Mark 53 VT Fuze - Microwave Encyclopedia

Mark 53 VT fuze

Updated March 5, 2006

Click here to go to our main page on microwave history

Click here to go to our page on radar

New for March 2006! The VT (variable time) fuze is widely regarded as second only to the Manhattan Project in terms of bringing technological advantage to the Allies in World War II. Before we get into this topic, and even though Microwaves101 is a politically incorrect web site, let's remind all engineers that no matter how "cool" weapon systems are, they regrettably cause loss of life, which is not always a good thing...

Here's a VT fuze that was for sale on EBay recently:

Guess what? The Unknown Editor has one of these puppies right in his living room (thanks to his Mom, who helped develop it!) which is autographed by some of the scientists that worked on it. Don't expect to see this one on Ebay! We'll post some photos of this hardware soon.

What's a fuze? Don't confuse the word with fuse... a fuse is an electrical safety device. A fuze is what is used to trip the warhead on a projectile or missile, so you can score a hit, even when the body of the weapon would have missed the target. Fuzes are used today on many a missile, of the "frag and shag" variety. However, more and more weapons are moving toward hit-to-kill, because you don't have to deal with a warhead, or for that matter, a fuze! But then there's the little problem of actually hitting the target...

Before the VT fuze was perfected, gunners had other tricks for hitting airborne targets, namely altimeter fuses. The German word fliegerabwehrkanonen, shortened to flak, was a formidable defense system that used barometric sensors to preset the altitude that shells exploded at, causing a 60 meter ring of death which had only a small chance of containing an aircraft. If the altitude was set too high, flak shells could pierce though a plane, and with luck and a change of underwear the plane could keep right on flying. The down side to this weapon system was the sheer amount of ordinance that you had to put into the sky. By 1944 millions of shells were expended each month, at a costs that exceeded the Eighth Air Force's Boeing B17 and other bombers that were taken out of action. Of course, firing that much stuff has the unintended effect of creating a target of opportunity for the Ninth Air Force, but that's another story (which you can buy here!)

Acht-Acht (88) Kanonen
bei der Arbeit!

Meanwhile, at Johns Hopkins University Applied Physics Laboratory in Baltimore, Maryland, worked proceeded for three and a half years to perfect the world's first radio sensor for munitions, the Mark 53 VT fuze. It's one thing to make a miniature Doppler radar out of vacuum tubes, it's quite another for the unit to work after firing it out of a cannon!

More history to come! In the mean time, here are some links on this topic:

http://www.jhuapl.edu/aboutapl/heritage/heritage.asp

http://www.history.navy.mil/faqs/faq96-1.htm

http://www.homestead.com/silverspringhistory/ww2.html

http://www.cantonrep.com/index.php?ID=187770

You are visitor number 3279 to this page.

All content copyright P-N Designs, Inc.