A group of 132 Sterling tractors with clean-burning liquified natural gas engines are going into service in the Los Angeles Basin following official delivery Monday.
The L-113 daycab tractors have begun hauling shipping containers from and to the Ports of Long Beach and Los Angeles as part of the Clean Trucks program aimed at reducing air pollution generated in the ports.

The Sterlings, with Cummins-Westport ISL-G engines, cost about $160,000 each, but are being largely paid for by nearly $12 million in grants and tax incentives from federal, state and local government agencies. They're being operated by California Cartage Co. of Wilmington, which previously began running five short-haul tractors with NG engines as part of a demonstration project.

Daimler Trucks North America, which hosted the ceremony in a yard at the Port of Long Beach, will build another 100 LNG tractors for use by drayage fleets and owner-operators at the ports, executives said. Sterling Truck Corp. will cease operations in March, but the ISL-G engine and fuel system will be offered on Freightliner M2-112 tractors, which are similar to the Sterling L-113 tractors with setback front axles delivered to Cal Cartage.

The gas-fired engines emit "near-zero" pollutants and already meet the 2010 diesel exhaust limits set by the federal Environmental Protection Agency, dignitaries noted. The engines do not need particulate filters or other 2010-spec aftertreatment devices and natural gas costs considerably less than diesel fuel, but the engines are expensive to build and add considerably to a basic tractor's price. Monetary grants from the U.S. EPA, the South Coast Air Quality Management District, and a state Clean Air bond issue are helping the ports subsidize truck operators' acquisition of the trucks through special purchase or leasing contracts.

These and other tractors will replace old, smokey diesel-powered tractors run at the ports by fleets and owner-operators, said port officials in welcoming the cleaner-burning vehicles. As part of their Clean Trucks program, the ports banned pre-1989 tractors, which were built before any emissions standards were set, effective October 1.

"According to one source, 50 percent of all port pollution would be eliminated by banishing pre-'89 trucks," said James Hankla, president of Long Beach's Board of Harbor Commissioners. "If that's true, it's already done."

"We want to be part of the solution" to the area's pollution problems, declared Cal Cartage's president, Bob Curry Sr., during the ceremony. About 40 of the 132 Sterling LNG tractors were already on the road, and the rest would be in service by year's end, replacing a similar number of older trucks. The new tractors gas up at an outside fueling station, but Curry said he wanted to acquire his own facility, for which governmental grants are also available.

The 8.9-liter Cummins-Westport ISL-G is rated at 320 horsepower and 1,000 pounds-feet. It uses advanced stochiometric combustion, cooled exhaust-gas recirculation, and a three-way catalyst to lower emissions to 2010 levels. Nitrogen oxide is measured at 0.02 gram per brake-horsepower per hour, and particulate matter at 0.01 gram. A 119-gallon stainless steel cryogenic saddle tank gives a range of 250 to 300 miles.

Daimler Trucks has approved the engine for use with an Allison 3000 automatic transmission, which the Sterlings have. The Allison helps the ISL-G briskly accelerate a loaded tractor and trailer from dead stops, and it will "outdrag" a more powerful engine with a manual transmission, Daimler claims in a special video.