Enforcer is the term given to a specially designed manual battering ram currently used by British Police forces to aid in gaining entry to premises

Door breaching

Door breaching is a process used by military, police, or emergency services to force open closed and/or locked doors. A wide range of methods are available, one or more of which may be used in any given situation...

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Construction

The Enforcer is of a steel tubular construction with a steel pad at the impact end so that it can absorb such impact, and a handle at the opposite end angled so that the user can swing accurately without actually applying their own pressure more than necessary. Further, there is a handle in the middle of the tube aiding the user in handling. The Enforcer can apply three tonnes of kinetic energy

Kinetic energy

The kinetic energy of an object is the energy which it possesses due to its motion.It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity. Having gained this energy during its acceleration, the body maintains this kinetic energy unless its speed changes...

 to door locks, whilst it is 58 cm long and weighs 16 kg.

Police use

In most forces in Britain, the Enforcer can only be used when authorised by a senior officer in charge of a search. In London

London

London is the capital city of :England and the :United Kingdom, the largest metropolitan area in the United Kingdom, and the largest urban zone in the European Union by most measures. Located on the River Thames, London has been a major settlement for two millennia, its history going back to its...

 the Metropolitan Police Service

Metropolitan Police Service

The Metropolitan Police Service is the territorial police force responsible for Greater London, excluding the "square mile" of the City of London which is the responsibility of the City of London Police...

s' Armed Response Vehicle

Armed Response Vehicle

An armed response vehicle is a type of police car operated by the British police. ARVs are crewed by Authorised Firearms Officers to respond to emergency telephone calls believed to involve firearms or other high-risk situations...

s and most station vans carry them. Within most forces an officer can only use such a tool once they have attended a course receiving training in the safe handling and operational use. Also, most forces maintain that the user wears gloves to minimise the shock created when a door is struck with the ram.

Enforcer Training Manual: http://www.whatdotheyknow.com/request/9685/response/23504/attach/2/2009030007434%2020090408%201229%20ENFORCER%20DATA.pdf