Trucks for Thawing Fire Hydrants Since the New York Fire Department no longer uses steam engines, it has purchased five one-ton International Harvester trucks equipped with gas burners for quickly thawing fire hydrants. The trucks have a two-man cab and they carry a water storage tank of 40-gallon capacity. Each unit has two fuel supply tanks of the bottle gas type, each carrying fuel for 1,500,000 B.t.u. One of the trucks has been assigned to the Yorkville section, and the others to Washington Heights, the Bronx. Flatbush and Brooklyn. During the severe cold weather of last winter, a number of fire hydrants were reported frozen.