Assault Engineering Brigades were designed to storm settlements and to break through heavily fortified enemy lines. Assault brigades were sent into battle to facilitate key breakthroughs in fortified defensive lines by means of combat engineering and sapping. Success in battle hinged on close coordination with infantry, armoured, mechanised, and artillery units. As soldiers of the assault brigades were not equipped with heavy small arms or their own artillery, they were immediately withdrawn after a successful breakthrough in the enemy lines to limit casualties. The most distinctive piece of individual equipment used by soldiers of the assault engineering brigades was the SN-42 steel breastplate.