I singled out the US because I meant to. Why can’t I single out the US? Is it a crime to say US?.As for my list if nations that would NOT do exactly what I suggest, I can mention lots. : Lichtenstein, Ice land, Tasmania, Tanzania, Central Republic of Africa, Zanzibar, Canary Islands…as for Intangibles, all I Know is that I am an officer and your not,BUT as they say in the Army, Officers know diddly squat and the real credit goes to the hard working men under the Officers, so I credit you for your tangible input as I try to achieve tangible goals.
Just as a matter of interest, let’s assume that Japan had an atomic bomb or several in July / August 1945.
How would they deliver it to anywhere that mattered as the Allies closed in on Japan from the Pacific and the USSR?
Ground delivery or air delivery?
Logistics / planes / etc for each type of delivery and resources available for such delivery?
To boost moral and instill fear of the unknown into the Allied forces, I would say the goal would not be to deliver the weapon straight to the mainland of US (hope I can say US freely), or England, but rather deliver the bomb short range to one of the nearby islands or main lands where there would be high concentration of Allied forces or Naval ships. It would have to be far enough to exclude harm of fallout coming back to Japan, but that would be one goal I think would be tangible. This way long range planes and fuel supplies would not be an issue. Groundburst if you could sneak it onto a ship and sail it towards a naval base. Maybe if the Japanese Kamikazes pretended to be defectors so the Allied forces could pull the ship into the naval base(hiding the bomb) then once its in the naval base. Kaboom!
Never mind after the war, what about before it?
The USSR and the evil of communism was something that was anathema to America, Britain, and the British Commonwealth countries before 1941, but come 1942 they’re pouring everything they can manage into Uncle Joe’s hands to support his war against their common enemy (with which the USSR a couple of years earlier had completed a non-aggression pact as well as carving up bits of eastern Europe in agreement with the Nazis after the war started).
All nations act in naked self-interest. They’re not like people, who sometimes put honour and duty above self-interest.
Did Japan have anything capable of reaching the US or England by that stage?
Bear in mind that the US couldn’t deliver its atomic bombs to Japan until it got its bombers within range by taking the islands close to Japan.
Did Japan have any bombers with the necessary load capacity?
Oh please of course NOT. And besides with Radar developed in the US, they would have been pegged off before they got close to the mainland. The only landmass closest to Japan was Pearl Harbor. Wasn’t their Internment camps set up there with their own people. Would they not be killing their own kind as a set back to their plan. The Japanese absolutely had no long range bombers capable of delivering the atomic bomb to the US. A submarine could snek through as they did in San Francisco but implosion is not the same as explosion. I stand by my reply. The logistics would be Impossible. The only way would be to detonate it nearby where there would be a considerable Allied Naval Base (Preferably US) (US) (US).
http://pacificstorm.net/en/articles/jp_bombers1.php
Japan’s lack of heavy long-range bombers, as they were understood by the western strategists, who were conducting an all-out aerial war by means of carpet bombing of industrial centers, military bases and residential areas in cities – the Japanese had no four-engine “flying fortresses,” capable of delivering several tons of ordnance over thousands of miles while flying at extremely high altitudes without fighter escort.
Herman2, I confess, I have no recollection of you before your recent return – I guess you didn’t make much of an impression on me back then, either. You offer up a short list of seven “nations” that includes three that aren’t even nations. I bow to your intellectual prowess.
As RS* pointed out, any nation (including Canada) will act in its own self-interest. Your reply also suggests you’re a tad confused about the difference between those which “would” do something if they had the chance, versus those which actually had such chances. The concepts are just a little different, as most readily grasp. And BTW, since you seem to enjoy fantasy, may I suggest you go read The Mouse that Roared? You might find the novel germane.
And you can certainly single out the US when that singling out is justifiable. But outside of your own mind, that doesn’t seem to apply in this case.
So far as being an officer here goes – well, you’re welcome to all the empty honorifics for your loud empty talk that you care to garner. Enjoy!
Well, the Japanese had successfully determined where MacArthur planned to launch Operation Olympic. In theory, they could have buried one or more bombs there for remote detonation as the landings came in, risking the bombs and their means of detonation would survive any pre-landing shelling. Any civilians who hadn’t fled the area would be of course just be viewed as making sacrifices for their emperor.
Puts them on the same basis as the Allies IIRC, as consideration was given to tactical use of atomic weapons in Olympic in the knowledge that Allied (being primarily and perhaps exclusively American) troops would suffer from radiation.
Again IIRC, there were times specified for Allied troops to move through atomic bombed areas after detonation to reduce radiation harm to them.
It could of also been Brave Australians RS. Don’t forget about them.
http://en.wikipedia.org/wiki/Operation_Downfall
“The Australian government requested the inclusion of Australian Army units in the first wave of Olympic, but this was rejected by US commanders.”
…The Australians are always the first to put their lives on the table . If Operation Olympic did go as planned the Lieutenant General Leslie Morshead would have been given a bums steer as he was obviously more qualified for the job than British officer, Lieutenant-General Sir Charles Keightley. Australian lives would be at risk from the fall out since i know they would have convinced Keightey to give the lead to Morshead. Morshead is an Australian officer in case you didn’t know of him.
I have no technical expertise in this area, but my understanding is that the destructive power of the American atom bombs dropped on Japan was in part related to being air bursts at carefully calculated heights to spread the damage across a wide area, which in turn was a compromise to allow sufficient fall to allow the bombers to get out of range of the blast.
If Japanese atomic bombs were buried at whatever was sufficient depth to protect them from pre-landing bombardments, to what extent would that reduce their range?
Would it be the case that the deeper they were buried, the less effective they became in blast damage over a given radius?
I have in mind an effect something like the well known WWI land mine explosion shooting a vast quantity of earth into the air in a fairly narrow funnel shape limiting the above ground damage (although that wasn’t the purpose of the WWI mine) to a small area.
pdf27 might like to comment on this.
I’m no technical expert either. You are correct about the air burst, and the depth of burial, being important factors. I would imagine the type of soil it was buried in would matter too. But at what point does it become “not worth” doing at a tactical level in a relatively small area? When the bomb losses 50% of its power? 75%? I can’t guess. I had been envisioning a shallow burial, protected/camouflaged by a relatively empty beach, more than any “bunker,” buried or otherwise. How much shelling is done to an empty beach, versus inland targets, especially given Japanese tactics during other recent invasions?
Under those circumstances, I don’t know what impact the shock wave would have on a nearby fleet, but suspect it might have been hard on landing craft at the least. I can’t count radiation as they really didn’t grasp the long-term ramifications yet.
The Japanese had a range of new conventional weapons that they held in reserve for defense of the home islands. Why would they treat this any differently? Waiting for the enemy to come to you would likely save dwindling resources and solve the logistical issue of getting the bomb to the enemy. Culturally, it also embraces a jujitsu-type philosophical approach, using the enemy’s concentration of strength against him. I doubt there would be another single point in time where so much was concentrated so tightly as during a landing, and if it did have major impact on the fleet, it could have bought Japan a major chunk of time. Or not, if the Soviets still came knocking.
My inclination is that the ideal ground based weapon against an amphibious invasion would be a Claymore type of shaped weapon.
Whether that would have been possible with the atomic bombs at the time, and the amount of concrete shaping behind it, is beyond me.
Very quick answer because I’m knackered:
The Effects of Nuclear Weapons gives 35 PSI as the overpressure at which those exposed will start dying, with lung haemorrhage starting at 15 PSI.
A 16kT airburst (Hiroshima) will give 35 PSI at 0.32 miles and 15 PSI at 0.36 miles.
The same weapon for a surface burst will give 35 PSI at 0.24 miles and 15 PSI at 0.29 miles.
Hence, an optimal airburst is 78% more effective at killing unprotected soldiers and 54% more effective at injuring them. The Hiroshima and Nagasaki bombs were IIRC given drogues to slow down their fall in order to give the (heavily stripped out - all armour and most guns were removed) B-29s time to escape; to the best of my knowledge the burst height was chosen without consideration of whether it would enable the crews to escape or not.
Thanks for the input, pdf. One of the things I’m still curious about is the effect of a ground blast on/near water. Underground nuclear devices can have “earthquake effects” and I’m wondering how that may work in a seaside situation, with shockwave potentially creating something like a tsunami. Especially for Higgins boats, which have never struck me as being especially nimble, I would think the risk of being swamped might be high, between the wind blast and waves. Even if troops survived and got ashore, resupply without landing craft might be daunting. Does your resource give any hint of that? I suspect most big boats would be too far out to sea to be roiled by the blast, but…
RS, another “mine” model to consider might be a bouncing Betty. With the ocean being basically flat, would the bomb need much height to get the impact of a blast at higher altitude?
Of course, Olympic was coming in on three beachheads, and the Japanese would need either a lot of bombs or very accurate placements for any of this to be worth anything…
An airburst is defined as the height at which the fireball does not touch the ground (if it does, energy is wasted digging out a crater rather than destroying things on the surface - so ground bursts are only used where you have something very tough you need to dig out). At 16kT the fireball has a radius of 0.13 miles, i.e. a minimum height of ~800 feet - can’t find the formula for calculating optimal airburst height offhand right now.
The BAKER test at Bikini gave the following wave heights:
Distance (yards) Wave Height (feet)
330 94
660 47
1330 24
2000 16
2700 13
3300 11
4000 9
From what I’ve read, the ships generally showed that they would have remained afloat until after their crews had died of radiation poisoning…
Thanks pdf. Even at a mile out, you’re getting 16 foot waves. I did try to find some info on how stable Higgins boats were – all I found was that their lead competitor in Navy testing for landing craft (The “Bureau Boat”) got swamped by 4-foot waves…leading directly to the choice of the Higgins.
I had thought the power of the airburst was related more to something like LOS with the explosion – straight lines, with the blast’s height removing deflecting obstacles, depressions, etc. I appreciate the clarification.
The book goes on at some length about shockwaves travelling rather well through water and bursting hull seams rather more effectively than the equivalent pressure wave from a chemical explosive (because it hit along the entire length of the ship, rather than only one bit). That probably isn’t a factor with small IC engine powered boats however, since they’re relatively immune to shock damage when compared to a steam plant and are liable to be swamped rather than crack seams.
It’s frustratingly unspecific about how pressure waves travelled (probably because that’s relevant to how effective a nuclear depth charge would be, and seems to be heavily influenced by the sea bed topography), but the impression I get is that all ships within relatively close range would be mission killed for certain and probably have their crews die over the course of a few days from radiation sickness. However, it would probably take a week or so for most large ships who weren’t sunk outright in the explosion to sink even without any damage control - Saratoga was only 450 yards away from the initiation point and took 7 1/2 hours to sink. Nagato was 770 yards away and sank 5 days later.
Sort of, but that’s counterbalanced by the fact that it’s simply further away. This really comes into play when selecting the optimum airburst height, rather than choosing between a ground or air burst - the optimum airburst height is rather larger than just “fireball does not touch the ground” and is really a balance between overpressure required directly over the target, device size and how much damage you want to do at a distance. I’ll see if I can dig out some stuff on that later.
No doubt an overly simplistic idea based on my very limited grasp of physics, but one of the few things I recall from school is that water is incompressible.
Does it follow that an explosion at a sufficient depth is pretty much fully contained by the water column (e.g. equivalent of a 500lb aerial bomb at 5,000 metres) but when it is nearer the surface the incompressible force is dissipated into the atmosphere by forcing the water column into the air (e.g. equivalent 500lb bomb in 3 metres of water)?
If so, would a very large explosion, be it nuclear or conventional, in shallow water such as that typically found in amphibious landings be less effective in bursting hull seams on surface ships than at deeper depths, such as 5,000 metres, where it might destroy a submarine (yes, I know crewed naval subs can’t go to 5,000 metres, but the Japanese didn’t have atomic weapons to explode in the sea or anywhere else, so this is all just speculation)?
Altight, I’m not going to say how long ago I took high school physics, but you’re starting to get out of my depth. 
I did take pdf’s informative post and looked up the fate of the Saratoga. It was sunk during Operation Crossroads, specifically held to test nuclear blast effects on ships. The Saratoga survived the first of two tests, but was sunk by the second. Details as per the ever-convenient if not always definitive Wiki:
A fleet of 95 target ships was assembled in Bikini Lagoon and hit with two detonations of Fat Man plutonium implosion-type nuclear weapons of the kind dropped on Nagasaki, each with a yield of 23 kilotons of TNT (96 TJ).
The first test was Able. The bomb, named Gilda after Rita Hayworth’s character in the 1946 eponymous film, was dropped from the B-29 Superfortress Dave’s Dream of the 509th Bombardment Group on July 1, 1946, and detonated 520 feet (158 m) above the target fleet. It caused less than the expected amount of ship damage because it missed its aim point by 2,130 feet (649 m). The second test was Baker. The bomb, known as Helen of Bikini, was detonated 90 feet (27 m) underwater on July 25, 1946. Radioactive sea spray caused extensive contamination.
The bomb that sank the Saratoga wasn’t that deep. I suspect the deeper the submerged blast, you not only get the distance factor pdf raised for airbursts, but also the increasingly diverse ocean floor topography (i.e., the deeper it is, the more diverse) would come into play to deflect the shockwave. also – the greater density of the water might help transmit the shockwave, but wouldn’t the greater weight of the water also consume the energy faster? I have some vague recollection of some such from a discussion of tsunamis and underwater quakes (which I could easily have gotten now confused). Certainly, shallow water amplifies the tsunami-generated wave…
pdf, it never even occurred to me to think of the blast blowing a ship’s seams. I thought of the blast effects of melting steel, but that’s at relatively short distances. It seems likely there’s a bunch of other things that at least this “armchair bomb expert” isn’t thinking of.
But since we’re talking about hypotheticals here – thinking strictly of wave effects, and we have possibly multiple Japanese bombs – what if two or more bombs went of simultaneously on different sides of a bay? From what I recall of wave interaction (is “harmonics” the proper term?), that would result in places where the effects of the two blasts would be canceled out – and also places where it would be doubled. Utterly impossible for the Japanese to predict where ships would be ahead of time, so the doubling/canceling/all points in between relative to ships would be a crap shoot. I don’t know if wind/air pressure shock waves would behave quite the same way, but I daresay you still wind up with a big mess. (Is there a prize for understatement?)