It’s the city that never sleeps, but when managers for New York City’s Department of Sanitation (NYCDS), Parks Department, and Department of Transportation (DOT) do sleep, they often dream of ways to improve fleet fuel economy while lowering overall emissions.

According to Spiro Kattan, supervisor of mechanics for the NYCDS, the city has been a forward thinker in the use of hybrid vehicles and trucks since hybrid technology became available. “Being known in the industry as early adopters, we get to use and test cutting-edge technology,” he said. “We’ll also be the pilot test bed for many vehicles. This allows us to prove the technology and see first hand what will work best for the city.”

According to Kattan, the department’s Deputy Commissioner of Support Services Rocco DiRico has been a driving force in challenging Kenworth manufacturers to find innovative solutions for department fleets.

Meeting Emissions Goals with Diesel-Electric

According to Kattan, lowering emissions is the biggest benefit of hybrid-vehicle use to New York City.

“In 2007, Mayor Michael Bloomberg announced a mandate to cut carbon dioxide by 30 percent by the year 2017,” he said. “We’re seeing up to a 30-percent improvement in fuel economy over non-hybrid delivery trucks.”

Nearly 40 percent of the Parks department’s fleet of passenger cars and light trucks/SUVs are hybrid, and it’s looking into hybrid-electric technology for its next set of street sweepers, which will join its garbage trucks.

The City’s sanitation department began running hybrid Kenworth T370s in 2009. It currently has nine in use as rack trucks, delivering parts repair shops in five boroughs. Five other Kenworth T370 hybrids are used as delivery trucks — shuttling tires to different service locations.  

The Kenworth T370 hybrids, purchased through Gabrielli Kenworth, feature the PACCAR PX-6 engine, rated at 240 hp and 560 lb.-ft. of torque, and the Eaton diesel-electric hybrid power system. The system uses an integral transmission-mounted motor/generator; frame-mounted 340v lithium-ion battery pack; and dedicated power management system. Electricity generated through regenerative braking is stored and used for acceleration, assisting the diesel engine. The hybrid system is monitored through an in-dash display. As the power requirements for different driving conditions change, the screen constantly updates the driver on the hybrid system’s status.

Medium-Duties Operate in Stop-and-Go Applications

“As for our medium-duty fleet, we’ve been using Kenworth hybrids in applications where stop-and-go work is necessary. That’s been the best application to get better fuel economy,” Kattan explained.

Within NYC Parks, 74 percent of its vehicles are operating on some sort of alternative fuel. “We’re running biodiesel [vehicles], have some equipment that is solar-powered, and we’re using 17 Kenworth T370 hybrids — eight have rack bodies with liftgates, and the rest feature five-yard dump bodies,” said Jonathan Ells, chief of staff for citywide operations.

With more than 29,000 acres divided up among 1,700 parks and more than 500 ball fields, New York City has the largest parks department in the country. The hybrid dump trucks haul dirt, sand, and clay to ball fields; they’re also used for general assignment work. The T370s with rack bodies are do-all vehicles and support a wide range of park activities, from skilled trades to general maintenance.

For the New York City DOT, nine Kenworth T270 hybrid bucket trucks are in service and a T370 hybrid is on order to hoist a 60-foot bucket. The Kenworth hybrids join 54 other T370 non-hybrids in the field.