... the check rails are at real> K-crossing options> K-crossing check rails... menu item. I reduced the length by 48" (i.e. enter a negative modifier), and for a single slip that's on the MS side for one half-diamond and the DS side for the other. To get it looking anything reasonable I had to reduce the end flare to zero, which unfortunately applies to both check rails. You would need to remember to flare the ends a little during construction: z_slip2.png I've uploaded the .box file for you: Z 1:6 single slip, but I don't really think it's a practical design. I would recommend a switch-diamond instead as explained above. (Right-click the link, then select Save Target As... or Save Link As...) regards, Martin. edit: while preparing this reply I have overlapped with Jim. There was a Proto:Z layout at a recent RMweb exhibition. I will dig out a link unless someone else gets ...