Why does the train not skid on the rails?
But in the actual operation, locomotive could slip, which is mainly due to the change of external conditions, the formula is in good condition to face, if there is oil, cream, water and other impurities on the track, or line quality is not good, may also be part of the locomotive itself result, the adhesion coefficient will decrease, when the locomotive traction motor traction play may be greater than the adhesive force, formed the so-called idle, the locomotive is harmful and must be eliminated quickly. Generally use sand to increase adhesion coefficient, no, then the locomotive will reduce load, reduce traction.
For example, calculation of the adhesion coefficient of domestic DC electric locomotive according to formula j=0.24+ (12/ (100+8v)), which is mainly for freight locomotives, passenger locomotive traction tonnage due to smaller, generally have relatively small, probably between 0.2-0.3.
The wheel of a train does not skid. Because the train in the design, it has calculated the adhesion coefficient between wheel and rail was reasonable, the coefficient to ensure the relationship between locomotive power and its weight and traction, but in the actual operation, but also train weight limit, so the wheel slip is generally not sub. At the same time, advanced locomotives now have automatic control systems to prevent skidding, and in the ice and snow season, the locomotive also has sand blasting equipment to prevent the wheels from slipping.
