Artillery effectiveness - Vehicles this time!

[John Kettler]

Alex and SlowMotion,

The first damaged/killed AFV pic is of an M577 command track sieved by 155mm shell splinters. The second is the much tougher Bradley. The third is a Centurion tank, and the fourth a T-72 tank. A ruined BMP-1 is the fifth pic. The sixth and seventh relate to vulnerable points on modern Russian AFVs, presumably as a way of showing the vulnerable systems on most modern AFVs and tanks. Skipping ahead, the ninth is a shattered M107 175 mm SP artillery piece. Even absent Google translation, footnote 4 pretty much says it all: A direct hit on an AFV with 155 mm PD fuzed kills the AFV so hit. This doesn't surprise me, even without explosive factored in, seeing as how a 155 shell weighs 42.18 kg. and has a terminal velocity of some 250+ m/s. Info from here, Figures 7-4, 7-5 and 7-16.

http://www.globalsecurity.org/military/library/policy/army/fm/6-40/Ch7.htm

During my time at Hughes Missile Systems Group, an M60? tank was destroyed by inert IIR Maverick missile impact on the engine compartment. Our weapon analyst computed the terminal KE for the weapon as being close to what a battleship shell produced at impact. This led to the joke: "We only have the warhead installed in case of a miss!" The impact of the fuel exhausted missile not only completely smashed in the engine compartment but set the tank on fire. I believe this was still a huge headache for noted armor collector Jacques Littlefield at the time of his death. You see, he somehow got the carcass off the range and was restoring the burnt out hulk. Call the task daunting!

Regards,

John Kettler

[c3k]

hcrof and John Kettler,

Thanks. I was, when I posted, thinking only of CM style units; the front troops. Yes, any type of soft, rear echelon (or just not armored) target would be vulnerable if not dug in.

John Kettler,

Very good information. The blast effects are quite impressive. I do have one little nit to pick regarding the fragmentation effect you list of the D-30 shell effecting 800m2. Those fragments would be heavier (due to shell vs. rocket shell wall thickness) than a 122 rocket. Therefore, wouldn't it stand to reason that the rocket fragmentation effective area would be reduced? Throw in my back of the envelope calculation of 1300m2 per incoming rocket and there are large "safe" areas. (And by "safe" I mean "world-rocking, eardrum rupturing, nausea inducing, splinter and rock filled, dust choked" kind of safe. ) Basically, not assured of being shredded by fragments. All that leaves out submunitions.

Thanks for the links.

With all that info, it reinforces my belief that artillery effectiveness is somewhat undermodelled in CMSF. That may be on purpose, to balance the accuracy and speed of artillery response.

I still think, especially based on what you posted, that a couple 155 rounds impacting on a building roof should be dramatically more effective in game. Shrug.

Thanks,

Ken

[John Kettler]

c3k,

At the time the BM-21 entered service, the 9M22 rockets it fired were a serious threat to the tanks of the period. We know this because tests with inert TOW missiles against M103 heavy tanks with live crews in them found even a propellant spent TOW quite capable of doing personnel endangering damage from impact forces alone against a buttoned tank. Sights, vision blocks, cupolas and more were smashed in scary early tests, necessitating special armoring of such kinetic weak spots. ISTR shock forces were also jamming the turret on occasion. Nor is there any doubt that a direct hit followed by warhead detonation would be very bad news for, say, an M48. Now, imagine all those rockets dumped into an assembly area where NATO forces are concentrating, with tanks, fuel and ammo being loaded, intermingled with logistics vehicles and men scurrying about. What a target!

Turning now to the vexed warhead issue, I actually found some authoritative data. Jane's, which lists the baseline warhead, the M-21-OF, as having a fill of 6.4 kg of TAG-F explosive.

http://www.janes.com/articles/Janes-Ammunition-Handbook/122-mm-BM-21-Grad-series-rockets-Russian-Federation.html

An APG abstract provides the following priceless grog data.

"Shell, 122mm, Soviet, Model OF-462, Ammonium Nitrate 80% - TNT 20%, will produce an average side fragment of 100.1 grains, with an initial velocity of 3089 fps, producing an average casualty range of approximately 82 feet. In the panel of 30 foot radius, 3.84 hits per square yard were inflicted, 1.49 of which were perforating. In the panel of 60 foot radius, 0.80 hits per square yard were obtained, 0.37 of which were perforating. The main fragment spray fell between 83 and 106 degrees from the nose of the shell."

Taken from here.

http://oai.dtic.mil/oai/oai?verb=getRecord&metadataPrefix=html&identifier=AD0394184

From Table 2 here at this authoritative artillery site, we learn that the OF-462 HE shell has a fill percentage by weight of 16.9, translating into 8.1 pounds (3.69 kg) of explosive, whose composition we now know. We've previously established that the M-21-OF has an explosive fill weight of 6.4 kg or 14 lbs, a substantial delta!

http://nigelef.tripod.com/wt_of_fire.htm

From the manufacturer, Splav, we learn that the M-21-OF weighs 18.4 kg, of which a staggering 6.4, we found earlier, are burster charge. 35% of the warhead is explosive, and I'd bet dollars to donuts TAG-F is far more powerful than what fills the OF-462. Average frag weights are given, too, allowing direct comparison. And just look at the cutaway drawing!

http://splav.org/en/arms/grad/m22u.asp

TAG (triaminoguanidinium) is indeed an advanced explosive and is quite powerful, as explained here. Presumably, TAG-F is in that same family.

http://docs.google.com/viewer?a=v&q=cache:N5zUOFXGDfsJ:www.asc2008.com/manuscripts/D/DP-11.pdf+TAG+high+explosive&hl=en&gl=us&pid=bl&srcid=ADGEESgPw7poarKDBw_cJJ5-tdnh2HQFVdnuR4vkRrqvwD9wG8hhb-kEpFK1_SeAdLfL_gPqcJcVLuzVADfbTiWwjJJSVn4fqvbHZ4SJ3f_t3iw3VJT903J-MS5qGIrxy5_GhkBUqk1F&sig=AHIEtbRz0n6w_Vkav9K2IlWA58H1lCpa_w

And from a U.S. patent application http://www.patentstorm.us/patents/5468313/fulltext.html we learn this

"Typical high explosives which can be used in the present invention include known and novel nitramines and other high explosives such as CL-20 (2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazatetracyclo[5.5.0.05,9.0 3,11 ]-dodecane), RDX (1,3,5-trinitro-1,3,5-triazacyclohexane), HMX (1,3,5,7-tetra-nitro-1,3,5,7-tetraazacyclooctane), TEX (4,10-dinitro-2,6,8,12-tetraoxa-4,10-diazatetracyclo[5.5.0.05,9.0.sup .3,11 ]dodecane), NTO (3-nitro-1,2,4-triazol-5-one), NQ (nitroguanidine), TAG nitrate (triaminoguanidinium trinitrate), PETN (pentaerythritol tetranitrate), TATB (1,3,5-triamino-2,4,6-trinitrobenzene), TNAZ (1,3,3-trinitroazetidine), ADN (ammonium dinitramide), DADNE (1,1-diamino-2,2-dinitro ethane), and mixtures thereof. Those skilled in the art will appreciate that other known and novel high explosives not listed above may also be used in the present invention. The high explosive will typically be present in a concentration from 50 wt. % to 80 wt. % and preferably from 60 wt. % to 70 wt. % of the total explosive composition. Polymodal particle size distributions of the high explosive are preferably used to obtain weight percent concentrations above about 65 percent.

Reactive metals may optionally be added to the explosive compositions of the present invention to achieve high heats of reaction. The reactive metal is preferably aluminum or magnesium, although other reactive metals may also be used such as boron, titanium, zirconium, silicon, or mixtures thereof. Selected metal alloys may also be used, such as aluminum/magnesium and aluminum/lithium alloys. These types of alloys have been used successfully in the solid rocket propellant industry. Such alloys react more completely than pure metals by virtue of the increased reactivity and lower ignition and cutoff temperatures. Increased metal reactivity further improves overall combustion efficiency which translates into the generation of greater amounts of heat during the reaction of the explosive. The reactive metal content of the explosive compositions within the scope of the present invention typically ranges from 0 wt. % to 20 wt. %, more preferably from 5 wt. % to 10 wt. %.

An oxidizer may optionally be included in the explosive compositions according to the present invention to assist in metal combustion. Typical oxidizers are preferably selected from AP (ammonium perchlorate) or AN (ammonium nitrate), although other oxidizers can be used such as HAN (hydroxylammonium nitrate), ADN (ammonium dinitramide), lithium perchlorate, potassium perchlorate, lithium nitrate, or mixtures thereof. Useful oxidizers are characterized by high density and oxygen content. The oxidizer will typically be present in a concentration from 0 wt. % to 20 wt. % of the total explosive composition."

I would note for the record that DoD's Soviet Military Power specifically and repeatedly commented on marked Russian superiority over the U.S. in explosives and their fielding of advanced explosives with amplified blast effects from the inclusion of (powdered) aluminum.

I'm no explosives expert, but I feel I've more than made my basic case: The 122mm rocket has both way more explosive fill and nastier explosive than a 122mm artillery shell, which really helps create a shattering effect on troops in the impact area.

As for the 155 HE vs. buildings, in real life: Prox to remove troops on the roof, PD to punch a hole in same and wipe out those nearby, Delay for devastating detonation within the building in order to wipe out occupants and collapse the structure.

Regards,

John Kettler

[John Kettler]

The entire Grad system in action is shown here, beginning around six minutes in, running through the end of the first vid and continuing briefly into the link following. Please take particular note of what things look like on the receiving end, as well as the manufacturing and engineering drawing sequences. Would say more, but my Russian is practically nil. A pity, given how info rich the vids seem to be.

Regards,

John Kettler

[John Kettler]

c3k,

Just to round things out, after the prior vid mostly devoted to the BM-27 Uragan with a bit of TOS-1 Buratino thrown in, this one covers more recent developments, BM-30 Smerch and its family of submunition warheads. Here, you can see the Bazalt SFW in action. Beginning to understand why I had nightmares sometimes as a Threat Analyst? Smerch is the business end of what the Russians called a reconnaissance-strike complex, a development they considered a "revolution in military affairs."

Regards,

John Kettler

[John Kettler]

c3k,

Here's the link I failed to include. Sorry about that!

Regards,

John Kettler

[John Kettler]

Here's a U.S. Army ordnance study that's about as topical as it gets: Fragment Penetration of Armor, complete with a section on artillery vs. AFVs.

http://handle.dtic.mil/100.2/ADA125824

Regards,

John Kettler

[John Kettler]

c3k,

Just found this gem: Fragment Penetration Tests of Armor. http://handle.dtic.mil/100.2/ADA125824 Even has a section on artillery vs. AFVs!

Regards,

John Kettler

[John Kettler]

c3k,

Looks like the first post got stuck (nothing showed), then posted belatedly. The second post, though, gave me a chance to fix the title.

Regards,

John Kettler

[John Kettler]

c3k,

What Marmot1 has to say here is quite useful. U.S. live fire tests found armor casualties from artillery frag damage to be more than twice what computer modeling predicted. Tests were conducted to determine Russian artillery effectiveness against our materiel and personnel in both PD and VT roles. Round quantity (56) suggests it represents a battalion 3 volley (18 x 3 = 54), with two rounds for adjustment.

http://www.militaryphotos.net/forums/showthread.php?t=23653

Regards,

John Kettler

[hoolaman]

It is fairly well proven in recent times that a large calibre artillery shell can damage and knock out an AFV if placed properly, it has happened dozens of times in Iraq.