The Pump Wagon is moved during the compulsory moves part of the player's movement phase. It always moves, pursues and flees a full 2D6". The player has no control over the distance moved, but he can decide in which direction to move the Pump Wagon before he rolls the dice. If the dice result will bring the Pump Wagon into contact with an enemy unit, then it is treated as declaring a charge and follows all of the normal rules (eg. the target unit can make a charge response as normal).