Preventing movement is just what you DO NOT WANT with Filcris, you do need to allow for this as I said in Post 7.
Ken, if you are thinking of a High Level Line a Bridge that lifts at one end will work fine. I used one of the Trainline Bridges on my friends 0 Gauge Line. Hinged at one end with slightly lifted Hinges that end so that the Rails do not catch. At both ends you can use loosely fitting Fishplates for Track Alignment. Hillman used to do Bridge Clamps, but these may be Tricky to find now. Then via a Micro Switch that the Bridge Activates when down, make Isolation Sections either side of the Bridge to stop Accidents. System works perfctly on his 0 Gauge Line, though you do need something to Hold the Bridge when 'Up'. We used a vertical piece of Wood.
Have left you a message in Conversations.
JonD[/QUOTE]
I wasn't suggesting continuous shouldering of the whole track - neither Mikes idea or my addition, prevent total movement. What has to be dealt with is two different co-efficients of linear expansion, plus the lack of rigidity in the plastic medium. I like the idea or a rotproof material and did, at one time, consider using it until I saw what happened to it in use.