Happy Friday, readers.  My name is Tamara Patton, and thanks to the ever-generous Jeffrey, I’ll be a new guest contributor here.  For those who’d like to know a little more about me and what I plan to offer, see the bottom of this post.  For the rest who just want to hear something interesting about Parchin, keep reading…

Many of you know that the alleged high explosives testing site at Parchin remains a key element of the “structured approached” that the IAEA is proposing to resolve outstanding issues on Iran’s nuclear program.  Experts in this area continue to debate whether this site is really worth the ultimatum – My colleague at SIPRI, Bob Kelley, recently gave his take in that debate, which was seconded soon after by Yousaf Butt.

As the debate continues, I thought it might be useful to take a closer look at how the many different dimensions we’ve been offered add up in the context of the site.  I came upon some interesting discrepancies.  Some of you know that I’m a fan of Google SketchUp — I gave the tool another go here.

Starting with the original drawing of the chamber (acquired by the AP and reportedly produced with information from an eyewitness), I was most struck by how off the reported dimensions seem in the context of the drawing.  Jeffrey already remarked on the oddity of the Oompa Loompa-sized door in the cylinder.  Another eyebrow-raiser is the diameter to length ratio of the cylinder (reported to be 4.6 m and 18.8 m respectively).  In fact, as far as I could tell from modeling the photo in SketchUp, the length of the cylinder in the drawing is indicative of about 6 to 7 m – nowhere near the supposed 18.8 m figure. Maybe the artist was a Picasso fan, but the disproportion in the dimensions seems a little too pronounced to have been unintentional.


If you assume a 4.6 m cylinder diameter, the cylinder length depicted in the drawing indicates 6 to 7 m, not 18.8. (Patton, SketchUp).


A related discrepancy is the placement of the collar in the drawing versus the way its dimensions are described by Danilenko (i.e. the second source of possible dimension info).  The press drawing seems to deliberately indicate that the collar is located at the rear of the cylinder.  Danilenko, however, describes that “the external part of the central section of a length of 9 m is strengthened with a reinforced concrete square section of 7.6 x 7.6 m2”.  The key word is central.  Apparently, wrapped around the center of the 19 m long cylinder would be this massive concrete collar, with the cylinder protruding on either side of it.

Like this:


SketchUp model of Parchin, illustrating how Danilenko's design would look if it were in the building. Dimension estimates: building length (30 m); building width (15 m); building height (~12m) ; cylinder total length (19m); collar length (7.6 m). (Patton, SketchUp)


Modeling these dimensions within the dimensions of the building at Parchin (heights are very estimated since these shadows are on a slope), the view above is what I got (shown with average height humans for scale).  So, is the information that came with the drawing actually at odds with Danilenko’s design?

Yes – and no.

If the length of the 19 m cylinder is partially covered in the center by the concrete collar, that leaves about 5.7 m of cylinder exposed on each side of the collar.  Interestingly, this is MUCH closer to the cylinder length that the original drawing depicts, seen here from similar viewpoints:


Comparison of AP drawing to SketchUp model depicting Danilenko’s design from a similar perspective.


So in this infamous drawing, are we maybe just seeing half the picture?  It is an interesting thought, though it seems unlikely that an “eyewitness” would have missed the other half of the 19m cylinder sticking out the back.

As far as the likeliness of Danilenko’s design being used for the accused hydrodynamic testing, there seems to be some growing agreement that the concrete collar (especially if placed around the cylinder’s center) would interfere with the devices needed to make a hydrotest test useful, such as high speed optical cameras, flash x-ray systems, and neutron detectors.  On top of this, as you can see from the SketchUp model, there’s not a whole lot of extra space in the building to support this kind of infrastructure once we use the dimensions described in the media and by Danilenko.

A final dimension of interest at the site is the heavy earth berm immediately south of the main building, which the IAEA says is indicative of the “probable use of high explosives in the chamber”.  Based on modeling off of shadows in the October 2012 Google Earth satellite image, I estimate that it is around 9-12 m tall, so very nearly the height of the building (estimated to be around 12-15 m tall).  It’s also about 6 m thick, 24 m from end to end, and located 4 to 5 m away from the main building.


The oddly shaped berm. ~9 m tall, 6 m thick, 24 m long. (Patton, SketchUp)


While this may seem like a large berm at first glance, it pales in comparison to the many other much larger berms in the greater Parchin complex.  These berms are also significantly wider, surround entire buildings, and they are sloped on both sides.  From the shadow casted by the berm in question, it is evident that it has a flat face nearest the building.  Strangely, the height to width ratio is almost exactly what is required for earth-bermed explosive storage magazines (i.e. a 3:2 slope), as illustrated in the figures in this report, though I can’t think of any sane reason for storing ammunition this close to a structure. (Ignore this! Or see the comments for some better info.)

Bob Kelley says that small, narrow berms like the one in question are more likely used to shield radiation beams like those from an industrial x-ray machine or accelerator.  He says that if the beam is collimated then you only need to shield where it is pointed.  This makes sense.  However, a remaining consideration is that unlike the closely packed buildings that the larger berms in the area are protecting, the site in question is much more isolated, and the berm is protecting the only two buildings around that would need to be protected.  I think this prevents us from completely ruling out an explosive shielding purpose for this berm.

In brief, I think that the numbers we’ve been presented in terms of dimensions for this site at Parchin bear closer scrutiny.  The two main sources of information don’t quite add up, and even if they did, the resultant design isn’t appropriate for hydrotests according to folks who know how those work.  If there are any berm experts out there, I hope you’ll give your opinion – this berm is an anomaly amongst others at Parchin, and further investigation could result in a fun new rabbit hole to dive into.

(Here’s that introduction I promised: As you might be able to tell, my favorite area of work resides at the very tiny area of overlap between the worlds of arms control and digital art.  Modeling has been very useful for wringing a third dimension of information out of satellite images and ground-view photographs, and I’m grateful to folks like Frank Pabian who have paved the way in this area .  I’m hoping to push that tool into some new directions through modeling some new sites and hardware.  I’m also excited about exploring new applications of other geospatial and data visualization tools for our field.  In short, these sorts of projects, experiments, and ideas are what I’d like to share, and I look forward to hearing what you think. -TP)