GB624771A - Method of blowing-up air raid shelters and the like buildings - Google Patents

Abstract

624,771. Demolishing buildings. JESPERSEN, A. H. C., and JESPERSON, P. KERRN-, (trading as JESPERSEN & SON, A.). April 11, 1946, Nos. 11177 and 11178. Convention dates, Nov. 7, 1945 and Dec. 20, 1945. [Class 68 (i)] In the demolition of an air-raid shelter or 'like building enclosing a relatively large cavity, an explosive charge is laid in the building, or in an enclosed space communicating with the interior of the building, and connected to a remote exploding means, apertures in the building are securely plugged, the building is filled with water so as effectively to submerge the charge, and the charge is fired to demolish the building to which the shock of the explosion is transmitted through the water. The water-filling hole may be a fresh one, or it may be left during plugging, and after firing it may be plugged or left open. The water may be charged with peat-dust, saw-dust or like materials which tend to choke any leakage cracks in the building. The charge may be enclosed in a vessel of expansible volume, e.g. a cylinder with a loose piston, the cylinder being completely immersed in the water or disposed partly outside the building to form an extension of the cavity. The cylinder may be directed downardly, it may be formed with one or more small gas-leakage apertures, and it may have a stop to limit the movement of this piston. The building may be covered in earth or sand before the charge is ignited. The Specification as open to inspection under Sect. 91 states also that the cavity may be empty of, or only partially filled with a liquid such as water, or i,t may be filled with combustible or explosive gas, such as oxy-hydrogen gas mixture or acetylene, which may be compressed before firing, and that the space enclosing the charge may be wholly outside the building. This subject-matter does not appear in the Specification as accepted.