1 November 2012

Evidence of large unguided Blast Bombs reported from Syria

FAB 500-M62 general purpose bomb Syria, Russian. Video sources analysed.

Please notice: this is a layman's post. If you read it please don't skip the notes during and at the bottom of the post. Also before you decide what to think of my writings: please read through my latest post (plead added 03/06/2014).

Photo posted on E.N.N.'s FaceBook page on 17/10/2012. Location stated is Talmenes, Idlib. Cropped.
- Latest updated November 4, 2012..
Around the beginning of October this year large unexploded bombs, like the one in the photo above, started to appear in video-reports from Syria. Seven of those video-reports are listed below. The reports at labeled as one being from the Aleppo region, one from Daraa and five from the area around Maraat Al-Numan in the Idlib Governorate:

#1: an unexplopded bomb laying with nose against a rock.
Uploaded 02/02/2013 to عامود حوران YouTube channel. Location: Busra Al-Harir, Daraa (according to title).

#2: a jet passing, a large explosion, then a bomb with smashed tail in a shop space.
Uploaded 12/10/2012 to YouTube channel. Location: Saraqib, Idlib (acc2 title).

#3: bomb laying in a yard.
Uploaded 12/10/2012 to YouTube channel. Location: Ma`arr Shamshah, Idlib (acc2 title).

#4: bomb laying in a field.
Uploaded 12/10/2012 to YouTube channel. Location: Ma`arr Shamshah, Idlib (acc2 title).

#5: bomb with tail section ripped off laying in the street.
Uploaded16/10/2012 to YouTube channel. Location: Hich, Idlib (acc2 title).

#6: bomb laying on the ground, supported by a tire.
Uploaded 19/10/2012 to YouTube channel. Location: Idlib (acc2 title).
#7: bombs laying in a green field.
Uploaded 22/11/2012 to hamzaansar8 YouTube channel. Location:Kafr Naha, Dar Taizzah, Western Aleppo counrtyside (acc2 title).

The bombs are clearly large aerial free fall (unguided) bombs. It is also clear, that they belong to the Russian/Soviet family of aerial bombs. Several of its members have already been identified as being used by the Syrian government airforce (OFAB 100-120 and OFAB 250-270 high explosive fragmentation bombs, the RBK 250 cluster bomb, the ODAB-500 fuel-air/vacuum bomb, and the BetAB 500 high explosive concrete penetration bomb), but just as clearly, this model differs from those earlier identified.

The assumption, since this new model started to appear, has been, that it is a version of the FAB general purpose bomb - a so-called blast bomb - but some uncertainty has remained, particularly about whether the size is 250 kg or 500 kg (over all weight).
This post is meant as an attempt at establishing the shape and size of the video-reported bombs, in order to make a comparison to reference material possible.

Eliot Higgins - who has been doing a massive effort reporting about weapons used in the Syrian conflict on the Brown Moses Blog - has gathered the main part of the videos listed, and from him I also got the suggestion, that the video-reported bombs might be of the FAB 500-M62 model.
Outline of a FAB 500 M62 taken from a Wikipedia illustration.
The above outline is of such a FAB 500-M62 from an illustration in Wikipedia. Wikipedia also lists some of the specifications of the model. Diameter (400 mm) and overall length (2425 mm) are useful in relation to this.

Another figure, that is important to be able to measure the size of these bombs, is the distance between the suspension lugs (used to attach the bombs to the hardpoints of helicopters and jets). According to the Russian Ministry of Deference's official reference book these have a standard spacing of 250 mm for bomb sizes of 250 - 500 kg across the different models/types (Many thanks to Vadim Naninets for helping with this).

From an immediate visual comparison to the video-reported bombs a number of characteristics correspond, the most clear of these being the tapering of the shape towards the rear: on these bombs - unlike other models - the volume, that contains the explosives, tapers over the last 1/4 of its length, and the tapering is then continued by a seemingly hollow tail section.
frames from a video no longer awailable and from the #2 of the list earlier in this post.
The suspension lugs are the two small protruding parts, which can be seen on the topside of both bombs.
To strengthen this comparison, and to try to reach a conclusion about the size, I have used frames from some of the videos to reconstruct an outline of the bombs.

In the image above frames from video-reports are used to draw the shape of the main body of the bomb (the smashed tail sections give a clear indication of where the hollow part starts). In the image below I have extended the lines of the tapering to get an idea of the overall length of the bomb. I have also indicated a relative measuring of diameter, lug spacing and overall length.
frame from video #5 of the list.
It is already clear that the reconstructed outline - even if it comes close - isn't an exact match of the outline from Wikipedia. But then; if the Wikipedia outline is measured it turns out to be a little too slim to fit the listed specifications, and as can be seen the specifications seems to match the reconstructed outline to a degree that is as good as can be achieved in a study like this

A few comments about the measuring:

I started this analysis before I had the confirmed spacing for the suspension lugs, therefore I have used the assumed 40 cm diameter as a reference unit.
By subdividing this unit into 10 cm sections, and transferring it to measure the spacing of the suspension lugs, it shows, that there is a good match with the 25 cm standard. I consider this a confirmation of the 40 cm diameter.

The overall length of the reconstructed outline is a few centimetres too long, but since I didn't have any clear indication of where exactly to end the tapering, this in no way contradicts the identification. I therefore find this a very convincing match, both to the general design characteristics and to the listed specifications of the FAB 500-M62.

* I must however emphasize, that this matching is aimed at bringing attention to these reports and to how they can be interpreted. This does not qualify for a certainty that can form basis for decisions on the ground (note added December 23, 2012).

About the FAB 500-M62 (with the above note in mind):

A general purpose bomb is designed to be used against targets, which are not hardened to resist extraordinary pressures. These targets could be logistics and communications (like railway junctions and radar installations), industrial and energy facilities as well as weaponry and personnel. The effects on the targets are caused by the air pressure - the blast - from the explosion (as opposed to a fragmentations bomb, which is meant to work by the explosion causing it's thicker casing to fragment, and to have these metal fragments shoot out against the targets).
The specifications in Wikipedia are referenced to the brochure of a manufacturer, and they correspond with specifications found on the website of another manufacturer, and according to these, the bomb contains about 200 kg of high explosives (see note 2).

Such an amount makes this one of the most powerful bombs reported to have been used in the conflict (see note 3). For comparison the OFAB 250-270, that have been seen making huge craters (see note 4), carries just below a 100 kg of high explosives, and the OFAB 100-120, which is typically dropped by the L-39 Albatros, carries about 45 kg. According to what I have read, only the ODAB-500 fuel-air/vacuum bomb have an impact of the same scale.

That this coincides with the government having lost military control of Maraat Al-Numan, and there by with a strategically important part of the M5 Damascus - Aleppo highway, seems an obvious reason for an escalation in use of weapons, like what this evidence indicates (see note 5).

* note 1: the locations of the videos listed are not verified, but unusually huge blasts, following air-strikes, have been video-reported from verified locations in the same area during this period.  
* note 2: another source puts the weight of the explosives at 300 kg. This causes some unclarity as to what can be assumed to be found in the video-reported cases. A possible reason for the 50% difference could be that the term TNT equivalent is used in relation to the 300 kg figure. If the 200 kg figure from Wikipedia refers to actual weight of explosives, this could possibly explain this.(added 17/12/2012).
* note 3: this is by the time of the publishing of the post (November 1, 2012).
* note 4: I can not say for certain, that the crater in the linked-to video-report is from an OFAB 250-270, but the size is similar to other craters, that started to appear in videos at the same time and in the same areas where also unexploded OFAB 250-270 where reported (link and note added 04/11/2012).
* note 5: Originally I made a jump form "very convincing match" to presenting thoughts, which were taking for certain, that FAB 500s are or have been used by the Syrian government air-force. Technically that was stepping outside what the evidence can tell. In theory all the videos showing unexploded bombs could be false or recorded elsewhere. Another issue, that might make such a jump invalid, is, if another bomb, that has the same design, exists. I'm not capable of excluding that either; therefore please apply you own judgement. (note about this added to original text 05/11/2012. Section "adjusted" 26/12/2012).

Addition, November 3, 2012:

Below I have added a frame-sequence from a video, which I suspect, shows the detonation of a bomb of this kind (see note 4). The location of this recording has been verified by Storyful as Maarat Hurma (about 15 km SW of Maraat Al-Numan), and the YouTube account has several similar recordings (added 03/11/2012).
frames from one of the videos, that I suspect shows the detonation of a FAB 500. Source: video on احمد الشيخو YouTube channel.

My reason to believe, that this could be a FAB 500, and not an ODAB 500 (fuel-air/vacuum), is the way the dust and smoke shoots out from a relatively small centre. The explosive fuel of the ODAB is spread to a larger area when it ignites. For reference: an earlier analysed recording of an ODAB explosion in this post.

Update November 13, 2012: Unexploded FABs used for (large) suicide bomb:
Photos published on the as-ansar.com forum with White Minaret logos. Left: (looks like) 4 FAB-500 duds and 4 other containers on a truck bed. Centre: view of targeted site. Right: the explosion.
Four objects (#1, 4, 6 and 8 from the left on the truck bed in image above) visually matching unexploded FAB-500s, are claimed to have been part of a suicide bomb, used by Jabhat Al-Nusra in Hama countryside. The target is said to have been a rural development building, which had been turned into a Shabiha and security base, and the number of casualties is claimed to be at least 200 dead plus "filling the hospital with hundreds of wounded".

According to AFP the attack took place in the morning on November 5. AlJazeera also mentions the attack on November 6 (2012), and the location given is a village called Ziyara. At the moment I have not been able to locate it on the map, but this compound has been suggested as the possible site. (many thanks to @troublejee for links and more, and to @Brown_Moses for pointing to possible FABs).


Caution: It is not to tell why these bombs didn't explode, neither is it possible to know what might still cause them to detonate. Handling these is potentially extremely dangerous. And in relation to bombs like these this endangerment involves anyone within a large radius.

Handling of unexploded munitions should only be done by professionals. Anyone else should take note of the ARMS guidelines:

- Avoid the area
- Record all relevant information from a safe distance
- Mark the area to warn others
- Seek assistance from the relevant authorities

- link to print-out poster and warning flags in Arabic and English from R.R.M.A.

Relevant posts on this blog:
- The Weapons Of The Syrian Air Force
- Syrian Airforce Unleashed
- Fuel air bombs? Evidence from Talbiseh
- Syrian Airforce use of the L-39 Albatros

- any correction and suggestions are welcome. You can either leave information as a comment or reach me via Twitter at @bjoernen_hj

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