Getting the London Stadium ready for the Premier League
What do you do when you don’t have a great view of the match? For West Ham United, which took over the London Stadium in 2015, the answer was to move the seats.
Author: Rob Gray, Diales Associate Director
The London Stadium, built for the 2012 Olympics, is used for many sports throughout the year, along with football. The stadium plays host to athletics meetings, Major League Baseball and concerts, and each of these events requires a different arena arrangement to give spectators the optimal experience. For football, bringing the fans close to the pitch considerably enhances the atmosphere, but the challenge for the Hammers was how this could be achieved while still allowing rapid conversion of the stadium into its athletics configuration. The solution was to build two temporary stands on top of the track, which could be removed during the football off-season.
For events specialist Arena, however, it wasn’t as simple as placing some seating over the track. The new seating had to to be connected to the accessways and concourses of the permanent stadium, which meant a series of bridges had to be constructed between the temporary seats and permanent structure. As the seats were effectively moved forward, closer to the pitch, space became available for a new bar area, which required a new platform above the permanent seats.
Demountable platforms are an area where Diales has unique expertise, and, having collaborated with Arena on many complex temporary event structures in the UK and Middle East, we were on hand to develop a solution for the stadium.
Arena intended to use its ASD system, formed from steel-framed panels on large-diameter steel legs. This type of system is ideal for heavy-duty usage, and sufficiently robust to remain in place for long periods.
The shape of the stadium bowl, coupled with the constraints that arose from constructing on top of an existing stand, made the proposed structure unique from an events industry perspective, and the design of such a structure was particularly complicated. Diales’ analysis capabilities meant we could develop bespoke 3D models of Arena’s proposed build and consider its impact on neighbouring structures, both when the stadium was empty and when stands were at capacity.
The structure of the stadium itself presented further challenges. The geometry of the temporary seating differed substantially from the stadium structure, which meant the structural support did not align. The temporary seating also had to be capable of resisting the weight of a stand full of spectators, as well as the significant dynamic lateral loads that can be generated at sporting events, both during access and egress, and at particularly exciting points in the match. For these loads to be safely transferred to the ground and load-bearing parts of the permanent stands, a complex support structure was inserted under the temporary stand.
Protecting the athletics track and terraces from damage when the temporary stand was erected was vital. The athletics track is vulnerable to damage from heavy loads and can be very tricky to repair.
To protect the track from damage that can occur under concentrated column loading, large spreader plates were installed to evenly distribute the loads, and the columns were kept close together.
The terraces presented a different dilemma. The terrace segments span between raking beams, which hadn’t been designed to carry columns – in effect, we were going to put loads onto the beams that the original designers would not have considered. Diales was able to reverse-analyse the beams, so we could work out what column loads they could carry. This analysis fed into the arrangement of the whole structure – in essence, the column loads were limited, and so the placement and spacing of columns was driven in part by the coordination of the ASD panel system with the positions of strong supporting structure.
Dynamic actions, particularly those associated with the movement of large groups of people in unison, can be hazardous in a stadium. A recent example was at Dutch football club NEC Nijmegen’s Goffertstadion. In October 2021, part of the stadium collapsed while away fans were celebrating victory – the dynamic action of the fans jumping contributed to the failure of the terrace.
Transferring the loads these actions create back to the permanent stand posed a further challenge, as the lightweight temporary stand required stabilisation to keep its occupants safe and comfortable. This was further complicated by the constraints of the stadium bowl – there was no means of resisting the loads where the deck connected with the permanent stands. This issue was overcome by making the structures self-stabilising, with all loads transferred to ground level. This required a complex arrangement of bracing and strategically located ballast blocks, to hold the stand in position without damaging the athletics track.
With Diales’ help, Arena managed to build the stands in accordance with the client’s brief, while providing a stable and safe structure which did not compromise the integrity of the existing terraces or athletics track. West Ham fans have enjoyed the improved views and proximity to the pitch that the temporary stands have brought to the stadium.
Originally written as part of the Driver Trett Digest, issue 24. To view the publication, please visit: www.driver-group.com/digest-compendium