Cargotec has delivered liquefied natural gas-powered (LNG) terminal tractors that fully meet California’s 2010 California Air Resources Board (CARB) standards for off-road vehicle emissions, while improving on the performance of equivalent diesel-powered units.
Twelve Kalmar Ottawa 4×2 terminal tractors powered by LNG have been delivered to California Cartage Company, a Southern California leading import trucking and distribution company.
Where some terminal operators have opted for California’s emissions credit scheme to meet new restrictions, California Cartage has made a voluntary commitment to LNG, with 50 per cent of its tractor fleet LNG-powered, supported by State of California funding. The latest deliveries represent the first terminal tractors to feature the new L-Series engine from Cummins, specifically designed to meet new 2010 CARB standards on Oxides of Nitrogen (NOx) and particulate matter (PM) emissions.
According to the engine manufacturer, PM emissions from LNG engines amount to 0.009 parts per million, compared to 0.01ppm from a standard diesel engine. L gas engines emit 0.1 ppm of NOx, compared to 0.13ppm by standard off-road diesel engines.
Casey Tubbert, U.S. Regional Manager, Terminal Tractors, says that the LNG-powered terminal tractors exhibited no performance loss when compared to conventional tractors powered by diesel.
"The LNG application requires a larger capacity engine, at 8.9 litres, compared to a 6.7 litre diesel model," says Tubbert. "This engine effectively uses 90 per cent of the fuel for traction, compared to 60-70 per cent for a conventional diesel engine.
"In our application it’s all about start-ability, which is based on torque. The LNG engine we use is rated at 250 hp and 730 lb/ft of torque, while the standard diesel engine we offer is 200 hp and 520 lb/ft of torque. In our LNG-powered tractors the performance is enhanced. Also noticeably different is that the lower emissions produced by LNG engines means that the spark ignition are much quieter than their diesel counterparts."
Although larger in size, Tubbert said that the L gas engine fitted into the existing Kalmar Ottawa chassis design with very few modifications. "The installation required no change to the cab," he says.
Cargotec, which delivers terminal tractors from its plant in Ottawa, Kansas in the United States, has almost two decades of experience in developing terminal tractors operating on alternative fuels such as Compressed Natural Gas, LNG and Liquid Petroleum Gas.
However, Tubbert doesn’t doubt the significance of the latest deliveries: "It is only a matter of time before terminal operators elsewhere are obliged to follow California’s lead on cleaner container handling equipment. The additional cost of purchase and operation of diesel engines currently being built is making alternate fuels look more attractive. The initial investment of LNG machines as well as their fuelling station is significant, but the absence of diesel emission fluids and exhaust regeneration make day-to-day operations more attractive. Once the infrastructure is in place for these vehicles, we will see more and more companies looking into this technology."