It's the Royal Festival Hall but not as we know it. About 30 miles of scaffolding tubes occupy the auditorium where music lovers used to sit listening to the world's finest orchestras. Laid end to end, the poles would stretch from Waterloo Bridge to Henley.

The Royal Festival Hall is halfway through an £111 million redevelopment - the first phase in the transformation of the whole South Bank centre.

This photograph shows the extraordinary extent of the building works in the year since the concert hall shut. It is due to reopen next June and, despite its current appearance, the refurbishment is reported to be bang on schedule.

The workers, clad in fluorescent jackets and hard hats, are standing in what will eventually become the removable orchestra pit.

Beyond them is the stage and in the foreground is the seating, stripped out to reveal the terraced concrete beneath.

Besides the 30 miles of tubing, there is a further 40 miles of scaffold boards, 2,160 square metres of temporary decking - enough to cover 35 squash courts - and nearly four miles of masking tape.

Almost 400 construction workers are on site each day.

The scaffolding is allowing the builders to remove the wave ceiling and replace it with a more modern, acoustically sharper structure based on the original design, while letting other workers down below refit the seating area and stage.

There will be a slightly reduced capacity of 2,882 seats but concert-goers will benefit from an extra three inches of legroom.

Project director Ian Blackburn said: "It has been extraordinary to play a part in a project that has seen the auditorium and foyers stripped back to the bare concrete. With so much completed on cost and to programme over the last year we feel confident that the hall will reopen on time.

"Visitors will be rewarded by an experience worthy of the ambitions of the hall's founders, combining the best of modern movement architecture with the world-class acoustics to which they aspired but were unable to achieve in 1951."

The 55-year-old venue is Grade I listed and the development has had to remain in keeping with the original design.