The job assigned to an Engine Company at a fire is determined by the arrival sequence of the engine. For this discussion, we will consider an assignment, to a report of a house fire. This type of assignment would include three engines, two ladders, and one deputy chief.
The first engine company to arrive on the scene of a working fire is charged with extinguishment. Mount Vernon Fire Department policy is for a quick interior attack on the fire whenever possible. This includes making quick entry to the fire building to find and extinguish the source or seat of the fire.
The second engine company to arrive on the scene of a working fire is charged with water supply to the first engine and then backup for the first crew in the building. The "usual" procedure for the second engine company is to stop at a hydrant closest to the fire and lay a 5 inch diameter supply line on the way to the fire building. This size supply line should be large enough to supply the first truck with water to spare. Once the second engine is at the fire building part of the crew will complete the hook up of the supply line to the first engine. The third engine is assigned to fill in any gaps, often stretching a 2nd or back up attack hose. In our organization this engine company may be assigned as RIC which is our Downed Fire Fighter Removal Team.