Analyzing Functionality of Landmines and Clearance Depth as a Tool to Define Clearance Methodology

During World War II (1939–1945), German forces placed approximately 1.4 million landmines along the Danish west coast as part of the West Atlantic Wall. After the war, manual clearance and the use of tanks with rollers operated by former German soldiers under Danish and British command removed the majority of these mines. While the boundary of each minefield was known in the area of Skallingen, the mines were randomly placed within each minefield. Thus, total clearance of the area and the remaining 72,000 mines was impossible. During the next 65 years, dynamic changes in the environment, including erosion, moved or rendered many of the mines inoperable, changing their depth and condition. In 1999, Denmark signed the Convention on the Prohibition of the Use, Stockpiling, Production and Transfer of Anti-personnel Mines and on Their Destruction (Anti-personnel Mine Ban Convention or APMBC). Clearance of the anticipated 10,000 remaining mines began in 2006. Since then, clearance has been carried out in three phases; the last phase ended in June 2012. During and after the first two phases, a number of Technical and Non-technical Surveys (TS, NTS) were completed to further determine the characteristics of the minefields. In particular, the current depth and condition of remaining mines were investigated. These investigations showed that Skallingen mines in contact with salt water for more than three years do not work as originally intended. This is due to the alteration of explosives in the detonators and the corrosion of metal in the fuzes. A three-dimensional (3-D) digital-terrain model of the 1945 surface also determined the recommended clearance depth to avoid clearance of unnecessary quantities of soil. These relatively inexpensive analyses at Skallingen resulted in the use of different clearance techniques to target each specific threat in the different geomorphologic terrain types. With the resulting information, the clearance operation was accomplished in a shorter time and at a lower cost. Clearance was also more environmentally friendly, for example, avoiding damage to sensitive marsh and beach areas by preventing unnecessary heavy machinery from entering the areas. Similar analysis of mines and soil composition in other mined areas could result in a more flexible approach to the clearance work and may reduce cost and risk.