Dozer Fleet Makes the Grade on Fall Line Freeway

Mon September 13, 2004 - Southeast Edition
Bill Elverman

Robinson Paving’s road to success parallels the path cut by Georgia’s ever-expanding Fall Line Freeway.

Based in Columbus, GA, the company is situated at the front door of the high profile project: a four-lane highway expansion cutting through Georgia’s peach, pecan and paper country.

Scheduled for completion in 2009, the reconstructed corridor will not only provide a direct shot from Columbus clear to the other side of the state in Augusta, but will also open up trucking routes, granting easier access to major roads such as Interstate 16 (to coastal docks in Savannah) and Interstate 75 (north to Atlanta and south into Florida).

The 215-mile Fall Line Freeway, when completed, will connect many small towns and villages along its path to the interstate system via a four-lane road for the first time. Traffic along these routes has become increasingly heavy, and the expansion is designed to make these towns more accessible and to make traveling through the region safer.

The Georgia Department of Transportation (GDOT) releases phases of the Fall Line Freeway for bid ––┬áRobinson Paving is currently working on two sections and is about to begin work on a third. The 5-mi. (8 km) phase that Darrell Robinson oversees along with superintendent Coy Tyson includes two bridges –– one over a creek that flows into the Flint River and another over a railroad that currently crosses Highway 96.

Robinson Paving is handling all of the grading, dirt work and asphalt paving for the stretch, while Southern Concrete of Albany, GA, has been subcontracted to build the bridge and Skruggs Company of Valdosta, GA, will pour the span’s concrete.

The dirt work portion of this stretch involves moving more than 900,000 yds. (823,000 m) of dirt cut from one stretch of the site and hauled to areas needing to be built up –– mostly the areas on either side of the two bridges. The east side of the bridge crossing the railroad will alone take 300,000 yds. (274,320 m) of dirt to raise to the height needed to build the road base and pave with concrete.

Robinson had allocated a full four months to properly build up and engineer the approaches to these bridges, but at the end of the second month, nearly 75 percent of the fill and grading is already complete.

Robinson attributes the speed in execution to quality job superintendents and reliable equipment. The most versatile pieces of equipment on this project are his dozers, including Caterpillar D6M, D48 and D8 models.

The newest addition to his fleet, however, has caught the attention of his operators for its newly designed controls and Hydrostatic Steering System (HSS). Komatsu’s D65EX-15 (190 hp, 5.09- cu.-yd. blade capacity with straight tilt blade) was brought on specifically for this project after its introduction in Fall 2003.

“Equipment manufacturers like Komatsu have come a long way with the HSS,” said Robinson. “With what the HSS has done for us in terms of production, I would hate to have to go back to the old style steering clutches. We still have a few tractors that have that, but the difference in maintenance between that and hydrostatic is so different. That machine [D65] spends a lot less time in the shop than something that has a steering clutch.”

The HSS features an independent hydraulic pump with engine power transmitted to both tracks without power interruption on the inside truck. The outside track moves faster than the inside track during turns, allowing for smooth, powerful turning with a maximum amount of material on the blade. Combined with its Palm Command Control System (PCCS), the machine is easy to operate.

Adrian Youngblood, a Robinson dozer operator noted the Komatsu D65 is “a real comfortable tractor, but it’s also fast and powerful … . It’s smooth, it’ll push big loads, light loads, and you can fine grade with it and everything.”

Dozers Add Power, Finesse to Slope and Fill Applications

In building an approach to a bridge, there are two main areas of work: the “cut,” where Robinson is pulling the clay needed to build his approach to the bridge, and then the approach itself. Dozers play integral roles in both.

In the cut, there are two main methods of extracting clay. Robinson Paving uses a 306-hp Komatsu PC400LC-6 excavator to continually load out four 30-ton Volvo articulated trucks with material while a pull-behind scraper also works to extract material for the approach. This area will eventually be brought to a final grade as part of the four-lane highway. Dozers handle two jobs here –– work the slope created by cutting into the land and push the scrapers when they get bogged down in sandier material.

“The pull-type scrapers load well in clay,” noted Robinson, “but once you get into sand, they only get partially loaded. That’s where we’ve used the D65 a lot –– pushing the scrapers through these sandy areas and helping them get good heap loads. We fabricated a push plate and added it to the blade, and that has given extra strength for pushing. We usually use the scrapers to cut ditches. And you may only have a short area to cut, so that is where [the extra pushing power] really comes into play.”

Keeping a good two-to-one slope in the cut areas is important to Robinson, both aesthetically and functionally. Slope work can be difficult, and his company’s dozers are regularly jockeyed between slope and grading work. Although not bought for slope work, the D65 has provided unexpected benefits there, too.

“The Komatsu has really surprised me on the slopes,” said Robinson. “For us, it really wasn’t bought for a slope machine, but our main slope machine is in the shop, so it’s picking up the slack. It’s got the power to climb the steep slopes and carry material to the top –– it’s done really well.”

The D65 features a controller that monitors engine speed, travel gear and travel speed. When a heavy load is applied or the machine is navigating a steep two-to-one slope, such as those encountered here, the controller automatically downshifts to optimize gear speed and provide high fuel efficiency.

On the east end of the bridge, the task at hand is slightly heavier. Robinson Paving must build up the approach 65 ft. (19.8 m) higher than the original ground (at its lowest point) next to the railroad tracks. With a width of 365 ft. (111.3 m) and an estimated approach length of 800 ft. (243.8 m), this “fill” will eat up roughly 300,000 yds. (274,320 m) of material.

Here, articulated trucks continually haul dirt that is quickly graded by the dozers and compacted by a rubber-tired tractor pulling two compaction wheels. The tractor, however, cannot navigate the two-to-one slope at the edges of the approach, so the dozers double here as a grading tool and compaction device.