Security door assembly.

摘要

A barrier structure particularly for use in protective doors designed to resist explosive charges applied to their outer surfaces, comprises a layer of timber 5 located between the outer and inner door plates 2 and 4. The purpose of the timber is to absorb the shock and thermal energy of an explosion occurring at or near the outer plate 2 and thus shield the rearward portion 4 of the structure from the damaging effects of the blast. Preferably the outer plate 2 is readily detachable from the remainder of the structure under the action of blast pressure transmitted to the interior of the structure, thereby permitting rapid dissipation of the blast and avoiding a concentration of pressure over a small area of the timber 5.