With compact equipment, the performance issues are footprint, traction, and ground pressure.

By Peter Hildebrandt

Compact utility equipment is definitely part of the landscape out there. Even on the largest farms or construction sites with all their huge equipment, the small compact utility equipment for the in-between task is turning out to be a must-have piece of equipment.

“Compact equipment is so adaptable and easy to maintain and repair that most farmers and other operators, regardless of farm acreage, now have this machinery,” says Bill Cunningham product manager of Carlisle Tire and Wheel, Aiken, SC. “The only question remaining is whether this is their primary or secondary use equipment. Its effectiveness and low cost are several reasons why it’s become so popular.”

What should you consider in ordering your skid-steer or compact loader? For instance, if you’re going to be doing a great deal of work in landscape or in sensitive habitats, you need to take steps to prevent turf damage. If you’re configured with tracks, should they be rubber or steel? How about tracks that fit over tires or systems allowing you to switch from one to the other? Users, dealers and manufacturers around the country give their take.

Footprint
The Linn County Road Department in Oregon uses a D-6 dozer for shaping and grading on construction projects and a tracked excavator for cleaning ditches or doing whatever excavation is necessary. The company’s smaller rollers used for patching during grading operations are compact equipment.

It has on occasion rented a compact excavator through Sunbelt Rentals to clean ditches on a very narrow road. “This compact equipment—a Bobcat excavator—was certainly something we’d consider purchasing if we didn’t have budget constraints,” says Jim Ableman, operations manager. “I can see where such equipment would be useful, as things do come up.

“The biggest issue for us is when we get out on the road and are using a backhoe with the outriggers down. The outriggers are used to provide tip-over stability. On one particular road we were working on, the two lanes were only 20 feet wide. Once the outriggers were put down, every time a car came by, despite flaggers controlling the traffic, we had to lift the outriggers up to let the traffic pass by.

“But with our compact equipment, it allowed the traffic to pass right through there without any problem at all. It’s amazing how just a simple thing like that can make such a difference work and timewise.”

Deschutes County, Oregon’s operations include both roadwork and their landfill operations with large machinery used in both areas. It also recently purchased compact Bobcat all-wheel drive equipment two months ago. This is a wheeled machine, not a skid-steer. It has an asphalt grinder, stump grinder, buckets and other attachments. It’s used for road shoulder work or road-widening projects.

“We also have an auger for this machine so when we’re replacing guard rails we’re able to make use of it,” says Terry Brown, Deschutes County field equipment mechanic. “We’d rented one for quite awhile and then decided finally we’d purchase one. It was bought with the attachments.

“Tires help with speed, as tracked equipment is slower. Also, we’re not working in too harsh an environment where anything would be slicing up the tires, enough to make steel tracks necessary. We do have foam filling on all our big loader tires down at our landfill, as that is a rough environment with lots of metal and nails.”

Deschutes County just traded in a 1991 wheel-loader with 29,000 hours on it, which only went through two sets of tires in all those hours of operation. “We never had a problem with the transmission or differentials, even with the heavy foam-fill in the tires, other than normal maintenance. Though the tires have some 1,000 pounds added per tire with the foam, the Caterpillar equipment seems to hold up just fine.”

As with Linn County, Deschutes County also has many narrow roads to work on. “Over the 20 years I’ve worked here, we’ve worked hard to get rid of road hazards, questionable trees and other debris. So we really needed this Bobcat. Stumps are usually ground down below the subgrade of the shoulder. It saves us from digging them out and hauling them away.

“With our asphalt grinding, we do a lot of patching, so we needed that function as well. This equipment has also been able to serve other functions as well. Recently we had a flood on a smaller creek ten miles from here. We were able to team up with the search and rescue and ended up using that Bobcat equipment to haul the sandbags down to the waterline, saving much manpower and man-hours in getting them where they were needed.

“This compact equipment is versatile machinery. We needed the speed of tires more than the floatation or protection from rough material that steel or rubber tracks provide. In the wake of a violent northwest storm in December 2007, our county sent three or four dump trucks, backhoes, and wheel loaders up to a small town northwest of Portland, which was under 3 feet of water. Under those conditions, it’s good not to have to depend on a rental yard to have the equipment ready for such emergencies that could mean the saving of property and lives.”

Talking About Tires and Tracks
Compact equipment does a good job of getting into places other equipment can’t. Having the right tires or tracks also makes a big difference in how quickly a job can get done. McLaren Rubber Industries manufactures a wide range of tracks and tires products for compact equipment in the range of 10-inch to 12-inch tires. Options on tires include several main categories within each of which there are a number of offerings.

Pneumatic tires can be used, perhaps the most inexpensive option. They come with the machine when purchased and they’re the most inexpensive to replace or patch. They can be flat-proofed with foam or other chemicals.

A second option is solid tires, which work in very abusive environments such as scrap yards or demolition sites. The third option is semi-pneumatic tires. These offer the benefits of both solid and pneumatic tires for cushioning, shock absorption, durability as well as being flatproof.

“The reason why semipneumatic tires are so beneficial is not because you want the benefits of both in one product but because you want to avoid the disadvantages of both those options,” says George Zafirov, McLaren advertising manager. “You want to be cushioned and you want to be durable and long-lasting, but that’s not what makes you pay. What makes you pay is avoidance of the flats coming with the pneumatics as well as the vibrations and deterioration on the machinery coming when the solid tires don't protect your axle from vibration from the ground. On a demolition site this is a concern. Imagine a pneumatic hammer attachment on a demolition site with solid tires on your compact equipment. That’s almost the equivalent of hitting the wall of your machine directly with a hammer.

“That’s why people either go with pneumatics on job sites to protect their machine when they’re using an air-hammer (despite the possibility of flats) or they rent a machine with solid tires on such a job site in order to avoid costly repairs in the long term. But another factor is the possibility of back pain for your operator. A number of serious problems arise that are inescapable. But we always do end up paying to avoid that real pain, whether from a flat bringing your project to a halt or from an operator out of work for a time due to job-related back pain.”

Compact machines are the first that plug in the holes and let you complete a project on time, not the big machines. Big machinery is for big jobs, tending to be slow and not requiring much moving around.

“A nimble, modern contractor competing with the big outfits, using less equipment and more technology, uses compact equipment,” adds Zafirov. Such machinery is less expensive, more attainable as an asset, has many attachment options to turn the machine into something of a “transformer.” All these factors contribute to the popularity of the machines.

“When it comes to such things as over-the-tire tracks, the best advice for the contractor is to know what job you are trying to do. There is no such thing as simply putting tracks on and getting all the traction the operator needs; there are certain tracks which will give you certain types of benefits. We’d love to have one set of tracks that would work for all jobs, but the fact is, different jobs call for different tools and we’ve come up with the three main tire tracks we carry.”

These include their Protrac Rubber, which are bolt-on rubber pads and are interchangeable with magnum plates. The Protrac Magnum, a more durable version, is heavier and lower to the center of gravity of the machine, making it more stable for demolition job, according to Zafirov. The Protrac Diamond is the company’s most economical version. This one is especially good at working on sloping terrain; the diamond shape crossbar configuration helps to avoid sideways sliding.

For steel tracks, McLaren offers a steel system with bolt-on rubber pads for mini-excavators. This fits a number of makes and models. There are steel tracks that can just immediately replace a rubber track without changing the undercarriage.

“That’s the key,” adds Zafirov. “You take off the rubber track and replace it with steel, and it works and fits. That type of system has its benefits and disadvantages. Obviously it lasts longer than the rubber track. But it is one option and you need to know what you want to do.

“Steel works well in gravel, demolition sites and harsh debris-strewn environments, ones that would quickly slice up rubber tracks. Steel works well in a rental yard, as many will rent equipment because they know the work to be done will be hard and abusive—something the customer renting doesn’t want to do to equipment they own themselves.

“The good thing about our steel tracks is that if you wear out a pad, you can just replace it for a few bucks; you don’t have to buy the whole system.”

Always Trade-Offs Between Tires and Tracks
For Bill Cunningham of Carlisle Tire and Wheel, considerations with floatation involve two to three application areas. The first is aggressive demanding applications involved with construction, the second is farmers with multiple general applications and the third involves more land-friendly uses such as turf management, which need floatation but doesn’t tear up the soil. Within these three camps there’s sometimes a single piece of equipment that will work for all three. But for turf management, a high-floatation, nonaggressive tire is desirable.

“Much comes down to tread design,” says Cunningham. “For turf, the shoulders of the tire should be more rounded and there should be fewer openings between the treads. It also helps to have more rubber on the ground and additional tread elements to flatten across the tread and cushion it on soil. The tread design is very tight, whereas in the aggressive traction fitments, there will be more space between the tread lugs improved soil traction. However, in a turf application such a tire would disturb the turf and soil.”

The same piece of compact equipment could be bought by two users with very different objectives and applications. The type of tire enables that equipment to work in various applications. “Most OEMs try to simply equip their tractors with a tread design that works for most field applications,” says Cunningham. “But if a user has a special use, he might make a tire change after purchasing the equipment. There are certain applications where tracks are advantageous, others where it doesn’t make economic sense for the extra initial cost.”

On the other hand, if flats are a concern, tracks may be the way to go, or putting foam fill into the tires. Each of those comes with a cost too. “But one thing about track systems is that you’re never going to get a flat,” adds Cunningham. “Another possible benefit is you can start work earlier in the season, when it’s still wet, whereas with tires you must wait until later when the ground dries out more. So, if you have a rush job, you’re already ahead with tracks.

“On the other hand, if you are committed to tracks, you may have a difficult time servicing them. Not everyone’s going to come out and help you out. You can have a whole different set of dimensional tests you never thought about. Once you’ve committed to tracks you need to align yourself with a full-service tracks dealer. With tires you usually can call a number of tire dealers to get on-the-farm tire service. The challenges are clearly different.”

Traction
Loegering Manufacturing of Casselton, ND, has put a strong focus as a company towards traction. “The tricky part is to be both productive and cost-effective as an operator with traction in your business,” says Tim Martin, marketing manager. Loegering originated as a maker of over-the-tire steel track that had applications in many different industries, but fitting primarily compact equipment such as skid-loaders. The company’s steel track system, as with the other manufacturers, is designed for rugged applications such as those with large amounts of rock or in forestry. Over the years it’s been able to design a number of different systems, but their latest is the Versatile Track System, or VTS, a bolt-on rubber undercarriage.

This system effectively turns a skid-steer into a track-loader and back with the same machine. Users are able to remove the tires from the hubs and, with the bolt-on VTS, have a rubber track system. “The market demand is growing in the direction of rubber tracks especially in the last five years,” says Martin.

Since Loegering has always focused on compact equipment, the VTS has been a natural progression. Much of the company’s technology is heading in that direction, instead of the more traditional systems with tracks directly over the top of the tires.

“Being able to swap tires for tracks or go back to tires is more cost-effective,” adds Martin.

“Just because our VTS system is new, it doesn’t mean it’s for everyone. There are cases where steel tracks would be better. Rubber would be best for something like sand; it works more like a solid foot, giving you more flotation and not allowing sand to get through the pads, as can be the case with steel tracks in sand.

“VTS really shines in that it’s a system easily removable when tires are called for, depending on the application. If you’re doing snow removal in the wintertime and don't need a track system, you can remove it and place your tires and chains back on and you have a cost-effective machine with which to move snow.”

Wolf’s Tree Experts of Knoxville, TN, uses its Loegering VTS system on a 268 Caterpillar loader. The company likes the flexibility of always being able to put the wheels back on the systems.

“We use a grinder attachment which is extremely heavy and with the extra floatation we get from the track system, it helps us out tremendously,” says Mike Wolf, vice president. The company does commercial land-clearing work mostly for utility line clearance.

It helps as well that the system is lower to the ground to handle much of the steep terrain where the work is done. “We find the track system to be a lot more durable than tires,” adds Wolf. “Also, there is much less downtime due to dealing with flats, as there are no tires to go flat. You can go over a lot softer terrain; it’s like getting a whole different machine out of your equipment.”

Wolf does extensive utility line clearance and their machines were purchased mainly to work in the wake of hurricane Katrina. “By modifying the adjustment on the track tension adjuster, we were able to avoid the problem of twisting or bending of that cylinder,” says Wolf. “We spoke to our Cat dealer before we did it; it was really a simple thing to do and has worked out well for us.

“We may do some modifying of the rubber spring suspension in the front of the track system. The track system pivots on its rear axle with a spring on the front axle so the tracks can move up and down in the front. But with our extremely heavy Fecon Tree Grinder hydraulically powered equipment on the front of our machine, it’s really wearing that rubber spring out. We’re thinking of installing a hydraulic cylinder there and hooking it to a bladder that we can charge with nitrogen to help hold the front of the machine up just a little bit.”

Wolf hasn’t made that change yet as he doesn’t view this as an extremely serious issue at this point. “We bought the VTS system through our Caterpillar dealer. In any case the Loegering equipment is really helping us out when it comes to getting in and out of the soft terrain we continually find ourselves crossing.”

Whether on tracks or on tires, compact utility equipment has become an undeniable part of the grading and excavation landscape.

Ground Pressure
When using a dozer blade, you need tracked effort, according to Gary Luther, sales and product manager with Grouser Products, West Fargo, ND. If loose material is being moved around, it’s not as critical. But if there’s much resistance being created, tracks are a must. The company specializes in steel tracks and dozer blades.

Grouser Products has an open steel bar track and a steel track with replaceable urethane inserts or replaceable steel insert plates. Grouser’s bar track is promoted as an OEM-supplied attachment by a majority of the OEM skid-steer manufacturers.

As with others in the industry, Luther feels that the most important thing to keep in mind when choosing products is to know exactly where and how the machinery is going to be used. “You can get into a steel track system for a relatively low outlay of money and go right over the existing tires of the machine. But with the same system, using a rubber track system would be some three times more in price and the continued maintenance is a natural consequence of rubber track systems.”

Grouser developed Soft Track with urethane inserts for the contractor in the industry that needs a sensitive surface track. “Rubber tracks are more suited to crossing concrete or asphalt. They’re also gentler in sensitive environments where you are not wanting to leave marks or scuffing, as well as natural areas or turf areas. This all comes with the price of higher upkeep, so typically there’s a tradeoff. Stay out of the rocks and sharp objects, and you may be just fine with the rubber or sensitive surface type tracks.”

Steel tracks are good in snow if the equipment can reach the bare ground. On packed snow and ice, tracks are not too much different than a set of ice skates when it comes to traction. But during the winter months, Grouser finds many of their products going into forested work regions. In order to minimize damage to the forest floor or surface at that time of year, it really helps to have steel tracks.

Another Approach
The most important thing to consider in selecting a skid-steer loader or multiterrain loader is the application the machine will primarily be dedicated to, according to Pierre-Laurent Verdon of SSL & MTL Marketing. This will help with the targeting of the right model to the precise configuration and the appropriate loader.

“To select the right product, you might want to consider the following factors: targeted productivity, site conditions, material type and density, future applications, and existing equipment,” adds Verdon. “Of course, the underfoot conditions will be key to decide if you are going to choose tracks or wheels.”

For work on asphalt, in a paving application for instance, an operator will probably want to choose a skid-steer loader. When work involves poor underfoot conditions or locations where the goal is not to tear the ground apart, the best option is probably a multi-terrain loader. If maintaining the pressure and the flow of the work tool at all times is the objective, a high flow XPS (extreme performance system) may well be the best choice, according to Verdon.

“The Caterpillar multi-terrain loaders feature an undercarriage system with a dual-level suspension and a large ground area which helps to maximize traction—and minimize ground pressure. Ground pressures are the lowest in the industry, ranging from 3.7 psi (25.5 kilopascals) to 4.5 psi (31 kilopascals). This should be a very good option when working on grass or poor underfoot conditions such as mud, snow, or slush.”

Pierre-Laurent Verdon feels that steel will always be a better fit if the machines constantly work in the rocks, though when it comes to versatility they might not be the best choice. Caterpillar has recently introduced steel idlers for multiterrain loaders for applications such as work in abrasive materials or which cause counter rotations.

“Counter rotations may cause high amounts of material to be ingested into the track, for example during the course of working on such projects as backfilling basements or filling foundations with base material,” says Verdon. “Steel idlers for multiterrain loaders are ideal for medium to high levels of rocky soils or cohesive material that builds up in the idler areas during operation, especially if it is not cleaned regularly.”

Good to Go on Lawns
“When choosing a compact loader, a contractor needs to first consider what applications the loader will be used for and in what conditions,” says Mike Fitzgerald, loader product rep at Bobcat. “The machine’s rated operating capacity, horsepower, physical dimensions, optional equipment and attachment utilization are just a few of the items a potential buyer would want to look at.”

Use of both over-the-tire tracks and compact track-loaders have become increasingly popular because of their ability to deliver improved traction, flotation, and riding comfort. They get contractors back on the job sooner and keep them there longer in wet, rugged conditions. Improved traction in mud, sand, or other loose materials makes it easier to move heavy loads without getting stuck, while a smooth, lighter ride over all terrain reduces downtime and helps minimize soil disturbance.

“A compact track loader might be the best option for contractors who work mostly in dirt and on established lawns because the machine’s track undercarriage provides a lower ground pressure and improved flotation and traction,” adds Fitzgerald. “Also, with a compact track loader, fewer repairs to existing surfaces equates to lower onsite costs and more profit.

The low ground pressure of compact track-loaders also helps contractors produce a smooth and even finish grade. “And because the machine’s tracks provide flotation, they reduce the need for rework and minimize the amount of hand labor needed to finish jobs, in turn reducing costs to equipment operators that much further.”

Not only does the track undercarriage minimize ground disturbance, but it also increases the loader’s ground-to-surface contact, which optimizes the machine’s power and performance on rough terrain and soft, sandy surfaces, and in wet, muddy conditions.

It also enables operators to easily push heavier loads, making compact track-loaders ideal for fine-grading applications.

“Bobcat does offer steel tracks for its line of skid-steer loaders,” says Fitzgerald. “The steel tracks fit right over the tires of Bobcat skid-steer loaders to provide improved performance in rough, rocky or muddy conditions, making for better flotation and traction; and reduced ground pressure.”          

Peter Hildebrandt is a writer specializing in science and engineering topics.

GEC - May 2008

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