The map was designed by Harry Beck, an English engineering draftsman in 1931. Beck drew up the diagram in his spare time while working as an engineering draftsman at the London Underground Signals Office. Beck based the map on the circuit diagrams he drew for his day job, stripping the sprawling Tube network down to basics. London Underground was initially sceptical of Beck’s radical proposal but it proved popular. It is a clear and comprehensible chart that would become an essential guide to London – and a template for transport maps the world over. Beck’s revolutionary design, with certain modifications and additions, survives to the present day and is set to serve London Underground and its millions of customers for many years to come.