zastęp to najmniejsza jednostka taktyczna złożona z ratowników stanowiących obsadę pojazdu bojowego. -
http://tinyurl.com/yd7f7a7i na podstawie odnośnika podanego przez bartka
Truck company: a group of firefighters assigned to an apparatus that carries ladders, forcible entry tools, possibly extrication tools and salvage covers, and who are otherwise equipped to perform rescue, ventilation, overhaul and other specific functions at fires; also called "ladder company"
Engine Company: A group of firefighters assigned to an apparatus with a water pump and equipped with firehose and other tools related to fire extinguishment.