The Maginot Line - A misunderstood history

Cupola GFM Model 1934, type B

Observation/machinegun cupola

In 1934, a new type of cupola was adopted. Just like the A type, it had 3 to 5 embrasures. It had slightly thicker armour and most importantly, much better protected mounts. These ball mounts were integrated into the embrasures and were capable of resisting a 25mm hit when in use, and could withstand a 47mm hit when closed/with it’s opening turned away.
The embrasures had a conical shape, able to withstand heavier impacts, this in contrast with the A types.

Height Outer ø Armour Weight
Small model
2.17 m 1.78 m 0.25 m 17t
Large model
2.55 m 1.88 m 0.30 m 27,0 t
Base for GM 0.67 m     2,5t
Base for PM
0.67 m     4,5t

The installed equipment was limited to a FM 24/29 or a diascope.

Two models were produced, the PM and GM model. The PM was meant to be used on fortifications with protection level 1 and 2 (refers to concrete thickness), and the GM on protection level 3 or 4 fortifications.