The development of German armoured material already started in the late 19th century when concrete forts like the ones around Metz were built. Besides conventional gun turrets, the first armoured plates for machine guns were developed. They formed the base design for the ones used in the 1930s and 1940s.
In the 1920s the Weimar republic first built new fortifications on the eastern borders. These were the predecessors of the later Regelbauten: small concrete isolated bunkers on only the most important rail, road or water crossings. Standardized armoured doors were introduced as well as plates for both entrance defence protection and weapon positions. Alongside the development of standard bunker designs throughout the 1930s, a large amount of standardized (gas proof) armoured parts were being produced. And with the weaponry getting heavier and more precise, the bunker's walls got thicker, and so did the armoured parts. They're collected in the Panzeratlas, a collection of A3 prints with basic drawings of every part ever designed until 1941.
The atlas is just a reference book and only shows rough dimensions. It does however show all armoured parts available until 1941. German armoured parts can be recognized by a number ranging from 1 to 900 with a certain extension: P7, P8, P9, P01, P2, P3, P4, P5 and P6. The extensions represent a year: P7 parts were designed in 1934, P6 parts are from 1942. However, these rules don't seem to be consistent because there are parts like 857P7 (2cm Flak turret) and 882P7 (double armoured door) which were introduced in 1943.
The Panzeratlas was an army project. Airforce and navy produced their own armoured parts which can also be found in army bunkers, mostly because of shortage of regular parts. Documentation of these parts is scarce, so we rely mostly on field work. For Luftwaffe material this is easier than Kriegsmarine parts. The Luftwaffe designed their own parts for the Luftverteidigungszone West (LVZ West), an anti-aircraft defence line backing the Westwall. This defence line, of which the construction was initiated in 1938, was never completely finished before the end of the 1940 Blitzkrieg. Together with the Westwall it was demobilised and the remaining armoured parts were put in stock. Three years later these parts were widely reused in the Atlantikwall.
The German navy remains a head ache for researchers. Although they didn't design their own armoured plates for weaponry, they did produce a lot of different armoured doors of which no original plans seem to remain. Only the designation T- (which obviously stands for Tür: door) is known. They also designed armoured range finding and gun turrets which strongly resemble the architecture of battle ships or are directly taken from abandoned or discontinued ships.
Our Panzeratlas is the cumulation of years of work. However most of it is still field work and until original documents prove otherwise, we can't guarantee all the information to be 100% correct. We use the original German typology and designations. Move over the links to see the English translation.