The term derives from the German “kessel” or “Kesselschlacht” – literally a cauldron battle, used to describe an encircled army about to be annihilated by a superior force (i.e.: “Kessel von Stalingrad”) describing the experience of soldiers within the kettle, as the situation would soon become “unbearable hot”.

The Kettle is a series of flanks or lines of officers, set up to subdivide the natural continuities which are inbuilt into public(ly accessible) spaces and has been used with increasing frequency in the UK since the mid-1990s to a state where it is now common practice.