page_title: Chobham armour
section_title: Development and application
hierarchical_section_title: Chobham armour / Development and application
caption_attribution_description: English: M1A2 SEP Abrams TUSK demonstrating Mounted Soldier System
context_page_description: Chobham armour is the informal name of a composite armour developed in the 1960s at the British tank research centre on Chobham Common, Surrey. The name has since become the common generic term for composite ceramic vehicle armour. Other names informally given to Chobham armour include "Burlington" and "Dorchester." "Special armour" is a broader informal term referring to any armour arrangement comprising "sandwich" reactive plates, including Chobham armour.
  Although the construction details of the Chobham armour remain a secret, it has been described as being composed of ceramic tiles encased within a metal framework and bonded to a backing plate and several elastic layers. Due to the extreme hardness of the ceramics used, they offer superior resistance against shaped charges such as high explosive anti-tank rounds and they shatter kinetic energy penetrators.
  The armour was first tested in the context of the development of a British prototype vehicle, the FV4211, and first applied on the preseries of the American M1. Only the M1 Abrams, Challenger 1, and Challenger 2 tanks have been disclosed as being thus armoured.
context_section_description: The concept of ceramic armour goes back to 1918, when Major Neville Monroe Hopkins discovered that a plate of ballistic steel was much more resistant to penetration if covered with a thin (1–2 millimetres) layer of enamel. Additionally, the Germans experimented with ceramic armour in World War I.
  Since the early sixties there were, in the US, extensive research programmes ongoing aimed at investigating the prospects of employing composite ceramic materials as vehicle armour. This research mainly focused on the use of an aluminium metal matrix composite reinforced by silicon carbide whiskers, to be produced in the form of large sheets. The reinforced light metal sheets were to be sandwiched between steel layers. This arrangement had the advantage of having a good multiple-hit capability and of being able to be curved, allowing the main armour to benefit from a sloped armour effect. However, this composite with a high metal content was primarily intended to increase the protection against KE-penetrators for a given armour weight; its performance against shaped charge attack was mediocre and would have to be improved by means of a laminate spaced armour effect, as researched by the Germans within the joint MBT-70 project.
  An alternative technology developed in the US was based on the use of glass modules to be inserted into the main armour; although this arrangement offered a better shaped charge protection, its multiple hit capability was poor. A similar system using glass inserts in the main steel armour was from the late fifties researched for the Soviet Obiekt 430 prototype of the T-64; this was later developed into the "Combination K" type, having a ceramic compound mixed with the silicon oxide inserts, which offered about 50% better protection against both shaped charge and KE-penetrator threats, compared with a steel armour of the same weight. It was, later in several improved forms, incorporated into the glacis of many subsequent Soviet main battle tank designs. After an initial period of speculation in the West as to its true nature, the characteristics of this type were disclosed when the dissolution of the Soviet Union in 1991 and the introduction of a market system forced the Russian industries to find new customers by highlighting its good qualities; it is today rarely referred to as Chobham armour. Special armour much more similar to Chobham appeared in 1983 under the name of BDD on the T-62M upgrade to the T-62 , was first integrated to an armour array in 1986 on the T-72B, and has been a feature of every Soviet/Russian MBT since. In its original iteration, it is built directly into the cast steel turret of the T-72 and required lifting it to perform repairs.
  In the United Kingdom another line of ceramic armour development had been started in the early 1960s, meant to improve the existing cast turret configuration of the Chieftain that already offered excellent heavy penetrator protection; the research by a team headed by Gilbert Harvey of the Fighting Vehicles Research and Development Establishment (FVRDE), therefore was strongly oriented at optimising the ceramic composite system for defeating shaped charge attack. The British system consisted of a honeycomb matrix with ceramic tiles backed by ballistic nylon, placed on top of the cast main armour. In July 1973 an American delegation, in search of a new armour type for the XM815 tank prototype, now that the MBT-70 project had failed, visited Chobham Common to be informed about the British system, the development of which had then cost about £6,000,000; earlier information had already been divulged to the US in 1965 and 1968. It was very impressed by the excellent shaped-charge protection combined with the penetrator impact damage limitation, inherent to the principle of using tiles. The Ballistic Research Laboratory at the Aberdeen Proving Ground, which later became a part of the Army Research Laboratory, initiated the development of a version that year named Burlington, adapted to the specific American situation, characterised by a much higher projected ta
caption: The most recent US Army M1 Abrams
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