Roll with it: mobile crushers offer recyclers and demolition contractors speed and versatility.

Recyclers and demolition contractors are increasingly turning to mobile crushing plants, both portable and tracked models, to provide their operations with the versatility and productivity they require. They can offer processing efficiency as well as help to reduce material hauling costs. But, perhaps most importantly, these plants easily can be transported to and set up at a jobsite, allowing recyclers and contractors to make the most of their time on site.

"The key feature of track-mounted equipment is its ability to relocate quickly and easily on a jobsite," says Tony Grygera, product support manager for Metso Minerals, Waukesha, Wis. "Because the machines do not have to be jacked, cribbed or otherwise supported, they can move as needed and be ready to work again within minutes."

Grygera adds, "By staying close to the work, the track-mounted crushing and screening system can reduce or eliminate the need for haul trucks and the costs of acquiring, operating and maintaining them."

Some smaller crushing plants may also avoid the transportation permitting requirements required for some larger, trailer-towed crushers, further adding to the convenience they offer.

In addition to the mobility factor, mobile crushers are often used for smaller volume jobs that require the machine to be setup in a tight area, Mike Vigil of Komatsu America, Vernon Hills, Ill., says.

In light of their mobility and easy setup, mobile crushing plants enable a user to handle multiple small jobs. "You can be crushing instead of setting up, which enables you to do multiple smaller jobs in one day," Tom Schaffhauser, sales representative for Hartl Crushtek, Norcross, Ga., says.

CLOCK WATCHERS

"As ever before and increasingly more so, time is money," Tom Barry, national sales manager for The Screen Machine, based in Reynoldsburg, Ohio, says. "The art and science of saving time is as much a strategic advantage as the labor and management skills that drive jobsite productivity."

Barry adds that recyclers or contractors could spend considerable time setting up portable crushing plants at a jobsite, but that tracked crushers can be onsite and ready to work in a matter of minutes. "After the commensurate unfolding of conveyors and 15 minutes of run time to warm up the hydraulics, operation mode is well underway," he says of tracked crushing plants.

"Keep in mind that shut down and disassembly time to leave the jobsite upon completion multiplies the time factor by a minimum of two," Barry remarks.

Grygera also stresses the importance of setup time when it comes to maximizing efficiency on the jobsite.

"Setup speed is always important; when you aren't crushing, you aren't making money," Grygera says. "But mobility and fast setup are no substitute for effective crushing and screening."

The smaller the job, the less time spent on setup and teardown, the better. "If the material to be crushed and screened is enough for only a few days, the time spent on setup is very hard to recover through higher capacity," Grygera says.

Stephane Guerchon, manager of Rubblemaster North America, Montreal, also points out the importance of job size to cost effectiveness. "If the contract is for a small amount of crushed material (1,000 tons to 10,000 tons) then the transportation and setup of the crusher will raise the cost per ton of the crushed material."

Gary Davis, general manager of Recycling & Processing Equipment, Peru, Ind., says setup time is critical to the jobs the company performs. Recycling & Processing Equipment is a contract processing company that specializes in asphalt shingles, but has also ground gypsum and animal carcasses for use in compost.

"We can unload in five or 10 minutes and be ready to crush," he says of the tracked crushing plants Recycling & Processing Equipment uses. He says he thinks the market is moving toward tracked crushing plants because they are highly mobile and can be quickly moved among the piles of material on a site, expediting the project. He praises the mobile units' versatility, saying that Recycling & Processing Equipment has used tracked crushing plants at nearly every job it's done in the last three years.

While C&D recyclers and demolition contractors understand the benefits of timely setup and teardown, they may be at a loss when it comes to selecting the right crushing plant size for their anticipated needs.

SIZING UP THE SITUATION

Metso's Grygera says that recyclers and demolition contractors should consider more than just size when shopping for a mobile crushing plant. "You have to weigh several factors," he says. "Manufacturers will help you pick a machine based on the types of materials, the anticipated tons per hour, maximum feed size and the range of products that you want to make."

Vigil agrees, saying that final product production volume and feed size would determine which size of crusher to buy.

While Barry says the most important criterion in crusher plant selection is the plant's match to productivity targets, he adds that the machine's structural integrity should also be a concern. "The structural integrity of the design along with the plant's operating features and benefits are what translates into supporting the lowest possible life-cycle cost," he says.

While mobility decreases as plant size increases, Grygera says, "All things being equal, the biggest machine (the one with the highest capacity) that is still practical and economical to transport and is quick and easy to set up will provide the lowest cost per ton. This is because the costs related to labor--feeding the machine, stockpiling, etc.--do not increase in direct proportion to capacity."

Schaffhauser recommends buying a mobile crushing plant with the largest in-feed opening and the most production available to minimize product preparation time.

Eagle Crusher Co. Inc., Galion, Ohio, believes plants can be large and still be portable. On its Web site, the company says its high-volume UltraMax plants "are highly portable. They are also quick in/quick out. Every model is outfitted with a standard built-in hydraulic lift/leveling system that gets it up-and-running in a fraction of the time that other crushers require."

Apart from machine size, recyclers and contractors should also consider the actual crusher type to buy. "If the material will have a lot of wire, you may want to go with a primary impactor," Grygera says. "An abundance of iron and/or highly abrasive feed would suggest a jaw."

The Screen Machine's Barry suggests that recyclers and contractors who are in the market for mobile crushing plants make use of information available on the Internet. "Machinery brochures, production estimates, videos of plants operating and contact information for professional willing to offer deeper dive data are just a click away," he says. "The fact is that processing material is as much as an art as it is a science. Contractors would be wise to speak to professionals on experienced based approaches to crushing and screening projects instead of just applying a few formulas to bid data."

Barry also suggests referring to operations manuals to get the most productivity out of a mobile crusher. "Tips for successful crushing results often must start by going back to the basics of having a thorough understanding of the factory-provided service and operations manuals," he says. "Usually the greatest barrier to crusher productivity is in the area of bridging of oversized material in the feeder region. End users should make sure that they do their homework and source machinery technology that addresses these pitfalls. As old as the process of downsizing material is, advancements in crusher design technology continue to make the difference in optimizing crushing crew profits," he adds.

STAFFING

Vigil says that most mobile plants require one operator, though portable plants, depending on their size, typically require a crew of two to five people.

Hartl's Schaffhauser says, "Most tracked crushers can be operated with two people, one running the crusher while the other one is running the excavator. If the material is sized perfectly, you can have one operator." He adds, "Our machine has a wireless remote control, which enables the excavator operator to operate the crusher while simultaneously operating the excavator."

Grygera says, "A well-balanced system should be relatively free from problems associated with surges and variation in material. A properly interlocked system will require a minimal amount of cleanup if the system has to be shut down unexpectedly. If those things are done," he continues, "then controlling the primary feeder--start/stop and speed--essentially controls the complete crushing operation, and this can easily be done by the excavator or wheel loader operator via radio remote control."

But if the system is a "hodge-podge of equipment lacking the interlocks and remote control capability," Grygera says an operator may be needed to monitor each piece of equipment.

Davis says he typically sends out two-man crews to perform the company's contract crushing jobs for the sake of safety, although one man can operate the shredder from the excavator using the unit's remote control.

Barry agrees that safety begins with two or more operators. "Many portable plants set up easily with one erector," he says. "However, even the most experienced plant operators can find themselves in situations where an extra pair of hands, eyes and the ability to communicate in a timely manner is critical to jobsite safety."

Apart from crew considerations, recyclers and demolition contractors should also consider the geographical area they intend to service.

HAVE CRUSHER, WILL TRAVEL

Determining a viable service area hinges on a few factors. Vigil says the specific geographic area is a determining factor. "Portable plants in the West have more geographic range than would a plant in the Northeast," he says.

"It depends on the job density in an area," Grygera says. "If there is sufficient work and a good market for the product, a crew may be able to stay within a 50-mile radius. If a job is a good fit and makes economic sense, it may be practical to go 250 miles or more," he says.

Grygera says companies operating in rural areas should be ready to travel farther for jobs. But despite the ease of transporting mobile plants, rising fuel costs can make longer-distance jobs less attractive. "The key issue for contractors is to know the costs of moving a plant and crew and to be able to calculate, beforehand, the profitability of the job being quoted," Grygera says. "The costs are important, but so is the price of the end product."

Rubblemaster's Guerchon says the only factors limiting a company's service area are the crew and crusher's availability. With the quick setup time for mobile plants, he says operators can move to another jobsite almost daily.

Davis describes Recycling & Processing Equipment as a "band of gypsies." He says the company will consider any job east of the Mississippi, though most mobile crusher operators work within a 100- to 150-mile radius of home base.

Davis says he definitely sees a trend toward the increased use of mobile crushing plants. "People are seeing the need for their versatility and their quick setup," he says.

The mobility and quick setup associated with tracked crushing plants also contributes to site safety, according to Barry. "Often rubber-tired units become buried in material over the course of days or weeks in the same spot. This immobility greatly adds to the amount of time required at time of exit of the jobsite," he says. "Tracked plants help facilitate a cleaner, safer work environment throughout the project."

The author is associate editor of Construction & Demolition Recycling magazine and can be e-mailed at [e-mail].