Track helix
A track helix is a track figure commonly used in model railway construction to overcome differences in height of a track in a limited space. For this purpose, the track is laid in full circles with a constant gradient, similar to a screw . The concept is well-known in the railroad with roundabouts and roundabout tunnels , but rarely more than a full circle is driven through here.
The maximum gradient results from the tractive effort achieved by the traction vehicle , the necessary clearance profile results in the height difference between the track turns. The minimum circumference can be calculated from this. The route is usually carried out in a closed structure, and in the case of large differences in height, such as in mountain scenarios, as an independent structure. Spiral tracks can be used in particular to reach shadow stations. A desirable side effect is the increase in travel time on the mostly unscaled short distances between two train stations.