Abstract <p>A calculation scheme for vertical oscillations of a 2a–2a type underframe is proposed. A system of six second-order differential equations describing oscillations in the vertical longitudinal plane is derived. A model of a locomotive section is built in the MathLab program using the Simulink application. The functions of body oscillation in the longitudinal vertical region of locomotive movement over time and the body tilt in the longitudinal vertical region of locomotive movement over time are determined.</p>