By the end of 1944 the basis of tank and infantry co-operation tactics showed distinct similarities whether German, US, or British. Whether well or indifferently performed in practice, the result of six years of war was convergence of theory. According to Handbook on German Military Forces,
When the enemy has well prepared positions with natural or constructed tank obstacles, the German infantry attacks before tanks and clears the way. The objective of the infantry is to penetrate into the enemy position and destroy enemy anti tank weapons to the limit of its strength and the firepower of its own support weapons, augmented by additional support and covering fire from the tanks and self propelled guns sited in the rear . . . When the tank obstacles in front of the enemy position already are destroyed, and no additional tank obstacles are expected in the depth of the enemy’s main defensive position, the infantry breaks through simultaneously with the tank unit…. In most cases, the infantry follows the tanks closely, taking advantage of the firepower and paralysing effect of the tanks upon the enemy’s defense. The Germans normally transport the infantry to the line of departure on tanks or troop carrying vehicles in order to protect the infantry.
Interestingly, US experiments with motorised infantry were underway as early as 1929 when a company of 34th Infantry was mounted in six-wheeler trucks as part of a ‘Mechanised Force’. This did not last long, however, and rival claims were staked by the infantry and cavalry – with the former wanting ‘infantry tanks’ attached, the latter seeking to become the umbrella to all mobile troops. Only in 1940 was an integrated force formed with the foundation of 1st and 2nd Armoured Divisions, and in 1941 five truck-transported infantry motorised divisions were planned. In the event only one motorised division was completed, and this was never used in its intended role. Efforts, therefore, focused on the creation of more all-arms armoured divisions. Initially, armoured divisions were mainly tanks with few infantry, but observation of European experience, combined with massive infantry manpower increases, made progressive revisions possible. By March 1942 the armoured divisional establishment wedded together two armoured regiments with a three-battalion armoured infantry regiment. In 1943 ‘light’ armoured divisions were also introduced with a better balance of three battalions of tanks with three of infantry.
The US armoured infantry platoon now numbered five squads, three rifle, one mortar and one light machine gun, each squad travelling in an M3 half-track. Capable of seating up to 13, the M3 was bigger than the M2 (that carried only 10), and was arranged with 3 seats across the front and 5 down each side. In the ordinary squad vehicle the leader usually sat front right, ready to handle the vehicle mounted .30 cal machine gun. As in the German arrangement, his assistant squad leader rode at the back next to the rear door, and more than one man was trained to drive, one of these being designated the assistant driver. The M3 armour was just adequate for protection against small arms and fragments, but would not stop much else, and there was no overhead protection on the driving compartment. Some dubbed the M3 the ‘Purple Heart Box’ on account of those injured in it.
Initial US theory paid relatively little heed to the notion of close integration of tanks and infantry, and early armoured establishments ensured that the latter were insufficient where they were needed. Gradually, and arguably from mid-1942, this began to change. Manuals made it very clear that the raison d’être of tanks, and by extension all their appendages within the armoured division, was the offensive. Within the tactical detail it was tanks that formed the cutting edge ‘striking force’, infantry that followed up. Yet there were exceptions. As the 1942 instructions FM 17-10 Armored Force Field Manual: Tactics and Technique, explained,
In attack the combat command groups are generally disposed into four parts: a reconnaissance force (consisting of organic reconnaissance units and attacking units), a striking force (the striking echelon consisting of tanks with engineers attached), a supporting force (consisting of the support echelon, i.e. the infantry, artillery and tank destroyer units), and a reserve. Whether the striking force makes the initial attack or main attack will depend on the terrain and the extent and dispositions of the hostile anti tank defences. . . . When the striking force makes the initial attack, the support echelon follows to seize and hold objectives taken by the striking echelon. When terrain is unsuitable for tank operation or anti tank defences are strong, the support echelon, supported by medium tank units, may lead the attack to secure ground from which the striking echelon may attack. The support echelon usually leads the attack in a penetration. The support echelon may be used to make an attack initially to serve as a base of fire for the striking force in an envelopment. The attack serves to fix the enemy and attract his reserves. In this manner it assists the advance of the enveloping or striking force.
Additionally, armoured infantry had roles in both pursuit and ‘encircling forces’. During an encirclement, for example, they might follow the tanks and take over and hold ‘critical terrain’ gained by the armour. North Africa and Italy would make it very clear that tanks without any attached infantry were at a serious disadvantage; whilst tanks, even in small numbers, lent vital fire support and morale advantages to their infantry compatriots.
Armored Force Drill, of January 1943, gave a range of formations for use by armoured infantry on the move. Whilst they could take up ‘wedges’ – inverted or otherwise, move in columns or stepped ‘echelons’, or any other form of deployment also used by tanks, the ‘diamond’ was described as ‘the basic formation for the infantry platoon’. In the diamond,
the platoon leader’s rifle squad and the two other rifle squads form a wedge, with the platoon leader at the apex. The 60mm mortar squad and the light machine gun squad are on a line in rear of the wedge formed by the rifle squads. The company may be formed in line, column, echelon, wedge, or inverted wedge, in each formation with the platoons in diamond formation.
As may be imagined, the larger company formations described needed much open space for full deployment, so in practice, and particularly in the closed country of Normandy or Italian mountains and hills, short lines, platoon wedges, or columns of various depths and dispersions were much more commonly seen. Experience also taught that fuller integration of tanks and half-tracks was often the best option. So it was that armoured infantry platoons were paired with tank platoons, the latter giving good long-range firepower and a measure of anti-armour protection, the latter ability to counter enemy anti-tank units and infantry, or hold a terrain feature.
Though fire from the vehicle was used in emergency, and a parked half-track formed a useful base of fire – particularly if concealed and mounted with the powerful .50 calibre machine gun, US tactical theory did not regard the M3 as a ‘fighting’ or assault vehicle, but more as a sophisticated, and partly protected, form of cross-country transport. In any case, as the Crew Drill manual explained, small-arms fire was much more accurate if the vehicle stopped. Standard procedure, therefore, was that in combat the main portion of the squads alighted before meeting effective fire, leaving one, or preferably two, men with the vehicle. Those left behind could move the half-track and fire its machine gun, perhaps in support, as an anti-aircraft defence, or to protect a given locality. If not needed immediately, the M3 retired to a given rendezvous or acted as battlefield taxi for supplies and wounded. As the squad dismounted its leader gave consideration to mission and tactical requirements, for if all weapons including the main machine gun were taken off the squad had fearsome firepower but limited mobility. Conversely, if the bazooka and machine gun were left behind the team could move with great agility but little power to confront vehicles or large numbers of the enemy. As a shorthand order the word ‘rockets’ was recommended: on hearing this the squad debused with the bazooka using two of the riflemen as anti-tank team, but left the machine gun behind. ‘No rockets’ meant that riflemen went lightly equipped.
In a well co-ordinated armoured infantry attack a combined formation went to ground near the target, and whilst infantry dismounted, tanks took up covered positions from which to put the enemy under fire. Depending on the results of reconnaissance or intelligence, the action might also be supported by artillery, mortars, machine guns, and the three useful M8 self-propelled howitzers that also formed part of the armoured infantry battalion. Taking advantage of covering fire, the armoured infantry advanced in dispersed formation, using their own fire and movement as required. If all went well, the infantry took up the ground, making sure that no anti-armour weapons were still lurking before the tanks came close in: if the infantry were held up tanks might be required to neutralise machine-gun nests or other centres of resistance. Whilst tank destroyers had the main task of dealing with enemy armour, tanks would also make engaging enemy vehicles a priority. Progressively, US armoured units adopted what became known as the ‘combat command’ approach, bringing together units or sub-units as required for task. Though arguably less dynamic than the German Kampfgruppe idea, and generally enacted later, the basic notion was very similar. As the manual 17-33 Tank Battalion, of December 1944, explained:
success in battle can be assured only by complete co-operation of all arms. No one arm wins battles. Success is attained when each arm, weapon and individual is employed to afford the maximum mutual support . . . tanks usually operate in close co-ordination with other arms, particularly infantry and artillery. The tank battalion may be part of a combat command; it may reinforce an infantry combat team. When operated alone, it is normally reinforced by infantry, engineers and other units.
So it was now, even when US armour was ‘alone’ infantry was still not far away. For defensive operations it was recommended that infantry, reinforced by other arms, should hold the ‘main line of resistance’, tank battalions being held as a ‘local reserve’ for the front-line infantry. The standard arrangement for an armoured infantry company in a defensive posture was with two platoons forward, and one back, giving support and depth to the position. Tanks could attack through infantry, though this required careful co-ordination, or support the infantry forward, and this applied to ordinary infantry as well as the armoured variety. As the new 1944 general-infantry manual FM 7-20 Infantry Battalion, explained,
In infantry-tank action, there are three initial attack dispositions: infantry leading, tanks leading, and infantry-tanks together. Infantry leads initially when reconnaissance has revealed hostile anti-tank strength or when the terrain in the direction of desired use is unsuitable for tanks; in this case the tanks support the attack by fire, generally from hull defilade positions. Tanks lead initially, when suitable terrain is available, in launching an attack against a hostile position having little anti-tank strength in terms of anti-tank guns, tank destroyers, antitank mines and other obstacles, or when these have been neutralised; in this case, elements of the infantry battalion follow within supporting distance and aid the tanks by fire and manoeuvre.
Where neither situation applied, or was unclear, attacks were launched with both armour and infantry in the leading wave so as to promote flexibility. Such was the ideal, but as can be imagined, commanding a ‘composite wave’ in action was no easy task, and not always successfully accomplished.
The organisation of the US armoured infantry battalion, c.1944. The three rifle companies are each divided into three platoons. Each platoon in its turn comprised three rifle squads, plus a mortar and a light machine gun squad. Platoons were thus 5 half-tracks and 49 all ranks at full strength. The battalion also included reconnaissance, assault gun, and mortars and machine guns arranged as HQ assets, as well as the ‘service’ company for maintenance and admin.
Twelve key tasks for armoured infantry were foreseen under 1944 instructions:
- Follow a tank attack to wipe out enemy resistance.
- Seize and hold terrain gained by the tanks.
- Attack to seize terrain favourable for a tank attack.
- Form, in conjunction with artillery and tank destroyers, a base of fire for a tank attack.
- Attack in conjunction with tanks.
- Clear lanes through minefields in conjunction with engineers.
- Protect tanks in bivouac, on the march, in assembly areas, and at rallying points.
- Force a river crossing.
- Seize a bridgehead.
- Establish and reduce obstacles.
- Occupy a defensive position.
- Perform reconnaissance and counter reconnaissance.
The armoured infantry arm was described as being characteristically ‘powerful, mobile and lightly armored’, and in battle armoured infantry were expected to advance in vehicles until forced ‘by enemy fire, or unfavourable terrain to dismount’. Generally, the ‘one to one’ balanced relationship of tank battalions to armoured infantry battalions held good for the remainder of the war. Post-war analysis suggested that possibly even a three armoured infantry to two tank units ratio was even better. Practical experience also suggested that the closer that infantry, any infantry, and tanks started out the more effective their collaboration was likely to be. ‘Tank riding’ – frowned upon early in the war – but widely seen on the Eastern Front, was formally adopted US policy by the campaigns of 1944. Where it was necessary for infantry to travel on tanks it was suggested that a tank company could carry from 75 to 100 infantry with 6 on the rear deck of a medium tank, 4 on the back of a light tank. ‘In rear areas more men can ride, when rope handles are provided. The infantry dismount prior to the launching of the tank attack.’
It has been said that compared to German armoured infantry tactics those of the Americans were poorly developed and unadventurous. This is not the full story. For crucially it has to be remembered that the tactical situation pertaining in 1940 was by no means the same as that in 1944. Early in the war German methods were novel, taking opponents largely by surprise: moreover, with the exception of relatively small numbers of anti-tank artillery pieces, and somewhat ineffective anti-tank rifles, Allied infantry had little with which to counter armoured carriers effectively. German mechanised troop theory called for close integration with tanks, and also accepted casualties as a given in terms of achieving a success as part of a bigger picture. The net result was that, in both Poland and the West, German ‘fast’ troops scored remarkable victories in concert with armour.
Until 1940 there were no US armoured divisions, and until North Africa no practical experience of armoured combat. Thereafter, major elements of German tactics were progressively taken up, and earlier British experience studied. Later in the war, however, when the USA managed to field armoured infantry in numbers, much had changed. The basic tactics were no longer new, the enemy was already thoroughly familiar with them, and worse was already deploying hand-held anti-tank weapons down to platoon and even squad level. Usually, German forces were on the defensive, and encounters between mobile forces rarer. The result was that when an M3 confronted even a small group of German infantry there was every possibility that one of them would be equipped with a weapon capable of completely destroying the carrier with a single round. In the face of this reality fighting from the vehicle was not merely dangerous, as it had always been, but obviously suicidal. So it was, that by comparison, it was almost inevitable US techniques should appear hesitant. Conversely, it was also the case that the Germans, particularly in the West after July 1944, became progressively weaker in tanks. With fewer Allied tanks required for large armour to armour engagements this meant that tanks could be used more widely in close infantry support operations.
As we have seen, the British approach was to mechanise infantry transport as widely as possible, but following early experimental work on attacks by fully tracked, but very small, carriers, the notion of full-blown ‘armoured infantry’ assault in vehicles was generally abandoned. So it was that in 1939 platoon trucks were motorised, and lorry companies also existed for the transport of nominated battalions from place to place on an ad hoc basis. Within the armoured division there was provision for two motorised battalions in establishments of 1939 to 1941, and this was later raised to three in May 1942, and, by April 1943, to four battalions per armoured division. One of these was the ‘motor battalion’ that formed an integral part of the division’s armoured brigade. The US summary TM 30-410 Handbook on the British Army, published in 1943 – but already slightly out of date, distinguished three types of British mobile battalion:
The machine gun battalion, which is at present assigned to corps troops, is based on the caliber .303 Vickers machine gun. It consists of a headquarters, a headquarters company, and four machine gun companies of 12 guns each. Each company is composed of a headquarters and three platoons. The battalion is completely motorised and all personnel are carried in motor transport. It has a strength of 29 officers and 711 enlisted men . . . The motor battalion assigned to each armoured brigade, consists of a headquarters company and four motor companies. Each company consists of three motor platoons and one scout platoon (11 Bren carriers). Each motor platoon consists of three sections, each self contained, operationally and administratively, in one vehicle. This battalion, with a strength of 26 officers and 774 enlisted men, has much greater fire power than any other in the British army…. the motorised battalion, formerly assigned to the support group of the armoured division, now forms the infantry component of the infantry brigade in the armoured division. Its organisation is exactly the same as that of the rifle battalion, but it is carried in motor transport.
Additionally, divisional reconnaissance regiments were also composed of infantry riding in various forms of transport, but later these were converted into the Reconnaissance Corps. As the 1941 Infantry Division manual made clear, standard drill for any motorised infantry was for the transport to bring them as far forward as possible without danger, then ‘debus’ them to operate much as any others. Whilst not attacking in ‘soft-skinned’ vehicles made perfect sense, lack of suitable armoured carriers made close co-operation between infantry and all but the slowest moving tanks problematic – and was arguably a significant tactical failing – particularly in circumstances that called for swift offensive action. Moreover, early in the war there were few signs of close co-operation between ordinary infantry, operating on foot, and the tank arm. Official doctrine of 1941, as spelt out in The Employment of Army Tanks in Co-Operation with Infantry, was that in the attack tanks would precede the infantry, with which there would be little direct interaction. During 1942, however, individual units began to practice closer co-operation in training. This was encouraged both by the increased numbers of infantry in armoured divisions, and by the fact that a number of new tank units were created from infantry battalions – and to these working with other infantry may well have appeared far more natural.
As of October 1943 British infantry divisions in Italy disposed of no less than 3,745 motor vehicles each, including over 900 motorcycles. This gave them a degree of tactical and strategic mobility not enjoyed by the enemy, but also meant that considerable effort, logistic and otherwise, had to be expended in maintaining these fleets. By the spring of 1944 Britain had obtained enough M3 half-tracks from the USA to mount the integral battalion of armoured brigades with tracked carriers. These were again operated much on existing principles, being used essentially as a ‘hardened’ transport to take forward infantry and their equipment, which then alighted to fight on foot. As in the US instance it would have been highly unrealistic to expect full ‘armoured infantry’ tactics at this date, given that enemy infantry could now destroy carriers with considerable ease.
Issued in May 1944, the key document governing British tank and infantry collaborations was The Co-Operation of Tanks with Infantry Divisions. As in US doctrine, it was envisaged that attacks be made in waves of varying compositions, and in British theory the waves were built of three main parts: the ‘assault’, ‘support’, and ‘reserve’ echelons. Each echelon was itself likely to comprise two or more individual sub-ports. An echelon could contain tanks, or infantry, or a mixture of both, but commonly there was some infantry with every one, and tanks normally formed at least a part of the ‘support’ echelon. It was the job of the assault echelon to attack ‘as closely as possible behind the artillery support’ and disrupt and dominate the objective. The support echelon provided immediate covering fire then itself moved forward to take up ground to ‘completely subdue the objective’ and oppose any counter attack. The reserve was kept in hand by the commander, and deployed as necessary according to events. In these essentials British and US techniques were fairly similar, albeit the nomenclature was different. What was rather different was that under British organisation dedicated ‘infantry tanks’ – slow, tough, and heavy beasts like the Churchill – were allotted to infantry divisions for ‘close co-operation, especially in beaching the enemy defences’. This broad concept went back all the way to the First World War, and had been reconfirmed when, at the beginning of the Second World War, a need was foreseen for well-protected armour to operate in the ‘shelled area’ helping the ‘break in’ of infantry into main defensive positions. Whilst many things had changed, and effective infantry tanks took years in development, it could be argued that in some senses things had come full circle, and the Atlantic Wall, Siegfried Line, other Axis defensive lines, and built-up areas did indeed require the attentions of heavily armoured tanks. Churchills, for example, did especially valuable service when converted for specialist roles in support of other arms; as a variety of ‘funnies’ on D-Day, or as ‘engineer’ tanks with heavy charge throwers blowing in enemy bunkers and strongpoints to allow the infantry to go forward. Conversely, the heavy infantry tanks were not of much use for rapid actions or sweeping manoeuvres.
The faster tanks, still known by the archaic descriptions ‘Cruiser’ and ‘Light’, were assumed to have specific purposes in terms of armoured exploitation by armoured divisions and in reconnaissance. Nevertheless, by this date it was acknowledged that distinctions were breaking down, for though tanks were designed for specific roles, ‘there can be no hard and fast rule regarding their employment, beyond the obvious one that they must be used in the manner which most effectively carries out the intention of the higher commander. Cruiser tanks have, in recent operations, supported infantry divisions with marked success, and infantry tanks have, on at least one important occasion, carried out valuable work in a role usually allotted to cruisers.’ Whilst tanks were best used offensively in numbers on narrow frontages, they could also be used successfully in smaller groups ‘always accompanied by infantry’. This would be of ‘moral’ as well as ‘material’ value. They were not to be used on their own, ‘for patrols or for leading the way into very close country or villages’.
How close infantry should actually get to tanks was still seen as problematic, since tank and infantry co-operation had to be close to prevent enemy infantry using hand-held anti-tank weapons, and advancing behind a tank also lent considerable protection from small-arms fire. On the other hand, armour attracted fire of all sorts and infantry very close to tanks could easily find themselves ‘exposed to heavy artillery concentrations’. Several possible solutions were offered. In the best eventuality the tanks went first, ‘neutralising the objective’ and the infantry caught up as quickly as possible before the tanks took serious loss. However,
A decision must be reached by the commander of the operation – usually the infantry brigadier – as to how close the infantry can move behind the assaulting tanks. Tanks normally move faster than infantry and draw enemy fire. It may, therefore, often be desirable for both to start together, with the result that the tanks draw ahead, but that the infantry will arrive on the objective while the enemy is still suffering the shock of the tank attack. In this way the infantry will obtain maximum advantage of the [artillery] fire plan which is designed for the support of the leading troops.
For a ‘main attack’ Co-Operation of Tanks with Infantry Divisions envisaged a set piece, preparation of which might take a long time, or as little as ‘one to two days’ or in an emergency ‘hours’. Execution at night would be preferable from the point of view of the infantry, but tanks rendered their most effective assistance in daylight. In planning infantry and tank units were to co-operate closely, with as many as possible seeing the ground over which the operation was to take place in advance. For main attacks artillery was vital, and a fire plan had to be laid that ‘caters for success’. The attack would ideally unfold as preparation of gaps, followed by the assault and consolidation. Assaulting infantry were not to stop to mop up any posts that remained short of the objective but to push on to it and hold it. As a British 2nd Armoured Division history explained, German troops had become very adept in their use of both the new anti-tank weapons, and snipers, sometimes holding their fire,
until the leading troops were a mile or more beyond them. To overcome this it was necessary for the attacking troops to advance in great depth, so that when the infantry had reached their objective their rear had only recently crossed the start line. In this way the infantry and tanks were spread out all over the ground just won and in a position to help each other deal with the snipers. All round observation in each tank was vital, because the enemy were just as likely to fire from either flank, or from behind, as they were from the front.
‘Main attacks’ were, however, only likely to be part of the picture as many operations were ‘fluid warfare’. In conducting advances in fluid warfare there was no hard and fast rule as to whether infantry or tanks should lead the way: indeed, open situations might demand tanks in smaller or greater numbers to the fore, whilst close country required infantry to lead clearing the path for armour. In the latter instance tanks would still be hard on the heels of the infantry aiming to neutralise machine-gun and mortar positions with their supporting fire. ‘Tank riding’ by infantry was encouraged, but only ‘outside small arms and anti-tank gun range’, as direct fire on tanks carrying infantry would probably result in heavy casualties, loss of morale, and difficulties for the tanks in firing back.
When infantry are to be carried on tanks, definite organisation and practice are required. The number of sub units within the unit of both infantry and tanks is dissimilar. One tank can carry a full section of infantry with its weapons. The infantry must have a drill for mounting the tank, for dismounting, and for quick assembly. Riding on the outside of a tank, especially across rough country, requires a certain amount of practice, and, as far as possible, troops whom it is intended to carry in this manner should not have their first ride when moving up to their assembly area for action.
Whilst it may reasonably be argued that British infantry and tank co-operation, and particularly ‘armoured infantry’ methods, lagged sadly behind the German, and that even later in the war much depended on the availability of US-produced materiel, there were two remarkable bright spots in British performance. The first was the general level of mechanisation achieved at an early stage, the second was a belated revival of the fully tracked carrier concept that pointed the way to something of a revolution in battlefield troop mobility, still being played out decades after 1945. What had been wrong with the old Bren and Universal carriers was that essentially they were too small, and too lightly protected, to do the job of transporting a section on the battlefield. Though fine for a machine gun or a mortar, this essentially limited them to carrying support weapons and stores – useful, but no substitute for section half-tracks. A key spur came from the Canadians who pressed into action the hulls of US 105mm self-propelled ‘Priests’ in the breakout south of Caen in early August 1944. Soon more were being converted in Italy, as were turretless Shermans. At the end of 1944 the ‘Ram Kangeroo’ appeared based on a Canadian Ram tank chassis. Some British armoured cavalry units were now converted experimentally so that whilst two squadrons retained their gun tanks, the third drove infantry carriers. The whole regiment operated together so that when progress was halted by resistance the tanks took up positions to bring the enemy under fire. The carriers headed for any convenient cover and unloaded the infantry, who could now advance and attack under supporting fire disabling or capturing any antitank weapons. Once this was underway the troops of tanks came up, using their own fire and movement to support each other onto and through the position.
Provisional standard carrier drill was reported in Current Reports from Overseas of April 1945. This stressed that whilst the tanks, carriers, and their infantry passengers were to operate as a unit, the idea was not to drive the carriers into the teeth of the enemy. Individual Kangeroos drove into suitable positions and halted with one man on the Browning machine gun. The infantry spilled out as rapidly as possible from all sides of the vehicle, which remained stationary until they were clear. The stated logic to this was that if the Kangeroo moved prematurely it might detonate mines, injuring the now vulnerable troops. The troops manoeuvred or attacked on foot, carriers remaining out of the way of anti-tank weapons, but close enough to support or pick up their sections when recalled. Interestingly, these basic notes on the actions of fully tracked carriers would still form the basis of battlefield tactics more than half a century later.