Grand Slam v MOAB....

[mikewint]

The US MOAB was developed for use in Iraq but was never used there as the massive numbers of Iraq troops/tanks never developed and the bombs effect was too wide spread to use on confined targets, i.e., civilian causalities
The MOAB uses 9.3 tons of TRITONAL a mixture of 80% TNT and 20% Aluminium powder. The Al has the effect of increasing both the heat and time of the blast. Thus Tritonal is 18% more powerful than TNT alone yielding the TNT equivalent of 11 tons. The MOAB is not a ground penetrator but an air blast weapon. The air blast has two basic effects. First it produces a massive supersonic shock wave and the extended time air blast sucks all oxygen from the area. The effect covers a radius of 150m ( 492 ft). The ground effect is similiar to the BLU-82 Daisy Cutters used in Vietnam
The Russians claim that their FOAB bomb at 7.1 tonnes (7.8 US tons) is a thermobaric weapon using a new type of high explosive plus Aluminium powder and Ethylene oxide. At 7.1 tonnes (7.8 US tons) of explosive it produces a blast equivalent to 44 tons of TNT with a blast radius of 300m (984ft). Russian films of their FOAB test are highly suspect. They never show the bomb and aircraft together and the blast appears to be a standard fuel-air explosion. Conventional explosives are a mix of fuel and oxidizer. The fuel-air bomb is all fuel and uses oxygen from the atmosphere
The British Grand Slam was a penetrator weapon designed to penetrate concrete bunkers before exploding. They could penetrate as deep as 40m (131ft) into the earth. The Grand Slam was filled with 4.144 tonnes (4.57 US tons) of TORPEX TORpedo EXplosive 42% RDX, 40% TNT, 20% Aluminium powder. Due to its penetration it produces a camouflet (cavern) which then serves to undermine existing structures by removing their supporting foundations.

 

[stan reid]

The U.S. tested the T-12 Cloudmaker bomb in the late 1940s that came in at about 44,000 pounds.

 

[stona]

It's probably worth mentioning that the Grand Slam was use in very small numbers, just 41 were dropped during the war, compared to 854 Tallboys.
They were perhaps most effective against viaducts and bridges, previously almost immune to attack, seven of which were destroyed in a ten day period in March 1945 by a combination of 18 Grand Slams and 78 Tallboys.

As an odd fact for a WW2 quiz, the Grand Slam (later Bomb, HE, Aircraft, MC, 22,000lb which doesn't have quite the same ring to it) was not officially approved for RAF use until April 1945.

The Germans described these bombs as 'Panzerbombe SAP', the Tallboy being 'Panzerbombe SAP 5400Kg'

Cheers

Steve

 

[pbehn]

The Germans described these bombs as 'Panzerbombe SAP', the Tallboy being 'Panzerbombe SAP 5400Kg'

Cheers

Steve

Any idea what SAP means?

 

[stona]

Any idea what SAP means?

Semi Armour Piercing, which would appear to be English, but I have a diagram, made by the Germans in July 1944, of a Tallboy and the title is, exactly as written
Brit. Panzerbombe SAP 12000 LB 5400 Kg
Bold original.
The diagram is extremely accurate, including internal detail, so the Germans must have dismantled an unexploded Tallboy. The German measurements are metric but transpose exactly to the British imperial measurements. They identify the structure of the bomb, from the fuses used to the tension locks to attach the tail (Spannschloss fur Leitwerk) in better detail than I've seen in any British drawing! Externally the diagram even notes the coloured ring with the explosive type stencil (grun), the smaller red ring nearer the nose, the screwed on steel tip (aufgeschraubte Stahlspitze) the body of the bomb as painted green (anstrich grun) and the tail section as riveted aluminium (Leitwerk-Aluminium genietet).
It makes a fine modellers reference
Cheers
Steve

 

[Walrus]

if this is an 'air burst' weapon, similar, in principle at least, to the WW2 'cookie' or 'blockbuster', why use it to try to knock out underground positions ?

From a report I saw, the heat from the explosion sucks all the air up and so out of the cave system (theoretically)

I was also wondering about the body count, thinking that the idea was to collapse the cave system.
But having been reminded here that the explosion was above ground, presumably the cave system remained largely intact.

 

[grunnvms]

I remember reading that the US used a similar weapon in the second Gulf war. It was meant to destroy underground bunkers by deeply penetrating in the earth before exploding. It was a newly developed bomb back then, in fact it was still warm from the liquid explosives they filled it with, when the USAF got it from the manufacturer.

 

[edgardo gil]

Airframe, the argentinians don´t rolling their bombs, they adapted a couple of MER on their Herk and they put a bomb in a tanker ship. I guess that if you talk about precision, that´s it. At least far more precision than rolling out the bomb on the back.

 

[newst]

1. The bomb drop was on the authority of the theater commander, an authority he already had when Obama was president. This was not ordered/controlled from the White House as too many military actions have been in the past.

2. The US had three options:
a. Do nothing.
b. Send infantry in to attack a well manned, deep, heavily defended and likely booby-trapped cave complex. While it can be done successfully it would be incredibly wasteful of lives (ours, the goal is to waste theirs after all) and material. Not only are the lives of his troops important as a moral consideration, the current political opposition in the US would go ape if there were an action with heavy loss of life. Just look where they went after the SF attack in Yemen where one man was killed. While the political situation shouldn't have any affect on the decision I suspect that it is possible that it did.
c. Drop a MOAB for an air burst. The tremendous overpressure and consumption of oxygen kills the Al Qaida in place. Infantry, US and Afghani, can then go in, count and identify the bodies, retrieve intelligence and take their time setting sufficient demolition charges to insure that the complex is destroyed.

 

[stona]

If it's such a good plan, why hasn't it been done before?
Steve

 

[yosimitesam]

I'm still slightly puzzled - if this is an 'air burst' weapon, similar, in principle at least, to the WW2 'cookie' or 'blockbuster', why use it to try to knock out underground positions ?
OK, there'd be some damage, but the whole idea of an air-burst weapon is to have maximum blast and shock-wave effect above ground, for example, to flatten structures and / or eliminate surface forces and equipment.
Of course, it may have been fused to detonate after entering the surface.

It's a thermobaraic, fuel-air mixture bomb. The bomb burts just above the ground and spreads an explosive "aerosol" like a cloud. Then detonators set it off. It has much greater overpressure (and pulse length) than regular bombs and the shockwave penetrates into caves, bunkers, etc. It works completely different from the deep penetration bombs of Dr. Wallace.

 

[stona]

The MOAB is thermobaric? I thought it was filled with H6. A thermobaric weapon would be filled with, essentially, fuel and derives its oxygen from the air. That does not match a high explosive filling like H6.

Cheers

Steve

 

[mikewint]

Check out my post #21. The US MOAB is NOT a fuel-air or thermobaric weapon however the presence of the powdered aluminium does mimic, to a degree, the sustained explosion of a thermobaric/fuel-air explosion. The extensive blast radius also mimics the oxygen deprivation of a thermobaric.
I believe that the US shied away from a thermobaric/fuel-air due to a report from the US Defense Intelligence Agency:
The kill mechanism against living targets is unique–and unpleasant.... What kills is the pressure wave, and more importantly, the subsequent rarefaction [vacuum], which ruptures the lungs.... If the fuel deflagrates but does not detonate, victims will be severely burned and will probably also inhale the burning fuel. Since the most common FAE fuels, ethylene oxide and propylene oxide, are highly toxic, undetonated FAE should prove as lethal to personnel caught within the cloud as most chemical agents.

 

[yosimitesam]

Semi Armour Piercing, which would appear to be English, but I have a diagram, made by the Germans in July 1944, of a Tallboy and the title is, exactly as written
Brit. Panzerbombe SAP 12000 LB 5400 Kg
Bold original.
The diagram is extremely accurate, including internal detail, so the Germans must have dismantled an unexploded Tallboy. The German measurements are metric but transpose exactly to the British imperial measurements. They identify the structure of the bomb, from the fuses used to the tension locks to attach the tail (Spannschloss fur Leitwerk) in better detail than I've seen in any British drawing! Externally the diagram even notes the coloured ring with the explosive type stencil (grun), the smaller red ring nearer the nose, the screwed on steel tip (aufgeschraubte Stahlspitze) the body of the bomb as painted green (anstrich grun) and the tail section as riveted aluminium (Leitwerk-Aluminium genietet).
It makes a fine modellers reference
Cheers
Steve

I know the "afterbody" or tail section was mostly hollow but I've never seen a diagram of how far into the tail-secton the rear of the bomb extends nor the actual shape (rounded?) of the rear of the actual bomb body. What does your diagarm show? Curious. Thanks.

 

[yosimitesam]

Check out my post #21. The US MOAB is NOT a fuel-air or thermobaric weapon however the presence of the powdered aluminium does mimic, to a degree, the sustained explosion of a thermobaric/fuel-air explosion. The extensive blast radius also mimics the oxygen deprivation of a thermobaric.
I believe that the US shied away from a thermobaric/fuel-air due to a report from the US Defense Intelligence Agency:
The kill mechanism against living targets is unique–and unpleasant.... What kills is the pressure wave, and more importantly, the subsequent rarefaction [vacuum], which ruptures the lungs.... If the fuel deflagrates but does not detonate, victims will be severely burned and will probably also inhale the burning fuel. Since the most common FAE fuels, ethylene oxide and propylene oxide, are highly toxic, undetonated FAE should prove as lethal to personnel caught within the cloud as most chemical agents.

I got my info from a CNN article. It was obviously FAKE NEWS! OMG! ) Thanks for the info.
<a href="5 things to know about the MOAB - CNN.com">CNN Story</a>

 

[pbehn]

I must say I find these technical reports deciding which ways to kill people are too unpleasant to use are more than strange, setting off 10 tons of explosive near people will not have a pleasant outcome.

 

[Shinpachi]

Interesting topic but isn't the C-130 or such a large plane a good target for the enemy now ?

 

[newst]

If it's such a good plan, why hasn't it been done before?
Steve

Obviously I don't know but I can think of some possibilities, the most likely being that there haven't been any targets where it could be used to advantage without massive collateral damage. The bomb has a one mile radius blast area. Any target it could be used on would have to be far away from civilians. In other cases there may have been times where it could have been used but other ordnance would do the job as well. Remember the MOAB wasn't used to destroy the complex, but to kill the fighters in the complex so that infantry could move in unopposed. How often does a target like that come around in an area where civilians aren't anywhere around? Not often I suspect. A good commander doesn't use a weapon just because it is available but because it is the proper weapon for the situation.

 

[fubar57]

Have any troops moved in to inspect the damage yet?

Never mind, found this though not sure of this source...

Yesterday's MOAB Drop - The Aftermath

 

[newst]

Interesting topic but isn't the C-130 or such a large plane a good target for the enemy now ?

The C-130 is a good target but it has been successfully used in low level combat for decades in its AC-130 gunship configuration. In this case though the bomb was dropped from a high altitude. I doubt that the Al Quaeda had any anti aircraft capability more effective than MANPADs, RPGs and perhaps 23mm cannon. None of those weapons would have the range to endanger the C-130 even if the Al Quaeda knew it was there.