Weapon detection arches to screen Notting Hill carnival revellers / 24dash.com, 21 August 2008
http://www.24dash.com/news/Communities/2008-08-21-Weapon-detection-arches-to-screen-Notting-Hill-carnival-revellers
"Revellers travelling to Notting Hill carnival will face mobile metal detection arches in Tube stations in a bid to discourage knife crime.Stations near the carnival route will be fitted with mobile metal detection arches, while at least 600 British Transport Police officers will patrol trains and stations using drug detection dogs and handheld metal detectors."