When more than 20 trailers filled with discarded rubber tires are lined up at your tire recycling facility waiting to be unloaded, there's no time to second-guess whether your equipment is up for the task. Luckily for Gary Steffan, plant manager of the Maryland Environmental Service (MES) tire recycling facility, that doubt never enters his mind. For the past three years, Steffan has relied on a pair of Bobcat® skid-steer loaders to work nonstop and keep the facility from drowning in a sea of rubber tires.
Tire recycling is just one of several services MES has come to offer since being established in 1970 by Maryland's governor and legislators. The self-supporting, not-for-profit public agency, headquartered in Millersville, Md., was given the important mission to protect and enhance the state's air, land and water resources. It works with both governmental and private sector clients in finding innovative solutions to some of the most complex environmental challenges.
The agency employs nearly 600 workers who are involved in more than 364 environmental projects that are located throughout three states and range in cost from $1,000 to $5 million. The projects include water and wastewater treatment, solid waste management, composting and organic projects marketing, recycling and marketing of recovered materials, dredged material management and recycling, hazardous material cleanup and engineering, and monitoring and inspection services.
In 2002, MES added the tire recycling service to its repertoire by opening a recycling facility in Baltimore. The driving force behind creating the facility was the fact that more than 6 million scrap tires generated annually in Maryland were simply being buried in landfills or burned as fuel. MES believed, however, that the tires still had value and use.
Today, the tire recycling plant grinds more than 8,000 tires per day and produces recycled rubber for numerous applications, including sports fields, playgrounds, horse arenas, road surfaces, and auto part manufacturing. The crumb rubber comes in sizes ranging from 5 to 40 mesh (0.5mm to 4 mm). A landscape grade material measuring 3/8-inch to 5/8-inch (9 mm to 15 mm) also is produced at the facility.
"Basically, at this facility all of the components of the tires are 100-percent recyclable because the metal is baled and sold as scrap; the fiber is used by waste energy facilities to burn for energy; and the rubber is used to make colored mulch and crumb rubber," Steffan says.
Knowing that the tire recycling facility would be a high-demand industrial environment operating nearly around the clock all year, Steffan says they needed equipment that could withstand those conditions. Among the first pieces of equipment purchased were two Bobcat S250 skid-steer loaders that would primarily be responsible for unloading the many truckloads of tires arriving at the facility's doorsteps.
"Sometimes it takes 45 minutes to unload a trailer, and then you have another trailer right behind that one to unload," he says. "We have a whole yard of trailers, so you can have an excess of 20 to 30 trailers loaded with tires."
Steffan, who oversees production and maintenance at the facility, says they chose the S250 skid-steer loaders because of their 2,500-pound rated operating capacity. In addition to buckets, they have industrial grapple, pallet fork, and dumping hopper attachments for each machine. The industrial grapple, which is composed of heavy-duty grapple forks that clamp down on the bottom of a bucket, is usually the most well suited attachment for unloading tires from trucks.
Besides residents who drop off their scrap tires at county disposal sites around the state, the MES tire recycling facility also receives tires from major retail companies such as Wal-Mart and tire manufacturers such as Goodyear. Typically, the tires arrive interlaced and stacked in bin trailers, Steffan says. The S250 skid-steer loaders with the industrial grapple attachment then go inside the trailers and unload the tires.
"There are a lot of other things around the facility that we use the industrial grapple for," he says. "For example, we'll have a pile of steel rims that we'll pick up with it. We get a lot of tires from the county disposal program that will have a lot of rims in them."
The facility processes all kinds of rubber tires in all shapes and sizes. While the industrial grapple seems to work better for unloading passenger car tires, Steffan says pallet forks are the best option when they need to handle truck tires. "We do a lot of processing of truck tires, which are quite large, and with the pallet forks, you can grab at least eight truck tires with this machine," he says. The pallet forks also are used to lift and haul the rubber-tire processing machines' rotary knives when they need replacing.
In any tire recycling facility, there's bound to be scrap metal lying on the ground. For this reason, facilities like MES opt to equip their skid-steer loaders with foam-filled tires to avoid the downtime and inconvenience that comes with constantly having to change flats. Steffan says his pair of skid-steer loaders still has the original foam-filled tires that they were purchased with three years ago, and the tires have served their purpose well. Even in trailers with metal floors, he says his operators can navigate and maneuver the skid-steer loaders without spinning the tires.
Once the scrap tires are unloaded from the trailers, they enter the extensive recycling process that ultimately ends in them being processed into crumb rubber. A portion of the crumb rubber produced annually at the facility is ground more finely into mulch and is colorized for use in landscaping. After going through several screening processes, the skid-steer loaders scoop up the rubber mulch in their buckets and then load it into the feed hopper of the colorizing machine.
In a facility packed with at least 50,000 square feet of rubber recycling equipment, maneuverability and visibility are paramount. Being able to turn within their own length enables the S250 skid-steer loaders to skirt around machinery and work quickly in trailer bins when unloading tires, Steffan says. MES operators also like the large front windshield of the skid-steer loaders' enclosed cab, which provides increased visibility around obstacles and to the attachment at work.
Believing the theory that operators are more productive when they're the most comfortable, Steffan says the enclosed cabs were also equipped with heat and air conditioning. Each day, the skid-steer loaders are working at least 16 hours, with each operator spending about eight hours behind the controls. Due to the extent of time operators spend in the Bobcat loaders, he says the heat and air conditioning haven't gone without being used. "The operators definitely use the air conditioning in the summer," he says. "A typical Baltimore summer day can be 90 degrees. Then you add in proximity to the processing equipment, and the equipment is giving out even more heat." In the winter, operators run the heat while inside the facility and when they're outside using the skid-steer loaders to clear snow off the grounds.
With only a few years under its belt, Steffan expects the number of scrap tires the facility receives to increase in the future, especially as residents and companies become more aware of the services it offers. By having equipment he can rely on, Steffan says there's no need to shy away from additional work. In fact, he welcomes it, because for every tire that shows up at the MES tire recycling facility, it means one less tire in the landfill or contaminating a river.