Volume 31, Issue 2 (April 1986)
The Breaking of Tempered Glass Vehicle Windows Using Broken Spark Plug Insulators
A novel and efficient method for forced entry into vehicles using broken spark plug insulators to break the windows was reviewed. Various experiments were performed in which a number of objects, varying in their physical characteristics, were compared to the broken ceramic plus insulators in order to examine the uniqueness of the latter in the breaking of tempered glass. A plausible mechanism was presented attributing the great efficiency of the insulators to their hardness in relation to other materials (MOHS scale), and to their potential for the concentration of force in one point because of the sharp, jagged ends.