machinery and radar antennas; and the cracking of
seams above and below the waterline.
Damage from Underwater Shock
The pressure pulse created in water by an explosion
on or below the surface is called an underwater shock. It
travels much faster than an air blast and can inflict
damage to ships at a distance of several miles. Possible
effects include damage to the hull, heavy machinery,
gun mounts, and electronics systems.
Damage from Water Waves
An underwater nuclear burst may result in waves
over a hundred feet in height, but water waves are
seldom the primary source of ship damage. The impact
o f wa t e r wave s m a y c a u s e d i s t o r t i o n o f t h e
superstructure, carry away deck gear, or flood through
damaged weather doors.
Damage to Ships Tactical Systems
Nuclear detonation can cause considerable damage
to tactical systems, including electrical and electronic
systems, sonar, radar and communications. Such
damage can be a result of an electromagnetic pulse
(EMP), transient radiation effects on electronics,
blueout, or blackout.
ELECTROMAGNETIC PULSE (EMP).—
Shipboard damage occurs when metal conductors, such
as electrical cables, antennas, and sensors, absorb EMP.
Computers and other equipment using solid-state
components are most vulnerable to EMP. Vacuum-tube
equipment is less susceptible. Personnel aren’t directly
injured by EMP, but they may suffer electrical shock if
they are in contact with a large conductor of electrical
energy.
Preventive measures to protect or h a rd e n
equipment against damage by EMP include metal
shielding, good grounding, use of surge arresters, and
the proper arrangement of electrical wiring.
TRANSIENT RADIATION EFFECTS ON
E L E C T RO N I C S ( T R E E ) . — T R E E o c c u r s i n
electronics systems as a result of exposure to gamma or
neutron radiation. The actual effects are determined by
the characteristics of the circuits in the electronics
package, the components in the circuits, and the
construction techniques and materials used to make the
components. In general, radios, radar, computers,
cables and wiring, and inertial guidance systems are
susceptible to TREE. The response of such systems to
radiation depends on the nature of the radiation and on
the specific components and operating status of the
systems.
B L U E O U T . — B l u e o u t i s t h e p r o l o n g e d
disturbance of an underwater nuclear detonation and is
caused by ocean basin shock reverberations that
interfere with passive sonar systems. The noise
resulting from the initial nuclear weapon detonation
(the interaction of steam and water and the pulsations of
the steam bubble) masks out all other sound for a short
period of time making it impossible for sonar operators
to listen for target data. The effects of blueout are
temporary.
B L AC KO U T . — B l a c k o u t , c a u s e d b y a n
atmospheric nuclear explosion, is the interference of
radio transmissions through ion fields formed in a
detonation. In a tactical situation, straight-line
communications (radar and radio transmissions)
between ships on opposite sides of the fireball will be
lost. Following a high altitude detonation, satellite
communications may be affected or lost. Blackout
alters or inhibits radar or radio waves and affects all
frequency bands.
Procedures to counteract the effects of blackout
include providing alternate paths for communications,
shifting radio operating frequencies, changing
transmission modes, and waiting for blackout effects to
diminish.
REVIEW 3 QUESTIONS
Q1. List the four types of nuclear weapon explosion
classification.
a.
b.
c.
d.
13-12
Student Notes:
