... . I can't remember what track spacing we used, but it was more a case of trial and error in those days. but as others have said, do allow for axle end-slop, bogie pin play etc. posted: 1 Jun 2010 08:52 from: Martin Wynne The Australian Model Railway Association have published a standard for passing clearance on curves. See: http://www.amra.asn.au/clearance.pdf Here is the relevant section for UK models at 4mm/ft scale (Group 3 in their classification): 2_010343_590000000.png© AMRA Thanks to Terry Flynn for drawing my attention to it. regards, Martin. posted: 1 Jun 2010 12:32 from: Geoff Cook Which is great till you look on page 10 of the pdf, were it gives 48mm for the minimum clearance for straight track for 1:76.2 4mm/ft group 3 How can we be closer on the curve than we can be on the straight Geoff Cook Last edited on 1 Jun 2010 12:35 by Geoff Cook posted: 7 Jun 2010 11:07 ...