More structures are employing the steel bending techniques that made the famous retractable roof on Centre Court possible

The now iconic retractable roof at Wimbledon has enabled many matches to be completed when the weather would have previously caused delays and left spectators huddled under umbrellas. Now play can continue uninterrupted until 11pm with the aid of the artificial lighting from 120 sports lights which are built into the roof structure. Using large structural steel supports with curved organic shapes to provide strength and weather protection, while making best use of natural light, has become even more popular six years on for both stadia and public buildings.

Spanning 77 metres, the roof structure at centre court is made up of 10 main roof trusses that had to be designed and manufactured to tight tolerances to provide the necessary load bearing capacity across such a distance. The design required the large box-section beams to be arched for additional strength; they were actually created in sections using precision shaped steel plates before being welded together on site and installed.

Greg North, Commercial Director at Barnshaws, comments: “We became involved with the Wimbledon project back in 2007 and in all, we delivered 66 sections for the roof structure, all precision curved. These were then assembled by Bolton-based Watson Steel Structures that was responsible for the steel construction on the project.”

Each completed roof truss weighed 70 tonnes on its own, but when the ancillary parts such as lights, motors and locking arms were added, this increased to 100 tonnes each. The addition of the fabric membrane that maintains the light and airy atmosphere of the court, along with the remaining components brings the total weight for the retractable roof to 1,000 tonnes.

The project also involved changes to the fixed roof structure so that it would provide sufficient support for the retractable section as well as increasing the seating capacity by 1,200. The success of this project has led to the proposal to install another retractable roof to Court No.1 in time for the 2019 championship.

Looking at the impact the project has had, Greg North comments: “Wimbledon was very high profile at the time, and it has led to Barnshaws providing curved structural steel to a large number of other iconic projects including Heathrow Terminal 5, Arsenal’s Emirates stadium, Manchester Victoria station and the Sir Chris Hoy Velodrome in Glasgow.

“In every case we have helped architects to bring their ideal designs to reality whilst maintaining the precision required in today’s modern buildings. The success of using curved structural steel, whether it is large tube sections, beams or box section to create structurally strong, relatively lightweight and aesthetically very pleasing structures is certainly fuelling new building development. Our bending and construction methods demonstrated at Wimbledon and then subsequently on the large structures we have been involved in since are certainly illustrative of things to come for this type of structure. ”