Heavy infantry armour in history


I wrote in the skirmishing blog post that pre-absolutism skirmishers seemed to have been skirmishers because they were low budget (and if self-equipped: poor) troops. At some times you didn't need more than a primitive sling and picked-up stones to be an effective skirmisher (albeit the mercenary skirmishers often used more effective lead projectiles and small cheap shields).

Heavily armoured troops tended to be expensive professionals of nobles whose life, horses and equipment were supported by multiple farming households.

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The often-reported problems and ineffectiveness* of present-time armoured infantry (armoured as wearing bulletproofing body armour, even including shoulder guards and somewhat bulletproofed helmets) made me think.

What if this is not something new, what if this is how it always was? Were more heavily armoured infantrymen of the classical and medieval period really of superior military value?

I suppose the easiest example to look at are late republican / early imperial Roman legionaries, for we know that they had very few servants and pack animals compared to heavily armoured infantry of other periods.

The reputation of these legionaries is still extremely high about two millennia later, but there's something odd:

The biggest and most important expansion of Rome's power happened from the last years of the First Punic War (about 240 BC) to the end of Augustus' reign (until 14 AD). The reforms of Marius that created the all-heavy infantrymen (which always needed reinforcement by dissimilar mercenaries) army of late Republican and early imperial Rome happened only in 107 BC.

The defeat of Carthage, conquest of Greece and conquest of half of Iberia fell into a period during which the Roman army had severe quality issues and was far from the now-common idea of Roman legionaries. The decades of warfare and neglect of family farms since around 260 BC had ruined the base of Roman power; the citizenry (and socii citizenry). Their army was divided into three classes of middle and upper class men, separated by wealth. By about 215 BC there was little left of what we would call middle class now.

The army was at the time about 30% lightly armed velites, skirmisher infantry no better equipped than most enemies (previously about 15%). Velites used for all we know no body armour. It's even questionable whether many of them used helmets. The role of velites and later particularly lightly protected hastati apparently kept growing until the Marian reforms, as Roman society became increasingly economically unequal and the middle class kept eroding through warfare and exploitation of the upper classes. The sum of light troops (including mercenaries) may have exceeded 50% rather often on Roman campaigns.

The classical trio of triarii (few rich men, mostly held in reserve), hastati (main infantry and velites (skirmishers, poorest men able to afford any regulation infantry armament at all)** 

So Rome's empire was in large part built not by the famed heavy infantry legionaries stomping their opposition by their own, but by armies which were in large part light infantry without body armour. The Roman demographic, economic, organisational strengths and certain details*** were almost certainly much more important factors in Roman military success than heaviness of arms and armour.

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I understand that heavy body amour was and is often preferable in pitched battle from the point of view of the user. Or at least it seemed so to those who had no heavy body armour, a phenomenon that we were able to observe during the early years of the Iraq occupation.

You could hardly motivate men to sign up for decades of legionary service without protecting them well. They had neither tetanus vaccine nor penicillin. There was no proper military pensions or disability benefits system for crippled discharged soldiers until the 20th century. They would turn beggars and probably starve real quick. There were historical mercenaries with little or no armour, but those were short-time mercenaries, hired only for a specific campaign.

The question remains whether heavily armoured troops were really more effective. I picked an example in which they could be compared almost 1:1 to light troops. Heavily armoured infantry of other eras had such a train of servants, pack animals, carts and other support that they could hardly be compared 1:1 to light troops. In some cases (mounted knights) it would be appropriate to compare them 1:3 or more.

I've read way too many books on historical warfare, but rarely have I encountered the notion that light troops might have been superior to heavy ones. The outstanding exceptions were (Parthian) light horse archers and that one victory of peltast skirmishers over Spartan hoplites. Then again, I am very confident in my assumption that not one modern author of those books has experienced a pre-firearms battle.

I remember only one source from antiquity urging the use of body armour to troops who did not use it; Vegetius****. It's worthwhile to note that he writes about body armour as the solution to military problems because the infantry of his day apparently did NOT use it. So it may be that he was a believer in body armour without actually being able to fully assess the military value upsides and downsides of the same.

I strongly suppose that investigating the true military utility of body armour in history is something that military historians should do. Modern armies should be aware that we might very well exaggerate passive protection at the expense of tactical mobility and endurance.









*: Slow, quickly exhausted, thus moving little during firefights

**:  The sources are not clear and this trio may have been rather about age brackets (age 15-46 overall, velites youngest and triarii oldest), with varying equipment quality within the age brackets. It is especially doubtful whether the most or even all Triarii used mail armour, as it was very expensive. In the end, it doesn't matter to this text, for a larger share of the poor among the levied meant a larger share of troops who could not afford good arms and armour (even though those were in the late Republic purchased from the centrally procuring state). There's no source known to me claiming that anyone but proletarii (the citizens normally too poor for service as infantry) got much equipment provided by the state. 

The rise of the share of velites was either driven by performance considerations or by the poverty of the levied men. Either way, the share of light infantry increased according to the known sources.

***: An example is that Romans built field camps on hills rather than close to rivers or lakes (where there's high risk of diseases) because they simply dug wells for water supply. Even in battle this was an advantage, as hills offered vastly superior positions and the Romans could wait for enemies on a hill even in Mediterranean summer heat. I have never seen mention of their enemies digging wells on campaign. The Roman armies had many such detail strengths.

****: See section "The arms of the ancients" here



Digital sovereignty

There's a European (and German) policy of pursuing digital sovereignty; reducing dependence on foreign cloud servers, for example. I am no expert on the topic (I was never terribly interested in it) and cannot comment on details, but what I saw through general news media was unimpressive.

We would need to address many more vulnerabilities and would also need to change a certain government attitude to reduce our vulnerability significantly.

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Back this summer Samsung announced that it had deactivated internet-capable Samsung TV sets that were stolen from a warehouse in South Africa. This is apparently built into all Samsung TV sets; Samsung can brick Samsung TV sets at will if they're connected to the internet. This is in principle a possibility for all kinds of internet-connected hardware.

Microsoft added a Microsoft Exchange Emergency Mitigation service recently. Exchange servers had been affected by malware to a catastrophic extent, and Microsoft developed this as a general countermeasure. To create and apply patches that remove a certain vulnerability to malware takes quite long, and malware can spread much in the meantime. It's much quicker to identify some commands the malware is using and to block those in your software. So Microsoft now builds into Exchange servers the ability to centrally brick them partially, but in effect also to brick them completely. Microsoft can de facto brick all Exchange servers whose admins haven't switched this default active emergency mitigation to off. There's no-one stopping them from coding their software to enable an override over this choice.

This points at a more general problem: Every automated software update capability is in effect a backdoor for the update provider. The software developer or someone who has thoroughly re-engineered and analysed the software can apply an update that turns the software non-functional or adds malicious functions. It can also be used to prevent further updates, as happened to some internet-of-things devices that were accidentally bricked by a poorly designed update in yet another anecdote and could not be repaired any more.

The malicious functions can include surveillance. Microphones can record sound, but loudspeakers can do so as well.

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In other words; it's not just Samsung or Microsoft or the U.S., just about every big player has the technical opportunities to shut down our economy, and this includes the ability to cause irreparable harm to our hardware.

A great internet shut down wall as set up by Russia wouldn't help at all (theirs only makes sense as an option for political oppression), nor would blocking certain IPs in the event of crisis. No matter how many satellite and fibreglass communication links you severe, a fingernail-sized storage device can smuggle all the malware into a country that's needed to turn a domestic network computer into the attack launch point.

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It would help to prioritise IT security over IT vulnerability. This sounds trivial if not offensively obvious, but then again we're talking about European and American governments.

So far the German government policies and the policies of the U.S., UK and so forth were aimed at implementing vulnerabilities and preventing much security and encryption. This stems from a mindset of bureaucrats who want more and more power, more and more authority - and this leads them towards favouring vulnerabilities that they themselves can then exploit. Even the BSI (German agency for IT security) has been compromised by this

The pursuit of backdoors, unpatched vulnerabilities and encryption weaknesses to enable the own surveillance, spying and sabotage is exposing our whole civilization to hacking on a scale that lets hacking against drug dealers, kiddie porn watchers and errorists look petty and irrelevant. A warlike scale of insecurity exploits could crash government and economy to a greater degree than the 1944 bombing of Germany and bring the railroad infrastructure to a halt for weeks (the German railroad control and signal techs in use are too diverse and antique for much more sabotage through software).

Yet again, I conclude that we need political leadership to understand the issue and to turn the bureaucracies away from pursuing their self-interest, pushing them on course to serve the common good. It's an ambitious request.



P.S.: Audited open source software (compiled by the user himself) with an automatic pause for automatic updates and an unpatchable reversibility of past updates would protect us pretty well. Physically secure and separated backups are a necessity. Encryption should be one-time pad encryption with satisfactory randomisers whenever practical.

A joke for you: The Israeli arms industry sends me press releases and stuff, and one of their companies seriously tries to sell cyber defence software. As if anyone not utterly stupid would trust Israelis with his/her/its cybersecurity after all their hacking (keyword Pegasus), obvious assassination campaigns and other subversive actions. They might have sold their stuff to the lying moron, but the rest of their target audience got to be corrupt or utterly, utterly stupid. That target group is probably the same as for U.S. military trainers abroad.



Fragmentation effects of artillery HE fires


Artillery high explosive fires are a complicated technical and tactical topic. Even the working of a shell itself is complicated. 

The radius at which the blast of the explosives kills is rather small and incendiary effects are usually unexpected and unintended side effects. Most of the HE effect stems from fragmentation.

Fragmentation of a simple steel shell is quite unpredictable, but there are some relationships known. Such shells burst into many tiny fragments and very few large fragments, some some fragments of intermediate size.

More ductile steel will create bigger and more big fragments (which was intended for heavy anti-aircraft gun shells), whereas more brittle steel will mostly produce tiny and small fragments.

Higher yield strength steel can be used to make shell wall thinner (but still withstanding the stress of firing), which allows for more explosives volume and mass for overall greater fragmentation effect. High yield strength steel tends tends to have high ductility as well.

Higher quality explosives can in theory be used to increase the effect. Pure TNT and the cheaper mix Amatol are classics obsolete by now. There's little reason to expect anything more powerful than RDX or a RDX/TNT mix in unguided HE shells. RDX is about 60% more powerful than TNT. RDX is ancient technology by now, so we can assume that the explosives of HE shells world-wide are of about equal quality within their shelf life.

A controlled fragmentation is possible by using a serrated the shell body, and the best way to do it is to serrate on the inside (which is trickier for production, and old hand grenades often used external serration). Serration on the outside raises the question of air friction and is less effective, but easier to apply. Serration on both sides calls into question the mechanical strength of the shell body even more (huge forces apply during acceleration and imparting spin in the barrel) and more than combines the required production effort (the serration patterns should match). Serrated shell bodies are used for rockets, mortars and hand grenades, but not gun shells due to structural weakness.

externally serrated / embossed

internally serrated / embossed











Another option to improve fragmentation is to have the fragments first (steel or tungsten balls) and then embed them into a matrix that allows the fragments to fly as intended upon burst. Another option is to use coils instead of balls, but I've never seen that option with artillery or mortar HE ammunitions.

So this is the state of art; steel or even tungsten balls embedded into a matrix. You can choose the material, explosive charge and ball size to tailor the shell for a certain penetration ability at a certain distance (ingoing shell velocity for a while). There are for example a couple hand grenades with such very small preformed fragments that they're for purposes of war harmless to personnel (except unprotected eyes) at twice their lethal radius already.

Small HE munitions are more efficient at fragmentation than bigger ones ceteris paribus. This is so because of the slowing air drag to the fragments. This was the driving force behind bomblet (submunitions, many small explosive grenades inside a shell, dispersed before impact) cargo munitions (ICM / DPICM), which are now banned by the cluster munitions ban in most countries.

It's nice to have temperature insensitive munitions (that still explode well when cold) and generally insensitive munitions (that leave the crew time to run away before they explode when there's a fire around the shell).

This was about the burst.

(link for more details:

https://www.daaam.info/Downloads/Pdfs/science_books_pdfs/2015/Sc_Book_2015-020.pdf )

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Next, keep in mind an artillery shell needs to be fused.

The typical fuses are delay fuses, time fuses, point detonation (PD) / point detonation super quick (PDSQ) and proximity (PROX, for artillery purposes always a radio frequency fuse triggered by its echo, with some counter-jamming precautions). Most fuses know two modes, to be selected by a tool; delay and PD is a common combination.

The point of having different fuses is to choose different locations of burst. Delay bursts inside the soil (for cratering) or buildings, PD/PDSQ is a cheap way of achieving some above-ground fragmentation effect (much better if it hits a tree), but many fragments go into the ground or up into the air when you fuse upon contact with the soil. Proximity fuses are meant to fuse the shell several metres above ground, so its fragments cover a large area and also hit troops who are flat on the ground. Time fusing is too tricky to use for this in indirect fires, and more relevant to illumination and smoke munitions.

This was about fusing.

(link for more details: https://en.wikipedia.org/wiki/Artillery_fuze )

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Next, let's look at the effect of angles. The angle of descent at explosion matters greatly. A shot at a very shallow angle will fragment to the sides, but project very few fragments forward. This is only OK if you use a delay fuse on flat terrain for a bouncing shot that explodes in the air after bouncing off the ground. This technique was in much use during WW2, but nowadays you simply pick PROX fuses for even better effect.

fragmentation pattern depending on angle and height of burst

A close to vertical angle is best for all-round fragmentation effect for a very slow ammunition (the picture depicts a shell moving more than twice as fast as a mortar bomb would) and greatly enlarges the lethal area compared to a 45° angle of impact. Fast-moving shells can have their optimum angle of descent well between 45° and 90°.

The angle of descent can be manipulated by howitzers (and to some degree also by most mortars) by choosing a different elevation angle and different propellant charge strength (more or less propellant modules). This also modifies the time of flight and a strong MRSI (multiple round simultaneous impact; how many shells arrive in first 10 seconds before troops in the target zone can react effectively) strike requires a mix of such combinations anyway to maximise the MRSI value.

(link for more details: https://nigelef.tripod.com/wt_of_fire.htm)

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Finally, let's keep in mind not all shells descend at the same velocity. Mortar munitions are often subsonic upon arrival, for example. This can also happen with howitzer shots. The motion of a fragment (ball) from the shell side wall is the sum of forward motion speed of the shell and sideward motion speed from the explosion. In the end, that fragment is moving diagonally forward to the side. The faster the shell at the time of explosion, the more pronounced this forward movement of the fragments. This matters much, for this forward movement means that the fragments are being driven into the ground. Fast shells need to be fused higher by the PROX fuse for optimum effect.

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So now we have the criteria for a maximum deadly HE shell:

  • not moving fast at time of explosion
  • descending well between 45° and 90° at time of explosion
  • embedded steel (good price) or tungsten (best effect) balls in matrix for controlled fragmentation effect with defined effective radius against a notional target
  • fused by a smart proximity fuse (ideally with PDSQ as backup and a time-based safety to prevent premature explosion in face of jamming)
  • preferably small calibre
  • also preferably NATO standard calibre for economic and cooperation reasons: 155 mm

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And this is it:

The older Russian 122 mm rocket 9M53F uses the very same principle, without the need to cope with a spin-stabilised shell's spin:

I seem to have underestimated the usefulness of the principle for spin-stabilised howitzer shells in 2015.

The ideal HE shell for suppressive fires (which have fallen a bit out of fashion as quantities of active duty artillery pieces have shrunk) and cratering is to have a cheap steel body and a PD/delay fuse. Cheap HE shells with delay fuse can also be used to intentionally create craters as obstacles especially on roads or as cover for friendly infantry. Not all firing missions have a use for high end maximum lethality ammunitions.

craters by HE shells of WW2 technology (source); quite capable of rendering roads unusable

Today we're expecting the first howitzer shots to be on target and for effect (exploiting surprise), but we would still shoot old school if satellite navigation systems failed and maps were insufficient. We would first use a salvo to observe where it lands, correct until the salvo is straddling the target and then switch to quick fire for effect. These first ranging shots would best be done with cheap HE shells with delay fuses. The cheap shell requires less expenses beforehand and the cheap delay fuse makes the impact very visible (thrown up dirt) and it would be least dangerous to friendlies who are often close to the target. The cheap and the high quality shells would better have matched external ballistics, though.












This blog post summed up enough to give the reader the basics to judge the own countries' artillery munitions approach. The German approach so far is -save for a handful of gold plated special munitions - to use insensitive explosives 155 mm HE shells with decent fuses and preformed fragments embedded in the shell walls. That would be fine, but the quantity of HE shells in stocks is (albeit not known to the public) bound to be small and part of those stocks may be older type shells at or past shelf life. Russia is widely understood to have huge quantities of really old (70's, 80's if not worse) artillery munitions, but they kept DPICM in their inventory, which gives them an advantage.

I suppose the details given here have brought across the message that the quality of HE munitions can multiply artillery effectiveness.



 *: among other things like accuracy, dispersion, communications, rapid fire control, sensors, quantity of artillery pieces, survivability of artillery pieces, quantity of munitions, reliable high throughput supply support, trajectory correction, placement of artillery pieces



The German army radio scandal

You may have read about the German army radio scandal: The German ministry of defence is about to purchase up to 20,000 radios of an analogue technology model from the early 1980's. The price per copy is expected to be outrageous (you could buy two new small cars for one museum piece-styled radio), and the order is going to Thales because they bought the developer of those Cold War era radios long ago.

The need to replace the old radios was obvious many years ago already (and published). We already missed out on buying late 1980's/1990's technology radios. The British Bowman program disaster and the huge excess of 1980's radios after the downsizing during the early 1990's may have contributed to this.

The scandal is a scandal because the need to replace the old radios was obvious, the technological progress in the field was obvious and the German army is obsessed with talking (and writing) about "Führungsfähigkeit", the ability to lead (for Americans; Command and Control, C2). And it interprets this ability in large part as the technical ability to communicate.

I have not yet any special insights into why the bureaucracy (and politicians!) failed so grossly, merely a couple suspicions. The list of my suspicions is topped by the guess that they went for a gold-plated maximum ambition solution, and then failed to get it done for the all-too-usual reasons of bureaucratic impotence. They clearly tried to get something customised to their requirements, for there are evidently plenty battlefield radio systems on the market, military-off-the-shelf and there was enough money in the budget all along if you know how to prioritise.

Some blame was put on politicians who spent on other things (such as warships - the parliamentary defence committee is infested by directly elected politicians from election districts with shipyards). The bureaucracy didn't put the necessary priority and bureaucracy resources on the radio procurement, though.

The radio procurement scandal also involves (though not mentioned in the recent reports that I saw) a miniscule quantity purchase of some modern radios a few years ago. AFAIK only special forces and the AFVs of a battalion for deployments received modern radios (aside from civilian satellite radios).


I have zero confidence that this extremely embarrassing scandal will lead to decisive change for the better. This is not a specific critique of any particular politician or any particular party. I simply don't think that ANY party has understood that the Bundeswehr is a bureaucracy that needs a harsh political leadership that breaks it away from the current path and forces a change of course towards doing the constitutional job of the armed forces. I don't expect any officers to be fired and no civilian bureaucrats to be kicked out of their positions of relevance at all in this most embarrassing Bundeswehr scandal of the post-Cold War period.

The blathering in writing will go on as well. They will write about a fantasy world in which the army is focused on getting command & control right, on getting combined arms right, on getting training realism right, on getting technical readiness up and in which 30+ years old concepts and hardware are still top notch. No concerns about them being easily countered by capable opposing forces will be part of the cheerleading articles. The senior officers will tell each other that they'll keep doing their job in the ultra-competent way they've always done it, and the tactics and techniques they learned at the Führungsakademie are the global gold standard.

I'd be surprised if the politicians who take the reins (ceremonially at the very least) will be able to see  through the B.S..



Link drop October 2021

I lost another complete (and long) blog post text (it only missed illustrations) because of the idiotic CTRL-Z bug in Blogger that leads to the whole draft turning blank. -.-

Now the topic (field artillery calibre choice/reasoning from Interwar Years to mid Cold War) might never be rewritten. 

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