The Clark & Webb Chain Brake used an "anchor" in the guards van, usually placed in the centre of a rake of up to 6 vehicles. It was independent of the locomotive. There is a good description here
http://www.rmweb.co.uk/community/index.php?/topic/97672-pragmatic-pre-grouping-mikkels-workbench/page-31&do=findComment&comment=2607577
Not even aware that the Heberlein brake system was used in the UK. Which UK railways was it used on, please?