Rail tie plate slip derailment cause

Smooth surface: The contact surface between the pad and the rail or sleeper is too smooth, resulting in insufficient friction coefficient.
Loose bolt: The bolt fastening force is insufficient, resulting in the pad cannot be firmly fixed.
Pollution: Oil, dust or other contaminants reduce the frictional properties of contact surfaces.

Excessive axle load: Heavy trains or high density traffic increase the longitudinal force of the rail.
Dynamic load: The extra force generated when the train starts, braking, or passes through a curve.

Temperature change: The thermal expansion and contraction of the rail may cause the pad to slip.
Humidity: Humidity may reduce the coefficient of friction.

Improper plate size: insufficient contact area with rail or sleeper.
Material problem: insufficient hardness or wear resistance of the pad material.