Field Experimentation Quantifying Rail Creep in a Curve on a Steep Grade: Influence of Train Weight, Travel Direction, Speed, and Consecutive Train Passes

Rail creep is the longitudinal movement of the rail relative to the sleepers, tie plates, or ballast and can cause several challenges for track maintenance and operations, such as sleeper misalignment, tight gauge, and increased risk of buckling. This paper quantified rail creep caused by 286 trains using longitudinal rail displacement data from both the low and high rails of two adjacent sleepers in a curve on a steep grade (1.76%). This research investigated the residual rail creep, the difference between the high and low rails’ creep (rail creep differential), the influence of train weight and speed, and the effect of consecutive trains passing in the same and alternate directions. 95% of the residual rail creep was lower than 0.01 in. (0.025 cm). Rail creep differential values were significantly influenced by total train weight when traveling downhill only, which could lead to sleeper skewing. Train speed did not significantly correlate with displacement within the studied speed range (4.6 to 34.6 mph [7.4 to 55.7 km/h]). The passes of consecutive trains in the same direction led to cyclic rail creep, regardless of the train direction. However, trains traveling in the alternate direction led to rail moving in the direction of train travel. Further, this research quantified temperature-induced rail creep that occurred without train movement. These findings suggest that changes between tractive and braking forces, train total weights and temperature may influence rail creep, warranting further investigation of longitudinal rail movement.