Hazards of Electromagnetic Radiation to Ordnance (HERO)

in various activities within the electromagnetic environment. A discussion of the various methods used to detect electromagnetic energy is beyond the scope of this TRAMAN. However, we must emphasize the importance of remaining alert to the danger of overexposure to electromagnetic radiation. Radiation hazards can be broken down into three categories: � Hazards of Electromagnetic Radiation to Ordnance (HERO) � Hazards of Electromagnetic Radiation to Fuel (HERF) � Hazards of Electromagnetic Radiation to Personnel (HERP) We will discuss each of these categories in more detail in the following paragraphs. Hazards of Electromagnetic Radiation to Ordnance (HERO) The high intensity radio frequency (RFR) fields produced by modern radio and radar transmitting equipment can cause sensitive electroexplosive devices (EEDs) contained in ordnance systems to actuate prematurely. The Hazards of Electromagnetic Radiation to Ordnance (HERO) problem was first recognized in 1958. The prime factors causing the problem have been increasing ever since. The use of EEDs in ordnance systems has become essential. At the same time, the power output and frequency ranges of radio and radar transmitting equipment have also increased. RFR energy may enter an ordnance item through a hole or crack in its skin or through firing leads, wires, and so on. In general, ordnance systems that are susceptible to RFR energy are most susceptible during assembly, disassembly, loading, unloading, and handling in RFR electromagnetic fields. The most likely results of premature actuation are propellant ignition or reduction of reliability by dudding. Where out-of-line Safety and Arming (S + A) devices are used; the actuation of EEDs may be undetectable unless the item is disassembled. If the item does not contain an S + A device, or if RFR energy bypasses the S + A device, the warhead may detonate. Ordnance items susceptible to RFR can be assigned one of three HERO classifications, based upon the probability that they will be adversely a f f e c t e d b y t h e R F R e n v i r o n m e n t . T h o s e classifications are: 1. HERO Safe. An ordnance item sufficiently shielded or protected to make it immune to adverse effects from RFR when used in its expected shipboard RFR environments. 2. HERO susceptible. Ordnance containing EEDs proven by tests to be adversely affected by RFR energy to the point that safety or reliability may be in jeopardy when the ordnance is used in RFR environments. 3. HERO unsafe. Any electrically initiated ordnance item that becomes unsafe when: a. Its internal wiring is physically exposed. b. Tests being conducted on the item require additional electrical connections to be made. c. Electroexplosive devices (EEDs) having exposed wire leads are present, handled, or loaded. d. T h e i t e m i s b e i n g a s s e m b l e d o r disassembled. e. The item is in a disassembled condition. f. The item contains one or more EEDs and has not been classified as HERO safe or susceptible by either a test or design analysis. To ensure the HERO safety and HERO reliability of ordnance systems, the Naval Sea Systems Command sponsors an extensive testing program to determine their susceptibility to RFR energy. HERO requirements and precautions are provided in NAVSEA OP 3565/NAVAIR 16-1-529/NAVELEX 0967-LP-624-6010/Volume II, Electromagnetic Radiation Hazards (U) (Hazards to Ordnance) (U). You will find your ship’s specific requirements in its HERO Emission Control (EMCON) bill. The commanding officer of each ship or shore station is responsible for implementing HERO requirements. He or she must also establish a procedure to control radiation from radio and radar antennas among personnel handling ordnance and personnel controlling radio and radar transmitters. The commanding officer does this through a command instruction based on the ship’s mission and special features. This instruction is usually part of the Ship’s Organization Manual and is the basis for department and division instructions. 3-2