On Sheriff Muir a few miles North East of Dunblaine there is a section of reinforced concrete wall in the middle of the moorland visible from the road.
It was built to emulate a sea wall with a characteristic overhang on the road or “seaward” side and an anti-tank ditch at the base. The front face is pockmarked with numerous impact craters characteristic of shell fire. Significant sections have the facing completely broken away down to the thinner (1/2″) reinforcing rods. Larger (1″) reinforcing rods from the core are also visible in places.
The Northern end of the wall is three meters thick but at the Southern end it steps down to a final width of about one meter. I assume these different thicknesses were to assess the effect of shell fire on different thicknesses of concrete found on sea walls.
In the three meter section there are several significant partial breaches in the structure, probably as a result of demolitions charges – possibly from the Churchill AVRE 290mm petard mortar with it’s “flying dustbin” 12kg demolition charge. These breaches are adequate for infantry to be able to cross the obstacle.
The northernmost of these is a full breach of the wall that’s 4m wide – enough for a Churchill or Sherman to pass through.
On the “landward” side there are large pieces of concrete that have been deposited some distance back from the wall which suggests a significant quantity of explosives were employed.
Being a relatively short section of wall, and with the various thicknesses, it’s unlikely this was used for troop training. The most likely explanation seems to be that this was used for testing the effects of different artillery shells and engineering equipment on a section of sea wall similar to that found at the landing beaches.
Several hundred meters to the South there is a blockhouse which I didn’t have the time to explore.