Tremendous Lethality of Russian 82mm Mortar

[rexford]

Miles Krogfus, who does some really great research on German, ALlied and Russian arms and armor using original documents recently sent me a copy of a U.S. analysis of Russian ordnance and armor (1953, By a metallurgist named Hurlich).

Following information and data is really telling with regard to 82mm Russian mortar:

1. Russian mortar rounds used cast iron which put out more fragments than forged steel used by U.S.81mm mortar, and shape of fragments from cast iron were of optimum shape (cast fragments tended to be small and rounded instead of long splinters from forged steel)

2. Russian mortar rounds appear to be designed for maximum fragmentation instead of blast

3. At 20' from blast point, Russian 82mm mortar puts out 4.3 times the number of effective hits of U.S. 81mm mortar which uses forged steel projectile (round detonated in middle of range, where center is surrounded by pine boards for measurement of average effective fragment density)

4. At 40' from blast point, Russian 82mm mortar makes 8.3 times the effective hits of U.S. 81mm mortar

5. Russians chose 82mm mortar size because captured 81mm ammo would work in their mortar, but when enemies captured Russian 82mm mortar rounds they would be useless with 81mm mortars.

6. Russian 120mm mortar was described as having "terrifying capabilities" due to the extremely high output of effective fragments

7. Russian mortar and artillery HE rounds have thicker walls and heavier weights of metal than corresponding U.S. ammo, which promotes fragment generation

8. British tests appear to have found that cast iron mortar rounds were more effective at casualty generation

[SgtMuhammed]

This fits with the general philosophy of each army. In the U.S. the primary anti-personel weapon was the rifleman while fire support (mortars and arty) were primarily responsible for dealing with fortifications. The better blast characteristics tend to perform better against hard points than the Soviet rounds which are optimized for use against enemy troops without cover.

[Guest Mike]

Somewhere I read that Cast Iron was always known to be better at producing fragments, but forged bombs had better ballistic properties and would fly further and more accurately - I think it was to do with surface finish and accuracey of shape - ie cast bombs are somewhat rougher, and the casting process has significantly larger tolerances than forging does.

[Spook]

Checking back to CMBO, the "blast values" of the various mortars are as follows:

US 81mm -- 18

German 81mm -- 19

British 3" -- 26

In CMBB,

Soviet 82mm -- 26

Thus while the Soviet mortar rates over its German & US counterparts, the British unit seems comparable.

It doesn't surprise me much of the Soviet 82mm mortar rating well. The Germans basically copied their 120mm mortar from captured Soviet 120mm types.

[Panzer76]

Interesting. Now the question is, does CMBB reflect this?

[Panzer76]

Originally posted by Spook:

Checking back to CMBO, the "blast values" of the various mortars are as follows:

US 81mm -- 18

German 81mm -- 19

British 3" -- 26

In CMBB,

Soviet 82mm -- 26

You cant use the CMBO blast and compare it with CMBB blast values because the general blast values in CMBB are higher than in CMBO. E.g. the same gun in CMBO has a lower blast value than in CMBB.

[ January 12, 2003, 08:03 PM: Message edited by: Panzer76 ]

[Krazy Canuck]

Originally posted by Panzer76:

Interesting. Now the question is, does CMBB reflect this?

Well it is 27+% greater than the Germans.

KC

Oops, your right, in CMBB the German 81 has a blast rating of 26, so, with egg on my face, I retract the previous.

[ January 12, 2003, 07:51 PM: Message edited by: Krazy Canuck ]

[John D Salt]

Originally posted by rexford:

[snips]

2. Russian mortar rounds appear to be designed for maximum fragmentation instead of blast

No surprise there. For most battlefield HE weapons, blast is such a minor casualty-causing effect compared to fragmentation that it can safely be ignored. Trawling through the WW2 OR files in the PRO, I have found numerous papers on fragmentation, but blast effects did not seem to have been much of a concern.

Originally posted by rexford:

7. Russian mortar and artillery HE rounds have thicker walls and heavier weights of metal than corresponding U.S. ammo, which promotes fragment generation

That seems wrong to me. According to exercise 7 in "Applied Operations Research: Examples from defense assessment" (Shephard, Hartley, Haysman, Thorpe and Bathe, Plenum Press, 1988) the optimum charge-to-weight ratio is something like 60 to 80%, whereas few ballistic projectiles have charges over 30% of total weight. Adding explosive filler is therefore a better way to improve effectiveness than adding casing metal.

Originally posted by rexford:

8. British tests appear to have found that cast iron mortar rounds were more effective at casualty generation

PRO document WO 291/107 mentions that the 7.5 lb bomb for the 3" mortar fragments as well as the 10 lb bomb, but I have not been able to find out what meterial either bomb was made of.

All the best,

John.

[Spook]

Originally posted by Panzer76:

</font><blockquote>quote:</font><hr />Originally posted by Spook:

Checking back to CMBO, the "blast values" of the various mortars are as follows:

US 81mm -- 18

German 81mm -- 19

British 3" -- 26

In CMBB,

Soviet 82mm -- 26

You cant use the CMBO blast and compare it with CMBB blast values because the general blast values in CMBB are higher than in CMBO. E.g. the same gun in CMBO has a lower blast value in CMBB.</font>

[YankeeDog]

Originally posted by Panzer76:

Interesting. Now the question is, does CMBB reflect this?

Well, "Blast Ratings" for German 81mm and Soviet 82mm are the same (26), but Rexford's post doesn't mention how German 81mm rounds compared to Soviet 82mm rounds, but rather just how US and Soviet rounds compared. IIRC, the Germans did use a forged bomb more like the US 81mm round that the Soviet cast bomb, though. If my recollection is correct, then one would expect US and German rounds to be similar in performance.

However, CM Blast Ratings are abstractions - they are intended to give a general idea of a shell or bomb's power, and are actually the averaging of a number of attributes which the engine tracks and models. IOW, two shells with the same Blast Rating might not necessarily be identical in effects - one might be more effective against troops in the open, but the other tend to cause more damage to buildings, etc.

So unless BFC wants to weigh in the question, it's difficult to say for sure if the issues Rexford brings up are modeled. I suppose you could build a test with 81mm mortar spotters firing on a troop formation and then track casualties and morale, but you'd have to do A LOT of runs to get a large enough sample size to say anything definitively since there's so much randomness in Artillery's effects.

Cheers,

YD

[Simon Fox]

Originally posted by John D Salt:

PRO document WO 291/107 mentions that the 7.5 lb bomb for the 3" mortar fragments as well as the 10 lb bomb, but I have not been able to find out what material either bomb was made of.

WO 291/129 "Lethality of 3" mortar HE bomb"

[ January 12, 2003, 08:25 PM: Message edited by: Simon Fox ]

[John D Salt]

Originally posted by Simon Fox:

</font><blockquote>quote:</font><hr />Originally posted by John D Salt:

PRO document WO 291/107 mentions that the 7.5 lb bomb for the 3" mortar fragments as well as the 10 lb bomb, but I have not been able to find out what material either bomb was made of.

WO 291/129 "Lethality of 3" mortar HE bomb"</font>

[Leeo]

<big>GROGS!</big>

(runs away giggling and tittering, flinging flowers along the way)

Seriously, heart-felt thanks to you folks who have the interest, persistence, and dedication to chase down all the little facts that contribute to making this game better in every detail.

<big>HUhh-Rrraaahhhh!!!</big>

[JasonC]

"More" I am prepared to believe. 4-8 times as much sounds much more like a comparison of the 120mm and the 81mm, than like a comparison of the 82mm and the 81mm.

[SgtMuhammed]

Well I know it is possible to greatly increase frag generation by how you shape the explosive cavity. For example if it is faceted it will give a better fragment yield. Maybe the Soviets did that, the report doesn't mention any examination of the shells other than that they were iron. American shells though do tend to break up into at least one or two large pieces with a bunch of small splinters rather than just a ton of small splinters.

[Michael Emrys]

Originally posted by JasonC:

Something argumentative and pedantic.

Jason! Where have you been, Boy? We've missed you. And you've missed a heaping metric ton of discussions and arguments.

Welcome back!

Michael

[rexford]

Originally posted by JasonC:

"More" I am prepared to believe. 4-8 times as much sounds much more like a comparison of the 120mm and the 81mm, than like a comparison of the 82mm and the 81mm.

Those are the ratio's of board penetrations after tests of 82mm and 81mm mortars.