... of 92mm centres seems enough to give a clearance envelope around passing vehicles: 2_011413_550000000.png On the prototype 6ft and 10ft ways are alternated on pairs of multiple tracks. This is shown well on the cover of this book: cvr_track_200px.jpg 2_011439_460000000.jpg Although not essential on a model, it looks more prototypical to do the same, and allows space for signal posts, etc. So adding the same 4ft difference (28mm) to 92mm gives 120mm. So for these tracks I set the TS spacing at 92mm and the MS spacing at 120mm: 2_011419_430000000.png A slightly smaller spacing than 92mm would be possible on the larger radius tracks, but it's more practical to keep them the same to avoid errors in construction and tracklaying. The .box file for this is attached below. If you adopt it you will need to realign the pointwork, but it's all good practice in Templot. But you might want to wait for my next reply, because the best way to reduce the centres into straight track is to use transition curves. p.s. a quick way to see which side is ...