Artillery 75mm vs. 81mm

[Incoming]

I noticed the 75mm artillery (axis and allies) have a much higher blast value than the 81mm mortar. for allies 39 to 18, axis 36 to 19.

What were the intended uses of the 81mm arty?

I assume the 75mm was used more against personnel while the 81 more against light vehicles and guns?

I have been using 81mm in most games against infantry, I guess 75mm is what i should be using for that purpose?

[Guest wwb_99]

75mm has a higher blast rating because the shells are bigger and heavier. 75mm shells are bigger & heavier because they are fired from field guns or howitzers as opposed to mortars. The barrels of the guns are much stronger, allowing them to use more explosive 'push' on the projectile.

81mm mortars are fired from, well, 81mm mortars. Just like the ones you can buy in CM. Note that they are man portable weapons systems.

The main purpose of 81mm mortars is to provide quick, on call fire support to front line troops. This is because mortars were part of the Battalion, not a higher formation. This means less people to beg for fire support, meaning it gets there alot quicker.

The purpose of both is to hit troops in the open. Neither is quite big enough to really damage dug in troops.

WWB

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Before battle, my digital soldiers turn to me and say,

Ave, Caesar! Morituri te salutamus.

[ParaBellum]

IMHO since both lack the blast radius for "killing" troops, I only use them to suppress the enemy. Since you get much more 81mm ammo than 75mm I usually take the 81mm for suppressing and something "heavier" for killing.

If you're low on points (1000 less) The 75mm is a good compromise, if you use them correctly.

Hope that helps you in any way...

And as you mentioned correctly, 81mm is great for taking out guns and to force tanks to button up if you don't have onboard mortars.

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Klotzen, nicht kleckern!

[Guest Martin Cracauer]

Anyone knows how many 81mm mortars would be realistic to have in a battallion and how many of them would be for FO use and how many with direct sight?

I assume the CMBO FO represents 4 pieces, right?

Martin

[Goanna]

Well in teh CMMC planning we were doing, the standard US Infantry battalion had 9-60mm mortars (I assume for direct fire support of the attached companies) and 6-81mm mortars which I would assume are to be indirect fired under the direction of the battalion HQ.

On the German side, a standard Panzergrenadier batallion had only a single 81mm mortar attached to the battalion.

Hope that helps some.

[jasoncawley@ameritech.net]

6 mortars. Both sides used mortar batteries of 6 mortars (Brits too). It is not obvious, incidentally, that CM is not depicting that already.

The rate of fire of light mortars is almost arbitrarily high. The real measure of the weight of support is therefore not the number of tubes, but the number of rounds fired. Which is 200 for the U.S. module and 150 for the German one, for example (a difference refected in their price).

A larger battery allows them to come down faster, and may therefore help to catch people before they get to cover, but it is mostly 6 of one, half a dozen of the other. Support by the battalion mortars, the most common for of indirect fire support by far incidentally, should be 1 module, not several.

Incidentally, the persistent confusion about German 81mm TOEs in Pz Gdr units, seems to reflect the fact that *armored* ones had only the company level mortars, while motorized ones had the same set up as leg infantry - 2 per company plus 6 for the battalion. And this is further confused by the units generally not being at full TOE strength.

When you look at the mortar strengths of units in a particular battle, you find battalions with 6, and 6, and 8, and 10, and 12, and 11 81mm mortars. They were trying to have 2 per company for direct fire, and a mortar battery at battalion level for the non-armored troops. (Why non-armored? Because the half-track mounted guys used more gun halftracks instead).

As for the 75mm indirect, their use varies a bit. For the Germans, that is the fire of the regimental gun company, using infantry guns. (Occasionally it might be captured Russian field pieces in a divisional artillery battalion, but that is relatively rare). The mountain troops also had 75mm howitzers.

For German "leg" infantry, this would be a relatively common form of supplimental artillery fire, but less common that divisional 105mm, and much less common that battalion 81mm mortars. The 75mm infantry guns were often used for direct fire as infantry heavy weapons, rather than "in battery" like this.

On the Allied side, the airborne both U.S. and U.K. used 75mm pack howitzers, because they are more easily landed by air. Along with 81mm or 3" mortars, it would be the most common for of fire support for them in air-landed situations, like early D-Day or Market-Garden. In addition, the U.S. cavalry forces would get 75mm indirect fire from their M8 HMC "assault guns", which were fired as a battery indirect, whenever the front was stable (screening, defense roles, etc). And last, every U.S. infantry regiment had a cannon company. Most of thes had already converted to 105mm pack howitzers, but some still had the older 75mm.

That is just who would have them stuff. In CM terms, the 75mm hits harder but with fewer shells; the mortars also "react" faster to calls for fire. The total hitting power is comparable for either type, with the 81mm more likely to effect every unit in the targeted area somewhat, but the 75mm more likely to mess one of two of them up badly. Both are meant to hurt infantry.

Both are primarily suppression weapons (meaning, keep someone from firing or pin them to allow infantry to rush them the moment the barrage stops). But can cut up troops in the open or in woods without foxhole cover, reasonably well.

These light arty types "don't do buildings" and are marginal against troops in wooded foxholes, able to pin them while the barrage lasts but not much else. They are fine defender's weapons because of this, less useful on the attack. But the mortars are a useful artillery type to lay smoke with, for attackers, because the quick response time and high ammo supply are key, and the payload mostly irrelevant, in that role.

[Simon Fox]

Support by the battalion mortars, the most common for of indirect fire support by far incidentally, should be 1 module, not several.

Why? If each module is 4 tubes then that's 2/3 of a battalions mortar platoon. What's the other 1/3 doing? IIRC correctly the Brits organised their mortar Plt into 3 sections of 2 tubes. A 200round module for 6 tubes isn't exactly generous. My inclination would be that for a battalion sized engagment over a longer battle (40-60 turns) supplying an extra module via a reinforcing mortar FOO wouldn't be unreasonable.

BTW the Brit armoured car regiments had organic 75mm support from the halftrack mounted version.

[Olle Petersson]

Originally posted by jasoncawley@ameritech.net:

The rate of fire of light mortars is almost arbitrarily high. ...

But only for about two minutes. Then the barrel is close to overheating, and the useful ROF is dropped radically to something in the magnitude of one rpm.

This isn't modelled in CM...

Cheers

Olle