Mechanized infantry

Mechanized infantryareinfantryunits equipped witharmored personnel carriers(APCs) orinfantry fighting vehicles(IFVs) for transport andcombat(see alsoarmoured corps).

U.S. Army mechanized infantry dismount from anM113 armored personnel carrierduring training in 1985.

As defined by theUnited States Army,mechanized infantry is distinguished frommotorized infantryin that its vehicles provide a degree of armor protection and armament for use in combat, whereas motorized infantry are provided with "soft-skinned" wheeled vehicles for transportation only.Most APCs and IFVs are fully tracked or areall-wheel drivevehicles (6×6or8×8), for mobility across rough ground. Some militaries distinguish between mechanized andarmored(orarmoured)infantry,designating troops carried by APCs as mechanized and those in IFVs as armored.

The support weapons for mechanized infantry are also provided with motorized transport, or they are built directly into combat vehicles to keep pace with the mechanized infantry in combat. For units equipped with most types of APC or any type of IFV,fire supportweapons, such asmachine guns,autocannons,small-boredirect-firehowitzers,andanti-tank guided missilesare often mounted directly on the infantry's own transport vehicles.

Compared with "light" truck-mobile infantry, mechanized infantry can maintain rapid tactical movement and, if mounted in IFVs, have more integral firepower. They require more combat supplies (ammunitionand especiallyfuel) andordnancesupplies (spare vehicle components), and a comparatively larger proportion of manpower is required to crew and maintain the vehicles. For example, most APCs mount a section of seven or eight infantrymen but have a crew of two. Most IFVs carry only six or seven infantry but require a crew of three. To be effective in the field, mechanized units also require manymechanics,with specialized maintenance and recovery vehicles and equipment.

History

GermanA7Vtanks inRoye, SommeduringOperation MichaelofWorld War Iin 1918

As early as 1915 theBritishinstigated atracked vehiclethat could carry 50 equipped troops under armour but the project got no further than trials before cancellation. Some of the first mechanized infantry wereGermanassault teams mounted onA7Vtanks duringWorld War I.The vehicles were extra-large to let them carry sizeable assault teams and would regularly carry infantry on board in addition to their already large crews that were trained asstormtroopers.All machine-gun-armedA7V tankscarried two smallflamethrowersfor their dismounts to use. A7V tank would often carry a secondofficerto lead the assault team.

During theBattle of St. Quentinin late March 1918, A7Vs were accompanied by twenty stormtroopers from Rohr Assault Battalion, but it is unspecified if they were acting as dismounts or were accompanying the tanks on foot. During the battle, tank crews were reported to have dismounted and attacked enemy positions withgrenadesand flamethrowers on numerous occasions.

Another example of the use of such a method of fighting is thecapture of Villers-Bretonneux,in which A7Vs would suppress the defenders with machine gun fire and assault teams would dismount and attack them with grenades.

The British heavy tank design was given an extendedhullto cross wide Germantrenches.ThisMark V**had space for fourteen troops. TheMark IXtank based on theMark Vwas designed solely for carrying troops with space for 30 but the war ended before the order was complete and they could be used.

Towards the end ofWorld War I,all the armies involved were faced with the problem of maintaining the momentum of an attack. Tanks, artillery, orinfiltration tacticscould all be used to break through an enemy defense, but almost all offensives launched in 1918 ground to a halt after a few days. The following infantry quickly became exhausted, and artillery, supplies and fresh formations could not be brought forward over the battlefields quickly enough to maintain the pressure on the regrouping enemy forces.

It was widely acknowledged thatcavalrywas too vulnerable to be used on most European battlefields, but many armies continued to deploy them.Motorized infantrycould maintain rapid movement, but their trucks required either a good road network or firm open terrain, such asdesert.They were unable to traverse a battlefield obstructed bycraters,barbed wire,and trenches. Tracked or all-wheel drive vehicles were to be the solution.

Following the war, development of mechanized forces was largely theoretical for some time, but many nations began rearming in the 1930s. TheBritish Armyhad established anExperimental Mechanized Forcein 1927, but it failed to pursue that line because of budget constraints and the prior need togarrisonthe frontiers of theBritish Empire.

Although some proponents of mobile warfare, such asJ. F. C. Fuller,advocated building "tank fleets", other, such asHeinz Guderianin Germany,Adna R. Chaffee Jr.in the United States, andMikhail Tukhachevskyin theSoviet Union,recognized that tank units required close support from infantry and other arms and that such supporting arms needed to maintain the same pace as the tanks.

As the Germans rearmed in the 1930s, they equipped some infantry units in their newPanzer divisionswith thehalf-trackSd.Kfz. 251,which could keep up with tanks on most terrain. TheFrench Armyalso created "light mechanized" (légère mécanisée) divisions in which some of the infantry units possessed small tracked carriers. Together with the motorization of the other infantry and support units, this gave both armies highly mobile combined-arms formations. The German doctrine was to use them to exploit breakthroughs inBlitzkriegoffensives, whereas the French envisaged them being used to shift reserves rapidly in a defensive battle.

World War II

U.S.M3 half-tracksand infantry on exercises,Fort Knox,June 1942

AsWorld War IIprogressed, most major armies integratedtanksorassault gunswith mechanized infantry, as well as other supporting arms, such as artillery andcombat engineers,ascombined armsunits.

Allied armored formations included a mechanized infantry element for combined arms teamwork. For example, US armored divisions had a balance of three battalions each of tanks, armored infantry, andself-propelled artillery.The US armored infantry was fully equipped withM2andM3 halftracks.In the British andCommonwealtharmies, "Type A armoured brigades," intended for independent operations or to form part of armored divisions, had a "motor infantry" battalion mounted inUniversal Carriersor later in lend-lease halftracks. "Type B" brigades lacked a motor infantry component and were subordinated to infantry formations.

TheCanadian Armyand, subsequently the British Army, used expedients such as theKangaroo APC,usually for specific operations rather than to create permanent mechanized infantry formations. The first such operation wasOperation Totalizein theBattle of Normandy,which failed to achieve its ultimate objectives but showed that mechanized infantry could incur far fewer casualties than dismounted troops in set-piece operations.

The German Army, having introduced mechanized infantry in itsPanzerdivisions, later named themPanzergrenadierunits. In the middle of the war, it created entire mechanized infantry divisions and namedPanzergrenadierdivisions.

Because the German economy could not produce adequate numbers of its half-track APC, barely a quarter or a third of the infantry in Panzer orPanzergrenadierdivisions were mechanized, except in a few favored formations. The rest were moved by truck. However, most German reconnaissance units in such formations were also primarily mechanized infantry and could undertake infantry missions when it was needed. TheAlliesgenerally used jeeps, armored cars, orlight tanksfor reconnaissance.

TheRed Armybegan the war while still in the process of reorganizing its armored and mechanized formations, most of which were destroyed during the first months of the German Invasion of the Soviet Union. About a year later, the Soviets recreated division-sized mechanized infantry units, termedmechanized corps,usually with one tank brigade and three mechanized infantry brigades, with motorized supporting arms. They were generally used in the exploitation phase of offensives, as part of the prewar Soviet concept ofdeep operations.

The Soviet Army also created severalcavalry mechanized groupsin which tanks, mechanized infantry andhorsed cavalrywere mixed. They were also used in the exploitation and pursuit phases of offensives. Red Army mechanized infantry were generallycarried on tanksor trucks, with only a few dedicated lend-lease half-track APCs.

TheNew Zealand Armyultimately fieldeda divisionof a roughly similar composition to a Soviet mechanized corps, which fought in theItalian Campaign,but it had little scope for mobile operations until near the end of the war.

TheRomanian Armyfielded a mixed assortment of vehicles. These amounted to 126 French-designedRenault UE Chenilletteswhich were licence-built locally, 34 captured and refurbishedSoviet armored tractors,27 German-made armored half-tracks of theSd.Kfz. 250andSd.Kfz. 251types, over 200 CzechoslovakTatra,PragaandSkodatrucks (the Tatra trucks were amodelwhich was specifically built for the Romanian Army) as well as 300 GermanHorch901 4x4 field cars.Sd.Kfz. 8andSd.Kfz. 9half-tracks were also acquired,as well as nine vehicles of theSd.Kfz. 10type and 100RSO/01fully tracked tractors.The Romanians also produced five prototypes of anindigenousartillery tractor.

Cold War

Swiss Armed ForcesPanzer 61andSPz 63/73armored vehicles deploying mounted infantry in 1979

On July 9, 1945, Decree of theState Defence CommitteeNo. GKO-9488ss, "On the Resupply of Armored and Mechanized Forces of the Red Army"was issued. It ordered the creation of mechanised divisions from many rifle divisions, included in the Armored and Mechanised Troops. In some cases, cavalry divisions and airborne divisions also became mechanised divisionsThe Sovietmotorised rifle troopsofficially appeared in accordance with the Directive of the Minister of Defense of the USSR No. org. / 3/62540 of February 27, 1957. This directive ordered part of the mechanized divisions and all rifle units and formations reorganized into 'motorised rifle' in the period 1957 to 1964.Creation of the motorised rifle troops was facilitated by large-scale mechanisation of the wholeSoviet Ground Forces.

This became possible due to the increase in the production ofarmored personnel carriers,self-propelled guns and so on. For example, in the period before the formation and in the initial period of the formation of themotorized rifle troops:

• BTR-40– in the period from 1950 to 1960s, 8,500 units were produced
• BTR-50— 1954 to 1970s – 6,500 pieces
• BTR-152— 1947 to 1962 – 12,421 pieces
• BRDM-1— 1957 to 1966 – 10,000 units

One or two motorised rifle regiments were also present in each tank division, and many tank regiments included one motorised rifle battalion.

After 1945, the Soviet Armed Forces andNATOfurther developed the equipment and doctrine for mechanized infantry. With the exception ofairborne formations,the Red Army mechanized all its infantry formations. Initially, wheeled APCs, like theBTR-152,were used, some of which lacked overhead protection and were therefore vulnerable to artillery fire. It still gave the Soviet Army greater strategic flexibility because of the large land area and the long borders of the Soviet Union and its allies in theWarsaw Pact.Armored vehiclesmeant infantry were capable of overcoming water barriers and having means of protection againstWeapons of Mass Destruction.

The US Army established the basic configuration of the tracked APC with theM75andM59before it adopted the lighterM113,which could be carried byLockheed C-130 Herculesand other transport aircraft. The vehicle gave infantry the same mobility as tanks but with much less effective armor protection (it still had nuclear, biological, and chemical protection).

In theVietnam War,the M113 was often fitted with extra armament and used as anad hocinfantry fighting vehicle. Early operations by theArmy of the Republic of Vietnamusing the vehicle showed that troops were far more effective while they were mounted in the vehicles than when they dismounted.American doctrine subsequently emphasized mounted tactics.The Americans ultimately deployed a mechanized brigade and ten mechanized battalions to Vietnam.

Themotorized rifle troopsof theSoviet Armed Forceswere the world's first infantry units that adopted a new class of combat vehicles in 1966 –Infantry fighting vehicles.BMP-1began entering service in 1966. In theFederal Republic of Germany,an approximate analogue, theMarder,appeared only in 1970. Unlike the APC, which was intended merely to transport the infantry from place to place under armor, the IFV had heavy firepower that could support infantry. TheInfantry fighting vehicleconcept was subsequently copied by almost all countries of the world.

The introduction of theBMP-1prompted the development of similar vehicles in Western armies, such as theWest GermanMarderand AmericanM2 Bradley.Many IFVs were also equipped with firing ports from which their infantry could fire their weapons from inside, but they were generally not successful and have been dropped from modern IFVs.

Soviet organization led to different tactics between the "light" and the "heavy" varieties of mechanized infantry. In the Soviet Army, a first-line "motor rifle" division from the 1970s onward usually had two regiments equipped with wheeledBTR-60APCs and one with the tracked BMP-1 IFV. The "light" regiments were intended to make dismounted attacks on the division's flanks, while the BMP-equipped "heavy" regiment remained mounted and supported the division's tank regiment on the main axis of advance. Both types of infantry regiment still were officially titled "motor rifle" units.

A line of development in the Soviet Armed Forces from the 1980s was the provision of specialized IFVs for use by theRussian Airborne Troops.The first of them was theBMD-1,which had the same firepower as theBMP-1but could be carried in or even parachuted from the standard Soviet transport aircraft. That made airborne formations into mechanized infantry at the cost of reducing their "bayonet" strength, as the BMD could carry only three or at most four paratroopers in addition to its three-man crew. They were used in that role in theSoviet invasion of Afghanistanin 1979.

Present day

Strykervehicle and dismounted infantry of the US Army's1st Brigade Combat Team, 25th Infantry Divisionin Mosul, Iraq, 2004.

At present, almost all infantry units from industrialized nations are provided with some type of motor transport. Infantry units equipped with IFVs rather than lighter vehicles are commonly designated as "heavy", indicating more combat power but also more costly long-range transportation requirements. InOperation Desert Shield,during the buildup phase of the First Gulf War, the U.S. Army was concerned about the lack of mobility, protection and firepower offered by existing rapid deployment (i.e., airborne) formations; and also about the slowness of deploying regular armored units. The experience led the U.S. Army to formcombat brigadesbased on theStrykerwheeled IFV.

In the British Army, "heavy" units equipped with theWarrior IFVare described as "armoured infantry", and units with theBulldog APCas "mechanised infantry". This convention is becoming widespread; for example theFrench Armyhas "motorisées"units equipped with the wheeledVABand "mécanisées"units with the trackedAMX-10P.

The transport and other logistic requirements have led many armies to adopt wheeled APCs when their existing stocks of tracked APCs require replacement. An example is the Canadian Army, which has used theLAV IIIwheeled IFV in fighting in Afghanistan. TheItalian,SpanishandSwedisharmies are adopting (and exporting) new indigenous-produced tracked IFVs. The SwedishCV90IFV in particular has been adopted by several armies.

A tracked IFV, the US30th ABCT'sM2A2 Bradley,on patrol in eastern Syria, 2019.

A recent trend seen in theIsrael Defense Forcesand theArmed Forces of the Russian Federationis the development and introduction of exceptionally well-armored APCs (HAPC), such as theIDF Achzarit,that are converted from obsoletemain battle tanks(such as the SovietT-55). Such vehicles are usually expedients, and lack of space prevents the armament of an IFV being carried in addition to an infantry section or squad. In the Russian Army, such vehicles were introduced for fighting in urban areas, where the risk from short range infantry anti-tank weapons, such as theRPG-7,is highest, after Russian tank and motor infantry units suffered heavy losses fighting Chechen troops inGroznyduring theFirst Chechen Warin 1995.

Many APCs and IFVs currently under development are intended for rapid deployment by aircraft. New technologies that promise reduction in weight, such as electric drive, may be incorporated. However, facing a similar threat inpost-invasion Iraqto that which prompted the Russians to convert tanks to APCs, the occupying armies have found it necessary to apply extra armor to existing APCs and IFVs, which adds to the overall size and weight. Some of the latest designs (such as the GermanPuma) are intended to allow a light, basic model vehicle, which is air-transportable, to be fitted in the field with additional protection, thereby ensuring both strategic flexibility and survivability.

Medium mechanized forces

In the lateCold Warand early 21st century, various countries developed medium infantry forces armed with armored vehicles, which typically consisted of wheeled armored personnel carriers, infantry fighting vehicles, and assault guns. Medium mechanized forces are characterized by having more strategic air and road mobility than heavier, tank-based armored forces while offering better armor protection for the formation than the lightermotorized infantryformation, in which vehicles were considered "battle taxis" due to poor protection. The earliest experiment was the short-lived Soviet Light Motor Rifle Division in 1987, which consisted of wheeled BTR platforms for its primary armament.In the 1990s, the United States exploredStryker Brigade Combat Team(SBCT) formation and doctrines, which was a medium mechanized infantry formation with all-wheeled platforms centered aroundStrykerarmored personnel carrier. In the early 21st century, China reformed its ground forces with the concept called Medium Combined Arms Brigade (CA-BDE), armed withType 08universal wheeled platform. A similar trend of adopting the medium mechanized forces was observed in European countries, including the Italian, Polish, and French armed forces.

Combined arms operations

It is generally accepted that single weapons system types are much less effective without the support of the full combined arms team; the pre-World War II notion of "tank fleets" has proven to be as unsound as the World War I idea of unsupported infantry attacks. Though many nations' armored formations included anorganicmechanized infantry component at the start of World War II, the proportion of mechanized infantry in such combined arms formations was increased by most armies as the war progressed.

The lesson was re-learned, first by the Pakistani Army inthe 1965 war with India,where the nation fielded two different types of armored divisions: one which was almost exclusively armor (the 1st), while another was more balanced (the 6th). The latter division showed itself to be far more combat-capable than the former.

Having achieved spectacular successes in the offensive with tank-heavy formations during theSix-Day War,theIsrael Defense Forcesfound in theYom Kippur Warof 1973 that a doctrine that relied primarily on tanks and aircraft had proven inadequate. As a makeshift remedy, paratroopers were provided with motorized transport and used as mechanized infantry in coordination with the armor.

See also

• Armoured warfare

Sources

• Dunstan, Simon.Vietnam Tracks: Armor In Battle 1945–1975.1982 edition, Osprey Publishing;ISBN0-89141-171-2.
• Starry, Donn A., General.Armored Combat in Vietnam.1980, Arno Press Inc.ISBN0-672-52673-5.