Royal Mail's Worldwide Distribution Centre on the years busiest morning.

Video capturing the Royal Mail's Worldwide Distribution Centre near Heathrow, London, on the years busiest morning - December 3, 2013. The 430,000 sq ft building is the size of six football pitches and sorts every letter and parcel to enter or leave Britain. Already 460,000 packages an hour travel along the centre's ten miles of conveyor belts. A 16ft-high snaking conveyor belt carries levered wooden trays that tip post bags down chutes, each visibly worn by the coarsely woven sacks. Each chute directs mail to a different country or area of the world. Further back along the conveyor-belt system, complicated software determines the route of each piece of mail. Destinations are identified by scanners that use 4.2million lines of code - more than on a Space Shuttle or Stealth Bomber. Opened in 2003 at a cost of GBP367million, the centre operates 24 hours a day. By next year, it will have fully replaced the eight foreign mail sorting offices that previously served Britain. Its 1,500 workers have had aviation security training and can access the sorting floor only by passing a fingerprint scanner.