Material Handling Key To I-95 Widening Success

By Steve Hudson | September 28, 2010

Interstate 95 between Savannah, GA, and the Florida line is one of the most heavily used sections of Interstate highway in the southeast — and five separate widening projects are currently adding new lanes to make traffic there flow more smoothly. The projects stretch along 33 miles of this coastal Georgia Interstate, and Brunswick, GA-based Seaboard Construction is handling grading, base and paving on four of the five.

Seaboard is general contractor on two the projects (with a total contract value of about $98.5 million) and is the grading, base and paving subcontractor (to APAC or Tidewater/Skanska) on two other projects. Seaboard's subcontract portion on those latter two is about $85 million. That gives Seaboard a total of about $183.5 million of the approximately $416 million in work currently under way on Georgia's section of I-95.

The overall project goal is to upgrade this section of I-95 to three traffic lanes. The project also includes construction of a full-depth shoulder lane, so only a new shoulder would be necessary to further upgrade the highway to four lanes at some future time.

"We're responsible for base and paving on 29 of the 33 miles of I-95 projects now under construction in Georgia," notes Steve Swan, Seaboard's president, and he adds that one key to the success of these four simultaneous projects has been careful attention to the planning, scheduling and execution of the material-handling aspect of the jobs.

Recycling Clearing Debris and Concrete

Seaboard's four projects are at various stages of completion, with a great deal of work now under way on the northernmost contract. That job is fairly typical of the I-95 projects, Swan says, adding that work began with clearing of the right-of-way. Seaboard called on Triad Supply and Services, based in Pembroke, GA, to handle the clearing.

"Triad cleared from right-of-way to right-of-way," Swan says, adding that Triad also installed new right-of-way game fencing.

What became of the large quantity of clearing debris? According to Swan, it was processed into chips on site and then hauled off-site to be used as industrial fuel. Among the users was the pulp mill in Savannah.

Recycling will also be a key component later this year as Seaboard works with general contractor APAC to remove and recycle existing concrete pavement on another of the Seaboard projects. The old pavement will be removed and recycled by Jacksonville, FL-based Mulliniks Recycling.

"It will be crushed to Georgia DOT GAB specifications," Swan says, "then used in the private market." This new source of crushed material, he adds, will help ensure that there is plenty of stone for use on the I-95 work as well as the private market needs.

Material Handling, I-95 Project Style

One key element in the success of these projects, Swan says, has been careful management and meticulous handling of the steady stream of stone flowing through Seaboard's two rail facilities in Sterling. "We plan on moving more than 1 million tons of material in this year alone."

The stone is mined and crushed at Vulcan Materials' Palmer Station Quarry in Macon, GA, in the central part of the state. The material is then transported by rail by Norfolk Southern Railways to one of two Seaboard offloading and stockpiling facilities. The larger of the two facilities, located at Seaboard's main office and primary asphalt plant, was recently expanded to handle up to 41 loaded rail cars at a time, while the nearby Green Swamp facility adds the capacity to handle an additional 12 cars. Rail cars may contain different types of stone, too, requiring the material handlers to manage not only how the stone is handled but where it is stockpiled.

Arriving at one of the Seaboard facilities, the loaded rail cars are temporarily parked on sidings inside and outside the Seaboard yard. They're then unloaded using an automated electric shaker system to speed off-loading of the stone. It takes approximately seven minutes to fully unload a 104-ton rail car, Swan says.

As the stone is unloaded from the rail car, a conveyor system transports the stone to two waiting wheel loaders, which in turn convey the material load by load to the appropriate stockpile area nearby. Different cars may contain different types of stone, too, requiring the material handlers to manage not only how the stone is handled but where and how it is stockpiled.

It's a massive challenge, particularly when it comes to the graded aggregate base (GAB) that will underlie the new I-95 pavements. The total quantity of GAB required for the four projects combined exceeds 2 million tons — a massive amount of stone — and handling it in an efficient manner is a massive challenge too.

"Imagine 104 tons per rail car and 41 rail cars per day, six or seven days a week, and you have an idea of the quantity of material that must be handled," Swan says.

Stockpiling and Storage

Seaboard is currently managing and operating three material-unloading facilities and two asphalt plants. All day-to-day coordination to keep this large machine going is conducted Claude Johns, Seaboard's Plant and Material Yard's superintendent.

Once it's unloaded from the rail cars, the stone is transported to various stockpiles, depending on type. Then, from those stockpile areas, the asphalt stone is transported to Seaboard's asphalt plant, where it is used to produce the mixes used on the projects.

Much of the GAB, however, goes directly to the I-95 construction area.

"Since we can only stockpile about 45,000 tons of GAB in our yard at any given time," Swan says, "we have been bringing much of the material to the Interstate and stockpiling it there in the median to keep the 336 rail cars rolling in the system."

The material is trucked to the central storage area in the I-95 median, where it becomes part of an ever-changing main stockpile. Large dumps are used to transport the stone to the central stockpile in the I-95 median.

Once the stone arrives at the central stockpile, a fleet of Cat and Deere loaders works the stockpile area to vertically pile the material after it arrives or to load it straight into smaller dump trucks for transport to specific parts of the various sites. Two loaders may work together to load each truck, increasing overall efficiency and speed.

Stone used for base is spread by one of several Jersey Box spreaders. The material is placed in two 6-inch lifts, and then compacted by Ingersoll Rand or Caterpillar vibratory rollers.

Selecting Equipment for Handling Stone

According to Swan, Seaboard looks for a number of specific characteristics in the loaders it uses to handle stone not only at the unloading and stockpiling area, but also various other uses on the projects.

At the yard, he says, a key consideration is the ability to quickly move large quantities of stone — something that's especially important in light of the enormous quantities involved.

"The loaders used in the yard are large machines dedicated to material handling," Swan says. The Caterpillar 972H machines are outfitted with 6.2-yard buckets in order to optimize efficiency.

The loaders are also chosen with an eye toward adequate clearance for easy loading of trucks as well as stockpiling. Maneuverability is another consideration, Swan says, noting that excess time spent maneuvering is time that cannot be used for handling material or loading stone into waiting trucks. Each 972 is outfitted with backup cameras and bucket scales to enhance safety and maximize loads.

On the job site, Swan continues, Seaboard also uses multi-use machines in the material-handling role.

"Multi-use machines increase versatility and utilization on the job," he says.

New Pavement

Needless to say, construction of new pavement is a major component of the job. On both of the projects where Seaboard is the general contractor, as well as on the project where Seaboard is serving as base and paving subcontractor to Tidewater/Skanska, the newly widened Interstate will be paved with asphalt. On Seaboard's APAC project, the final pavement will be concrete.

Seaboard is handling the asphalt paving using Caterpillar and Roadtec extendable screed pavers and Roadtec material transfer vehicles. The HMA is being produced in Seaboard's main Sterling, GA, plant; it's a Terex E400 with a capacity of approximately 385 tons per hour.

To transport the mix to the paving crews, as well as to handle the large quantities of GAB, the projects are keeping a fleet of 65 to 85 trucks busy on any typical day. This does not take in account the long bed trailers that continually feed the stockpiles.

In addition to the resurfacing and new lane construction, the project includes a significant amount of drainage construction. This work, which has taken place either in the median or outside the new roadway, has included extension of existing pipe, the addition of new median drains, rebuilding of various drainage structures, and extension of several existing culverts.

Focus on Safety — and Coordination

In some ways, having four such closely-spaced projects going on at one time is much like having one very large project — and one of those ways is safety and coordination. Under the direction of Kim Jones, Seaboard's full-time safety director, the company promotes constant safety awareness. This begins with weekly toolbox safety meetings, but Seaboard's safety program also includes direct safety incentives in the form of quarterly and yearly safety bonuses.

"Our supervisors and employees take safety very seriously," Swan says, "and they work hard for those bonuses too."

A major part of safety awareness on a project such as this, Swan adds, is developing a constant awareness of the dangers posed by motorists.

"The driving public is by far the biggest safety problem on jobs like these," he says, adding that some drivers have been clocked in the work zones at more than 90 miles per hour with workers less than a foot from the speeding vehicles.

Safety is enhanced by Seaboard's careful attention to coordination of the many elements involved in the I-95 projects.

"We meet for 2-1/2 hours every week just to go over crew needs, equipment needs, operational issues, and material availability," Swan says.

And through it all, the matter of efficient material handling and planning has been the key project element driving the rest of the work.

"With four projects going on at the same time," he says, "if we didn't give a great deal of attention to material handling and scheduling, we would be dead in the water."