You aren’t relying on the device creating sufficient heat - frankly it won’t. It will however create sufficient heat to set fire to a very large area, which when combined with the right atmospheric conditions will create a firestorm. Certainly from photos of Hiroshima and Nagasaki it would appear that everything capable of burning close to Ground Zero has done so - note the way that a number of masonry buildings appear pretty much intact, so the flattening of the area was not done by blast. Whether that technically qualifies as a firestorm or not I don’t know, but the effects can’t have been all that dissimilar.
There’s no question that almost all the combustible structures near the hypocenter of both the Hiroshima and Nagasaki atomic bomb attacks were completely destroyed by blast and heat. There is also no question but that an atomic explosion can create a firestorm under certain conditions, but neither of the two atomic bombs dropped on Japan were sufficient to create a firestorm.
The definition of a firestorm is; “A large usually stationary fire characterized by very high temperatures in which the central column of rising heated air induces strong inward winds which supply oxygen to the fire”
The crucial element of a firestorm are the very strong (some definitions state 'hurricane force") winds which develop and feed oxygen and more combustible material into the central fire.
The bombing of Dresden created a true firestorm, as did the 9-10 March, 1945, incendiary bombing of Tokyo. Witnesses in both cases described very strong winds created by the fires which sucked small vehicles, trees, roofs, and other items into the fire, along with people and animals. These are the only two instances of which I am aware, of true firestorms, although it’s entirely possible that the incendiary bombing campaign carried out by the US XXI Air Force against Japanese cities in 1945, may have created others.
Have already read the comment, but read it again at your suggestion.
I assume you stand by your original statement that a nuclear explosion “doesn’t suck much (any) oxygen out of the air”?
Since neither of the nuclear explosions over Japan in 1945 appear to have started a firestorm, it seems to me the prospect of a nuclear explosion killing or incapacitating defenders in underground defenses through oxygen depletion would have to be very slight.
Question; has any atmospheric nuclear explosion anywhere in the world, under any circumstances, been known to have created a firestorm?
Correct. A nuclear initiation essentially consists of a very small ball of incredibly hot gas. The soft X-rays given off by this ball superheat a larger volume of air (the fireball), with the thermal pulse and blast effects coming from this fireball. There will be a small amount of Oxygen within the fireball reacting with Nitrogen in the atmosphere (one of the original concerns in the Manhattan project was that the atmosphere would catch fire as a result), but that’s about the only actual oxygen consumed by the device itself. Hence the “much (any)” comment - some will be consumed, but it’s an insignificant amount. The blast and thermal pulse however will replicate much of the destruction caused by the RAF fire raids of WW2.
I’m pretty sure there won’t have been any firestorms as a result of nuclear initiations anywhere in the world - Hiroshima and Nagasaki are the only candidates as the atmospheric nuclear tests which have taken place were all AFAIK situated to minimise what could catch fire in order to reduce fallout.
Well, I suspect then that the answer is no, no atomic explosions have ever initiated true firestorms.
I have seen references to a “firestorm” occurring at Hiroshima, but I believe this is a loose application of the term; the description is too brief and only mentions a “whirlwind” associated with the blaze triggered by the blast. There is no mention of the very strong winds accompanying a true firestorm, nor of oxygen or other combustible materials being sucked into the fire. It appears that both Hiroshima and Nagasaki experienced fires of severe intensity, but of too brief a duration to generate the conditions for a true firestorm.
I have reviewed all of the accounts in my possession of the Nagasaki atom bomb explosion, and none of them seem to mention anything other than a large conflagration triggered by the blast. No mention of very strong winds or materials being sucked into the fire is made.
Do you have a source that indicates gas would be introduced into the underground fortifications by use of artillery shells? Or are you just surmising that would be the method? It doesn’t seem to be a very effective way of using poison gas. On Iwo Jima, I believe, the plan was to lay down a gas barrage on the surface of the island, and then land specially trained troops who would pump gas into the fortifications through the ventilation openings. The Japanese would counter, of course, with gas masks and protective clothing, which probably would become less effective as the gas concentration became increased with time.
Wizard,
In WW1 shells were THE main way gas was used. Yes it was also released by canister so prevailing winds would carry it over the enemy lines but that depends on the winds.
If you have watched the PBS documentary, The American Experience Victory in the Pacific
Yes, I’m aware that artillery barrages were the primary method of releasing gas on enemy lines during WW I. However, the enemy generally wasn’t dug into caves and underground bunkers during WW I, and it just seemed to me that firing a gas shell into a cave entrance wouldn’t be a very efficient way of delivering the large quantities of gas that would be required to saturate the many tunnels and deep chambers typically found in Japanese defensive fortifications.
Wind and other meteorological conditions are always of concern when using poison gas, no matter what the delivery method. During WW I there were several occasions when changing winds blew the poison gas back in the faces of those who had released. Rain, winds, temperature, humidity, even clouds and sun can all have unpredictable effects when using poison gas.
On Iwo Jima and Okinawa, the Americans sometimes pumped gasoline into the ventilation shafts of recalcitrant enemy fortifications and then ignited it with WP grenades. This seems like a much better way of delivering poison gas, as well, especially if the fortifications are very extensive.
In any case, I was just curious if there were any concrete pl;ans or if any American troops had been trained in any tactics applicable to the delivery of poison gas, in anticipation of the Kyushu landings.
Thanks for the links, I had not seen these documentaries.
Agreed. However, I would suggest that the duration of the fire is a function of the nature of the target rather than the nature of the bomb - the incendiaries dropped on Dresden or Tokyo typically had a pretty short duration burn too. However, there is one possibility that is bomb-related - and that is the amount of blast damage created. When trying to create a firestorm, the RAF would typically drop large HE bombs first to break open roofs, etc. to let the incendiaries in, whereas completely flattening an area will create a firebreak. It is possible that the way a nuclear device works (thermal pulse first, then blast) may have a similar effect in damping down a fire. So much depends on device size and distance from the initiation point however - blast and thermal effects do not drop off in the same way with distance.
I concur, and yes, the duration of the fire would normally more to do with the nature of the target than the type of bomb employed. I did not suggest otherwise. On that topic, it’s informative to note that during the Tokyo incendiary bombing of 9-10 August, the bomber stream was not one big formation, but rather a long line of bombers that, in effect, kept adding incendiary bombs to the fire over a period of several hours. The planners of the Tokyo bombing did add some high explosive GP bombs to the bomb loads, in order, I presume, to break up and scatter combustible material and possibly, to deter fire fighting personnel.
I’d be curious as to whether that was down to logistical concerns (e.g. airfield restrictions) or deliberate design. The RAF usually tried to get very concentrated raids over the target, although that may have been more to do with overwhelming the German nightfighter defence - not a problem the USAAF faced over Japan!
U.S.A.A.F. B-29 bombers were flying much lower and stripped of much of their armament than their European counterparts as the Jet Stream made high altitude bombing far more difficult IIRC. Perhaps the need for concentration over the target was mitigated by the increased accuracy and low levels?
The reason the 9-10 August Tokyo incendiary raid did not feature compact formations of B-29’s had to do with many factors.
As PDF27 points out there were no significant numbers of night fighters over Tokyo and the few that were there, were ineffective, therefore there was no need for tight formations to concentrate defensive firepower. In fact, General LeMay ordered the B-29’s that participated stripped of most defensive armament so they could carry more bombs.
Normally, when conducting high altitude bombing missions using high explosive bombs, the B-29’s used very compact formations to concentrate the bomb patterns and increase the number of bombs on, or near, the target. In order to achieve these compact formations with large numbers of aircraft, the first bombers to take off would circle at a rendezvous point while the later bombers joined up, and the formation was completed. This required an extra margin of fuel which meant the B-29’s had to carry smaller bomb loads. For the Incendiary raids, LeMay deleted the extra fuel margin in favor of heavier loads of incendiaries, thus the bombers simply took off and headed for the target without formating. Tight bomb patterns were not required due to the very low bombing altitudes (7,000 to 14,000 feet) of the incendiary raids. The main bomber stream was proceeded by “pathfinder” planes which dumped their flares and incendiary bomb loads in an “X” pattern. Succeeding bombers simply bombed into the heart of the growing fires.
North Field on Tinian, from whence most of the B-29 raids originated, was, in August, 1945, the largest air field in the world with four identical runways which could accommodate large numbers of aircraft taking off, but it still could not launch enough aircraft to obviate the need for the aircraft to rendezvous, if tight formations were required.
Well guys, I’m sure the RAF could have got 1000 Lancasters to pattern bomb the invasion beaches with Grand Slams. Now THAT would have taken care of the caves!
In fact, I wish at Iwo Jima they had done just that using B-29s to carry the Grand Slams and maybe have stopped alot of them from using the caves.
Happly, the Japanese surrendered and we didn’t have to try moving soldiers over radioactive ground or firing mustard gas shells into caves (for you see that is how they would have delivered the gas, with shells.)
Did the RAF have that many Grand Slam bombs in stock? What base would the Lancasters have flown from? Could they have been sure of even hitting the underground fortifications? And even if they did, just how effective would such bombs have been against underground fortifications? And just what effect would giant craters all over the invasion beaches have had on the Allied troops, tanks, and other vehicles which would have had to traverse them?
No offense, but I’d like to hear from some experts who actually knew the what kind of performance to expect from the Grand Slam bombs, and the other factors I’ve questioned, so could you please cite some authoritative sources?
He’s been banned as a spammer anyway, but for your actual point…
The effects of a bomb (overpressure, blast, etc.) decline with the cube of the distance from the bomb to the target. Double the distance, you have an eighth of the effect. Hence, doubling the size of the bomb only gives a 25% increase in useful area - which is why big bombs are only used against either extremely hard targets (railway viaducts, the V-3 site, etc.) or where damage needs to be kept very concentrated (the blockbusters dropped during the RAF fire raids - removing the roofs in a large, continuous area was more effective at getting a big enough fire started than smaller, spaced-out bombs).
The other point people miss about the Tallboy and Grand Slam bombs is that they needed to be dropped from a long way up to be effective - they were in fact originally designed to be dropped from 40,000 ft, to explode below their target and undermine it. Barnes Wallis was planning a newly designed bomber just for these bombs, but it never got off the drawing board for obvious reasons. The B-29 could probably just about have done this with Tallboy, but it wasn’t until the B-36 came along that this was possible with Grand Slam - by which time tactical nuclear weapons had made the entire idea obsolete anyway. Stripped out Lancasters could make it up to about 20,000ft with Tallboy and a bit less with Grand Slam, which was just about enough to work but not enough to use the bombs as originally designed.
It’s also worth noting that only a few of the very best squadrons in the RAF ever dropped these bombs, starting with 617 squadron whose motto “Après moi le déluge” may give you a hint as to where you might have heard of them before. The bombs were very rare, took an enormous amount of time to make and each aircraft only got one to drop at a time - so were only ever used for very, very precise targets and highly trained crews.
All points I was aware of, hence my questions. And the poster had not been banned at the time I posted my response. I suspect the poster wasn’t serious about the issues anyway, since his message seemed to ignore the obvious negative factors of such a suggestion. The book I have on Barnes Wallis details the problems associated with the design, production, and use of very large bombs, and gives a good idea of the limitations of these very specialized weapons.
