Mahan_Stephen@lanmail.ncsc.navy.mil (01/24/91)
From: Mahan_Stephen@lanmail.ncsc.navy.mil
I studied the effects of EMP (Electromagnetic Pulse) a few years
ago as related to some work I was doing for the US Navy, and have a few
ideas to throw into the EMP thread.
EMP is not necessarily line of sight. Under certain circumstances (out
of atmosphere near earth blasts) there can be an area of high EMP
located about 1/4 circumference of the earth away from the blast.
The current version of the military standard guiding design of military
hardware for EMC (Electromagnetic Compatibility), MIL-STD-461C, has
provision for shielding from the effects of the EMP pulse and the
associated induced currents on input/output leads. All items which have
been designed and produced since this standard went into effect (about 5
years ago) and were REQUIRED TO MEET this standard should survive an EMP
event. Depending on the strength of the pulse (up to 100 kV/M), almost
every other electrical system would be toast.
During the early atomic tests after WWII there were incidences of
flourescent light bulbs exploding and even of cables being fused at
regular intervals due to the EMP of the blasts.
Disconnecting equipment is a good thing in theory but in practice the
lack of advance warning of a blast, especially for a device delivered by
stealth (smuggling, for example) would preclude such a solution.
Finally, completely unrelated, a knot is the abbreviation for a nautical
mile per hour, and as such is already a unit of velocity. A knot per
hour is an acceleration, and a low one at that. (flame off)
Stephen Mahan
Naval Coastal Systems Center
Panama City, FL 32407-5000
mahan_stephen@lanmail.ncsc.navy.mil