major@beaver.cs.washington.edu (Mike Schmitt) (03/27/89)
From: ssc-vax!shuksan!major@beaver.cs.washington.edu (Mike Schmitt) > > I've read stories about a ten ton (??) bomb being used in Vietnam. > > Supposedly it was pancake shaped and had to be drop out (using rollers > > and a drogue 'chute) of the back of a C-130 Hercules. They were used > > to make instant Landing Zones for helos. Plus I think that one was used > > to destroy a bridge. Does anybody have anything more substantial on this? > > Also, were these "pancake bombs" the largest (in terms of weight) > > conventional bombs ever dropped in wartime? Are these the 'daisy cutters' that made the LZs? They weren't THAT good. It left 3-4 foot high tree stumps all over the LZ - which meant the assault helos had to hover over them while the troops exited. Carrying a 50lb rucksack - that hurts! > The C-130 bomb weighed 15,000 lbs. It was a gas bomb ie it allowed propane, I 'heard' (ie totally unsubstantiated) that this 'propane' bomb created a very distinct 'mushroom shape' cloud - and that the Air Force was told not to use it anymore in Vietnam - for obvious reasons. (can anyone clarify this?) major
howard@cos.com (Howard C. Berkowitz) (03/28/89)
From: howard@cos.com (Howard C. Berkowitz) In article <5144@cbnews.ATT.COM>, ssc-vax!shuksan!major@beaver.cs.washington.edu (Mike Schmitt) writes: > > > From: ssc-vax!shuksan!major@beaver.cs.washington.edu (Mike Schmitt) > > > > > I've read stories about a ten ton (??) bomb being used in Vietnam. > > Are these the 'daisy cutters' that made the LZs? They weren't THAT > good. It left 3-4 foot high tree stumps all over the LZ - which meant > the assault helos had to hover over them while the troops exited. > Carrying a 50lb rucksack - that hurts! > > > The C-130 bomb weighed 15,000 lbs. It was a gas bomb ie it allowed propane, > I think the bombs we are discussing are fuel-air explosives, sometimes implemented as a single canister and more often as cluster munitions. They use ethylene oxide, not propane; their delivery height and such is relatively critical, because the gas cloud must form and have the proper fuel-air ratio before a separate igniter actuates -- these do not have a single burster charge! If anyone has the Fort Bragg Student Text on special forces techniques, it will show a field expedient version of a fuel-air explosive, involving a small burster charge scattering gasoline, _flour_, etc., and then firing a secondary incendiary charge to ignite the fuel. In _Red October_. Tom Clancy uses fuel-air explosives to get extremely high explosive yield within a (no spoilers) relatively confined space. He called the weapons Pave Pat Blue, which may be correct; memory does not serve. I consider his example highly unlikely, since it would be quite difficult to get the necessary air-gas ratio in a constricted area with obstructions -- these bombs are meant to form an airburst! > > I 'heard' (ie totally unsubstantiated) that this 'propane' bomb created > a very distinct 'mushroom shape' cloud - and that the Air Force was > told not to use it anymore in Vietnam - for obvious reasons. > (can anyone clarify this?) Virtually any large explosion creates a mushroom cloud -- see pictures of ammunition ship explosions such as Texas City and Halifax. -- howard@cos.com OR {uunet, decuac, sun!sundc, hadron, hqda-ai}!cos!howard (703) 883-2812 [W] (703) 998-5017 [H] DISCLAIMER: Opinions expressed are not necessarily those of the Corporation for Open Systems, its members, or any standards body.
cmr@cvedc.UUCP (Chesley Reyburn) (03/29/89)
From: cmr@cvedc.UUCP (Chesley Reyburn) >From: "ross paul weiner" <esco@tank.uchicago.edu> > stuff deleted I remember seeing a short article on this in Life magazine while I was 'defending' Germany in 1968. They called it the 'cheeseburger' bomb because (they said) of what it did to the impact area. There was also a picture of one of the impact areas. It sort of looked like a cheeseburger in black and white. The center was dark and there was a white area around the dark part. Don't remember what kind of explosive was used. I do remember that it was on a pallet with a cargo chute and rode in a Hercules. ============================================================= Chesley Reyburn ...tektronix!ogccse!cvedc!cmr ECAE Software, Prime Computers, Inc. ...sun!cvbnet!cvedc!cmr 14952 NW Greenbrier Parkway ...sequent!cvedc!cmr Beaverton, Oregon 97006 Phone 503/645-2410 =============================================================
henry@zoo.toronto.edu (Henry Spencer) (03/29/89)
From: henry@zoo.toronto.edu (Henry Spencer) > I 'heard' (ie totally unsubstantiated) that this 'propane' bomb created > a very distinct 'mushroom shape' cloud - and that the Air Force was > told not to use it anymore in Vietnam - for obvious reasons. I can't answer on the latter part, but any big, hot explosion near ground level will create a mushroom cloud. The hot fireball tends to rise, being lighter than air. Air drag and cooling due to mixing will slow it, but mostly around its periphery. This tends to reshape it into a doughnut- shaped vortex, with the internal circulation moving down on the outside and up on the inside. The rise of the fireball plus the extra upward motion at its center pulls the stalk of smoke and debris upward beneath it. Large charges of conventional explosives will give a small, brief mushroom cloud. It's entirely believable that fuel-air explosions would too. Henry Spencer at U of Toronto Zoology uunet!attcan!utzoo!henry henry@zoo.toronto.edu
maniac%garnet.Berkeley.EDU@ (George W. Herbert) (03/31/89)
From: maniac%garnet.Berkeley.EDU@ (George W. Herbert) In article <5169@cbnews.ATT.COM> howard@cos.com (Howard C. Berkowitz) writes: > I think the bombs we are discussing are fuel-air explosives, sometimes > implemented as a single canister and more often as cluster munitions. > They use ethylene oxide, not propane; their delivery height and such > is relatively critical, because the gas cloud must form and have the > proper fuel-air ratio before a separate igniter actuates -- these > do not have a single burster charge! > > In _Red October_. Tom Clancy uses fuel-air explosives to get extremely > high explosive yield within a (no spoilers) relatively confined > space. He called the weapons Pave Pat Blue, which may be correct; > memory does not serve. I consider his example highly unlikely, > since it would be quite difficult to get the necessary air-gas ratio > in a constricted area with obstructions -- these bombs are meant > to form an airburst! It is a) possible and b) easy to make FAE's with built in oxygen. The Ethelyene O2 you refer to is a sign of such developments. Such bombs need not get _any_ mixing w/atmos, and can be detonated more reliably as a result. Besides, a sub that's 32 feet in diameter and 600 feet long has (roughly) a half-million cubic feet of air inside (A little high, but the exact math is not critical :) and will provide lots of oxygen if you use propane. george william herbert maniac@garnet.berkeley.edu ps-this is a little off the subject, but does anyone out there have performance info or experience with LOX-based explosives? I have problems finding any, and a combination of administrative paranioa and some slight regard for own health prevents me from experimenting.
silber@p.cs.uiuc.edu (04/03/89)
From: silber@p.cs.uiuc.edu >Large charges of conventional explosives will give a small, brief mushroom >cloud. It's entirely believable that fuel-air explosions would too. They don't even have to be that large, just fairly hot. Some of the f/x explosives they use produce nice little mushrooms about 6' high. (Oddly enough, the best example I've seen of this was on the Monty Python epsiode about "the importance of not being seen", a major tenent of modern tactics.) ami silberman
howard@cos.com (Howard C. Berkowitz) (04/05/89)
From: howard@cos.com (Howard C. Berkowitz) In article <5272@cbnews.ATT.COM>, maniac%garnet.Berkeley.EDU@ (George W. Herbert) writes: > In article <5169@cbnews.ATT.COM> howard@cos.com (Howard C. Berkowitz) writes: > > I think the bombs we are discussing are fuel-air explosives, sometimes > > implemented as a single canister and more often as cluster munitions. > > They use ethylene oxide, not propane; their delivery height and such > > is relatively critical, because the gas cloud must form and have the > > proper fuel-air ratio before a separate igniter actuates -- these > > do not have a single burster charge! > > It is > a) possible and > b) easy > to make FAE's with built in oxygen. The Ethelyene O2 you refer to is a sign > of such developments. Such bombs need not get _any_ mixing w/atmos, and can > be detonated more reliably as a result. There seems to have been some misreading here. Ethylene, ethylene oxide, propane and acetylene (discussed later) are different molecules: ---O--- | | - CH2=CH2 CH2 CH2 CH3-CH2-CH3 CH=CH Ethylene Ethylene oxide Propane Acetylene I don't have all the chemical reference books I once had, but some information will help. In general, in constructing a bomb, one wants the most energetic compounds available which will not explode prematurely. Single carbon-carbon bonds ( - above) are more stable than double (=), which are more stable than the triple bond in acetylene (see typographical nightmare above). "Bridging" oxygen bonds, as seen in ethylene oxide, ethers, etc., are releatively unstable. Acetylene, for example, is highly energetic and unstable; it can detonate (while under at least 2 atmospheres pressure) without additional oxygen. I believe acetylene is far too unstable to make a practical military explosive; it's better than nitroglycerine but that's about all I can say given an acetylene tank might very well take a shock from the Bad Guys. To give a comparison, the Merck Index give the explosive concentration range of acetylene as 3-65% fuel to oxygen. By contrast, the explosive range of propane is 2.37-9.5%. Extrapolating from their molecular structure, I would assume ethylene and ethylene oxide are less stable than propane but more so than acetylene. I would not expect either ethylene or acetylene oxide to explode without forming an optimal fuel-oxygen mixture. Looking at the propane range above, one needs, at best, approximately 9 times as much oxygen as fuel. This would massively increase the bomb size if the oxygen were carried internally. Even if it were, the cloud would still have to form. Where does the cloud form? In air... > > > > In _Red October_. Tom Clancy uses fuel-air explosives to get extremely > > high explosive yield within a (no spoilers) relatively confined > > space. He called the weapons Pave Pat Blue, which may be correct; > > memory does not serve. I consider his example highly unlikely, > > since it would be quite difficult to get the necessary air-gas ratio > > in a constricted area with obstructions -- these bombs are meant > > to form an airburst! > Besides, a sub that's 32 feet in diameter and 600 feet long has (roughly) > a half-million cubic feet of air inside (A little high, but the exact math > is not critical :) and will provide lots of oxygen if you use propane. ^^^^^^^ see figures above; it is fairly critical. > > ps-this is a little off the subject, but does anyone out there have performance > info or experience with LOX-based explosives? I have problems finding any, and > a combination of administrative paranioa and some slight regard for own health > prevents me from experimenting. In _Secret Weapons of World War II_, often quoted here, I believe there is some discussion of LOX and fuel oil on harbors; it fizzled. There may also be a general reference in Stanley Lovell's book on Office of Strategic Services (OSS) R&D; I believe it is titled _Of Spies and Strategems_. As I remember, no one could get consistent explosions. -- howard@cos.com OR {uunet, decuac, sun!sundc, hadron, hqda-ai}!cos!howard (703) 883-2812 [W] (703) 998-5017 [H] DISCLAIMER: Opinions expressed are not necessarily those of the Corporation for Open Systems, its members, or any standards body.