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.
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