The Centre Court at Wimbledon now has a retractable roof so play can continue whatever the weather.

As the annual Wimbledon tennis tournament starts today (22 June 2009), a new retractable roof over the Centre Court will be unveiled in the case of rain, which previously stopped play.

The new 5,200m² roof, part of a £100 million overhaul at the All England Lawn Tennis Club, can close or open in around eight to ten minutes, and is one of the first concertina-type moving structures ever attempted in the UK.

Measuring 65 x 75 metres, the hydraulically operated structure is a “folding fabric concertina” with steel trusses supporting a translucent fabric skin. The roof now allows the feature matches and finals to be played under cover during the inclement weather over the two weeks of The Championships.

Architect Populous and structural engineer Capita Symonds designed the new roof, modelled on the 1922 dodecahedron form which provides the distinct intimate Centre Court atmosphere with a droop down leading edge to focus spectators’ eyes to the action on the grass court.  The use of the translucent fabric, Tenara, for the retractable element affords natural light into the arena and in part retains the open-to-air quality of the 1920’s stadium.

To ensure that both the players and spectators are comfortable when it is closed, airflow removes condensation from within the bowl, which is expected to take up to half an hour as the environment stabilises.

Once shut, the roof will remain closed until the end of the match, raising the possibility of some games finishing indoors while bright sunshine has replaced showers outside, thanks to the changeable SW19 climate.

Furthermore, an extra six rows of seating on three sides of the upper tier have increased the capacity from 13,800 to 15,000. New wider seats have been installed as well as new media facilities and commentary boxes.

The roof was built by Galliford Try and SCX Group designed and supplied mechanical and electrical equipment.

The numbers:

8 litres per second of fresh air per person pumped into the bowl to manage the environment
9 chiller units required to cool the air
10 minutes (maximum) that the roof takes to close
10 trusses holding up the roof
16 metres - height of the roof above the court surface
30 minutes – maximum time expected before play can start/continue after the roof is closed and the internal environment is controlled and stabilised
43 miles per hour - wind speed up to which the roof can be deployed/retracted
77 metres - the span of the moving roof trusses (width of football pitch = 68m)
70 tonnes - weight of each of the 10 trusses without extra parts
100 tonnes - weight of each of the 10 trusses with all extras – eg motors, locking arms
100 percent of the roof’s fabric which is recyclable
214 MM per second - maximum speed of truss deployment
1,200 extra seats installed in 2008
3,000 tonnes - combined weight (both fixed and moving) of the roof
5,200 square metres, area of retractable roof when fully deployed
7,500 Wimbledon umbrellas, needed to cover the same area as the retractable roof
15,000 maximum spectator capacity
143,000 litres per second – total amount of conditioned air that the air-management system supplies to the bowl
290 million tennis balls – number that could fit in the Centre Court with the roof closed