Mortars vs Artillery

[kalos72]

Question...obviously range is a big difference but is there a "use" or "design" difference between say a heavy mortar and a towed howitzer?

[CDAT]

I am not now, and never have been a red leg, but my understanding is that the arc of fire is also a big difference.

[Webstral]

I'm not a red leg either, so my knowledge has real limits.

As CDAT points out, the ballistic trajectory of the round is dependent upon the type of artillery used to fire it. The higher the muzzle velocity, the flatter the trajectory of the round. Flatter trajectory means longer range, all things being equal.

The category Field Artillery includes two types of tube artillery: field guns and howitzers. Field guns achieve higher muzzle velocity than howitzers, As a consequence, field guns have comparatively longer ranges. The flat trajectory of fire from a field gun means that the gunners can't hit targets behind a hill. Howitzers, with their lower muzzle velocity, can be used to hit targets behind a hill but suffer from range limitations.

Mortars, with their comparatively low muzzle velocity, have several advantages over their cousins in the field artillery. The high arc trajectory of a mortar round in flight means the crew can put mortar rounds into a trench. Obviously, they have to know what they are doing to make this happen at ranges of 1km or more. Still, the high angle of descent of the round makes getting an HE round into the enemy's trench feasible, if not very easy. This very possibility is what brought mortars back into common use in WW1.

One advantage of the low muzzle velocity of the mortar round is that the firing of the round develops a much lower pressure compared to the pressure generated inside a howitzer or field gun. Consequently, mortars can be much lighter than a howitzer or field gun firing a shell of equal caliber. Also, the shell casing of a mortar round can be made thinner than the shell casing of a field artillery round of equal caliber. A 120mm mortar round would pack more HE than a 120mm howitzer round, if there were a 120mm howitzer round. So a 120mm mortar unit is useful for really delivering punishment out to 5km, whereas the markedly smaller 105mm howitzers pushes its rounds out much further.

Again, I'm no red leg, so you have to take my somewhat anecdotal observations about mortars v field artillery with salt. When I have looked at fire mission planning for the 120mm mortars that are assigned to heavy battalions versus the missions assigned to the 155mm field pieces supporting a brigade, the mortars fire more smoke per tube. One has to bear in mind that these two IF systems are apples and oranges. In US doctrine, medium and heavy mortars are often assigned at battalion level in platoons of 4-6 tubes. Howitzers and field guns typically are organized as battalions of 18-24 tubes assigned to brigades or larger formations. The concept of use is derived from the characteristics of the pieces.

It's a shame I'm not with my NG infantry unit anymore (other than the fact that had I stayed with them I'd have done a second tour in Iraq and a tour in Afghanistan by now). I'd be able to call on one of the mortarmen for better answers.

[kalos72]

Great info, thanks guys.

From the doctrine perspective, I wonder if it was just the feeling a battalion didnt need to reach out and touch someone at 15km since that would be outside its AO?

In my game, light battalions, with additional heavy weapon support, are assigned a county. Currently they are given light mortars at the platoon level and 4.2's at the battalion level. I was wondering given their typical AO, if heavy fire support would be needed.

[unkated]

The other trick is that light mortars (50-81mm) are small enough that they do not require any specialized means of transport, so to attach them at company or battalion level does not require a peculiarity in the TO&E, or an attachment, nor does it require specialists from another branch of the army - mortarmen are infantrymen.

The point is to provide the battalion some extra support at a low tactical level, where the response time is very short. And, yes, the range on light mortars is more likely to be directly applicable to the needs of the battalion or company.

Once upon a time, Regiments had a gun section for the same reason.

Uncle Ted

[Askold]

Originally Posted by unkated

The other trick is that light mortars (50-81mm) are small enough that they do not require any specialized means of transport, so to attach them at company or battalion level does not require a peculiarity in the TO&E, or an attachment, nor does it require specialists from another branch of the army - mortarmen are infantrymen.

The point is to provide the battalion some extra support at a low tactical level, where the response time is very short. And, yes, the range on light mortars is more likely to be directly applicable to the needs of the battalion or company.

Once upon a time, Regiments had a gun section for the same reason.

Uncle Ted

I think that is their main selling point.

A cannon with the same firepower would be much heavier and need to be transported by vehicles. Meanwhile there are mortars that are light enough to be carried by one person (WW2 had some tiny mortars being used...)

Grenade launchers and grenade machineguns also offer firepower to infantry units but having a few 81mm mortars a kilometer or two away from you does offer nice fire support AND they can usually reach far enough to help another company in the battalion AND the ammo is usually more versatile. (HE, WP, Flares, smoke and so on.)

[swaghauler]

The US Army has no proper "field guns." A field gun was a WW2 term for a towed Anti-Tank gun. the Russian 37mm, 57mm and 76mm WW2 Anti Tank guns were "field guns." The US embraced the concept of a "general utility platform" for its artillery after WW2. This was based on observations about the German use of the 88mm Flak gun as an AT gun, an AA gun, and a fire support weapon. The Army later dropped any AA missions from the field artillery.
The US Army did continue the concept of a multipurpose gun with regards to AT and fire support. Both the M102 105mm GUN/HOWITZER and The M198 155mm GUN/HOWITZER that I served on with the 10th Mountain had HEAT warheads and the M198 could fire the Copperhead laser guided AT missile. Both the HEAT and The Copperhead could be fired indirectly if needed. You would fire the HEAT at an extremely steep angle to induce plunging fire (for bunkers) and the Copperhead would stabilize itself in flight. Mortar crews were just our little brothers. We were even slated to begin using the same fuses in our rounds (they were converting over to ours). While AT missions were part of our training; I would not have wanted to do it in real life. Our guns had manual traverse and elevation. Our 155mm shells weighed 96 lbs and we had a maximum effective range of 18km with conventional shells. The newer "base bleed" shells (which generated a gas vortex behind them) were good for about 22km (depending on the shell- HE, GAS, HEAT, etc..) our enhanced RAP rounds (rocket assisted projectile) were good for almost 40km but our Circular Probability of Error (CEP) increased significantly. The CEP of conventional shells was about 100 meters around intended impact point. Newer low drag and base bleed rounds brought that down to 30 meters CEP at 15Km and about 50 meters CEP at maximum IFR.

It is important to note that the rounds a 105mm, 155mm, or 203mm Howitzer fired travel at just under 900 meters a second. it would take TEN SECONDS for a round to travel 9km. The IFR rules in Twilight2000 should take this into account.

In my game it takes 1 minute to call a fire mission plus 2 rounds to fire the gun. I then add the appropriate flight time. My players will often "make a stand" to give the FO time to "call fire." The FO also is required to have a Topo Map and a compass in order to call fire (he must determine the enemy's grid coordinates). My players made the FO the navigator as well.

When determining hit location of rounds; I use 1d20 - FO's roll under skill/hit chance X 5m for deviation of the rounds (0 means an "ATTABOY!, or direct hit- these are much coveted in the artillery) with a CEP of 100m. I use 1D6- FO's roll under his skill/hit chance X 5m for rounds with a CEP of 30m. On a miss; I add the amount missed by to the CEP roll.
I also divide the Indirect Fire Range into 4 range bands which add (12km IFR becomes SHT-3km, Med-6km, Lng-9km, Ext-12km) with appropriately decreasing to hit skill to represent the difficulty of long range fire.

I hope this helps you out.

Swag

[kalos72]

Nice details swag!

Unkated - I am thinking of moving the heavy mortars to the company level and adding 2-3 towed pieces to the battalion level.

Anitarmor/scouts are at the battalion level as well.


Thoughts?

[ArmySGT.]

Originally Posted by kalos72

Question...obviously range is a big difference but is there a "use" or "design" difference between say a heavy mortar and a towed howitzer?

Cannon are direct fire. Howitzers are indirect fire. Mortars threw a bomb over a wall or high enough upward to fall straight down and not at an angle. This got a bomb into a trench work or to impact near the base of the wall on the defenders side. Mortar bombs are lower velocity and pound for pound often have greater explosive filler than a shell.

Early blackpowder breech loading mortars are massive to absorb the detonation of an explosive bomb in the breech should one prematurely detonate. Mortars came before howitzers until explosive shells had matured enough to not blow up in gun barrels destroying them. Howitzers also came about as the defenses were built and manned further out creating more depth in the defense that was outside the maximum range of many mortars.

[kalos72]

Here is the idea we are working with...remember this is for my campaign and isn't expected to fit most of yours.

I think the medical platoon is too big and I dont know how to break down the "service" platoon yet so its just a made up number...

[Apache6]

Kalos 72:

All comments are recommendations worth at least what you paid for them. (humor attempt)

I'm assuming (but could be wrong) you are using LCV to be "light cargo vehicle" and UCV to mean "larger cargo vehicle." Is that correct?

If this is a US based organization, I think it would much more likely be a Task Force then a Battalion, since there are units that would normally be reinforcements to a Inf Battalion, as opposed to organic elements (Engineers, MPs, and Artillery for example).

In the Headquarters Company consider adding a "Command Post" section. This might include a Intelligence Section (S-2) (the Scout and Snipers would likely work for them), an operations Section (S-3)(+/- 7 men who run the Command Post(CP)), Logistics Secition (S-4) and Comms Section (S-6).

Assuming they have radios and when static wire capabiliities, I recommend you add a Communications Platoons, 5 - 7 (including the S-6) men who work in the Bn Command Post and those who are assigned to Co and Platoons.

The Support Section: For T2K might look something like
Logistics Section HQ: 2 men (Logistics officer and his chief)
Armory Section: 4 men
Supply Section: 17 men (primarily concerned with fuel and food stockage and delivery)
Mess (Food Service) Section: 13 men (Mess Sgt and 3 x 4 man teams each cooks for a Co with a field kitchen trailer?)
Motor Tranport Maintenance Section: 18 men
Ammo Section: 6 men
Medical Platoon (your numbers don't look too high assuming no other support).

I'd recommend you enlarge your engineer platoon (give them 13 man squads).


I'd recommend you consolidate the light mortar squads and HMG Squads from your companies into a "weapons platoon." The weapons would actually operate in support of the rifle platoons but they would likely be more effective, beter supplied and better trained if in a platoon, where they could be massed as required.

- Your unit is very light on anti armor weapons. You may want to consider giving "bazookas" or RPG-7 or 16 at least at Platoon Level, and maybe add a "Anti-Armor" platoon at Bn Level (with towed AT Guns or ATGM?)

[kalos72]

Apache - Thanks for the feedback, always welcome.

1 - Light Combat Vehicle and Unarmored cargo vehicle
2 - US based - Texas Based
3 - Nice detail on the HQ Company thanks - will do
4 - Same with Support thanks
5 - MP was supposed to be the quick reaction style force before I added the Scout Platoon - Scout Platoon is also the Anti-Armor support as needed
6 - Weapons Platoon at the company level? I would need to increase the numbers to make sure that each platoon had the right heavy weapons support - makes sense

[unkated]

Originally Posted by kalos72

Here is the idea we are working with...remember this is for my campaign and isn't expected to fit most of yours.

You did ask.

It doesn't seem particularly light to me. But weight is in the eye of the beholder, I guess.

However, looking at basics -

• Your basic platoon has a lot of elements for one guy to handle (7 - two weapons, two mortar, 3 maneuver squads), and that's before you add in anything other attachments he might get (say an engineer squad, AT team, crew from a weapons squad), or being called to ask about artillery). The common wisdom is 3-4.
  
• Also, for a 'light' unit, 4 of the 7 elements of a basic infantry platoon have sedentary jobs (set up here, fire that way; when the attack is done, pack up and move on). Doesn't strike me as mobile. Even with vehicles, that's a lot of guys not in the assault who are also not available during the pack-up and move phase.

Uncle Ted

[ArmySGT.]

1989 Soviet Artillery Regiment

[kalos72]

Originally Posted by unkated

You did ask.

It doesn't seem particularly light to me. But weight is in the eye of the beholder, I guess.

However, looking at basics -

• Your basic platoon has a lot of elements for one guy to handle (7 - two weapons, two mortar, 3 maneuver squads), and that's before you add in anything other attachments he might get (say an engineer squad, AT team, crew from a weapons squad), or being called to ask about artillery). The common wisdom is 3-4.
  
• Also, for a 'light' unit, 4 of the 7 elements of a basic infantry platoon have sedentary jobs (set up here, fire that way; when the attack is done, pack up and move on). Doesn't strike me as mobile. Even with vehicles, that's a lot of guys not in the assault who are also not available during the pack-up and move phase.

Uncle Ted

Thanks Ted.

"Light" originally meant more the lack of mechanized/armored support but to your point with all the extra firepower I added perhaps "light" should be more just "infantry".

Can you explain a bit more on your thoughts of the "3-4 wisdom"? I am not sure I follow you.

[CDAT]

Originally Posted by kalos72

Thanks Ted.

"Light" originally meant more the lack of mechanized/armored support but to your point with all the extra firepower I added perhaps "light" should be more just "infantry".

Can you explain a bit more on your thoughts of the "3-4 wisdom"? I am not sure I follow you.

I think he is talking about span of control, you try to keep any commander from having to large a span of control 3-5, three being ideal, five a bit much for most people, more is bad as you start to loose out on the ability to keep track of what is going on with your guys.

[kalos72]

Gotcha,

Thoughts about moving the light mortars and HMG squads to a weapons platoon at the company level, what about the heavy mortar platoon I have there now?
Leave it combine them all into one weapons platoon?

Seems to make sense to combine them except the heavies will never be assigned to a platoon like the other support weapons.

[Adm.Lee]

Originally Posted by kalos72

Can you explain a bit more on your thoughts of the "3-4 wisdom"? I am not sure I follow you.

The rule of thumb in making TO&Es is that a commander shouldn't have to control (keep track of) more than 5 elements. The Soviets (see Suvorov) called it the "span of command", so all of their tables are built on 3s, and assume attachments. Less than 3 elements, and you can fold this unit into somewhere else; more than 5, and you need to break it down into two units.

Example: Motor-Rifle Battalion CO: 3 MR companies + mortar battery, possibility of engineer and/or tank attachments, in addition to specialist platoons that might either come to his attention or might be run by the XO as part of the HQ company.

Some COs could easily handle more than 5, but one shouldn't build army-wide TO&Es on the smart guy.

[Askold]

Mortars are usually better kept in designated support platoons of the infantry company or in separate mortar companies.

Simply because if you have a platoon/squad/section/etc that has both indirect fire weapons you face the problem that either the artillery/mortars can't shoot because the enemies are too close or the other squads are useless as the enemy is beyond their effective range. The range issue is even bigger with cannons.

...And endangering weapons that can have 40km range is unnecessary.

But when the heavy weapons are in a separate support unit/platoon you can park them further back from the front line and use them more effectively.

[kalos72]

Something like this work for the battery?

Section Leader and Platoon Sergeant will work as "Chief of Smoke" and radio operators are assigned out of the Comms Section as needed so they are listed here. Adding Ammo Section now...

Field Artillery Battery - 42 men / 10 UCV / 4 towed howitzers
Battery Headquarters – 6 men / 2 UCV
Battery Commander
Battery XO
Battery 1st Sergeant
Driver (x2)
FDC Section - 6 men / 2 UCV
Section Leader
Platoon Sergeant
FDC Specialists(x4)
Howitzer Section (x2) – 15 men / 4 UCV / 2 towed howitzer
Section Leader
Section Chief (X2)
Gunner(x4)
Loader (X6)
Ammo Carrier(x2)