11. The result is consistent with the kinematic result in that the critical speed depends inversely on the taper. 12. The critical speed of the catenary for that particular run was 532 km / h ( 331 mph ). 13. For initial flow speeds which are not significantly above the critical speed , the transition appears as an undulating wave. 14. In rotor bearing systems any rotational speed that excites a resonant frequency is referred to as a critical speed . 15. Out of this work came the concept of a critical speed at which point hunting would become a problem. 16. The critical speed of the test track catenary was then to be increased solely by increasing the tension in the wire. 17. This made electric motor speed independent of diesel engine speed, so the diesel could run at an optimum and non-critical speed . 18. A more complete analysis, taking account of the actual forces acting, yields the following result for the critical speed of a wheelset: 19. Whereas IAS can be reliably used for monitoring critical speeds well below the speed of sound this is not so at higher speeds. 20. The wheel gauge implicitly appears in both the numerator and denominator, implying that it has only a second-order effect on the critical speed .