Log Pillbox

(DZOS), an enclosed field defensive earth-and-timber structure designed for machine guns, artillery guns, mortars, and other means of firepower; it protects the weapons and men from enemy fire. These pillboxes were used extensively in the Soviet-Finnish War (1939-40) and in the Great Patriotic War (1941-45) and became known as logged fire emplacements (DZOT). Light, reinforced, and heavy log pillboxes were built. Light pillboxes provided protection against bullets and shell fragments, reinforced pillboxes protected against direct hits by shells and mortars up to 80 mm and 50 kg aerial bombs, and heavy pillboxes protected against a direct hit by shells up to 155 mm and 100 kg aerial bombs. These pillboxes were built of logs, usually of double walls with the space between being filled with earth, stones, gravel, or other material. Embrasures were made in one or several walls for observation and for directing firepower in set sectors. The entrance was usually in the rear, with a covered, curving passage leading to it.