The battlegroup gun

This blog post will argue for a multi-purpose, relatively short-ranged "battlegroup gun".

Army artillery was historically divided into siege artillery, fortress artillery, field (battle) artillery and regimental (infantry) guns.

The distinction between field artillery (later divisional artillery) and regimental or infantry guns (later battalion mortars) was driven by a need for long-range main effort artillery that dominates the battlefield on behalf of the army (or Napoleonic-era corps, later division) commander and some artillery that supports an infantry regiment (later battalion) on behalf of the the regimental (later battalion) commander.

The latter was required to be more mobile (lightweight) to keep up with an infantry advance and being too short-ranged for a higher level main effort weapon was an advantage rather than disadvantage.

I wrote a lot about this before, but decided to revisit the topic:



The German army neglects the battalion indirect fire support. We have very few 120 mm mortars in active use. 155 mm howitzers (also not exactly many) cannot cover all indirect fires needs, though. They would often be 15+ km away, and radio communication may be unreliable over such distances. Their 155 mm shell is fine for long ranges, but rather inefficient for fragmentation effect since the removal of cluster munitions from the arsenal. The original reasoning for the 150...155 mm calibre was to penetrate field fortification overhead covers, and post-WW2 it was a quite efficient calibre for bomblet cargo shells. Nowadays its only really relevant lethal munition is the high explosive shell, which covers a rather small area with effective fragmentation effect relative to its weight. 155 mm is also rather inefficient for illumination munitions, and those are regaining importance since infrared illumination shells can nowadays assist the troops' night vision goggles in overcast and new moon nights. (IR-Illum may be unnecessary due to an alternative, though.)

Another advantage of an organic fire support is the shorter time of flight. Arms manufacturers can create nice presentations claiming that their gold-plated 155 mm round can provide fire support to dispersed troops in a 80+ km radius, but those rounds might be in flight for well over a minute while organic howitzers might deliver effect with cheap rounds with about 10 seconds time of flight and their dispersion would be so small that guidance would be superfluous.

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Now let's think about the land face of war: I suppose we could think of a corps area as a very shallow fish pond. The corps HQ may draw neat brigade icons on the map, but the fish tank would actually have much smaller fish than that; battalion battlegroups*, likely further divided into often independently manoeuvring company-sized battlegroups. Some fish would rest, a few would move, and sometimes there's a flurry of activity and suddenly all of them move for a short time and shoot for an even shorter time.

There would be no "front line". The corps commander would be well-advised to rather give frames to the manoeuvre forces; a line which opposing forces shall not pass and a line which friendly forces shall not pass without explicit (per-)mission by him. Orders might also be focused on points; reach this point by a certain time. (I'll lay out another command technique approach in a later blog post.) The manoeuvre forces would have arrangements for cooperation and if needed hierarchical decision-making (between commanders of formations or units of the same level), but most decisions would be made by leaders on the spot. 

There's something remarkable about mobile warfare, and such land warfare would be a mix of hiding/resting an rapid movements/clashes. You don't really need great firepower ranges when you're highly mobile. There's no advantage to having your artillery far from your spearhead if this doesn't add to security - and it would not with a mobile battlegroup. Instead, the artillery might be tasked to help secure the less line-of-sight combat-capable elements of the battlegroup (munition vehicles, fuel vehicles, bridgelayers, electronic warfare vehicles, air defence vehicles and so on). Additionally, you could simply move some 10 km towards some bridge or helicopter forward operating base if you wish to shell it and are 10 km too far away for it.

The one reason to give a battlegroup long-ranged (~40 km) artillery could be to enable a massing of fires from multiple battlegroups in one fires mission on one target. This could make sense, but I suppose it's needlessly troublesome. This burdens the mobile battlegroups with the munitions required to support other battlegroups and the battlegroup artillery piece becomes a much bigger and thirstier (likely tracked) vehicle. The fires would be tell-tale signs giving away the bivouac site or forcing the battlegroup to keep its own artillery outside of its bivouac (and thus less secure).

I suppose the superior approach is to divide the brigade into up to four battalion battlegroups and one support group. The support group would provide centralised services and an umbrella of support (electronic warfare, area air defence, long-range artillery fires). This allows for the desirable massed fires out to 40 km, or with exotic munitions out to 80 km from the brigade supply group. 

Meanwhile, the battalion battlegroups could mirror this with their own split; multiple company battlegroups and one battalion support group which would include much less ambitious support (bandaging, two days worth of supplies carried, short range air defences, <20 km range artillery fires).

A use of the 105 mm calibre allows for artillery fires from wheeled vehicles**, which are well-suited for rapid movements with little fuel consumption, little fatigue and few maintenance needs.


(105 mm howitzer high explosive shells typically weigh 15 ...17 kg, 155 mm HE shells typically 42...44 kg. The difference in area covered with fragments is not nearly this great because fragments of a given useful size lose velocity rapidly. The greater quantity of fragments of a 155 mm HE shell can keep a good area density of fragments farther out, but it cannot magically sustain the energy of the identical fragments and their initial velocity is similar. Alternatively, it could go with fewer bigger fragments. The optimum design usually depends on what effect on impact is required. NATO prefers the 155 mm calibre mostly for more efficient use of personnel (a 155 mm gun requires about as much personnel as a 105 mm gun) and greater range. 150...155 m calibres were subjectively preferred over 105 mm during both world wars, but tables telling how many shells are needed for a given purpose (suppression or destruction) treat both calibres as substitutes and tend to show that you need less shell mass with 105 mm shells to do the job. Both 105 mm and 155 mm use the same one fuse per shell, and fuses add a substantial cost to the shell and explosive filler.)

The 105 mm calibre could effectively provide support with high explosive, multispectral smoke, (near-)infrared illumination and even a special fin-stabilized (slip ring***) mortar bomb for extremely close high angle fire missions (down to 400 m as 120 mm mortars can do, this requires 80° maximum elevation). They might also deliver precision guided munitions occasionally, particularly fin-stabilized ones with slip ring.

A 105 mm gun could even be used to launch guided subcalibre (such as naval 76 mm HE) projectiles at much higher velocities than the full calibre muzzle velocities, which in combination with 80° maximum elevation would offer an effective heavy anti air gun capability. This might be useful to destroy (or deter) at the very least flying observation drones without expending missiles that cost 1+ M € apiece on them.

Another option would be to use a 320° training ability of the turret (assuming a dead angle for low elevation shots caused by a hardened cab; so 360° training, but 40° not usable for lower register shots) for some auxiliary anti-armoured vehicles capability. Suddenly appearing armoured recce vehicles, IFVs and from some angles even MBTs could be defeated with tandem shaped charge (fin stabilized) rounds in fixed combustible shell cartridges.

This mirrors the multi-purpose potential of brigade-level artillery, especially the MRLs just as the battalion battlegroup-level support group mirrors the brigade-level support group.

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The objective that drove my reasoning might be obvious to the reader by now; the battlegroups should be as compact and agile and least be burdened with tasks as possible. They should thus be limited to line-of-sight combat troops and some essential support for the same, not with any further support tasks. We should leave as much of the fuel and munition carrying and consumption to the brigade support group.

The conventional answer would be to use 120 mm mortars, and I suppose that the much greater versatility of 105 mm SPGs with turret is obvious as an overwhelming advantage. Additionally the spin-stabilized 105 mm shell is just as deadly as a 120 mm mortar bomb, but has much less dispersion. Very flat shots out to maybe 2 km distance could normally be considered to have more dispersion in range than mortar shots, but electronic fusing based on counting the revolutions (the spin length being known, as it's defined by the barrel rifling) enables accurate fusing at a set distance. Very flat 105 mm shots would furthermore be much harder to detect for counter-mortar/counter-artillery radars than the always high angle mortar shots.****

So to summarize; I'm in favour of an army indirect fires triad:

  • battalion-level 105 mm turret SPG (multi-purpose) under battalion BG CO command and only in emergencies supporting other BGs
  • brigade-level 155 mm SPG (main effort firepower, low priority on multi-purpose) under brigade CO command and supporting beyond the brigade
  • brigade-level variable calibre MRL (multi-purpose) under brigade CO command, but also some external fire missions (mostly area air defence)

That being said, the German army (Heer) doesn't pursue such an approach. Its MRL force is diminished, having a marginal quantity of munitions (PGMs) in storage only. Its mortar force is close to non-existence. Our brigades lack organic 155 mm SPG fire support. This may be considered acceptable as long as there's divisional 155 mm SPG pool that could be parcelled out, but we have too little of that as well. As of Spring 2021 we had a total of four artillery battalions (155 mm SPG and 227 mm MRL) for a total of eight brigades (counting the German-French brigade as well). That's three arty Bn for seven German-only brigades. It appears it's more important (to the bureaucracy and politicians) to have almost 11% of our military personnel in the medical branch. That doesn't sound inflated at all, right?


P.S.: In the end, a mere look at the organisation and quantity of indirect fire support in the army suffices to declare our army leadership catastrophically inept, if not suspicious of being compromised by the FSB. This problem dates back for many years (1) (2). 

Disclosure: I have a weak spot for solutions that are modest, if not austere. This may have influenced my reasoning.

*: Up to 1,000 troops and 100 motor vehicles, led by a major or lieutenant colonel.

**: I would rather prefer 8x8 offroad logistical trucks as basis than smaller vehicles, as this minimizes the convoy size and quantity of needed drivers. /2014/08/the-dragoon-problem-lingers-on.html

***: Avoiding that the munition gets much of a spin from the barrel rifling, as much spin  renders fin-stabilization impossible. Fin stabilization allows 80° maximum elevation for indirect fires and it allows for much simpler 2D course corrections.  

****:  Counter-mortar/counter-artillery radars typically scan the horizon to detect shells, rockets or mortar bombs as soon as possible, during their ascent. Hills, woodland and buildings can create a dead angle in which these radar beams would not detect the ammunitions in flight. Mortar bombs with their apparently very reflective metal fins furthermore create a stronger echo than howitzer shells.

Edit: I may have been a bit too harsh on the Bundeswehr regarding mortars here. There are 120 mm mortar carriers (refurbished, but very slow M113 version)  in light infantry and mountain infantry battalions and towed (by 4x4 car) mortars in airborne battalions. It's still a very badly neglected arm.




  1. The only part I ahve an issue with is:

    "The distinction between field artillery (later divisional artillery) and regimental or infantry guns (later battalion mortars) was driven by a need for long-range main effort artillery that dominates the battlefield on behalf of the army (or Napoleonic-era corps, later division) commander and some artillery that supports an infantry regiment (later battalion) on behalf of the the regimental (later battalion) commander."

    The opposite actually happened: The regimental guns of the bats in the 18th cebtury were combined in 6-pounder batteries under the command of artillery officers during the Napoleonic wars.
    Then one of these batteries was assigned to divisions or brigades (Prussia) but still under command of an artillery officer. (The reappaerance of regimental guns in the French army for a few years was the exeption.)

    The heavy (12 pounders) were under command of the corps, later divisions. This approach was used until 1914, there was then only one kind field cannon in addition to one kind of howitzer.

    Only in the second half of WWI infantry guns (under the command of the bat/regiment) were seen again.

    The use of siege artillery as corps artillery ("Fußartillerie*) was an Prussian invention of 1904.

    Good discussion is found in Müller "Geschichter der Feldartillerie), published in 1873.

  2. As i wrote in the article about fractals in the structure, one can also regard such an unit: battalion-level 105 mm turret SPG (multi-purpose)as the main combat unit as a replacement for the main battle tank. If you replace the MBT in the current brigades with an heavily armoured mulit purpose SPG (a kind of new generation Sturmgeschütz) you have both functions in the same unit and this "SPG" would not longer be support units, but main combat units. To make this possible one have only to give the 105mm Howitzer SPG a more heavily protected plattform (stronger passive armour, softkill, hardkill) and you can use them nearly like MBTs, but also like an SPG and for air-defence etc

    So in a brigade you then do not need an seperate artillery unit in a support group to the four bataillon battlegroups and therefore the support group becomes much smaller and more mobile. The same in the bataillon battlegroups. You can mix there mechanised infantry and such "SPG" companies together in a combined mech bataillon and you have all you wish again with a smaller support element because one of the main elements of the support unit is now an main combat unit.

    One have only to discard the MBT instead, who is also questionable as a system for the next war. More versatily means fewer support units, means faster and more flexible combat units.

    As future warfare will happen more and more in the cities one should also think about the problem of the elevation which is not sufficient with main battle tanks and with the fact, that even in earlier wars (like WW2) assault guns were the most effective urban combat weapon.

    There are even turrets with an 105mm canon available now from cockerill for example, which offer today an indirekt fire range of around 10 km and are for the use on tanks, and could use ATGM (Falarick). This turrets could very easily be improved with a little more range and all the possibilities you mentioned for anti-air etc


    Now think of an similiar turret but with heavier armour and other protection on an heavily armoured plattform and you have the Sturmgeschütz 2.0 which could replace the standard MBT and the standard SPG in one new type of system.

    1. I wrote this
      but I disagree with you because I prefer to add serious VShoRAD capability to tanks. This means 76 mm 30...60 rpm -5...+43° elevation main gun + bulletproofed rocket launchers for a total of 8 blast and AT-HVM rockets (no reserve rockets in the hull). AT-HVM (~CKEM) would penetrate as well as a 130 mm gun past the first few hundred metres (and ripple fire would be devastating). Blast rockets of that size would finish a building in one shot, better than a 130 mm gun could with HE or HESH. 76 mm would be superior against infantry, aerial targets and AFVs up to good IFVs.

      BTW those Cockerill turrets have no provisions for indirect fires in the fire control system and the cartridges are fixed, not semi-fixed. The 105 mm gun cannot shoot like a howitzer. This could be changed, but munition supply into the turret would be quite slow.

  3. SO:

    Your summarize shows that you want 155mm SPG and MRL on the brigade level and 105mm SPG (multipurpose) on the bataillon level. This leads imo to very big brigades which then will also become slower and less mobile even with smaller support groups. I guess, that you want this because you want a structure of corps and brigades without divisions between them. Is that guess correct?

    Under the assumption this corps-brigade structure is here the target, this would inevitable make the brigades to mini-divisions which could have two problems imo: first this mini-divisions will be to slow in comparison with other brigades but will not be able to deliver much more fighting power in comparision. In praxis the fighting power will be nearly the same between such a mini-division and a much smaller brigade. As i understand you here, you therefor want to build bataillon battle groups out of the brigade as an answer to this. But why then not use a compact division with only a few thousand man more than the brigade aka mini-divison and have organic smaller brigades within the division? The overall structure would be the very same, but the compact division-brigade structure would have more fighting power and could absorb more losses and still function. Its endurance in combat would be better, the brigades as mobile as the bataillon battlegroups and you can then move the 155mm and MRL to the divison level and free the brigades of this units. This would greatly enhance the mobility of the brigades and would decrease the demand of ammunition, fuel etc, so it is better for the logistics.

    Instead of an around 6000 to 7000 man brigade which would be imo the result of your suggested 155mm SGP and MRL on brigde level - you could use an 10.000 man division, with the same units on divisional level which would give you better organic brigades instead of the bataillon battlegroups. Overall the compactdivision-brigade structure seems for me more organic and overall better in comparison for conventional warfare.

    1. My main scenario is the first 2...3 weeks of a Baltic conflict, with Russian strategic surprise attack. Few NATO brigades could rush to the scene this quick with Oder and Vistula bridges crashed.
      So an area of known size with few NATO/EU troops in ground combat formations. The concept of support umbrella delivers about the same technically given effective umbrella radius for both brigades and divisions.

      The size of the brigades does not matter as much as the qty of brigade/divisional support groups. So divide the guesstimated non-militia forces present by the qty of required brigade/divisional support group and I arrived at what's rather a typical brigade size than a typical division size.
      The brigades wouldn't manoeuvre as one wieldy formation anyway.

      Thus I see no role or purpose for divisions. Greece, Taiwan or South Korea could arrive at completely different conclusions. Late-comer armies such as the British Army and U.S.Army could arrive at completely different conclusions as well, for their forces could be tailored for different scenarios than the first two or three weeks of Baltic Conflict.

    2. Interestingly your argumentation here is very similar to that of Douglas Mac Gregor, who also argues against divisions with nearly the same arguments. He claims therefore that brigades with around 4000 men would be the better solution for this area and wargamed several szenarios in the baltics for comparison which showed clearly the problem a divisional structure would have there.

      My question is, if this is not an dangerous overspecialisation and if it would not be better to make the armed forces overall more versatile and more able to fight very different szenarios. Also what if an war does not only happen in complete different parts of the earth and if it goes on for an much longer time than three weeks?! I know your political agenda of defence and the holy grundgesetz, but the political reality is quite different. The armed forces should therefore not overspecialise in an baltic scenario but need an structure with which they can fight in very different scenarios, including also expeditionary warfare. I know your position against this kind of warfare, but it is an political reality.

      Or is it the complete other way around that you want such an force structure and such an overspecialisation explicitly because you want to prevent that the armed forces can be used for other scenarios and especially expeditionary warfare elsewere? Is your target to prevent the use of armed forces in other scenarios through such an force structure?

    3. A military establishment costs much in budget and opportunity costs (personnel not being productive in other jobs). This downside requires justification. Thus a force structure requires justification.
      The Baltic scenario is the least unlikely legitimate collective defence scenario and thus my benchmark.
      The Ukraine is not a NATO or EU member and thus there's no legitimate collective defence scenario there. Aggression against Turkey looks pointless, and super unlikely to go beyond some retaliation harassment actions by non-state actors.

      There is no sufficient justification for non-defence warfare. Use this as test to judge overseas missions:

    4. What about an war between greece as an eu member and turkey? The eu is also an military alliance and therefore germany must then assist greece. IMO an war with turkey is more likeley than an open conventional war with russia. Or what about a kind of civil war or mass-terrorism in the country itself (for example from rightwing groups and/or the querdenken bewegung developement etc)

    5. The stupid little Cold War there is merely a political challenge, not a military one. Turkey would be fucked if it attacks regardless of how much the EU forces fuck up.

      The Bundeswehr is not tasked to deal with domestic unrest. The police is meant for law enforcement. We have more police than military personnel.

  4. The drive towards electric cars creates a new infrastructure to recharge batteries. I think at some point military vehicles will also run completely on batteries. This in turn would allow to replace chemical propellants with fixed size acceleration tubes with size variable electrically powered linear accelerators. How soon do you think this would happen and how will it modify your analysis?

    1. Batteries cannot discharge much energy quickly. You need capacitators for that. Recharging those does not require much battery capacity relative to driving for hundreds of km.

      Personally, I expect that military vehicles will keep running on liquid fuels. Flying drones will use battery-electric power and land vehicles will use hybrid (liquid fuels + battery-electric) power. There's no sensible replacement for kerosene for combat aircraft, and batteries won't suffice for tracked AFVs for the foreseeable future.
      We may rather see greenwashing (biofuels mimicking diesel and kerosene) than any other substantial change in the 2020's.

      I read much about alternative means of propelling shells since the 1990's, and just about nothing came of it. The only real innovation were temperature-insensitive propellants. Another change is that higher chamber pressures became acceptable in small arms and artillery and artillery barrels keep getting longer.