As mentioned in the forum, my inspiration for model railways came from & followed my visit to the models built by the Late Rev Peter Denny. It was his concept of using a fiddle yard (hidden sidings) where trains emerged from & disappeared into. Peter Denny developed this further by making the fiddle yard a huge turntable to turn the trains around so that they could return to the layout. His trains were no longer than five feet in length, his layout was from 1906 where train lengths were much shorter than those of my era, the 1960s. For me to use this feature would require a turntable, seven feet long & the space to turn it around. That was when I worked out that I could achieve the same feature by using a static fiddle yard but with space for a loco at either end. That needed a length of at least seven feet, separating the electrical feeds from each end of each fiddle line does just that. Working out the sequence diagrams so that an appropriate loco is working a particular train is quite challenging and a lot of fun. It makes it all very real. Our two longest fiddle lines will accommodate a five coach train or eighteen goods vans, with locos at either end. At least using a fiddle yard the trains actually go somewhere, out of sight & return later.