Path: utzoo!utgpu!watserv1!watmath!att!cbnews!military
From: jeff@aplcomm.jhuapl.edu (JEFF NANIS )
Newsgroups: sci.military
Subject: Re: VT rounds
Summary: Proximity fuzes
Keywords: JHU/APL, VT
Message-ID: <15598@cbnews.ATT.COM>
Date: 14 Apr 90 04:12:08 GMT
References: <15516@cbnews.ATT.COM>
Sender: military@cbnews.ATT.COM
Organization: JHU/APL, Laurel, MD
Lines: 31
Approved: military@att.att.com



From: jeff@aplcomm.jhuapl.edu (JEFF NANIS )

In article <15516@cbnews.ATT.COM> nelson_p@apollo.com writes:

>   Forgive me if this is a stupid question:  I was reading
>   a book on the battles in the area of Pork Chop Hill in
>   the Korean War and I saw frequent references to an artillery
>   round called a VT round.  From context it appeared to 
>   be some kind of antipersonnel, proximity-fused round.
>   What is it exactly and what does VT stand for?

	The proximity fuze was developed (as opposed to being invented -
the Brits though of it and told us) in 1942 by the place where I work,
the Johns Hopkins Applied Physics Laboratory. It basically involved mini-
aturizing a radar and putting it in the nose of an artillery shell, 
enabling the shell to explode when it reached a pre-set distance from
ground or target. It was called VT for Variable Time - a decptive ruse for
security, to make it sound as if there was just a fancy timer inside, 
instead of a whole CW radar.

	The Battle of the Bulge was the first use of VT in ground combat. 
It had been used earlier, with great effect, at sea, in 5" shells, decimating
Japanese air raids and kamikaze attacks. Its use was delayed over land by
concern of dud rounds being captured and exploited by the Germans. 

--
Jeff Nanis			"You can't send me out there,		
jeff@aplcomm.jhuapl.edu 	 I'm an analyst, not a field agent!"
	Not an official opinion which might get me put in jail.