On Mechanization and Combined Arms.

While the tank was invented and initially fielded during World War I, World War II was really the first conflict to feature large scale armor formations, and put the theory of the tank into practice. Considerable thought had gone into the best doctrine for the use of the tank between the wars. Some doctrines were more successful than others. In the US during the interwar years, there were two primary schools of thought. Cavalry saw the tank as a replacement for the horse*, a means of rapid movement on the battlefield to turn flanks, raid the enemy rear, and exploit breakthroughs. Tanks should be light and fast. The tank would be the decisive arm, and all others should support it. The Infantry primarily saw the tank as a direct fire support asset for the rifleman. Tanks should be slow and heavy. The Infantry would be the decisive arm, and all others should support it.

That’s a gross oversimplification of the schools of thought, but sufficient for now. But a funny thing happened on the way to victory in World War II- it turned out, both major schools of thought were wrong.

The original US table for an armored division had two regiments of tanks, and one regiment of Armored Infantry, mounted on half-track personnel carriers. But it quickly became apparent that the “heavy” division was unwieldy, and, more critically, lacked enough infantrymen. Aside from the 2nd and 3rd Armored Divisions, eventually all US armored divisions in World War II would adopt a “light” table, with one regiment of tanks, and one regiment of armored infantry. In effect, the ratio of tanks to infantry went from 2-1 to 1-1. And by the end of the war, it wasn’t uncommon for an armored division to be augmented with extra infantry battalions, or even a regiment from a regular infantry division, in essence giving a ratio of 1-2.

Today we think of the tank as the ultimate tank killer. But prior to World War II, and indeed, through most of the war, US doctrine held that the very last thing tanks should be used for was killing tanks. That’s a large part of why the M4 Sherman was initially fielded with a rather anemic 75mm gun. The gun was quite suited for firing on bunkers and pillboxes. It’s rather poor performance against armor wasn’t thought to be a major handicap. By the end of the war, both the thinking on the best means of killing tanks, and the main armament had changed.

After the war, the rough numbers of infantry units to armor units was generally maintained at around 1-1. Armored Infantry eventually gave way to what we today call mechanized infantry. Carriers for the infantry have evolved from the half track through the M75 and M59 Armored Personnel Carriers, to the long serving M113 to todays M2 Bradley family.

In whatever vehicle they used, mechanized Infantry formations were always expected to operate alongside tank formations, with each arm supporting the other. Both armored and mechanized infantry divisions contained a balanced mix of tank and mech infantry units.

The fielding of the Bradley family, heavy on firepower, but light on numbers of actual infantrymen, made sense in western Europe when the US faced a Soviet Union with massive numbers of tanks and other armored vehicles, including thousands of BMP fighting vehicles and and BTR armored personnel carriers. Interestingly, the Soviets too had balanced formations of infantry and armor, though their mix of “motorized rifle” formations had a rough mix of one BMP formation (heavy on firepower, lighter on dismount infantry) to two BTR formations (light on firepower, heavy on dismount infantry).

The US saw the Bradley as needed to whittle down the numbers of Soviet vehicles. The problem was, the compromises needed to mount both an automatic cannon and the TOW missile launcher meant that something had to give, and that was the number of dismount infantrymen per vehicle. Whereas for many years the rifle squad was 11 or twelve men, eventually it shrank to 9 men. But in Bradley units, each Bradley could only deploy six, or maybe seven dismounts. And that’s under the cheery assumption that the unit was at 100% strength.

While that was generally acceptable for western Europe facing the Group of Soviet Forces in Germany (GSFG), for other theaters, that left a dearth of dismounts available for those missions that require large numbers of troops actually on the ground.

That lack of actual numbers of infantry, when history has shown that large numbers of infantry are required on the combined arms battlefield, was part of the impetus for the introduction of the Stryker Brigade Combat Team. The Stryker is often belittled in comparison to both the Bradley, and the M113. But the Stryker is not a replacement for either. Rather, it is a recognition that earlier light infantry units simply didn’t have the operational mobility to move around the battlefield. The weapon of the Stryker BCT isn’t the Stryker vehicle, it is the dismount rifleman.

No real point to all of this. Just putting some random thoughts down.


*Of course, not all Cavalry officers thought this. Many right up until about 1940 still saw the horse as a viable weapon of war.

Bradley Relatives – The MICV and AIFV

When discussing the early Bradley prototype, I brought up the Mounted Infantry Combat Vehicle (MICV) of the 1960s.  To be complete, I should also mention the Armored Infantry Fighting Vehicle (AIFV) as the other infantry fighting vehicle (IFV) developed prior to the Bradley prototypes.  If the XM-723 was the “mother” Bradley, then the MICV is perhaps the “grandmother” and AIFV a “sister.”

Armies do not develop weapon systems in a vacuum, rather evolve them based upon assessments of the existing systems.   After a decade or so of evolution, the US Army fielded the excellent M113 Armored Personnel Carriers (APC).  Great vehicles for their time (and still useful today), but these were for all purposes “battlefield taxis.”  From the infantryman’s perspective, this got him to the battlefield without getting the boots muddy but kept him from contributing to the battle until dismounting.  At the time planners felt future battlefields would be polluted with nasty radiation and chemical agents.  Thus sprang the idea of allowing the infantry to fight from the vehicle, to dismount on the objective.

The Infantry School itself first dabbled with such a vehicle with a modified M113.  With benches allowing back-to-back squad seating, the infantry used firing ports cut into the sides.   Eventually the M113’s vendor, FMC Incorporated, offered a factory-built refinement along the same lines, which received the designation XM734.   Although typically seen with the standard .50-cal M2, some XM734 tested 20mm cannons.


(See this Flickr photostream for “walk around” photos of a XM734 on display at the Orange County Florida Sheriff’s Office.  The track came that way in a round about way, after seeing Israeli use!)

In the mid-1960s, the Army opened the MICV-65 program and tested XM734s alongside an offering from the Pacific Car and Foundry, XM701.   Pacific Car based the later on the chassis of their M107/110 series of heavy self-propelled guns.  Like the FMC vehicle, Pacific Car gave their vehicle firing ports and options for a turret mounted .50-caliber or 20mm gun.  In trials the XM701 emerged as the better vehicle.  But after further testing, the Army rejected the type in 1966 as too heavy for transport in theater support cargo aircraft (at the time C-141s).


But the MICV project was not a drive up a blind alley.  The Army still wanted something.  In 1968 a task force led by Major General George Casey (father of the current Army Chief of Staff) used the experience from the MICV project to define the attributes desired for an ICV.  More importantly, the task force also laid the ground work for just how the Army would use any ICV.  At the time, FMC offered a revised XM734.   Although using the same base M113 chassis, the XM765 featured improvements to crew stations and fuel storage.

XM765 at the Infantry Museum

The XM765 featured a commander’s turret with a 20mm cannon (although the one pictured above has a smaller turret with fittings for a .50-caliber mounting).  On each a revised and sloped side bristled with four firing ports.  Two additional ports on the loading ramp covered the rear of the vehicle.  The ports allowed infantry to use their M16 rifles (and often cited are the M3A1 grease gun SMGs, always one of my favorites!).  Fuel tanks moved from the sides of the crew compartment to under the floor.  The downside was the XM765’s use of the M113 powerpack.  With all the extra weaponry, to keep decent performance figures FMC reduced the armor.   For this and other reasons, the Army didn’t bite on the XM765 opting to continue pursuit of something better.

But that did not prevent FMC from continuing development.  In the early 1970s the company started offering an even more refined XM765 as the AIFV to foreign customers.  The Netherlands ordered 880 AIFVs in 1975 as the YPR-765.  The Dutch specified some revisions to crew arrangements, fewer firing ports, and used an aluminum-steel laminate.  But the AIFV retained the M113A1 power train.  In the turret, the Dutch variant mounted a Oerlikon Contraves 25 mm KBA-B02 cannon.

Dutch YPR-765 AIFV

So when General DePuy said “…the Dutch are ahead of us…” this is what he had on his mind.  Sort of ironic, you think?   The AIFV became a cheap alternative to the Bradley, Marder, or Warrior IFVs.  Twelve other countries, including Belgium, Egypt, Turkey, and Philippines also purchased quantities of the AIFV. Variants include TOW missile carriers and specialized C2 vehicles.

The Dutch continue to use the YPR-765 today, even sending some to Afghanistan.  Recent improvement programs removed the turret but improved armor arrangements, and is designated the YPR-765A1.


The Egyptians opted to upgrade their 1,200 AIFVs to a new Egyptian Infantry Fighting Vehicle (EIFV) standard with a “Bradley” turret including  a 25mm Bushmaster gun and TOW launcher.

EIFV Design Diagram

And with all that talk, you want to see some boom-boom!  Well here is the boom-boom!


A Dutch YPR-765 in Afghanistan.

And another one from the “gun line”:


See why I say “sister” of the Bradley?

And, for the record, the Dutch beat the US again – getting armor into Afghanistan!