... book will make it clearer I suspect. 2787_121516_300000000.jpg The X is the probable hinge point for the elbow and the lines either side are the lateral support rails which I have to confess I didn't know existed before now. Kind regards Andrew Last edited on 12 Aug 2019 20:25 by Andrew Duncan posted: 13 Aug 2019 16:08 from: Tony W Hi Andrew. You may find this picture useful. It appears GWR. You have answered one of my questions as to what the additional pieces of rail were for. 2151_131059_030000000.jpg There is much detail here, the wider and longer center timber is obvious. There are also locking bars visible. Regards Tony. posted: 14 Aug 2019 06:22 from: Andrew Duncan P Tony W wrote: Hi Andrew. You may find this picture useful. It appears GWR. You have answered one of my questions as to what the additional pieces of rail were for. 2151_131059_030000000.jpg There is much detail here, the wider and longer center timber is obvious. There are also locking bars visible. Regards Tony ...