Challenging the IFV concept - Part 1

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Infantry fighting vehicle (IFV, Schützenpanzer/SPz in German) discussions are usually about which is better, whether the protection is sufficient, whether the new model is a good design or about the dismount strength.

We've become used to IFVs as self-evident combat vehicles, as self-evident as are main battle tanks (MBTs).


I tend to think way outside the box and often come to unorthodox conclusions (and surely don't hit the nail every time - a 3/5 hit rate would already be phenomenal). My thinking about the IFV concept was stirred up by several exceptions to the rule and by military history.

Let's begin at the origins.

The Germans deployed (similar to some French vehicles) Schützenpanzerwagen, SPW (SdKfz 251 and SdKfz 250) during WW2.

These were half-tracked vehicles to get a better off-road capability than all-wheeled vehicles. The off-road capability was indeed quite good because of the large tracks and therefore low ground pressure (the similar American half-tracks had much smaller tracks and inferior off road capabilities; they even needed front drums as aid to cross trenches).
Fully tracked vehicles required more elaborate gearboxes and were expected to be much more expensive. The compromise at the time was therefore a half-track.

This gave the infantry of armoured divisions (actually just a portion of it) protected mobility. The infantry was able to keep the pace of the tanks in all terrains and were available for the combined arms combat. These SPW were bullet-proof (except against AT rifle and equivalent bullets), but not shell-proof. Their protection wasn't superior to 1920's tanks, but they faced 40's anti-tank defences. Nevertheless, bullet-proof was better than no armour.

The rise of light shaped charge-based anti-tank weapons (Panzerfaust, Bazooka, Panzerschreck, Piat) during 1943-1944 provided infantry with deadly short-range anti-tank self defence weapons. Tanks were no longer able to easily overrun infantry without serious losses.

These infantry AT weapons were effective at ranges like 30-150 m and easily outranged by normal infantry weapons (rifles, machine guns), though.
The users of such AT weapons were difficult to spot by tanks (limited fields of view are still a problem for tank crews) and much easier to spot by infantry.

The solution to the Panzerfaust problem was to use infantry (and mortars, artillery) instead of tanks against their users and to support the infantry with tank weapons over a safe distance.
Mortars and artillery were able to kill infantry, but were poor at spotting it. The use of infantry support for tanks was therefore of utmost importance.

A normal infantry attack was dangerous and slow. Infantry dismounting from tanks (tank desants) was faster but exposed to extreme risks.
This was the point when the SPW concept proved its worth again; these vehicles carried infantry at high speed and enabled it to fight with its weapons and with good vision - still outranging the AT weapons. Even a hit by a shaped charge was not necessarily a disaster - shaped charges aren't very effective behind thin armour plates (much of their effect is based on turning the armour into fragments).

The only remaining problems at that time were the short range of the German flamethrowers (very effective weapon kit for SPW vehicles in WW2) and the SPW's vulnerability to shells.


WW2 ended, but the technical-tactical challenge didn't end in 1945.

The conclusions of German officers from WW2 were clear:
The Panzergrenadiere (~mechanized infantry) should get a vehicle that
- was as mobile as the tanks (full track, speed, power/weight)
- had a shell-proof frontal armour plating
- carried about eight Panzergrenadiere for primarily mounted combat
- had a serious weapon (12.7 mm MG or 20 mm autocannon) for ground combat and air defence

The intent was that the combat would happen mounted if possible - this enabled very quick actions at tank speed instead of infantry speed. The Panzergrenadiere had to defeat the enemy infantry (which had only short-ranged light anti-tank weapons). The mounted fight required good vision when mounted - this meant that the vehicle should be open.

The Heer (German army) finally got a technically flawed vehicle (HS30). The vehicle had also a conceptual shortcoming; it wasn't able to resist shells (or shaped charges). Costs and fuel consumption would easily have been twice as high if that tactical requirement was met. Germany wasn't rich at that time, so the HS30 (and all later IFVs) had to be protected inadequately.

The NBC battlefield plannings and the rise of proximity fuses for artillery and mortar shells also questioned the wisdom of an open-topped battlefield vehicle. It became necessary to provide a protective roof, but the Heer still stuck to the principle that the Panzergrenadiere were meant to fight mounted.

The IFV/SPz concept was in serious trouble during the late 50's and early 60's because of its vulnerability, but that was only the beginning.

The next problem - and this should have been a K.O. hit for the concept in my opinion - was that the effective range of infantry anti-tank weapons increased while the effective range of mounted infantry was stagnating.

It became eventually during the 70's obvious that an IFV with mounted infantrymen would be at high risk (and not the scissor to the paper) when facing infantry at short range.
IFV crews were - just like the main battle tank crews - better off with long-range fire tactics and a call for indirect fire support against infantry. There was no range any more at which mounted Panzergrenadiere were able to defeat enemy infantry without catastrophic risk.

IFVs were nevertheless improved - they got anti-tank missiles to assist the MBTs in tank battles (and to bolster their morale), sometimes at the cost of one infantryman less.
Passive low light and even passive infrared sights were introduced and fully stabilized main guns (autocannons of 20-40mm calibre) with laser rangefinders and ballistic computers became standard. The IFV became an autocannon-armed combat vehicle that complemented the MBTs with its dissimilar armament. It also happened to carry infantrymen, but they had ever less ability to fight mounted; they were often reduced to using firing ports with minimal vision, and even these were at times blocked by armour upgrades.

The IFVs became really expensive and therefore inevitably really few. Some Western armies didn't compensate for this with the provision of enough cheap APCs (armoured personnel carriers) for supplementary mechanized infantry, though. The armour and mechanized infantry brigades of NATO forces are often dangerously weak on infantry.

There's actually some hope for the survivability of IFVs today; active protection systems and many other advances (mostly against shaped charges, not so much against shells/kinetic energy penetrators) may finally give the equivalent of shell-proofing to future IFVs like Puma.

Mounted combat for Panzergrenadiere is nevertheless an anachronism. Some modern IFV designs provide only hatches for two dismounts, more for observation and last ditch defence than as offensive conceptual mainstay. Today's dismounts can be happy if they have seen the surrounding terrain before they're ordered to dismount.

Modern IFVs are reduced to autocannon combat vehicles - they should not be called IFVs or Schützenpanzerwagen at all.
Our armies are clinging to the IFV as mainstay of infantry power in armour and mechanized brigades - the result is a very weak infantry component, a weak link in combined arms warfare.


This got quite long, so I'll post my suggestions in a second part.
I'll place more emphasis on non-hardware topics in the next weeks.

S O

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