Wrecking an outmolded, inadequate bridge or blowing up a reinforced concrete warehouse to carve a path for a new freeway is quite similiar to wartime demoltion of a bridge vital to enemy supply lines or the blasting of a weapons supply center. Consequently, recent studies at Stanford Research Institute, Menlo Park, California, primarily directed toward leaning more about high-explosives phenomena to aid military operations, have resulted in information with considerable potential value for civilian wrecking operations related to problems of highway realignment and urban rebuilding and redevelopment. Blasting concrete for military or civilian purposes usually involves the breaching of walls, the breaking up of foundation piers or beams, or the complete destruction of obstacles. And explosive "pancake" provides the best result for breaching walls. Thus a 20 pound TNT charge, 16 inches square and one and three-fourths inches thick, will demolish a wall 3 feet thick, 5 feet high, and 9 feet long. Longer walls require additional charges of similiar weight and shape. Data obtained from the study indicate that greater explosive blocks rectangular in form sas compared with th epresent Army standard square block. For example, a charge 1 by 2 by 12 inches will cut a 12 inch square steel plate as efficiently as a standard block 2 by 2 by 11 inches in size. Less explosive is thus required to cut structural steel plate, girders, pipes, and rods. The suggested dimensions also simply the calculation of charge weights by putting it on a pounds per foot basis.