A Pennsylvania contractor who specializes in difficult site preparation projects has found that renting vibratory rollers is a cost-effective alternative to owning them.
Doug Thomas, president of Thomas Construction Company, Grove City, PA, said that his company has found a growing niche in the site-preparation market working on sites with difficult geotechnical conditions or requiring clean-up of hazardous materials. His business, which he founded in 1974, is now growing rapidly because many larger contractors in his area have abandoned site preparation work in favor of major highway paving projects.
Thomas said his company owns about 90 percent of the equipment it uses. Other equipment is rented for specific projects if it is not available from his fleet. When a project is completed, the rented equipment is returned or moved to another project. Renting equipment can be very cost-effective when there is not a continuous need for a specific machine, Thomas said.
Vibratory rollers are a good case in point. “Besides the rollers I own, I rent rollers as needed,” Thomas said. “One reason I rent rather than buy some rollers is that there is no work for them (in Pennsylvania) during the winter months. Soil compaction jobs are shut down here each year for three to three and a half months, so I send the rollers back to the dealer. This means that they are never sitting idle at my expense.”
Currently, Thomas has a Bomag BW213 vibratory roller in his fleet and a new BW211D-3 on rent from Doyle Equipment Company, Cranberry Township, PA. Thomas has been impressed with the BW213. “This machine has worked flawlessly since new. With over 1,500 hours on it, we have had no major breakdowns,” Thomas explained. “This is a good reliability record because vibratory rollers necessarily take a beating from the vibrations they create.”
The BW211D-3 is 9.9-metric-ton (11 ton) class vibratory roller with a 213-centimeter (84 in.) wide drum. Introduced to the U.S. market at ConExpo ’99, the BW211D-3 was specifically designed for the rental market. It offers a competitive price tag (and rental rates) without sacrificing compaction performance.
Thomas rented the BW211D-3 to help prepare a site surrounding a new building constructed for the manufacture of wooden trusses. Thomas was called in by the builder because of the geotechnical conditions encountered at the site. The site was all glacial till, or unconsolidated drift consisting of clay, silt and gravel.
The potential problem at the site was the silt. If left in place, it would slowly migrate up into the stone base to be laid by Thomas for a parking lot. To solve this problem, Thomas first excavated 7,646 cubic meters (10,000 cu. yds.) of material out of the area. Then he laid down a geotextile blanket that allows water to drain through it, but prevents silt from passing up to the stone base.
The base consisted of a 30-centimeter (12 in.) lift of Pennsylvania DOT No. 3 stone, followed by a 10-centimeter (4 in.) lift of DOT No. 2A modified stone. The BW211D-3 required only one pass per lift to complete compaction. Operator Joe Lyons set the vibration frequency on the BW211D-3 at 2,160 vpm and the amplitude at .18 centimeters (.072 in.). Lyons reduced vibration frequency to 1,800 vpm near the building to prevent damage to the footings. The BW211D-3 also offers a second amplitude setting of .09 centimeters (.036 in.).
Lyons said the new roller performed well. “While the BW213 is an excellent roller, the BW211D3 is even better. It steers more precisely, maneuvers more easily and the rear visibility from the operator’s seat is much better. The top of the machine’s rear hood slopes down, making visibility much better than is possible on the other roller that has a flat-top rear hood.”
A total of 19,114 cubic meters (25,000 cu. yds.) of material was excavated at the site. In turn, Thomas laid 15,300 metric tons (17,000 tons) of stone in order to bring the site to the proper grade for paving.
“This project is a good example of well-trained, intelligent equipment operators and quality equipment working together to produce a quality base for paving,” Thomas said. “We like these challenging projects because most of our competition cannot handle them. The next project we are sending the new Bomag roller on is a land reclamation site. It was a refuse dump back in the 1950s so it has become a hazardous materials clean-up project. This type of site work has become one of our specialties.”
“It is intelligent, dedicated employees and high quality equipment that have made our company successful,” Thomas continued. “I make my employees number one in importance followed by having the best equipment I can buy or rent as number two.”
For more information, call 309/853-3571 or visit www. bomag-americas.com.