Gun Post

It sounds like you are expecting there to be standard designs, like pillboxs, but I suggest that these generaly were tactical and improvised positions, their layout and the materials would depend on availablity and the local terrain and local command and defence needs and experience

More often than not they would have been built by the men who were to man them, the only constant being the positions suitbility for a particular weapon or weapon mount

Thngs like that also seemed to depend a lot on the whim of the local builder who might not always follow the plans!

The only standard bit is where the gun was bolted down. There are examples in the Defence of Britain book but I have always wanted a comprehensive guide to all mountings so they can be identified from diameter, number/size/spacing of the bolts etc.

I did once start copying pages from a few books but lost them now.

Would it also be dependant on who built them? I assume the Army would have been part of aerodrome defence, possibly Home Guard until the RAF Regiment was up and running. A lot of weapons pits appear on aerial photographs from the period and these appear to be rings of earth or sandbags with a gap to get into it. They do not seem to be perfectly round.

Did the Army have a section in their fieldcraft manual for AA defence positions and did the RAF Regiment use the same? I can't seem to locate my copy of the Airfield Defences book, I suspect the wife has tidied things up, but I doubt it covers local initiatives.

Doesn't matter who built them, the blokes who sat in them would have soon made them "better"