Rolling contact fatigue is still an important problem in various phenomena in railway fields such as wheel shelling or squats of rail. Therefore, a method was developed and prepared to observe the fatigue crack propagation under mixed loading of tensile and inplane shear modes that can simulate rolling contact conditions by an in-plane biaxial fatigue machine. In the experiments, simplified cycles were applied to the analysis of rolling contact fatigue cracks including the effect of fluid trapped inside the cracks. Growth rate laws for wheel and rail steel were obtained by means of least square regression analysis in terms of the effective stress intensity factor range.