# Theory and Practice of Determining the Dynamic Performance of Traction Rolling Stock
## 3 Dynamic Performance of a Diesel Locomotive on Turnouts  
The dynamic performance of the diesel locomotive on turnouts was determined with the measurements made when the diesel locomotive was passing turnout's No. 13 of grade 1/9 and No. 29 of grade 1/11 on rails R65 located at the Belle station. The direction when the locomotive CKD6E-2108 moved forward with the first wheel pair from the station towards the entrance switches was taken as the direct course of the diesel locomotive [14]. Figure 3 shows the oscillograms of the primary measurements of dynamic processes recorded at turnouts. The frame forces were determined as the product of the transverse displacements of the wheelset relative to the bogie frame and the stiffness of their connection. During the processing of tasks, the quasi-static component was considered. The estimated values of the processed tasks were determined as the arithmetic average of the three largest measured values at one speed [15]. The dependence of the ratio of frame to the static load from the wheelset on the rails on the speed of movement is shown in Figures 3 and 4. Figures 4 and 5 show that the ratio of frame forces to the static load from the wheelset on the rails is within the allowable range [13]. In the considered range of speeds, when the CKD6e-2108 diesel locomotive passes the turnouts P65 of grade 1/9 and 1/11, this indicator does not exceed 0.31 when moving sideways nor 0.15 when moving in a straight line [16]. Thus, the frame forces of the diesel locomotive during the passage of turnouts P65 grades 1/9 and 1/11 meet the requirements in the entire range of speeds at which the tests were carried out. Based on the instantaneous values of the frame forces and the coefficient of vertical dynamics of the first stage of the spring suspension, the values of the stability factor against wheel derailment were calculated (hereinafter in Figures and Tables--KZU). The minimum value of the stability factor against wheel derailment when passing turnouts is summarized in Tables 1 and 2. The obtained dependencies of the stability factor against derailment of the wheel from the rail speed are shown in Figures 6 and 7. The data given in Tables 1 and 2 and Figures 6 and 7 show that the stability factor against wheel derailment when the locomotive passes turnouts on its side up to a speed of 50 km/h and in a straight direction up to 90 km/h are in acceptable limits, i.e., they take values of at least 1.4. The results show that the dynamic performance of the diesel locomotive when passing turnouts meets the requirements of the \"Norms for Permissible Speeds of Locomotives and Wagons on Railway Tracks of Gauge 1520 (1524) mm of Railway Transport of the Republic of Kazakhstan\" (hereinafter referred to as the norms for permissible speeds) [17; 18]. Consequently, the speed of movement on the turnouts in accordance with the norms for permissible speeds of movement according to the assessment of dynamic indicators is limited to 40 km/h when moving on the turnouts on the side and the design indicators when driving on the turnouts in the forward direction [19]. Figure 4: The ratio of frame forces to the static load from the wheelset on the rails on the CKD6E-2108 diesel locomotive when driving on turnout’s P65 grade 1/9 and 1/11 on the side. Figure 3: Vertical movements of the bogie frame relative to the wheelset of the locomotive CKD6E-2108 when moving along turnouts, mm. Figure 5: The ratio of frame forces to the static load from the wheelset on the rails on the CKD6E-2108 diesel locomotive when driving on turnout’s P65 grades 1/9 and 1/11 in a straight line.