Laser Based Technique to Help Defuse Unexploded World War Bombs

Posted Apr 11, 2018 by Prerit Tomar

Laser Zentrum Hannover e.V. (LZH) together with LASER on Demand GmbH and Kampfmittelräumdienst Hamburg (KRD) is currently working on a laser-based bomb defusing project. The project, titled DEFLAG, is targeted towards providing a laser based solution for defusing unexploded bombs of the World War era, which still remain a serious threat in many parts of the world. At the Hannover Messe 2018 event from April 23 - 27, LZH will be showcasing processed bomb shells at the Pavilion of the State of Lower Saxony.

The challenges and dangers of conventional defusing methods are enormous and still highly topical: The amount of weapons hidden underground in Germany is difficult to predict, but according to KRD estimates, about 60,000 tons are still in the ground. During the defusing process there is an extremely high risk of unwanted detonation, especially in complex ignition systems. Often blowing up the dud remains as a last resort.

In the DEFLAG project, the project partners LZH and LASER on Demand are working on a procedure to defuse the bombs by targeted deflagration. In contrast to a detonation, a lower pressure wave is created during deflagration and the explosive is converted only to a small extent. The project partners notch the bomb casing with laser radiation and trigger the deflagration in a second step. In cooperation with the KRD, a field-compatible and automated processing platform is to be created – to safely defuse even dangerous unexploded bombs.

Essential for the project is not to exceed a critical temperature limit on the underside of the material, to drive out material from the ablation groove and to ensure process mobility. Scientists at the LZH have so far been able to notch up to 25 mm thick steel sheets using a combined melting and flame removal process. In doing so, they achieve an ablation depth of up to 16 mm with an external gas supply. At the Hannover Messe, they show processed bomb casings and material samples. The LZH will show this exhibit also at the LASYS in Stuttgart from June 5 - 7, 2018.

The DEFLAG project "Safe Deflagration of Duds by Laser Technology" is being funded by the German Federal Ministry of Education and Research within the scope of the Federal Administrations "Research for Civil Security 2012-2017" program. The fire department Hamburg / bomb disposal team is the Associated Partner.