Turrets such as these are often installed by planetary defence forces, and can provide a first line of defence to Imperial settlements and infrastructure. Occasionally they survive long enough to be utilised by other Imperial forces that get mobilised to war zones after the initial contact with the PDF has been made.
These turrets are something that I threw together fairly quickly to add a little bit of flavour to my epic games. They were fairly simple to make, and I might do up some more down the track.
The turreted weapons themselves are spare chimera turrets that I had lying around. The anti-air turret is a spare from a fire raptor model.
The bases are flocked with sand, primed grey, washed with black and drybrushed with under hive ash.
On the back I put some little pieces of smaller zippy tie to represent a ladder or door.
Alternatively I can just use them as scatter terrain to add a little atmosphere.
So very quick to make and using up some of my pile of spare bits. Win-win!