||This article possibly contains original research. (September 2009)|
Tank classification is a taxonomy of identifying either the intended role or weight class of tanks. The classification by role was used primarily during the developmental stage of the national armoured forces, and referred to the doctrinal and force structure utility of the tanks based on design emphasis. The weight classification is used in the same way truck classification is used, and is intended to accommodate logistic requirements of the tanks.
Many classification systems have been used over the nearly one hundred years of tank history. An early division in the definition of roles was between Infantry tanks intended to focus on supporting infantry in the assault, and cruiser tanks intended for classic cavalry missions of exploitation, screening and reconnaissance. As World War II progressed, the separation of "infantry" and "cruiser" roles generally disappeared and the "universal tank" started to take over.
Classification has always been determined by the prevailing theories of armoured warfare, which have been altered in turn by rapid advances in technology. No one classification system works across all periods or all nations; in particular, weight-based classification was inconsistent between countries and eras.
The weight classification system has been eliminated due to the world-wide adoption of the main battle tank. Modern tank designs favour a modular universal design eliminating these sorts of classifications from modern terminology. All main battle tanks are typically armed with weapons with similar characteristics but some may be armoured more than others.
Tanks are often referred to by weight-based or role-based classification, such as 'light', 'medium' or 'heavy'. There were many names given to different tank types, and similar names did not assure similar design goals. Some light tanks were relatively slow, and some were fast. Some heavy tanks had large-calibre, low-velocity, anti-infantry bunker-busters, and some had high-velocity anti-tank guns. Furthermore, expected weights for a given tank type vary over time; a medium tank of 1939 could weigh less than a light tank of 1945.
Light, medium, and heavy have other meanings than just weight, e.g., relating to gun size, the amount of armour, and, most importantly, tactical role. In 1948 France, Canada, and America agreed to classify tanks as light gun, medium gun, or heavy gun. This lasted until 1957, when the Fourth Tripartite Armour Conference recommended to replace medium and heavy tanks with a single class — Main Battle Tanks.
After World War II, less expensive armoured cars and more specialised tracked vehicles gradually took over the roles of light tanks. Heavy tanks were shown to be incapable of keeping up with mobile warfare, but advances in engine, weapon, and armour technology allowed medium tanks to acquire the best characteristics of heavy tanks—the ultimate in mobility, firepower, and protection were rolled into the main battle tank (MBT).
World War I
In World War I, the first tank, the 28-long-ton (28 t; 31-short-ton) British Mark I, was designed for supporting infantry by crossing trenches and attacking machine-gun posts. Initially, there were two types with two roles: the 'males', armed with two naval 6 pounder (57 mm) guns and machine guns, and 'females', armed with only machine guns that supported the 'males'. Later tanks armed with a single gun in one side sponson and machine guns on the other were named "hermaphrodites". A lighter British tank introduced into service in 1918, at 14 long tons (14.2 t; 15.7 short tons) and armed with machine guns only was given the designation "Tank, Medium Mark A" and known as the "Whippet".
The two-man 7-tonne (7-long-ton; 8-short-ton) French Renault FT was known as a light tank.
Super-heavy breakthrough tanks such as the Char 2C (69 t or 68 long tons; 76 short tons) or the K-Wagen (120 t or 118 long tons; 132 short tons) were nearly completed before the war ended. In comparison, the current British MBT, the Challenger 2, weighs some 60 t (59 long tons; 66 short tons).
Between the wars
British tank designs in the immediate post-WWI era were developments along the same design as the Mark A and were named as Mediums being around 18 long tons (18 t; 20 short tons). The first tank to enter service that broke with the design was known as the "Vickers Light Tank" (it weighed about 12 long tons or 12 tonnes; 13 short tons). It was renamed as the Medium Mark I in 1924 as the earlier heavy and medium tanks went out of service and lighter tanks - 5 long tons (5 t; 6 short tons) or less - came into service.
World War II
Tank models were developed before and during World War II according to different philosophies, with different combinations of armour, mobility, and armament. Each major nation developed its own doctrine of tank use, and therefore different tank models to suit. New doctrines explored the role of the tank as a fast-striking unit.
Tank doctrine in the UK declared that one group of tanks would accompany infantry in a similar role to World War I, while another group of 'cruiser' tanks would then exploit a breakthrough, in a role similar to cavalry. In the USSR, 1930s tank doctrine specified three groups of tanks: one 'breakthrough' tank in the infantry support role, one tactical breakthrough tank to clear the combat area, and a 'fast tank' for operational maneuver. In Germany, the ideas of Heinz Guderian established the need for unified tank formations, but with a mixture of armaments for differing roles.
In the United States, doctrine evolved so that the main purpose of the tank was to provide infantry support and exploitation of breakthroughs. The antitank role was given to tank destroyers. There was no analog to the cruiser tank in pre-war US doctrine. There were those within the US Army which advocated a more modern force with tanks in the cavalry role, but their suggestions were not put into place by the time of the US's entry into World War II.
Light tanks, such as the PT-76, continue to play an important role in tank warfare, however many are being replaced with IFVs and armoured cars. The light tank is still more used than main battle tanks in many armies for various reasons: financial, terrain-related (muddy terrain, jungle), or doctrinal dependence on airborne divisions.
Main battle tank
Advances in tank design, armour, and engine technology allowed tank designers to increase the capabilities of tanks significantly without always resorting to heavier designs, although weights did gradually increase. High explosive anti-tank (HEAT) ammunition was a threat to tanks and could penetrate steel armour thicker than was practical to put on a tank. Advances such as the British-designed Chobham armour limit the effectiveness of weaker HEAT rounds, but the vulnerability still remained.
On 7 November 1950, the US Ordnance Committee Minutes (OCM), order #33476, ceased utilizing the terms heavy, medium, and light tanks and redesignated tanks by the gun system, e.g. 90 mm Gun Tank M48 Patton, etc. with heavy gun tanks (120 mm or 4.724 in), medium gun tanks (90 mm or 3.543 in), and light gun tanks (76 mm or 2.992 in), although these gun terms were often still shortened to simply heavy, medium, and light tanks.
The term "main battle tank" (MBT), in the US, was first generally applied in 1960 to an all-purpose tank, armed and protected as a heavy tank, but with the mobility of the medium tank (the introduction of M60 Patton). The MBT would form the backbone of modern ground forces.
Many Cold War MBTs evolved more or less directly from late World War II medium tank designs. However, in the 1960s and 1970s, a generation of purpose-designed main battle tanks appeared, starting with the British Chieftain tank. These vehicles are less obviously influenced by wartime templates (the Chieftain, for example), weighing as much as a World War II heavy tank and possessing far greater firepower and armour, while retaining the mobility of the previous Centurion design. Similarly, the US M1 Abrams series, the German Leopard 2, the British Challenger, French Leclerc and Russian T-90 tanks are all main battle tanks. The defining feature of the main battle tank type is neither its weight, mobility, nor firepower, but instead the idea that only one type of tracked armoured vehicle is required to carry out the roles of breakthrough, exploitation and infantry support.
Many types are also described by their tactical role, which depends on contemporary military doctrine. For instance, 'infantry' and 'cruiser' tanks are British classifications of the 1930s and '40s; 'infantry', 'fast', and 'breakthrough' are Soviet types of the same time period.
British and Soviet tacticians up to the time of the Second World War classified tanks into three major roles: infantry, light, and cavalry. Infantry tanks supported infantry units, to integrally support dismounted infantry actions. Light tanks performed the traditional cavalry role of scouting and screening. Cavalry or "cruiser" tank units were meant to exploit breakthroughs and fight other armoured formations. Well into the 1930s, some generals[who?] saw tanks as merely serving in support roles for large conscript armies of foot soldiers and horse cavalry.
The infantry and cavalry tank roles were abandoned by the end of the Second World War. World War II tanks were generally classified by weight and role: fast, relatively inexpensive light tanks for reconnaissance, general-purpose medium tanks, and slow heavy tanks for breakthroughs and long-range fire.
World War II
The idea for this tank was developed during World War I by the British and French. The infantry tank was designed to work in concert with infantry in the assault, moving mostly at a walking pace, which required it to carry heavy armour to survive defensive fire. Its main purpose would have been to clear the battlefield of obstacles, suppress or destroy defenders, and protect the infantry on their advance into and through enemy lines by giving mobile overwatch and cover.
The British came back to the concept in the pre-Second World War era. The infantry tank did not need to be fast so it could carry more armour. One of the best-known infantry tanks was the Matilda II of World War II.
A cruiser tank, or cavalry tank, was designed to move fast and exploit penetrations of the enemy front. The idea originated in "Plan 1919", a British plan to break the trench deadlock of World War I in part via the use of high-speed tanks. This concept was later implemented in the "fast tanks" pioneered by Walter Christie.
They were used by the United Kingdom during World War II. Cruiser tanks were designed to complement infantry tanks, exploiting gains made by the latter to attack and disrupt the enemy rear areas. In order to give them the required speed, cruiser designs sacrificed armour compared to the infantry tanks.
The Soviet fast tank (bistrokhodniy tank, or BT tank) classification also came out of the infantry/cavalry concept of armoured warfare and formed the basis for the British cruisers after 1936. The T-34 was a development of this line of tanks as well, though their armament, armour, and all-round capability places them firmly in the medium tank category.
Tanks have often been modified for special purposes. The most common is to provide armoured capability for combat engineers. These include tanks carrying large-calibre demolition guns, with flails or ploughs for mine-clearing, or flame tanks armed with flamethrowers. The tank occasionally may lose its weapons and the chassis alone may be used, as in bridge-laying tanks.
Another important modification was the amphibious tank. These designs were modified with waterproofing and propulsion systems, to be able to traverse open water.
Unmodified tanks can be fitted with equipment, such as mine-clearing ploughs, to give them ancillary roles.
Tanks are sometimes classified as belonging to a particular generation, although the actual definition and membership in these generations is not clearly defined. Soviet and Russian military planners organise tanks into a generation of tanks up to 1945, and four generations of main battle tanks, while Canadian strategists organise main battle tanks into three generations. The military of the People's Republic of China also recognises three generations of its own tanks.
- Bud, Robert; Gummett, Philip, eds. (2002). Cold war, hot science: applied research in Britain's defence laboratories, 1945-1990. NMSI Trading Ltd. ISBN 1-900747-47-2. p.123
- B T White British tanks 1915-1945 p35
- Hunnicutt[page needed]
- "The Soviets saw tank generations in this manner: 1920-1945, first generation; 1946-1960, second generation; 1961-1980, third generation; and 1981-present, fourth generation. Since the last really new tank design, the T-80, came out in 1976, they feel that they have not produced a true Fourth Generation Tank Design. In comparison, they count the M1 Abrams, Challenger, and Leopard 2 as Fourth Generation and the LeClerc as Fifth Generation." —Sewell 1988, note 1.
- "The Canadian Directorate of Land Strategic Concept defines three generations of Main Battle Tanks. The first generation of post World War II Main Battle Tanks includes the U.S. M48/M60, the German Leopard 1 and the British Centurion and Chieftain. The second generation includes most of the 120 mm (4.724 in) Main Battle Tanks such as the American M1A1, the German Leopard 2 and the British Challenger. As for the third generation Main Battle Tank, they include the latest 'digital' tank such as the French Leclerc and perhaps the American M1A2 and the German Leopard 2A5." —Lamontagne 2003, pp 7–8.
- Lamontagne, J.G. Pierre (2003). Are the Days of the Main Battle Tank Over?. North York, Ontario: Canadian Forces College. (PDF)
- Sewell, Stephen ‘Cookie’ (1998). “Why Three tanks?”, in Armor vol 108, no 4, p 21.
- Hunnicutt, R. P. (1984). "Patton: A History of the American Main Battle Tank." Presidio Press. ISBN 0-89141-230-1.