<P> Bomb disposal officers often wear heavy armor designed to protect against most effects of a moderate sized explosion, such as bombs encountered in terror threats . Full head helmet, covering the face and some degree of protection for limbs is mandatory in addition to very strong armor for the torso . An insert to protect the spine is usually applied to the back, in case an explosion blasts the wearer . Visibility and mobility of the wearer is severely limited, as is the time that can be spent working on the device . Armor designed primarily to counter explosives is often somewhat less effective against bullets than armor designed for that purpose . The sheer mass of most bomb disposal armor usually provides some protection, and bullet - specific trauma plates are compatible with some bomb disposal suits . Bomb disposal technicians try to accomplish their task if possible using remote methods (e.g., robots, line and pulleys). Actually laying hands on a bomb is only done in an extremely life - threatening situation, where the hazards to people and critical structures cannot be lessened by using wheeled robots or other techniques . </P> <P> In the mid-1980s the state of California Department of Corrections issued a requirement for a body armor using a commercial ice pick as the test penetrator . The test method attempted to simulate the capacity of a human attacker to deliver impact energy with their upper body . As was later shown by the work of the former British PSDB, this test over stated the capacity of human attackers . The test used a drop mass or sabot that carried the ice pick . Using gravitational force, the height of the drop mass above the vest was proportional to the impact energy . This test specified 109 joules (81 ft lb) of energy and a 7.3 kg (16 lb) drop mass with a drop height of 153 cm (60 in). </P> <P> The ice pick has a 4 mm (0.16 in) diameter with a sharp tip with a 5.4 m / s (17 ft / s) terminal velocity in the test . The California standard did not include knife or cutting edge weapons in the test protocol . The test method used the oil / clay (Roma Plastilena) tissue simulant as a test backing . In this early phase only titanium and steel plate offerings were successful in addressing this requirement . Point Blank developed the first ice pick certified offerings for CA Department of Corrections in shaped titanium sheet metal . Vests of this type are still in service in US corrections facilities as of 2008 . </P> <P> Beginning in the early 1990s, an optional test method was approved by California which permitted the use of 10% ballistic gelatin as a replacement for Roma clay . The transition from hard, dense clay - based Roma to soft low - density gelatin allowed all textile solutions to meet this attack energy requirement . Soft all textile "ice pick" vests began to be adopted by California and other US states as a result of this migration in the test methods . It is important for users to understand that the smooth, round tip of the ice pick does not cut fiber on impact and this permits the use of textile based vests for this application . </P>

When did the us military start using body armor