Study on the Effect of Maintenance Conditions of Turnout for Switch Throwing Force

Turnouts consist of complicated and movable structures, therefore the risk of failures is higher than a normal track.Though there are various causes of switch failures, the influence of track irregularities and maintenance conditions for switch failures is still unknown.To avoid the switch failures, it is required to study the influence between switch throwing force and track irregularities and maintenance conditions.In this paper, we make formulae to calculate the switch throwing force depending on the types of track irregularities and maintenance conditions and calculate them in a case as an example.The results showed that the influence of the vertical and lateral displacement of the area near the tip of the tongue rail, the lubricated condition on the slide baseplates and the over tensioning of a stretcher bar are significant in some cases.