Sapper army
A Sapper Army (Russian: сапёрная армия) was a multi-brigade military construction engineer formation of the Engineer Troops (Soviet Union) of the Soviet Red Army during World War II. Formed to construct large-scale defensive works, sapper armies were used from late 1941 until mid-1942 when the Red Army opted to organize smaller and more flexible construction engineer formations. Although the organization of military construction engineers into an army-level echelon was unusual, the use of dedicated troops for military construction was common to many armies of World War II. == History == Reeling from the German invasion of 1941, the Soviets decided to organize large military construction engineer formations to construct defensive works on a massive scale.