When you're talking about the world's oldest underground network, every birthday is a big one. But when it turns 150, a serious celebration is in order.

Earlier this year the London Underground launched a commemorative Barber Osgerby-designed £2 coin and a series of artworks by artist Mark Wallinger, now displayed in all 270 stations citywide.    

Now, as part of the festivities, and in keeping with the 13-year strong Art on the Underground initiative, Transport for London has commissioned visual tributes from 15 international artists. The 15 works - one for each decade of the Tube's existence - vary wildly, though each is a contemporary take on the London institution.

One of the most poignant is Corin Sworn's 'Waiting for a Train', for which the artist researched the Underground's photography archives to represent passengers of different ages and eras in recurring poses. Their silhouettes take on the colours of the network lines and patterns from the Tube moquettes.

These days London's Tube stations double as public art galleries (it's been noted that with more than a billion customers passing through them each year, the network may very well be the largest art gallery in the world). 'The Tube is a rich environment for artists,' says Justine Simons, head of cultural policy for the Mayor of London's office and member of the Art on the Underground panel, 'and these incredible artists have come to the challenge with an openness and a curiosity which has resulted into fantastic projects.'

Full sets of the posters can be admired at Gloucester Road, St James's Park, Southwark and London Bridge stations. Proceeds from the limited-edition prints, available to purchase through Transport for London, will go on to support future Art on the Underground initiatives.

TAGS: LONDON