Traction tires or bullfrog snot?

[RobertInOntario]

Rob: Can I assume it's the GWR Autotank?
I took the tyres off mine years ago. It works OK. I think the prototype could take 2 autocoaches.

One problem is that the wheels have a groove for the tyres and this can grab the railhead if you have narrow rails. If the new goop has set enough, you might trim it round with a knife.

David, yes it is the GWR auto tank. I did trim a bit around the wheels and that's helped a lot but I think I could trim them even more. I use code 100 track, so no problems there with thin rails getting stuck in the grooves.

Without tires, it ran smoothly and well but couldn't even haul one coach! Now it can easily pull 2-3.

I'll try to post some pix in due course.