Abstract We studied numerically the propagation velocity in a force cooled superconducting cable. The numerical model comprised a one dimensional model for the copper/superconducting matrix and a one dimensional model for the helium flow. The propagation velocity appears to keep rising with time rather than becoming constant as assumed in many theories. This is mainly caused by the induced pressure waves that cause a temperature rise of the coolant away from the normal conducting zone. Mass flow rate, initial disturbance and conductor length are less important parameters. Operation pressure and wetted perimeter have an important influence on propagation velocity.