# Efficient Railway Turnout Design: Leveraging TRIZ-Based Approaches
## 5 Discussion and Validation  
The designs have been numerically validated by simulating the dynamic behaviour of a passing train using Universal Mechanism 7.0 software [55].  
The geometry and the operating conditions of the proposed design have been validated for a conventional line turnout, which is valid at speeds of up to 200 km/h. The design may also be valid for high-speed lines, but this status would require that different dimensions be adapted to suit these conditions. This aspect will be the subject of future research.  
The analyses were carried out to measure two different speeds for the front bogie of a freight wagon.: 40 km/h and 60 km/h. Lateral frictional resistance was analysed to understand the operation of the turnout. These results were obtained for all four wheels of the bogie.  
Figures 15 and 16 show the total friction on the two front wheels of the bogie with a conventional turnout and with the proposed turnout, respectively.  
Figure 14: Detail of the mechanism used to transform the motor rotation into the displacement of the connecting plate.  
Figure 15: Total frictional resistance of the front wheels in a standard turnout.  
Finally, [PERSON]'s criterion is used to relate the vertical and lateral forces--which were analysed previously--in order to determine the real possibility of a rise in any of the wheels of our bogie. Therefore, despite being a consequence of the calculations shown above, it is possible to analyse whether the probability of uplift has been reduced in the heart area in a simple manner, which is the primary objective of this project. If the vertical force is greater than the lateral force in the wheel-rail contact, [PERSON]'s criterion will be less than one, and, therefore, it is a safe zone. [PERSON]'s criterion is one of the most conservative measures in the field of railway derailments.  
As shown in Figure 19, until the bogie begins to take the curve (with a radius of 300 m), [PERSON]'s criterion is centred around 0 because of the low risk of derailment on the straight. After 0.5 s, the bogie is inscribed in the circumference of the turn itself, such that its lateral force and flange-rail contact increase, with [PERSON]'s criterion increasing to almost 0.8. This figure is the highest value and, therefore, indicates at which point there is more theoretical risk of derailment. Due to the construction characteristics of the crossing, although [PERSON]'s criterion is high, if the speed is adequate in this section, derailment should not occur. During the turn, the values of the criterion stabilise at around 0.4--a reasonable value representing a low risk of derailment. Before facing the gap space, as a consequence of the straightening of the road, the lateral effort is again reduced, and the value of [PERSON]'s criterion decreases. At around 2.5 s, once the left front wheel has passed the gap and has lowered the height of its centre of mass because of the lack of support, a shock occurs that increases the risk of derailment in the surroundings to 0.6 in terms of [PERSON]'s criterion.  
\begin{table}
\begin{tabular}{l l} \hline
**Lateral Force Results** & **Result** \\ \hline Maximum force for conventional turnout & 16,744 N \\ Maximum force for turnout proposal & 15,803 N \\ Percentage improvement & 5.6\% \\ \hline \end{tabular}
\end{table}
Table 8: Results obtained for the maximum lateral force of the right front wheel of the bogie.  
Figure 18: Total vertical force in the proposed turnout.  
As explained, [PERSON]'s criterion presented a reduction as being a consequence of the elongation of the point of the heart, and the most interesting values were observed in the right front wheel, which passes between the right rail and the check rail. For both wheels, the risk of derailment was reduced relative to the classic crossing, as reflected by a 6% reduction in [PERSON]'s criterion.  
A more detailed analysis of results can be seen in the previous work referenced in [55].