Röchling shell

Röchling shells were bunker-busting artillery shells, developed by German engineer August Coenders during World War II, based on the theory of increasing the sectional density to improve penetration.

[2] They resembled fin-stabilized arrow shells, but had a discarding flange acting as a driving band instead of fins.

They were regarded as a German secret weapon, and there is speculation that their use was limited in order to reduce the chance of dud shells being recovered and exploited by the Allied forces.

[12] Preserved small-size fin-stabilized prototype of Röchling shell (36 cm long) is since 2020 exhibited in the Museum of Czechoslovakian fortifications,[13] inside the fort Hůrka [cs].

Remnants of full-sized test shells are still visible in the walls of the fort.

Turret of the Fort Maxim Gorky, near Sevastopol, against which Röchling shells were used
The picture shows the ceiling of a tunnel inside Fort d'Aubin-Neufchâteau. The concrete and steel shown at the ceiling is completely bent.
Impact of a Röchling shell that hit Fort d'Aubin-Neufchâteau. Picture is taken around 20m underground.