AggMan Staff | Published on December 2, 2011

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The Emissions Battle

Hybrid construction vehicles are pitted against conventional diesel vehicles in $2 million study to determine reduced emissions benefits.

Scientists at the University of California, Riverside’s Center for Environmental Research and Technology (CERT) have received a $2 million contract for a first-of-its-kind study of hybrid construction vehicles.

Kent Johnson, an assistant research engineer at the Center for Environmental Research and Technology, is working on the two-year hybrid emissions project being funded by the California Air Resources Board (CARB). The project will allow researchers to evaluate the emission reduction benefits of two commercially available hybrid construction vehicles: a Caterpillar bulldozer and a Komatsu hydraulic excavator.

The two-year project, which is being funded by the California Air Resources Board (CARB), will allow researchers to evaluate the emission reduction benefits of two commercially available hybrid construction vehicles: a Caterpillar bulldozer and a Komatsu hydraulic excavator.

“Hybrid construction vehicles are just now becoming available,” Kent Johnson, an assistant research engineer at CERT and the principal investigator on the project, said in a written statement. “We have been asked to use our emissions testing experience to quantify what their benefit is.”

Johnson will be assisted by two co-principal investigators: Tom Durbin, a research engineer, and Wayne Miller, who lead the emissions and fuels research group at the Center for Environmental Research and Technology.

The project is the latest in a nearly 20-year history of emissions testing at the CERT. Initial research focuses on cars in a stationary setting. Later projects shift to trucks and on-the-road testing. Currently, much of the work is done with portable emission measurement systems (PEMS), which have been used on everything from on-road and off-road vehicles, stationary sources, locomotives, port vehicles, air craft, harbor craft, and ocean-going vessels.

The research is part of a larger effort by CARB to expand the use of hybrid technology to help meet the goals of AB 32, a 2006 state law that aims to reduce greenhouse gas emissions to 1990 levels by 2020. That would be about a 30-percent reduction. It also calls for an 80-percent reduction below 1990 levels by 2050.

Little is known about the potential benefits of hybrid technologies for construction equipment because of their unique and diverse duty cycles when used, according to CERT.

Manufacturers are saying the hybrid vehicles reduce fuel needs by 20 percent and cut emissions by 30 percent, Johnson said.

The $2 million will be divided two ways, Johnson said. Half of it will be used as an incentive voucher to get 20 to 30 hybrid construction vehicles in use. The other half will fund testing in six vehicles, which will be scattered throughout California.

Behavior of those vehicles will be characterized on a second-by-second basis during in-use operations at construction sites using portable emission measurement systems. Researchers at CERT will design standardized tasks, such as lifting a heavy object.

The performance of the hybrid vehicle will then be compared to that of conventional diesel-powered vehicles.

The project will help establish the methodology for making comparisons under such varied conditions. The project will also consider the differences between emerging hybrid implementations by leading manufacturers.

The project may provide data that could contribute to a hybrid incentive program under AB 118, a 2007 law that established a voluntary incentive program administered by CARB to fund clean vehicle and equipment projects, research on biofuels production and the air quality impacts of alternative fuels, and workforce training, according to CERT.

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Vulcan Helps a Virginia School Rock with Spirit

The Lorton, Va., location of Birmingham, Ala.-based Vulcan Materials donated a 14,000-pound “Spirit Rock” to Silverbrook Elementary School in Fairfax County, Va. For a video of the rock being delivered to the school, go to

Joe Bosco, assistant principal, and Dr. Melaney Mackin, principal of Silverbrook Elementary, were present with Vulcan employees Jim Cooper, plant manager of Graham Quarry, and Jess Brindisi, district sales manager for the operation.

Great Lakes Limestone trade up 2.4 percent in September from 2010

Shipments of limestone on the Great Lakes totaled 3.5 million net tons in September, a decrease of 6.7 percent from August, but an increase of 2.4 percent compared to a year ago, according to the Lake Carriers Association (LCA). September loadings were 4 percent off the month’s five-year average, LCA reports.

Shipments from U.S. quarries increased 10 percent compared to a year ago and were only marginally below the month’s five-year average, according to LCA. However, loadings at Canadian quarries were off more than 22 percent compared to a year ago and 8.5 percent below September’s five-year average. Through September, the limestone trade stands at 19.7 million tons, a decrease of 3.9 percent compared to the same point in 2010, and a drop of 13 percent compared to the five-year average for the for the first three quarters.

                              2006          2007          2008             2009          2010        2011     Aver. 2006-10


                               2006            2007           2008           2009            2010         2011      Avg. 2006-10


U.S. ports: Calcite, Mich.; Cedarville, Mich.; Drummond Island, Mich.; Kellys Island, Ohio; Marblehead, Ohio; Port Inland, Mich.; and Presque Isle, Mich. Kelly’s Island ceased operations in the fall of 2009. Canadian ports: Bruce Mines, Manitoulin Island, Port Colborne, and Smelter Bay (all Ontario). Port Colborne ceased shipping by vessel in 2006. Source: Lake Carriers Association

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