From: glhurst@onr.com (Gerald L. Hurst)
Newsgroups: alt.engr.explosives
Subject: Re: Way Cool Vortex Cannon
Date: 9 Nov 1996 05:02:54 GMT

In article <9611072033591.DLITE.dfready@delphi.com>, dfready@delphi.com
(Douglas Ready) says:

>I am planning to build an improved vortex
>cannon from a heavy wall stainless steel
>200 litre drum ( looks pretty much like
>a USA 55 gallon ).
>
>Has anybody ever done or seen anything like
>this and care to offer any suggestions?

I've made a few vortices with explosives, including small shots of
condensed HE in 55 gal drums.  I'd start with say 50 grams of 
whatever explosive in the middle of a stack (1 or more) of truck tires 
on the ground and go from there.  The well-formed smoke rings from 
such a shot move quickly at first then slow to a hover.  The smoky 
vortices are visually impressive and  make a characteristic. noise 
as they race upwards. Precision in the placement of the charge helps. 
The tires are reusable indefinitely.

BTW, an upright 55 gal mild steel drum will tolerate 5 grams of  
explosive (C-4) stood off from near the center of the base but the 
bulging is pronounced.  

The tire method is cleaner and lets you use a lot more oomph.  I 
have not used low explosives for such shots but I can think of 
no reason why they would not work.

Jerry (Ico)