Ratio of armour to infantry

[Volkodav]

It is said that tanks save lives but also that dismounted infantry protect tanks from tank hunters with ATGWs, so in a nutshell neither is as survivable without the other as they are when deployed together.

I suppose what I am interested in is the ratio of armour to infantry that provides the greatest versatility and survivability in delivering the desired results. I would assume it can change depending on the level of threat and the type of terrain. It would be interesting the hear what has worked well in the past and what is expected to be best in the future.

The starting point I would assume would be a 50/50 mix or tanks vs Mech or Armoured Infantry as seen in the current US brigade structure.

 

[OPSSG]

The starting point I would assume would be a 50/50 mix or tanks vs Mech or Armoured Infantry as seen in the current US brigade structure.

The ratio varies quite a bit across armies, due to differences in threat matrix and terrain. In some cases, a tank platoon (of 4 tanks) may be paired with a company of Armoured Infantry (AI) carried in Infantry Fighting Vehicles (IFVs); with 11 IFVs, but excluding the support vehicles attached; which is a ratio of 1 tank platoon to at least 3 AI platoons (1 to 3 ratio - but note that for a Singapore AI platoon consist of 3 BxIIs, and Singapore tank platoon consists of 4 L2SGs). At a larger unit level, a tank company (of 14 tanks) paired with a battalion of Armoured Infantry (AI), with 3 companies of AI carried in 33 IFVs (not counting the organic support and specialist vehicles in the armour battlegroup, which is over 60+ vehicles).

It is normal to see a tank battalion paired with at least two AI battalions, in the force structures of many armies.

It would be rare to see 1 tank battalion paired with only 1 AI battalion - in a 1 to 1 ratio, you may not get enough infantry support, for certain tasks.

 

[Waylander]

A ratio of 50:50 is usually not found even while one could get the impression when looking at the HBCTs if the US Army.

Tank or MechInf heavy teams are still build as a ratio of 50:50 in the actual maneuver elements would give sou the worst of two worlds with not enough dismounts for infantry heavy work and smaller numbers of armour for mobile operations in open terrain.

In Germany for example we often exchange one platoon at company level. But everything from getting a platoon of infantry without giving up a tank platoon or pure tank companies and vice versa is possible. It depends on the mission and circumstances.

 

[Feanor]

My guess is the only real answer you'll get will be situation dictates. Soviet tank units had a 1:3 ration (infantry to tanks). Soviet motor-rifles had the reverse. Current Russian brigades have generally kept this ratio, but have increased the size of both tank and infantry btlns so the ratio may have actually shifted, without us being able to tell. Of course in actual operations there are incidents where a infantry company is supported by a tank company, or where an infantry btln has a tank platoon attached.

 

[OPSSG]

In Germany for example we often exchange one platoon at company level. But everything from getting a platoon of infantry without giving up a tank platoon or pure tank companies and vice versa is possible. It depends on the mission and circumstances.

Could I trouble you to explain march order/formation considerations when tanks operate with AI? Or how mutual support works with tank/AI co-operation (to a specific scenario)? That way, Volkodav can get a sense of how much infantry support is needed for tanks.

 

[RobWilliams]

It is normal to see a tank battalion paired with at least two AI battalions, in the force structures of many armies.

That's basically what it's like in the British Army, one Tank Regiment + 2 Armoured Infantry battalions per armoured brigade

But this is paired with an armoured cav regiment + one heavy protected infantry battalion to make up the entire brigade.

 

[Volkodav]

Thanks guys, quite informative. I used to be across some of this in the early 90s but am well and truly out of date and relying on possibly faulty memories.

It will be interesting to see how the Australian Army ends up with the new Armoured Cavalry Regiments but on current scales we are looking at two Sqns of tanks supporting three Brigades, even with a notional third Sqn they still seem a little light on compared to many other modern armies. Almost sees like the USMC structure of one tank Btn supporting an Infantry Division of nine Battalions.

 

[Waylander]

Could I trouble you to explain march order/formation considerations when tanks operate with AI? Or how mutual support works with tank/AI co-operation (to a specific scenario)? That way, Volkodav can get a sense of how much infantry support is needed for tanks.

In the attack the majority of the force is going to be armour with the attached MechInf trailing behind. IFVs with ATGMs (like Marder or Bradley) may provide cover from an initial overwatch position but is left out in the following overwatch rotation.

When needed (like when securing a wooded and possibly mined area) the MechInf and Engineers come forward with tanks providing covering fire when possible.

In the defense actual positions are dictated heavily by terrain, nevertheless MechInf heavy combat teams tend to be used as the first line of defense with the attached armour elements getting plucked into holes with less cover, dismounts in the heavy terrain and IFVs in positions from which they can get the most out of the range of their ATGMs. In case of a delaying action IFVs need to be kept closer to their dismounts for fast relocations.

Tank heavy teams are normally held back for counterattacks or to plug holes in open terrain and provide a fallback line.

Heavy or urban terrain sees tanks relegated to supporting fire and kind of mobile pillbox usage.

As armoured warfare tends to become rather fast and the enemy tends to be rather uncooperative naturally all this flies out of the window fast...

We hunted down infantry in rather heavily forested terrain with half platoons of tanks without any infantry support as what remained of our attached MechInf after it cleared an obstacle couldn't mount up fast enough.

But as we were able to breach their line of defense faster than expected it just happened that we could ran amok in their rear and wreck havoc among their rear units with us hitting some of their positions from behind.

Even in exercises infantry tends to become itchy when tanks are coming their way, especially from the rear and without them being prepared for it.

 

[OPSSG]

^^Thanks for the prompt reply.

Even in exercises infantry tends to become itchy when tanks are coming their way, especially from the rear and without them being prepared for it.

When an infantry unit is attacked from the rear by tanks in an exercise, we always start by blaming higher command for the intelligence failure - that is why our ATGM teams and engineers are out-of-position to conduct delay operations. hehehe

Almost sees like the USMC structure of one tank Btn supporting an Infantry Division of nine Battalions.

Not sure about USMC structure but Singapore's combined arms divisions (3rd, 6th and 9th) lack tanks too. And the ratio of 1 tank battalion to 9 other fighting units (3 AI battalions + 6 Infantry battalions per combined arms division) sounds about right in our context (without counting engineers, division artillery, C4I and a logistics field support group).

Additional Note: With the introduction of the Terrex Infantry Carrier Vehicle (ICV), select Singapore Infantry battalions are motorised in ICVs; and once trained as motorised infantry, the SAF retains their capabilities for duration of their reserve cycle (i.e. 10 years).

 

[Abraham Gubler]

The ratio between tanks and infantry depends on a lot of things. The most important is what type of combat is being engaged in. If it is combat in close terrain then the tanks are providing support to the infantry. In which case the typical ratio of tanks to infantry is one regiment of tanks per division of infantry.

If you are engaged in manoeuvre warfare over open terrain then the infantry is there to support the tanks. In this case the ratio of infantry to tanks depends a lot on the specific type of terrain and how many close assaults you can expect. The ratio can be as low as one battalion of infantry per brigade of tanks or even as high as two battalions of infantry per regiment of tanks.

Also of importance in determining the gross number of tanks in manoeuvre warfare is what kind of supporting units you may have. For example the mech inf may need dedicated tanks for the infantry support role, armd recce capability may need tanks for firepower and also the formation anti-tank capability may need tanks unless you have a dedicated anti-tank system/unit… These are actual tanks not counting the tank variants which are in armd engr units.

In the Australian context an independent squadron of tanks (which is a tank squadron with a special equipment troop of bridgelayers and dozers) per infantry brigade is typical. The VietNam war demonstrated a need for a second tank squadron per brigade in medium intensity counter insurgency operations but this need could be filled by a cavalry squadron equipped with IFV type vehicles and was in part filled in VietNam by a troop of M113 FSVs.

I think one squadron of tanks, fully fleshed out, per ACR will be a great achievement if it can be reached. Providing more than just an engineer carrier version of the new IFV but for the mech cbt engr sqn is a lot more important. A proper breaching vehicle system (Shredder) and a combat engineer tractor (Terrier) are needed. Not to mention the bridgelayer and dozers needed by both the tank sqn and the mech cbt engr sqn and most probably the IFV equipped squadrons as these vehicles will most likely not have a river swim capability. Oh yeah and the self propelled medium gun for the artillery. Which can just be off the shelf M109A6s if said finger is removed from said orriface.

 

[Volkodav]

Ok so in theory a battalion / regiment of tanks per brigade would be nice for manoeuvre warfare while a squadron / company or two would suffice for counter insurgency. Depending on the intensity of combat other types of DFS vehicles could supplant some of the tanks for some roles.

The thing I have never understood with tank units is why they don't have integral infantry / assault troop support at troop or at least squadron level to assist with security, OP, vehicle maintenance and route clearance duties. If you have three tanks in a troop you have, depending on the type of tank, 9 or 12 blokes, if you have four tanks that's 12-16 crew. An APC, AIFV or even CFV with another 5-12 troops would make a world of difference in the capability of the troop.

 

[Abraham Gubler]

The thing I have never understood with tank units is why they don't have integral infantry / assault troop support at troop or at least squadron level to assist with security, OP, vehicle maintenance and route clearance duties. If you have three tanks in a troop you have, depending on the type of tank, 9 or 12 blokes, if you have four tanks that's 12-16 crew. An APC, AIFV or even CFV with another 5-12 troops would make a world of difference in the capability of the troop.

The tank provides its own security. Even in the old days before APUs and long endurance batteries when laagered up the tank will have a crewman on the turret with a flex mounted MG. Frankly this is a better self defence capability than most infantry sections in a night harbour. A tank squadron in laager is not the sort of thing anyone would want to try and sneak up on.

And there is the LAD to provide help with maintenance beyond the indigenous capability. Two tiffies and an ARV is a lot more help than a section of veggies could ever be. And in those other missions the tank would almost certainly be part of a combat team with some mech inf to provide their kind of support.

 

[Volkodav]

The tank provides its own security. Even in the old days before APUs and long endurance batteries when laagered up the tank will have a crewman on the turret with a flex mounted MG. Frankly this is a better self defence capability than most infantry sections in a night harbour. A tank squadron in laager is not the sort of thing anyone would want to try and sneak up on.

And there is the LAD to provide help with maintenance beyond the indigenous capability. Two tiffies and an ARV is a lot more help than a section of veggies could ever be. And in those other missions the tank would almost certainly be part of a combat team with some mech inf to provide their kind of support.

Even in the APC sections we were short of people with a driver having to jump out and run ahead to check under bridges etc, then you would have your listening post and further out your OP leaving only the drivers with the vehicles. Tanks with their larger crews were actually better off but still with two blokes at the listening post and three or four at the OP you would be pretty short with only six or seven back with the tanks. That said you lift a platoon with your APC section and all your problems went away, the grunts always seem surprised at how much you could see from the turret at night but also how hard it was to see / find the APCs in laager, day or in particular at night.

The thing is it was so much easier with even a couple of extras along for the ride, you could do so much more with only a small increase in the number of heads, especially if they were trained in D&S and Radio/Gunnery. It also gave you spare crew to mitigate fatigue.

The other factor is it would give you the ability to insert additional skills in the troops, say a limited combat pioneer, medic or even designated marksman function.

 

[Waylander]

Pure tank combat teams camping somewhere alone are rather unusual.
The attached MechInf is able to provide the manpower for a more extensive cordon.

And as Abe said, it's not as if the tank company by itself has not enough guys for basic security duties.

It's also not only the guys in the combat platoons but also the rather big coy command group and the 1st staff coy of the bn including the technical group which helps with maintenance when necessary. Everything that can't be handled by the crews or maintenance guys of the company/batallion is forwarded to a maintenance unit and it's forward maintenance spot anyway.

 

[Volkodav]

Pure tank combat teams camping somewhere alone are rather unusual.
The attached MechInf is able to provide the manpower for a more extensive cordon.

And as Abe said, it's not as if the tank company by itself has not enough guys for basic security duties.

It's also not only the guys in the combat platoons but also the rather big coy command group and the 1st staff coy of the bn including the technical group which helps with maintenance when necessary. Everything that can't be handled by the crews or maintenance guys of the company/batallion is forwarded to a maintenance unit and it's forward maintenance spot anyway.

I suppose I am just remembering the Australian Army operating on a shoe string. There were support elements, we just never got to see them with all work being done by the crews (within the troop) on their own. This included engine replacements, suspension work as well as the never ending track bashing. Its that memory of how hard it is when you don't "own" the supporting capability which is pretty much always the case in Australia, or was back in the 90s when I played soldier.

I do like the idea of a "modular" establishment where platoons/troops and companies/squadrons can be mixed and matched as required by the circumstances at hand but it is a must that the units concerned train as they intend to fight. In the old days we could mix and match and try different things when the spare heads were available and from my limited experience when we had the extras things worked better.

 

[Waylander]

It is always difficult to find the right balance.

Usually day to day training and operations are better handled by "pure" units with all elements of combined arms warfare coming together for several training maneuvers over the year.

Mixing Armour and MechInf coys in a bn is IMHO at the threshold of too much mixing to be worth the hassle with mixing at brigade level being the upper end.

IMHO brigade level mixing is better as one makes training and day to day operation easier in the bn. Mixed bns may enable the mech inf and armour guys to train together more easily but for real combined arms training one needs to get the other players to join as well so that real combined arms training takes place just as often as with pure bns.

 

[Raven22]

Tanks with their larger crews were actually better off but still with two blokes at the listening post and three or four at the OP you would be pretty short with only six or seven back with the tanks.

You are never going to have tank troops manning LPs/OPs. What a waste of capability. As Abe said, a tank troop has no problem protecting themselves in the field. They are the biggest concentration of combat power on the battlefield after all.

The thing is it was so much easier with even a couple of extras along for the ride, you could do so much more with only a small increase in the number of heads, especially if they were trained in D&S and Radio/Gunnery. It also gave you spare crew to mitigate fatigue.

I think you'll find that just about every job in the military would be so much easier with extra soldiers attached. That doesn't mean it's a smart thing to do.

The other factor is it would give you the ability to insert additional skills in the troops, say a limited combat pioneer, medic or even designated marksman function.

Or just attach engineers from the CER, a medic from the CSSB or marksman from an infantry battalion? Ie, the whole combined arms thing?

I suppose I am just remembering the Australian Army operating on a shoe string. There were support elements, we just never got to see them with all work being done by the crews (within the troop) on their own. This included engine replacements, suspension work as well as the never ending track bashing. Its that memory of how hard it is when you don't "own" the supporting capability which is pretty much always the case in Australia, or was back in the 90s when I played soldier.

That's because there's a difference between crew tasks and technical tasks. Why bother the A1 ech to bash some track? That is a crew task. Ditto replacing tie rods, ditto doing the monkey work for pack changes. If the crew aren't doing those tasks they aren't doing their job. It doesn't mean the system is broken.

 

[Rimasta]

There about a thousand factors here. Political calculations in some cases to determine forces available, terrain, supplies, speed of advance (can the infantry keep up?), opposition, are just a few to consider. We all saw what happened to Syrian tanks and IFV's without adequate infantry support. But in Baghdad in 2003 its plausible more infantry could have been a burden to the tanks, at least during the initial advance to seize the highway interchanges along the MSR.

 

[Volkodav]

You are never going to have tank troops manning LPs/OPs. What a waste of capability. As Abe said, a tank troop has no problem protecting themselves in the field. They are the biggest concentration of combat power on the battlefield after all.



I think you'll find that just about every job in the military would be so much easier with extra soldiers attached. That doesn't mean it's a smart thing to do.



Or just attach engineers from the CER, a medic from the CSSB or marksman from an infantry battalion? Ie, the whole combined arms thing?



That's because there's a difference between crew tasks and technical tasks. Why bother the A1 ech to bash some track? That is a crew task. Ditto replacing tie rods, ditto doing the monkey work for pack changes. If the crew aren't doing those tasks they aren't doing their job. It doesn't mean the system is broken.

Fair call, remember I am a dinosaur who last played with APCs in the late 90s back when there was a Ready Reserve and we had an army of ones, I am, inspite of my efforts, more than a little out of date.

Looking at it from a whole of army point of view concentrating capabilities in specialist battalions and regiments and deploying tailored combined arms combat teams, battle groups and task forces makes sense.

I am very curious to see how the Armoured Cavalry Regiments evolve.

 

[FirstSpear]

I liked the 1980s ACR

Fair call, remember I am a dinosaur who last played with APCs in the late 90s back when there was a Ready Reserve and we had an army of ones, I am, inspite of my efforts, more than a little out of date.

Looking at it from a whole of army point of view concentrating capabilities in specialist battalions and regiments and deploying tailored combined arms combat teams, battle groups and task forces makes sense.

I am very curious to see how the Armoured Cavalry Regiments evolve.

IMHO, the most interesting test case of what this stream is discussing, in the US Orbat anyway, was the ACR model of the early 80's, before Bradleys came into full use in Infantry units. The Cavalry units (i.e., the nominally dedicated armored reconnaissance units, as opposed to outright armored units) of the US army deployed maneuver units which were subdivided into elements of 4 tanks (originally M60s but quickly M1s), 2 AT vehicles (with M150s being the original kit before the M901 became available), 2 or 4 heavily armed M113s (.50 cal with shield instead of 7.62 without shield) carrying each a team of 5 dismounts. The element sometimes also had a SPM loaned from the maneuver unit for good measure (these tended to be M106s, so 107mm armed mortar carriers). The interesting thing happened when the M3 Bradleys arrived in Germany and units were able to cease operating the M150s or M901 side by side with the M113A3s as the Bradley accomplished both missions. The only major downside was the number of dismounts. Space for additional Tow rounds and a hefty amount of sighting kit was traded in and two of the dismounts were lost per vehicle. For the screening role of cavalry, 3 guys are enough to go set up an OP near a building or a forest clearing so as to allow the vehicles to remain out of IR and more importantly acoustic range. But they're not enough of a trip wire to know if you're stumbling on an enemy infantry force.

In Lebanon (Grapes of Wrath), the IDF used to assign an infantry squad to many tank platoons (essentially twelve tankers in three tanks to twelve guys in an APC). Since there were 9 dismounts, we're back to three per tank. So even if the US model for 'saturated' environments like flanks of the Fulda Gap were similar in ratios, the IDF issue in Lebanon was small ATGM teams sneaking a hit from a mile out at an M60, Shot or Merkava. They used the infantry as an additional trip wire for close security when the vehicles were immobilized at the top of a ridge providing overwatch for a column (a lot of THAT!) but they also doubled the pairs of eyes (the loader in a tank doesn't see much) to help spot ATGM teams in the distance. I remember an instance where a TV crew carrying a camera was spotted two miles out by an APC mounted infantry squad and killed by the tank crew they were covering at 3200 meters behind a brick wall they hid behind. At that distance, I guess they looked a lot like an ATGM team.

In 2006, IDF carried 3 or 4 dismounts in several tanks within two tank companies to bring along more of a reaction force into the ATGM saturated environment of SL. Contrary to a lot of reporting, I'm told the crews really benefited from the dismounts being available. In particular when damaged tanks needed to be evacuated without having another MBT lose part of its crew to handle the rescue.

I should say I respect everything that has been said here but I disagree about the benefits of 'pure' units. I think that's a lot of rear view mirror stuff. Combined arms at very microscopic levels is the way of the future. I see a very small maneuver force (as small as 500 men) divided into two assault units and one full size sapper unit. The way of the future is IED-like ordnance whether mines if a state actor or IEDs if non-state --either way, it will be outdated for commanders to expect speedy movement without much sapper support. In urban environments, they'll provide access through buildings to avoid front entries and to handle tunnels immediately. In other situation, they're a force multiplier to free the forward movement in the attack and to speed up the preparation of defensive obstacles in the defense.

Each Regiment can then have two armored assault batts and one 'pure infantry batt' to tailor the task forces. In the airmobile role, you'd still deploy two airmobile assault batts (including their own sappers) and one 'pure para or other infantry batt' for reinforcement or rapid reaction. Generally, US and IDF doctrine in movement are now quite differentiated but the USMC's current trend is, IMHO, very much trending to the IDF model of two parallel punches to essentially Thatch Weave their way forward. Best,