When Henry Moore completed his Shelter Sketchbooks in 1940–41, he had created a vision of the capital—unparalleled in underground writing—that unified the subterranean world and the streets. His work echoes the prints and photographs of the building of the Metropolitan Railway in the Victorian period by showing people on Tube platforms, but now the people of the city are no longer just spectators. The trains have disappeared completely from Moore's drawings, leaving the people centre stage. Moore was not alone in his creation of what has been called an ‘abiding city’ in wartime. Many of the parallels of wartime London are expressed through its Tube system: first, the underground continued to provide London with a functioning transit system which was less subject to the disruptions caused by bombing that often disabled both public and private transport systems at street level. It acted as a unifier of the metropolis during the various phases of the Blitz, linking the city together in a way that offered continuity and stability to a population under siege. Secondly, the underground played a key role as shelter for around four per cent of London's population with up to 177,000 people sheltering during the worst phases of the Blitz. Whilst it had also provided shelter for people in the First World War, this had not been culturally and socially transformative but now the Tube became a world beneath the city. In the Second World War, the role of the underground became one of the shaping episodes of the Home Front, embracing a national as well a metropolitan dimension within the mythology of wartime Britain. This was a city under siege, suffering a most intense, unpredictable and seismic bombardment during the Blitz. It was an underground that attained an unparalleled cultural visibility through the drawings of Henry Moore, documentary photography and writing.

Tubism, the cultural form of modernity on the underground, collapsed as a result of this process as the London Passenger Transport Board was transformed into a wartime organization and stripped of its corporate status.