Talk:Alleged Chemical Attacks, March 25-April 3, 2017

Haley, March 30 vs April, 9. Good catch. But what does it mean? In theory, she is a Cabinet member and is supposed to represent views of the executive branch as a whole. But she is a bit of a loose cannon in the tower, so she may be representing mostly herself? A tower wing? --Resup (talk) 14:06, 20 October 2017 (UTC)
 * Presumably, she was on script with the Trump White House in both cases, in a bold step back and two steps forward on the Syria hostility campaign. Considering the first step in that awkward dance came hours after the CW reports, it raises some questions (how long until a serious backtrack is needed now? - it was a few days). To be fair the reports were kind of low-key, no fatalities, etc. But still, some reports of both chlorine and sarin-ish material, in different areas, could have led to a pause. They now say sarin is confirmed in this prelude to Khan Sheikhoun. Need to add that I guess.


 * And on Haley - not sure who picked the photos to show in her diatribe, for example. Don't close your eyes, she insists, brandishing ... a kid with a line across his neck (irrelevant I suspect, but to some a sign of strangulation), and at least one girl and a woman with blood from the nose and not the mouth (suggests a skull injury, not rain or even inhalation injury from an irritant poison). Why those two images? Would she have used the one with four wounded children laid together if she knew about it? --Caustic Logic (talk) 12:27, 21 October 2017 (UTC)

Hell Cannon?
The chlorine cylinders seen near the al-Lataminah cave hospital evidently fell from a high altitude. But what else could put them in the air except a helicopter?

The Wikipedia article on Hell Cannon mentions a variant called "Jahim (Hellfire) Cannon", using this article in al-Akhbar as source.
 * ''The Hell Cannon was followed by the Jahim (Hellfire) Cannon which replaced the gas cylinder bomb that weighs no more than 40 kilograms or 88 pounds (three quarters of the weight is explosives) first with an industrial oxygen cylinder then with a water-heating tank.

Industrial oxygen cylinders are identical to industrial chlorine cylinders. If such a weapon exists, evidently it could propel the chlorine cylinders in the air high enough to cause the damage and deformations seen.

The Orontes River is the long-established front line between the rebels and government forces. It is only 600 meters south of the cave hospital and 450 meters south of the site of the March 25, 2017 incident. It is conceivable that the area is targeted by artillery and that stray shells might fall near the hospital. Wikipedia claims that the Hell Cannon has a range of 1.5 kilometers, but this might be a reference for the early small caliber variant. It is conceivable that the "Hellfire Cannon" might propel a gas-filled cylinder up to 3 km.

I suspect some terrorist group in al-Lataminah was targeting government territory with chlorine cylinders. Some of them fell short and landed on the White Helmets cave hospital. -- Petri Krohn (talk) 21:02, 22 October 2017 (UTC)


 * For the weapon, cool find and I'm an instant fan of that possibility. Up to 3 km? Best method is to use about 2.5 km of that in vertical travel. I imagine the hospital was targeted on purpose (why isn't clear - to blame Assad, and probably at least one other unknown reason). And I still don't see how this tank punched through (how much?) soil and then the concrete roof. I don't know how that happened, but otherwise, for this or other big tank attacks, this hellfire cannon is likely. (otherwise, it could be some catapult, etc.) --Caustic Logic (talk) 23:49, 22 October 2017 (UTC)


 * A thought experiment: Find data for a commercially available oxygen cylinder, weight, volume, maximum pressure. Calculate the amount of energy required to fill the cylinder to maximum pressure. Convert this energy to potential energy: how high would this amount of energy raise the cylinder and its contents from the ground? Repeat the calculation for over pressure at twice the maximum certified pressure. The result will give some estimate of how far the cylinder can be propelled without it breaking up.
 * Potentially one could rig the cylinder into a water rocket. The altitude record for water rockets was 630 meters, but they may have used plastic Coke bottles. -- Petri Krohn (talk) 14:18, 23 October 2017 (UTC)

Quite interesting, do not have time right now but may try later. Quick comment is that (1)on escape compressed gas will do work against surrounding air, accelerating (or compressing) it, so it will not (all) go into potential energy of raising cylinder up; in fact one needs to add momentum conservation (and mass conservation). (2) when we compress gas into cylinder, a sensible scenario is that it happens at constant temperature; while if gas escapes quickly, perhaps a sensible scenario is that it is adiabatic. If we care about work it will be different for adiabatic vs constant temp, eg if we compress it and allow temperature to raise we will have to work harder. Adiabatic work of gas at pressure p in volume V into atmospheric pressure po is p V/(ga -1) [ 1 - (po/p)^((ga-1)/ga)] where ga is approx 1.4. 120 liters compressed to 110 atmospheres is 2.8 megajoules which is same amount as raising 100 kg at 2.8 km height--but as stated above it will spend most of it pushing air around not raising itself into skynet --Resup (talk) 17:22, 23 October 2017 (UTC)
 * Actually, trying to make a 'rocket' powered by compressed air is not easy at all, in addition to underpowered, it will be unstable, may rotate and not go up as intended, unless stabilized somehow; putting chemicals on it in addition is quite insane, one would not know how it all ends up. There are easier ways to do it, usual hell cannon; rigging and exploding it on the ground, etc. Trying to use compressed air, it seems simpler to try a large pneumatic 'airgun', not a rocket. Also if they invented something of such sort, it will be used in battles, not just for a single provocation. --Resup (talk) 15:43, 24 October 2017 (UTC)


 * The state of the art in gas launched projectiles is mainly for avalanche control. See for example Avalauncher. I've seen slightly bigger versions than that and I've heard of conventional howitzers being converted to use compressed nitrogen. Overall it's unlikely any gas launcher can fire a projectile more than a couple of km, and that would be a few kilos max weight. --Charles Wood (talk) 01:18, 25 October 2017 (UTC)


 * I don't think it has to be compressed gas or anything. It's not like a water bottle rocket where the contents are the fuel. Who wants an empty chlorine tank flying bad enough to spray themselves with all it's chlorine, right? (probably misunderstanding, I'm an ignoramus here, but...)I figure it has to be an explosive firing in the tube, like a bullet out of a gun, and then it just flies like a bullet, with no engine. It may not go very far. Insn't that about how the Hell cannon works? Or it has some detachable engine that comes off in mid-flight (if possible)?
 * The latest version in discussion above is about using compressed air instead of explosive to push a 'bullet' out of a gun. There is quite reasonable Wikipedia article on hellcanons (basically guns/canons, with a variant that tail is inserted in the barrel while the charge is outside. Wikipedia also mentions compressed air variant as known to be used but the link is dead. Compressed air may have some advantages to explosives, for the purpose at hand, as it is weaker and pressure may be controlled, and may allow this sitting fully in the barrel, without damaging it or leaving residues or tails traceable to gun firing. What was actually the case with those yellow cylinders, do not know (dropping from air is a no-brain option too) --Resup (talk) 16:07, 25 October 2017 (UTC)


 * Possible evidence of usage by HTS-led rebels on March 22, in their Hama offensive, to help overrun Khattab: http://libyancivilwar.blogspot.com/2017/10/the-chlorine-tank-used-on-khattab-in.html