... topic: 3674 Switch diamonds posted: 21 May 2020 18:49 from: ikcdab Recently found this pic online.Outside of the switch rails there are fixed rails which the switch rails seem to butt against when closed. There is a better picture on pafe page 22 of iain rices 4mm finescale track book which says its old oak common. What are these fixed rails for? 1588_211343_540000000.jpg posted: 21 May 2020 22:21 from: Nigel Brown Presumably they stop the switch rails from spreading. Maybe using slide chairs wouldn't be as effective in this instance? posted: 21 May 2020 22:41 from: ikcdab that looks possible, though i dont see why ordinary slide chairs couldnt have been used? posted: 21 May 2020 22:59 from: Martin Wynne Hi Ian, Those backing rails to support the closed switch blades are standard practice on GWR switch-diamonds. Full details in David Smith's GWR track book, which I can't put my hands on just at the moment. I think there was also some discussion about this in Andrew's Yeovil layout ...