As so often, the US army led the way to the next major development, the armoured personnel carrier (APC), which initially consisted of an armoured box mounted on tracks, carrying an infantry squad of twelve men. A far-seeing operational requirement was issued in September 1945, and the outcome, the M75 APC, entered service in 1951, setting a trend which has continued to this day.
Subsequent development followed two main strands. The first was for a so-called ‘battle taxi’ whose prime role was to move the infantry about the battlefield, giving them protection and speed of movement, and delivering them to a point near the objective from which they could then advance on foot into the assault. For such a requirement the infantry inside the vehicle needed only to be able to see out in order to orientate themselves and to be able to disembark rapidly.
The other school of thought maintained that what was required was an infantry combat vehicle, which not only carried a heavy weapon in the turret but also provided the infantry with the means of fighting from inside the vehicle. In such a vehicle, it was claimed, the infantry could actually fight from their vehicle, keeping the enemy’s heads down by the sheer volume of small-arms fire and disembarking only when actually on top of the objective.
The other main area of difference was over tracks and wheels. Tracks conferred exceptional cross-country mobility but were noisy, expensive, required considerable maintenance, and tended to damage road surfaces – a major consideration in peacetime. Wheels, on the other hand, were cheaper, more reliable, quieter, easier to replace if damaged, and, when on roads, not only did less damage, but also enabled the vehicle to move much faster. On the other hand, wheels were more vulnerable to damage, and did not provide such a good cross-country capability.
The first of the ‘battle taxis’, the US army’s trend-setting M75 APC, entered service in 1952. It carried a driver, a commander and a squad of ten men. It was of all-steel construction and was high, making it difficult to conceal, and it was not amphibious; it also had a petrol engine. Nevertheless, it was an impressive start. The M75 was followed by the M59, which entered service from 1954 onwards. This too was of all-steel construction, but was cheaper than the M75 to produce and was amphibious in calm conditions.
Still not satisfied, the US army persevered and its efforts in this particular development chain culminated in the M113 APC, which became the archetypical APC between 1960 and 1985. The original US army requirement was to provide a lightweight armoured personnel carrier for armour and infantry units; it had to be capable of amphibious and air-drop operation, have superior cross-country mobility, and be adaptable for multiple functions by means of kits and/or modification of its superstructure. The designers succeeded in meeting all of these objectives, and the M113 proved to be one of the most successful military designs of all time, with over 80,000 being produced for service in at least fifty armies in a production run which lasted from 1960 to the early 1990s.
The M113 had a body fabricated from welded aluminium, which protected the crew (commander, driver and eleven infantrymen) from shell splinters and small-arms fire. It was powered by a diesel engine, giving a maximum speed of 64 km/h and a range of 320 km (later increased to 485 km). The infantrymen sat on two benches facing inwards, and exited through a downward-opening rear ramp. The basic vehicle was armed with a pintle-mounted 12.7 mm machine-gun, although many users mounted heavier weapons, of which the largest to enter service was a turret-mounted 76 mm gun in an Australian version. The M113 was fully amphibious with little preparation, being propelled in the water by its tracks. Apart from the normal infantry versions a large range of specialized versions were produced, including bulldozers, flame-throwers, mortar carriers, radar vehicles, anti-aircraft gun/missile carriers, command posts, anti-tank weapons carriers, and transport for engineers, communications and recovery operations.
The M113 was very successful, but one of the reasons for its longevity was the difficulty experienced in finding a successor. By the early 1960s the US army had decided on a requirement for a mechanized-infantry combat vehicle (MICV), the first attempt at which was a vehicle designated MICV-65, of which five prototypes were produced, but it was considered too large and development ceased. In 1967 the Armored Infantry Fighting Vehicle (AIFV) appeared, which was in essence an M113 adapted to meet the MICV requirement, but this too was deemed unsatisfactory and development ceased, although the design was later produced in large numbers for the Belgian and Dutch armies.
In 1972 the XM723 programme started, which was intended to lead to a vehicle which would serve in both armoured and infantry units, carrying a crew of three plus eight dismounting infantry. After many vicissitudes, repeated reviews (most of them antagonistic), much criticism and many redesigns, this programme resulted in the M2 Bradley Infantry Fighting Vehicle (IFV) and the initial production vehicles were eventually handed over in 1981, with the first unit forming in March 1983. Forty-one M2s were issued to each infantry battalion, where they replaced M113s, although many M113s continued to serve in other roles.
The M2 was constructed of welded aluminium with spaced, laminated armour on the front and sides, and was armed with a turret-mounted 25 mm chain-gun, a coaxial 7.62 mm machine-gun and a twin TOW anti-tank missile launcher. The vehicle crew consisted of commander, driver and gunner, and seven infantrymen were carried, of which six were provided with firing ports and periscopes. Thus, after a protracted and very expensive development process, the US army finally obtained a MICV which was only marginally better than the German Marder (see below), which had preceded it into service by some fifteen years.
The Soviet army initially followed a policy of transporting infantrymen in motor-rifle units in motor-rifle divisions in wheeled APCs, starting in the 1940s with the 6 × 6-wheeled BTR-152, a very ordinary design, which used a truck chassis with a new steel superstructure to carry seventeen infantrymen. This was replaced in the 1960s by the BTR-60, an 8 × 8-wheeled, open-topped, boat-shaped vehicle, which carried a crew of two and twelve infantrymen. The original open top meant that the men could disembark quickly over the sides, but they had no protection from overhead artillery bursts, nor could the vehicle be made NBC-proof; this was rectified in later versions, which had a covered-in roof with hatches. The vehicle was fully amphibious and was powered in the water by water jets. The original pintle-mounted 7.62 mm or 12.7 mm machine-gun was later replaced by a turret-mounted 14.5 mm machine-gun, and firing ports were provided for some of the infantrymen. This was an efficient design and quite unlike anything then in service, making it another example of the radical thinking of which Soviet designers were capable. The BTR-60 was later complemented by the improved BTR-70.
Motor-rifle units in tank divisions were mounted in tracked APCs, the earliest version being the BTR-50, which entered service in the mid-1950s. This was based on a light-tank design, but, like the wheeled BTR-60, it had a large, open troop compartment, from which the men jumped to the ground. This was replaced in the 1960s by a design even more outstanding than the BTR-60: the BMP-1. This was a very low, fully tracked vehicle constructed of welded steel plate and carrying a crew of three and an eight-man infantry squad. The BMP-1 weighed 13.5 tonnes fully loaded and was armed with a new 73 mm low-pressure gun, with an AT-3 (NATO = ‘Sagger’) anti-tank guided missile mounted above it. The BMP-1 had full NBC protection and was fully amphibious, and excellent ballistic design gave protection against small-arms fire up to 12.7 mm calibre. A later version, the BMP-2, appeared in 1982; this was essentially a modernized BMP-1, but armed with a 30 mm cannon and an AT-5 (NATO = ‘Spandrel’) anti-tank missile system.
The BTR-60/70 and BMP-1/2 again showed that the Soviet General Staff and designers were capable of daring and innovative thought, producing designs which, on their appearance, caused some alarm in the West. Pictures were the only evidence that most Western defence experts had of these APCs until examples were captured in the Middle Eastern wars, but there was also a very lively debate in Soviet military journals on their employment in combat, with officers of all ranks joining in the frequently heated discussions.