... wrote: Out of curiosity, how would you know that the turnout would require a curviform V? Hi John, There is no specific rule, the track designer is assumed to know what he/she is doing. As it happens this question has crossed with what I'm currently doing in the Templot Companion to replace the explanation in the old 2000 track planning tutorial. Prototype curviform V-crossings are not used where not actually needed, because they involve messing about with the spacing of the crossing chairs and timbering. See: 2_290827_170000000.png The general guidelines are: 1. where the diverging track is part of a crossover, or leads to a loop or lay-by siding or other track running generally parallel to or alongside the main road -- always* use a regular (or generic) V-crossing. If there is no connected pointwork you may prefer to use a parallel type V-crossing instead. 2. where the diverging track needs to curve away from the main road, for example in a double-junction or in yards - ...