under the pipe and then connect them at the eye holes of the machine. They generally try to find the center of gravity on the load before lifting. When lifting, it’s important to keep the load as close to the front blade as possible for maximum lifting capacity.

When placing pipe with a mini excavator, try to fi nd the center of gravity on the load before lifting. When lifting, it’s important to keep the load as close to the front blade as possible for maximum lifting capacity.

“There are two ways to move the material once it’s lifted: 1) stick and boom or 2) lifting the load and tracking the machine,” he continues. “You want the machine positioned as close to the hole as possible because when you lift the load, you’ll lose stability. So, the stick and boom movement technique is optimal to keep the machine in one place. Another thing to keep in mind is as you reach out with the load, the max. capacity decreases.”

If you do have a thumb attachment, that would be the best way to move pipe. But be careful — pipes don’t grip as well as, say, tree trunks. Too loose a grip will let the pipe slip out, where as too tight and you’ll end up with crushed pipe.

“A good way to grab the pipe is to raise the blade and trap the pipe between the blade and the ground,” recommends Edgar Chavez, Director of Marketing for New Holland and Kobelco Construction. “So when you grab it you can get a grip on it before moving it. It’s also a good idea to wrap a chain around the pipes once the thumb has grabbed it.”

In addition to a thumb attachment, a mini excavator also offers auxiliary hydraulics and quick couplers for easy attachment changing. “[Mini excavators] can switch from a bucket to a hammer to remove hidden obstacles, be fitted with a thumb to move brush and debris, use a compaction wheel to compact the trench or use the dozer blade to backfill or level off a pad,” says Dave Wolf, Marketing Manager of Excavators for Case Construction Equipment.

One of the more unique evolutionary adaptations of the mini excavator is the backfill blade on the front of the machine. In addition to adding stability when excavating, the blade makes quick work of backfilling and grading once the excavating has been done, the pipe’s been placed and it’s time to move onto a new task.

“A lot of utility contractors will use the mini ex as a dual piece of machinery, especially with the dozer float option on Cat machines. Grading applications are handled because even a moderate operator can produce an exceptional grade,” says Wilson. “The dozer float allows the dozer blade to deactivate the hydraulic circuit to allow the blade to free float with gravity. So the operator can backfill and then drive over the trench and reverse back and the blade will match the contour of the ground. When the hydraulic circuit is activated, the operator would have to manually be controlling the blade height which often leaves a washboard grade, rather than a smooth one.”

Some species, like the skid steer and mini excavator, evolved on similar tragectories and inhabit the same work space, creating a community of equipment survival. The skid steer and mini ex tag team is among the most popular and productive examples of this equipment behavior on the jobsite.

Another popular blade option is a four-way blade that can be hydraulically controlled to angle left and right, as well as up and down. Angle the blade left or right and one pass down the spoils you can backfill a small trench.

Naturally Selecting Equipment

Stepping into the compact industry doesn’t take as much capital as the larger equipment — you can get your hands on a skid steer for between $16,000 and $40,000 and a mini excavator for between $30,000 and $60,000. Of course, the price of renting these machines is far less. But if you find yourself attached to the mini machines and are using them more than 65 percent of the time, it’s time to buy.

“At certain times, of course, contractors want to conserve their outlay of cash, so renting rather than buying is a short-term option. But the decision also depends upon the job at hand,” says Gregg Zupancic, Product Marketing Manager of Skid Steers for John Deere Construction and Forestry. “Rental contract periods provide complete flexibility for the contractor, but as you extend the rental period into months or more than a year, your economic incentive for renting instead of buying a machine diminishes. Renting also provides an inexpensive way to try out new pieces of equipment, almost as a paid test drive or demonstration. Without committing to a long-term purchase, you can get to know how a skid steer or compact excavator fits your needs.”

But evolution never stops, even in the equipment industry. Compact utility loaders (also called mini skid steers) evolved from the mighty skid steer loader and even new variations continue to crawl out of manufacturer think tanks. One of the most successful has been the compact track loader, which offers a tracked undercarriage as opposed to wheels for better floatation and less ground pressure for delicate worksites. Excavators, on the other hand, have similarly taken on wheeled undercarriages for quicker mobility around a jobsite. It’s only a matter of time and demand before a new variation of tiny machines fills a niche.

Jason Morgan is Associate Editor of Utility Contractor.