... that rail joint -- on the GWR the wing rail and switch stock rail are in one piece. That's not an option on a 2-rail model. By default this increased double-slip clearance is on for 00/EM etc, but off for P4/S7 etc. This can be changed as required. It does of course reduce the slip road radius, which is why it applies only above 1:6.5. Note that this applies only to double -slips. Here is the tip clearance help: 2_100640_250000000.png If you turn this off, you should find that the auto-generated double-slips match your own very closely. But you may then have more trouble building them. Generally for EM and 4-SF I suggest a switch opening of 1.75mm (using a 20p coin as a gauge). If your interlocking requires both switch blades to be open at the same time you may find that quite tricky to achieve, bearing in mind that you must maintain electrical insulation between them. In many cases the interlocking is such ...