A wetdown is a ritual celebrated by many volunteer fire departments in the United States in which squads of firefighters from neighboring towns ritualistically commission a new fire apparatus by anointing it with water sprayed from the visitors' firefighting equipment.
If two new apparatus' are commissioned, then it is considered to be a "Double Wetdown". If three new apparatus' are commissioned, then it is called a "Triple Wetdown". Or if four new apparatus' are commissioned, then it is considered as a "Quadruple Wetdown".
The tradition dates back to the late 1800s, when fire departments used horses to pull a fire apparatus to fires. After fighting the fire, the crews would wash and ready the horses and the apparatus in preparation for the next call, then they would push the apparatus into the station's bay.[1][2][3]