... topic: 711 Curviform type of V-crossing posted: 26 Jan 2009 11:58 from: Martin Wynne Howard wrote (in another topic): what exactly is a curviform crossing Hi Howard, This screenshot shows a turnout with contraflexure, or negative curving. In other words, it is clearly a left-hand turnout (trace the track centre-lines), but it is curving in the opposite direction, to the right: curviform_exit.png In fact it is two turnouts overlaid. One is set for a generic type of V-crossing. The other is set for a curviform type of V-crossing. You can see that they are identical, apart from the alignment of the rails between A and B, forming the exit for the turnout road: curviform_exit1.png In the case of a regular or generic V-crossing, these rails are curved to the same radius, and in the same direction, as the main road (the lower centre-line above). This is the normal situation, for example in a curved crossover ...