Canon de 32 modèle 1870/93

The Canon de 32 modèle 1870/93 à glissement was a French railway gun used by the French Army during World War I and World War II. Although the majority of combatants had heavy field artillery prior to the outbreak of the First World War, none had adequate numbers of heavy guns in service, nor had they foreseen the growing importance of heavy artillery once the Western Front stagnated and trench warfare set in. Since aircraft of the period were not yet capable of carrying large diameter bombs, the burden of delivering heavy firepower fell on the artillery. Two sources of heavy artillery suitable for conversion to field use were surplus coastal defense guns and naval guns. However, artillery designers of the time were faced with a paradox: while large caliber naval guns were common, large caliber land weapons were not due to their weight, complexity, and lack of mobility. Large caliber field guns often required extensive site preparation because the guns had to be broken down into multiple loads light enough to be towed by a horse team or the few traction engines of the time and then reassembled before use. Building a new gun could address the problem of disassembling, transporting and reassembling a large gun, but it did not necessarily address how to convert existing heavy weapons to make them more mobile. Rail transport proved to be the most practical solution because the problems of heavy weight, lack of mobility and reduced setup time were addressed. The Canon de 32 modèle 1870/93 à glissement started life as six Canon de 32C modèle 1870/93 coastal defense guns which were converted to railway guns. The guns were typical built-up guns of the period with mixed construction consisting of a rifled steel liner and several layers of iron reinforcing hoops. In French service guns of mixed steel/iron construction were designated in centimeters while all steel guns were designated in millimeters. However, reference materials don't always distinguish the difference in construction and use either unit of measurement.