Most "Fire trucks" - I'm assuming you mean Engines - carry 500-1000 gallons, usually more on the 500 size. A "Water Tender" generally around 2000 gallons.
Software engineer, or IFSAC Apparatus Operator engineer? On the west coast we absolutely refer to our pumping apparatuses as fire engines; when Engine 813 is dispatched from our station to a call we bring the whole vehicle and not just the engine block!
