The de Bange 155 mm long cannon mle. 1877 was the French artillery piece that debuted the 155 mm caliber in widespread use today. Although obsolete by the beginning of World War I, the 155 L was nonetheless pressed into service and became the main counter-battery piece of the French army in the first two years of the war.
155 K 77 cannon at Salpa Line Museum, Miehikkälä, Finland
overview
breech
A 155 L pulled into position at the Pontarlier artillery school, 1905-1910
Charles Ragon de Bange was a French artillery officer and Polytechnician. He invented the first effective obturator system for breech-loading artillery, which remains in use. He also designed a system of field guns of various calibers which served the French Army well into World War I: the Système de Bange.
Cannon breech with de Bange system.
DeBange breech, function of the obturating ring
Detail of the de Bange mechanism on a 155 mm de Bange siege cannon.
De Bange obturator mechanism on the de Bange 90 mm field cannon.