By Mark van der Feyst
When a positive-pressure fan is operating at a structure fire, it has the tendency to “walk” away. This happens from the vibrations created from the engine and the centrifugal force created by the rotating shaft. If the fan has been set up and left alone for a short while, it is common to find it in a different position upon return.
To stop this from happening, most fans are equipped with wheel locks. This will stop the fan from wheeling away but there is still the tendency for the fan to move. Wood chocks are sometimes effective when used to chock the wheels in position. A firefighter may need to use his or her feet to hold the fan’s wheels in place. This will definitely prevent the fan from walking away. If this is the method chosen, use proper hearing and eye protection.