There is a tunnel mouth on my route card that has a blue/white chequer "No Refuges" board on both sides. Surely if there are no refuges on either side this becomes a limited clearance and should be signed as such with red/white chequer "Limited Clearance" boards.
Thoughts...?
I can see your logic, but I think these blue/white boards don't mean exactly the same thing.
Do correct me if I'm wrong here but I don't believe "limited clearance" specifically excludes the presence of refuges in a given lineside area - rather, it refers to the fact that lineside clearance is, in fact, limited - and there may be refuges in the zone marked by red/white signs, but the overall clearance is limited compared to a non-signed area of track. A good example of an area of limited clearance where refuges are provided is a railway tunnel.
The blue/white "No refuges" areas I believe are areas of limited clearance
which have no refuges whatsoever. The specific difference between these two is for lineside workers - obviously, areas without refuges would require more in the way of safety precautions, whereas where refuges
are provided, one could get out the way of an approaching train easier.
Again, don't quote me on any of this, but this specific difference - while minor - is a critical piece of information for any lineside workers who might be out on the track for whatever reason. There's some BR-era training videos on YouTube that might help to explain further.