M4000 ID: Structural Questions

October 13, 2019
updates 10-14

As I've said a few times, I for one am not that inclined to doubt the Bellingcat identification of the scraps linked to the 2017 sarin attacks in Idlib province. There was almost surely no aerial attack to get the scraps there, so if the planted debris points to the binary sarin bomb M4000, I have no problem with that. I still wasn't ready to start doubting that ID just recently, but there was the issue of the wrong-sized caps that looked compelling. I just now finally took a careful look at that and I'm more prepared now to raise a serious doubt.

M4000 is still a very good overall match, very similar if not the same. And even these serious differences I'll explain could, as far as I know, be chalked up to differences between an inaccurate schematic picture (one of unknown purpose, after all) and the real thing. In fact out of caution if nothing else, I'm banking on that option. But then this might point to a wrong ID worth noting, or even to serious deception afoot. And so it seems worth explaining here.

One good point at least in Philip Watson's "M4000 the sarin Deception" ongoing investigation is in part 1 where he cites a point raised by German researcher Michael Kobs, who stands by the measure of the twin filler caps in the schematic as too small to match the scraps it was said to identify - not off by a debatable hair either - carefully going by the given length and its scale, the green caps as drawn in are only around 70mm - about 2/3 of the 105-107 mm Bellingcat claimed. (tweet) A smaller cropped version of that graphic is at right.105 mm per the given scale is measured out, and the cap that wide superimposed, to compare with the much smaller one shown on the schematic in green. In fact that cap would not quite fit between the shown suspension lug and the mid-tank dividing ring (the items just on and just left of the red lines here)

There's a distortion of some images making the bomb look longer than it should, but Kobs is sure this didn't affect his measure, which is proportional only to the length shown; the caps were simply too big compared to the bomb itself in order to match.

There are other differences besides this same one apparent with the recently unveiled 2013 example - taken by Bellingcat as the first view of the M4000 in real life. I noticed researcher Qoppa999 had also shows how the caps on this are too large to match the schematic, besides the suspension lugs (marked in yellow) being spaced differently. Furthermore, the tailfins stick out a bit further than designed before the ring wraps around them, leaving that stub of a mixing arm (presumably) more visual than it should be. At least according to this drawing, the first-seen example of an M4000 raises some questions whether it even IS that.

Quick note: Qoppa used the stretched view, so the vertical proportions don't match (the video image has a "fatter" bomb than the drawing). But this doesn't effect proportional measures along the length. These caps are designed carefully to a specific gauge, I'm fairly sure. So we have a real discrepancy, and if the schematic is correct about the M4000's caps, then we're seeing something very similar but different.

Noting how Qoppa's size difference is about the same as Kobs', and noting the different lug placement, I wondered about the 2017 scrap with filler cap and attached suspension lug. How far apart were they? It's hard to read clearly, as the lug is on another plane, the metal having cracked and curled back. I tried estimating the distance it runs (thin red line trying to follow the curve) to the lug (dark red outline) or its axis (heavier red line). Then I tried to imagine that red thread pulled out straight and tight, being sure not to overdo its length. This surely underdoes it for a minimum distance to the lug (I'm still working on another method to better gauge that distance).

Putting that alongside Kob's comparison, and then adding Qoppa's, all at approximate scale, and tracing the minimum lug distance with a dark red box is well under the true distance that Qoppa marked - later and on another unit - in yellow. I suspect that lug is the same distance out on the yellow band, for a different design than shown.

Adding, again: I finished the other graphic - sort-of. I tried cutting different panes of the metal in GIMP2 and stretching them flatter so the cracks lined up. I didn't try reconstructing everything else, just the edges and basic proportions, I hope, between the rim of the cap and the base of the suspension lug.

Then I re-did that using a couple of different views.

That's all a bit imprecise but with some value, and makes a smart-looking image, I think. And I think it helps, as I place this literally on top of the prior comparison and trace an orange box up and it nearly lines up with Qoppa's yellow. And then I notice I included Qoppa's image a hair too large or actually shifted a hair to the right, so the lineup will be about perfect, actually.

Here are those proportions compared in a simplified image to clarify the difference. Again, both scales here are relative to the overall bomb, and the extra length Qoppa identified doesn't even play in.

I checked the 2014 example from Tishreen to see if it fits the pattern, but it's too distorted to tell. The caps seem to be same large size we've been seeing, but what looks like the mud-caked forward lug seems to be right next to or almost in the mud-caked cap. It might also be bent, broken, or missing, and the unit seems quite distorted there. It's not a good, clear example.

Back in context: the 105-107 mm Bellingcat had for the filling cap on the 2017 scraps seems to be about the right size, both for itself and for the 2013 example(s). The OPCW's investigators likewise measured 105mm. And the distance from the cap to the nearest suspension lug also seems to be the same between these field examples, and so these were probably made according to the same design. And that, again, is drastically different in spots from the M4000 as shown in the famous diagram.

That leaves us with these possibilities:
- It's the actual M4000 that's just truer than some crude diagram that might - for example - show an early design prototype, rather than the final form (I think an option on these lines is pretty likely)
- It's an unknown different or variant model (it seems possible that the Syrian military would produce two bomb so entirely similar)
- It's a forgery; this could in fact be someone's try at re-creating the M4000

The last option will tempting to many, so I'll urge caution; this may be nothing but a logical possibility worth listing. But some aspects to pursue include the 2013-14 examples with their sheet metal color that appear to have never been painted with the standard green primer, nor given any other markings. While I'm not sure how to assess the materials and welding as seen on the earlier examples, the craftsmanship might be crude. We could wonder with the 2014 example if the support ring on the tailfins popped off due to shoddy welding by Islamist impersonators.

If so, it seems they got the caps wrong, and anything we can't see could be done wrong or be missing. Its ability to actually carry out the M4000's apparent design to mix sarin precursors would pretty doubtful.

But then again I don't mean to make too much of this, and there are many unknowns. There are also differences between the 2013 examples (lack of damage suggesting no airdrop as alleged) and the 2017 case(s) (seeming extreme blast damage and perhaps years worth of weathering, and perhaps green paint that was lacking in the earlier cases), besides the apparent structural similarities. It's still not clear to me who was deploying (dropping or lobbing) these things. Therefore, it's best to just consider the options until there's enough clarity to decide, or at least to narrow it down.