Load ’em up; versatility and productivity are key when considering material handling equipment
Published in: Recycling Today
Date: 11/1/2003
By: Toto, Deanne
Material handling is essential to recycling applications handling post-consumer materials from municipal recycling programs, scrap metals or C&D materials. Whether moving material within the yard, loading processing equipment or packing trucks and railcars with processed materials for transport, the goal is efficiency and productivity. But how can recyclers be sure they’ve selected the right machinery for their unique operations?
With a few basic considerations in mind and a willingness to tell equipment dealers the details of their operations, recyclers can confidently select the proper combination of material handling equipment for their operations.
SIZING THINGS UP. Material type, size and density are among the primary considerations when selecting material handling equipment such as skid steers and wheel loaders. These loaders are most often used in combination with a bucket for material that is smaller and more uniform in size, yet dense and heavy.
“We start backwards from the material you’re handling and its density,” says Doyle Long, senior work tool manager for Caterpillar Inc., Peoria, Ill. “What you have to get down to is how much material you have to move per bucket load. Then when you know material density, and that gives you an idea of the size of bucket that you need,” he says.
“You want a bucket that is going to be able to load in two to four passes,” Andrew Bonde, product marketing manager for John Deere Construction & Forestry Co., Moline, Ill., says. “Two is ideal. You don’t want to spend too much time loading.”
The bucket size then determines the size of the loader and its lifting capacity. “If you want to look at it very basically, a wheel loader is a teeter-totter, and the Society of Automotive Engineers has defined what percent of the tipping load of a loader you can use as a payload and still be considered safe,” Long says.
As with any rule, the occasional exception exists. “In one of our recycling applications, the loader is used to load aluminum cans and plastic bottles into a sorting machine,” Keith Rohrbacker, construction equipment product manager for Kubota Tractor Corp., Torrance, Calif., says. “In this case the load is very light. They custom made a bucket that was as large as possible to fit the hopper, rather than limiting the size based on safe operating weight,” he says.
“It’s good to understand the specs of the machine: the breakout force, the lift capacity, the maximum material density per cubic yard,” David Wolf, marketing manager for Case Construction Equipment, Racine, Wis., says. “Those are all restrictions you need to understand.
“Most people have a good feel for what they need to have, for how much material they, need to move. I’d say that’s the most important thing,” Wolf continues. “But they also have to consider the application.” Application constraints include dump height and the size of the recycling yard or the material recovery facility (MRF).
Bonde adds that loaders have to be able to lift the required material density to the required height; therefore the height of the vehicles used to transport the material should be taken into account, as should the height of the hoppers and conveyors on size-reduction and processing equipment.
David Morice, wheel loader product marketing manager for JCB Inc., Savannah, Ga., says lift height requirements will help recyclers determine whether they need a standard wheel loader or one with an extended boom option.
The same considerations apply when selecting skid steers. George Chancy, JCB’s compact equipment product marketing manager, says, “If in fact they need to raise the material up to a certain height to dump or to discharge, the machine obviously has to clear the minimum height requirement. Also, sometimes there are height restrictions inside of buildings where too large of a machine might interfere with overhead water utilities, sprinkling systems, door jambs, etc.,” Chaney says.
The space constraints of the recycling yard or MRF facility also affect loader sizing. Compact loaders or skid steers may be more attractive to recyclers working in tight spaces, while larger wheel loaders or excavators may be more suitable for those without space restrictions.
BANTAM-WEIGHT VERSATILITY.
“The skid steer is notorious for manueverability,” Lance Schulz, loader product specialist for Bobcat, West Fargo, N.D., says. “The size of a machine offers so many advantages versus other construction equipment.
“The foremost things about skid steers is that they are maneuverable and very versatile,” Chaney says, adding that the machines provide high-duty cycle times and considerable output. He says C&D recyclers in particular welcome skid steers because of their versatility, productivity, speed and power. “They are quick, nimble and also very powerful,” he says.
Schulz says that while horsepower is important, it is not the sole indicator of a loader’s performance. Instead, he suggests considering a balanced system. “One metric worth investigating is a machine’s axle-torque rating,” Schulz says. This rating is the direct measure of the power available at the wheels. “If axle torque is not adequate, it’s going to be difficult to be productive.”
JCB identified that some attachments require more hydraulic flow or pressure than others in order to obtain optimum productivity, Chaney says. “That sometimes becomes the requirement that they try to satisfy. The primary requirement of the application, dictates what size, type or spec of machine they operate,” he says.
The advent of quick-hitches also lends to the versatility of these compact material handlers, enabling operators to quickly change out attachments depending on the task.
“Skid steer loaders can be outfitted with countless tools, whether it’s buckets or forks or hammers or shears to be used in demolition applications,” Neil LeBlanc of Caterpillar says. “The skid steer is basically a highly mobile tool carrier and a loader or processor of bulk materials.”
Caterpillar’s Long adds, “There are places where you just can’t put an excavator or a wheel loader. If you need mobility, and you’ve got tight quarters, or if you need mobility and at a lower production rate than a wheel loader requires, a skid steer is obviously a more efficient way to do it.”
Skid steers are typically available with either a radial-lift or a vertical-lift (also known as parallel-lift) arm. Long explains that radial-lift arms swing through an arc, meaning that the arm has little forward reach when fully extended. Parallel- or vertical-lift arms, however, maintain forward reach by rotating the bucket or attachment forward as the arm rises.
Manufacturers are also trying to combine advantages of skid steers and wheel loaders in one machine. Bobcat produces an all-wheel steer loader that allows users to select one of two steering modes–skid steer or all-wheel steer. “It’s an all-wheel-steer loader with skid steer capability,” Schulz says of the compact machine. He says the machines offer enhanced material handling, less ground disturbance and improved tire life in the all-wheel-steer mode, while offering maneuverability in confined spaces in skid-steer mode.
Compact wheel loaders compete with skid steers for customers within recycling markets. Kubota’s Rohrbacker says some of the features that give compact wheel loaders an advantage are better visibility because the operator sits higher; maneuverability without surface damage; lower sound level at the operator’s ear; and more comfort in part because of less vibration.
Wolf says, “If you’ve got the room and long load and carries, then I would say definitely go with the wheel loader. It’s going to be a little more comfortable for the operator. Ride control always helps: less wear and tear on the machine, less wear and tear on the operators.”
ON THE MOVE. Wheel loaders are employed in recycling applications because of their strength and mobility.
“If you have to carry over long distances, then a wheel loader is going to be more suitable for that,” Wolf says. Excavators are better suited to situations where they can sit in one place and pick through material, thanks to their long reach. “But excavators are not very quick to move. I would say if you can get all the material within reach of an excavator, it’s going to be more efficient than a wheel loader. But if you have to carry a long distance, a wheel loader is going to be better,” he adds.
Long agrees. “The rule of thumb that I apply is, if you can do it with an excavator without moving, then that’s a better tool. The exceptions would be when you’ve got to move or when you’ve got a space constraint,” he says.
Adding a grapple or a bucket with a thumb to an excavator enables it to handle material of inconsistent size and type, while wheel loaders are most often used for handling bulk material of a consistent size.
LeBlanc says, “Generally I would use an excavator if I had bulk materials that were long and stringy, because I’ve got a variety of different work tools or attachments that are best suited to pick up those long, stringy pieces, whereas the wheel loader, because of the fixed bucket, would not be best suited to do that.”
JCB’s Morice says excavators provide a high-rise cab for improved visibility. Wheel loaders, however, offer mobility, moving from place to place fairly quickly. Productivity is better with a wheel loader when you are dealing with a very wide area.
Versatility is key when selecting material handling equipment, Long says. “If they’ve got a broad cross section of material types and sizes, I would definitely recommend that they equip the loader with a coupler, so they can go back and forth between a couple of different bucket sizes or to a fork and top clamp.”
Long continues, “We’re selling a very high percentage of our loaders with couplers on them today anyway, regardless of the application.” The trend toward versatility is influencing manufactures. “It is much easier to get an operator to take advantage of the versatility if you make it easy for him to switch tools. On a wheel loader, if he has to pull a pin-on tool off and replace it with something else, he just won’t do it. It takes him an hour to get it done. You might even consider a multi-purpose bucket, one that you could grab things with.”
Working with an equipment dealer or manufacturer can help recyclers choose the right material handling equipment for their operations.
“Sit down with the equipment manufacturer and show him the job, show him what you are trying to do,” Long says. “Whether it’s a wheel loader or an excavator, you need to build as much versatility into it as you can. I would recommend couplers on both wheel loaders and excavators to give you the ability to switch tools when the job conditions change.”
ON GUARD
Material handling machines destined for recycling markets are often equipped with guarding packages that serve to protect the machines and their operators from the harsh environments.
“I think we as manufacturers are getting better at customizing guarding solutions for demolition customers,” Andrew Bonde, product marketing manager for John Deere Construction & Forestry Co., Moline, Ill., says. “It can range from protecting the cooling package from airborne debris, to providing cylinder guards so that the cylinders don’t get scored or damaged, to providing guards around the glass portions of the cab to protect the operator.”
Bonde adds that John Deere has focused on providing guarding solutions that will fit the customer’s application, as some are more rigorous and demanding than others.
David Morice, wheel loader product marketing manager for JCB Inc., Savannah, Ga., says belly plating, or heavily plating the underside of loaders, is popular within the recycling industries.
“Depending on some applications, they might want to have what they call wire braiding on the hydraulic hoses that are exposed in the boom or bucket area,” he adds.
The author is associate editor of Recycling Today and can be contacted via e-mail at dtoto@RecyclingToday.com.
COPYRIGHT 2003 G.I.E. Media, Inc.