Thanks all for your comments, indeed there appears not to be a 'one solution fits all', so I think it remains for me to try some different techniques and see what happens in each case.
It occurs to me that if I can somehow allow for some longitudinal and lateral movement yet somehow prevent the track from heaving up, then I might be at least some way there. To that end, I had an idea to use modified cable fixing clips (for want of a better term!) thus:
In this form it's not quite tall enough, and it also would potentially restrict longitudinal movement. However, if I modify it slightly to this:
... and raise the height of it using the bit I cut off, I get this:
Hopefully if I can nail these into the block base where necessary, then the track will at least not ride up on top of the ballast but will be able to move in the other two planes.
I also have taken delivery of a sieve today, so with some luck I ought to at least try this fixing/ballasting method out tomorrow.
Thanks again all for your help, very much appreciated.
It occurs to me that if I can somehow allow for some longitudinal and lateral movement yet somehow prevent the track from heaving up, then I might be at least some way there. To that end, I had an idea to use modified cable fixing clips (for want of a better term!) thus:
In this form it's not quite tall enough, and it also would potentially restrict longitudinal movement. However, if I modify it slightly to this:
... and raise the height of it using the bit I cut off, I get this:
Hopefully if I can nail these into the block base where necessary, then the track will at least not ride up on top of the ballast but will be able to move in the other two planes.
I also have taken delivery of a sieve today, so with some luck I ought to at least try this fixing/ballasting method out tomorrow.
Thanks again all for your help, very much appreciated.