anti-tank weapons

anti-tank weapons. The first anti-tank weapons in 1916 were armour-piercing bullets fired by machine-guns, low velocity (LV) HE shells from 77 mm. (3 in.) artillery pieces, with a 1:25 chance of a hit at ranges beyond 300 m. (1,000 ft.), and the 57 mm. (2.2 in.) LV guns mounted in some British and German tanks. Also a few mines were laid, predecessors of millions laid in the Second World War (see mine warfare, 1).

Between the World Wars, however, development focused on much more accurate, high velocity (HV) guns firing solid shot to penetrate armour by kinetic energy (KE). Pieces with calibres ranging from 13 mm. (.5 in.) to 50 mm. (2 in.) with muzzle velocities (MV) up to 850 m./sec. (2,800 ft./sec.) were in general use in tanks by 1939 and with the infantry on towed field carriages. Also, very significantly, German doctrine (not initiated, as sometimes stated, by Hitler himself), stipulated the use of their 88 mm. (3.4 in.) anti-aircraft gun with an MV of 811 m./sec. (2,660 ft./sec.) in the dual anti-tank role, when possible.

The gun versus armour contest which began in the 1920s (see tanks) made inevitable increases in weapon size and weight to defeat the thicker, higher quality, and sloped armour being fitted to tanks and assault guns. The appearance in 1941 of the Soviet KV1 tank, with frontal armour which at medium ranges defeated even the dual-purpose German 88 mm. gun, not only necessitated the use of the 105 mm. (4 in.) field gun which had an MV of 835 m./sec. (2,740 ft./sec.) with a 14.5 kg. (32 lb.) shot to score a kill, but also made essential the fitting of the 88 mm. to the heavy German Tiger tank to cope with T34/76s. And as a stopgap, improved 50 mm. and 75 mm. (2.9 in.) guns with longer barrels and more sophisticated ammunition, to increase MV, had to be mounted in the standard Mark III and IV tanks. For example, the mounting of a 48 calibres long 75 mm. gun in the up armoured Mark IV in 1942 enabled it to defeat T34/76 out to 2,000 m. (2,190 yd.) whereas the T34's 76 mm. (2.9 in.) gun failed against the up armoured Mark IV at 1000 m. (1,095 yd.).

Improved projectiles were as important as larger calibres and longer barrels. At an early stage the Germans recognized that solid armour piercing (AP) shot broke up against face-hardened armour. To prevent this they added a soft metal cap to AP shot (making APC) and later increased MV by adding a streamlined ballistic cap, making APCBC. They also increased MV by fitting a rigid metal carrier round a lightweight shot (APCR) to raise (for example) the 88's MV from 811 m./sec. with APCBC to 936 m./sec. (3,070 ft./sec.), but with the penalty of impaired accuracy beyond 600 m. (2,000 ft.). The British sub-calibre shot in a plastic sabot (or carrier), which was discarded after firing (APDS) was far superior to APCR as reduced air resistance increased MV and there was no loss in accuracy. But accuracy also depended on good optical instruments (the Germans' were best) and range estimation by eye, the latter being difficult beyond 400 m. (1,300 ft.). This was a contest in which neither the Japanese nor the Italians seriously engaged. The former used no gun larger than 57 mm., field or vehicle mounted, while the latter's largest tank-mounted gun was 47 mm. (1.8 in.), though they did have a 75 mm. self-propelled gun (see artillery). However, the larger field pieces in their service were mainly of German or Allied manufacture.

By the middle of the war the vastly increased size of KE anti-tank guns had become an embarrassment. They were difficult to conceal, clumsy, expensive to manufacture, and required bulky ammunition which created stowage and logistics problems. The invention of the hollow charge (see explosives) chemical energy (CE) projectile seemed to offer a solution. On the principle that a shaped charge of high explosive directs a very high velocity jet of molten gas and debris through armour with pressures as much as 200 tonnes/per square inch, High Explosive Anti-Tank (HEAT) warheads were developed by both sides for both conventional artillery pieces and small hand-held projectors (see PIAT and rocket weapons). Since a HEAT warhead's effect is degraded when spun—that is, fired from a rifled barrel—they were of more use in unrifled projectors for the infantry. It was not economically viable to produce armour which defeated these weapons, but as their maximum range was about 100 m. (330 ft.) the most effective counter was closer infantry escort and fire support for tanks.

Aircraft mounting HV guns up to 57 mm. (2.2 in.), or rockets, were also a threat to tanks. Of the two the gun was the more deadly since ballistically unstable rockets had only a 0.5% chance of a hit/kill—they were credited with grossly inflated destruction of tanks during the Normandy campaign and elsewhere.

In the final analysis the tank was the best anti-tank weapon system, followed by the tracked assault gun; the small field anti-tank gun, though cost effective in 1940, had become too cumbersome and vulnerable towards the war's end. For anti-tank rifles see small arms.

Anti-tank weapons: Anti-tank guns

Kenneth Macksey

Bibliography

Macksey, K. , Tank versus Tank (London, 1991).
Ogorkiewicz, R. , Armour (London, 1960).