... have lost me on the 102" radius curve. I'm not aware of changing it from anything else. The regulations require a continuous check rail on curves below 10 chains radius (104" in 4mm/ft) on running lines, but there is no such requirement for yards and sidings. It would depend on the frequency of derailments. I can't see any continuous check rails in the photo. File below. cheers, Martin. Attachment: attach_3107_3685_kyle_tandem_modif ied.box 80 posted: 3 Jul 2020 08:17 from: Julian Roberts 3591_030315_380000000.png posted: 3 Jul 2020 08:31 from: Julian Roberts Hi Martin I've managed to upload an image now. The check rail I mean is here on the left of the semaphore signal (as we look at the image). Just to be clear, when I designed the track plan following the map as closely as possible, this particular section was about 52" radius, followed by a relatively straight connection to the single slip. The redesign of the tandem you did incorporated this section, smoothed out to a ...