Wembley Stadium, London

The new Wembley Stadium is the largest sports venue in the UK and the second-largest stadium in Europe. The all-seat stadium is owned by the Football Association (FA) and operated by its subsidiary, Wembley National Stadium (WNSL).

The old Wembley Stadium opened in April 1923. Construction of the new Wembley Stadium began in October 2002 and it was officially opened to the public in March 2007. The final stadium costs amounted to approximately £798m ($1.5bn).

The aim of the project was to design and build a state-of-the-art national stadium, unlike any other in the world, which would be the home of English football and host large events such as Cup Finals, music events and athletics.

The stadium is the home ground for the international matches of the England national football team and the English domestic cup finals. It hosted the FA Cup, Rugby League Challenge Cup, National Football League and FA Community Shield.

The stadium also hosted the 2007 and 2008 Race of Champions. Apart from sporting events, it also played host to music concerts for George Michael, Madonna, Coldplay, Mettalica, U2 and Oasis, as well as charity music shows including Concert for Diana and Live Earth.

Furthermore, the stadium was a venue for the 2012 Olympic football finals and the Rugby World Cup in 2015.

Details of the old Wembley Stadium

The old Wembley Stadium, with its much-loved twin towers, stood tall as a standing memory of British sporting history until it was closed in 2000, before being demolished in September 2002. The venue was originally developed as the main attraction of the 1924 British Empire Exhibition.

Construction of the old Wembley Stadium began in January 1922 and it was inaugurated in April 1923. Architects Sir John Simpson and Maxwell Ayerton designed the stadium, which had a capacity of 127,000.

FA Cup finals between 1923 and 2000 and League Cup finals between 1967 and 2000 along with seven European finals were held at the ground. The old Wembley Stadium witnessed its home team winning the FIFA World Cup in 1966.

Wembley stadium design and architecture

The design of the new stadium is both functional and architecturally significant. Sir Norman Foster designed the arch and the roof structure, with the remainder of the stadium designed by architects Foster + Partners and Populous (formerly HOK Sport).

The stadium is designed like a bowl, with unique features being retractable roof panels and the arch, which were developed in response to the requirements of the stadium, one of which was the need for a high-quality grass pitch to achieve UEFA five-star stadium status.

The roof panels, which retract to the south, allow as much daylight and ventilation to reach pitch level as possible. The arch itself is not just a cosmetic feature, but also supports the north roof and a sizeable area of the south roof.

Constructing and raising the arch

The arch was fabricated on-site using steel modules fabricated by steel subcontractor Cleveland Bridge. Cleveland Bridge left the project shortly after due to serious contractual difficulties with the main contractor Multiplex.

The arch was lifted in four key stages in June 2004 and temporarily supported on five restraining cables. Structural engineers from the Mott Stadium Consortium worked closely with Multiplex and the newly appointed steelwork subcontractor Hollandia to transfer the load, in excess of 1,300t, to the permanent cable net and eyebrow catenary cable. The final positioning of the arch to 112° was completed at the end of 2005, with the arch being rotated to take up the full roof load.

The Wembley arch and roof design

The arch was designed to give the appearance of solidity without incurring the penalty of high wind loads. The arch has a lattice form consisting of 41 steel rings (diaphragms) connected by spiralling tubular chords and is formed of 13 modules with two tapering end sections.

The arch is 7.4m in diameter at the base and weighs 1,750t. It tapers at its ends and is supported on 70t hinges which are in turn supported on concrete bases founded on piles 35m deep.

Inclined from the vertical, the arch is held in position by a series of forestay and backstay cables tied to the main stadium structure. The leading edge of the north roof is in turn suspended from the arch by the forestay cables.

Cables from the arch are arranged in a diagonal pattern to help spread loads to control in-plane bending, while also providing out-of-plane restraint to resist buckling. The arch structure is 133m high, with a span of 315m and is the longest single-span roof structure in the world.

The 50,000m² roof is essential to the operation of the stadium as a sporting and concert venue. Weighing about 7,000t, the roof has several retractable edge sections that can be manoeuvred to allow direct sunlight to reach all parts of the grass pitch. The roof can also be retracted in approximately 15 minutes to cover every seat inside.

The arch at a 68° tilt from the horizontal supports 5,000t of the roof structure. With its load-bearing capabilities, the arch allowed designers to eliminate the need for columns within the interior, which means that every stadium seat has an unobstructed view of the pitch.

The arch also provides a beacon for the stadium, illuminating the north-west London sky on match days. The designer’s vision for the arch was a tube of light that would hover over the stadium at night creating an iconic statement.

To achieve this effect, 258 metal halide floodlights were mounted within the arch to illuminate the internal faces of the lattice and the structural rings that form its structure.

As the arch is lit from within, the outer faces remain dark and increase the dramatic effect by adding depth and contrast and giving the appearance that the light is trapped within the lattice structure. The arch also has an aircraft safety light at the top.

Aurecon, a pioneer in the use of BIM technology for arch and roof design and documentation, worked on a visualisation tool in developing the concept together with the architects and during the documentation of their complex 3D form.

Pitch laying details

The laying of the new Wembley turf was completed in June 2006. The process took a week and required more than 10,000m² of turf to create the new playing surface. The turf arrived at the stadium in giant rolls measuring 12m to 16m long and 1.2m wide and was transported in 25 lorry loads.

The fibre sand pitch is made up of an underlying web of heating and drainage pipes plus 22,161t of crushed stone, gravel, grit, sand and a blend of sand/soil and fibre. The grass used for the turf was selected from 250 different varieties with each square metre of turf containing between 150,000 and 200,000 leaf blades.

The roof is left fully open between events to allow the turf to be exposed to direct sunlight and ventilation. The sub-air system installed under the pitch has ducts that can supply warm air to the pitch to heat it. The same system can also be used to remove excess moisture from the pitch if required.

Wembley Stadium features

The stadium encloses four million cubic metres within the walls and under the roof. Its construction required 90,000m³ of concrete, 23,000t of steel and approximately 56.3km of heavy-duty power cable. As many as 4,000 piles were used to form the foundations, the deepest of which was sunk to 35m depth.

The stadium roof rises 52m above the pitch and the circumference of the building is 1km. The roof structure covers 11 acres, four acres of which are movable. The 90,000-seat capacity makes it the second largest stadium in Europe next to the Nou Camp stadium in Barcelona with a capacity of 98,000.

The seating is steeply banked so that no seat will have a restricted view. Minimum seat depth is 80cm, with a minimum width of 50cm. The seats have more legroom space and are arranged in three tiers from lower 34,303, middle 16,532 and upper 39,165.

The stadium can be converted into an athletics venue by virtue of a removable steel and concrete platform, which rises 6m above the football pitch. Installing the running track decreases the stadium’s capacity to 68,000. The front row at each end is now from 8m to 13m from the touchline, compared with 40m in the old stadium.

In addition, 310 wheelchair spaces with attendant companion spaces are provided, apart from increased capacity for other physically impaired spectators. There are 400 media seats, 2,618 toilets and four main banqueting halls, the largest of which can accommodate 2,000 people. The stadium incorporates an external concourse surrounding it, which can cater food and drinks for 40,000 spectators at a time.

Facilities

The stadium has 26 lifts, 30 sets of escalators and 164 turnstiles for the convenience of spectators. It has 34 bars, eight restaurants, 688 food and drink kiosks, 98 kitchens and 107 steps in the trophy presentation routes placed in and around the stadium. It also features 47 retail units including programmes, merchandise and betting. Seven cash machines are conveniently located around the stadium.

Financing for the new Wembley Stadium

The parties involved came to an agreement on a fixed-cost contract to overcome financial concerns over the new stadium. Under such an arrangement, the client is protected from exposure to budget overruns or delays in construction, which was borne by Multiplex (UK), the main contractor.

Cyril Sweett acted as an independent consultant for WNSL in April 2002 and cleared the Multiplex contract as representing value for money. A National Lottery fund investment of £120m was made into the stadium. The financial backing of £426m for the project was secured through the West Deutsche Landesbank of Germany. Ken Livingston and Brent Council secured £21m in funding for the project and a further £17.2m from WNSL for improvements to transport infrastructure in the area around the stadium.

Contractors involved

The main contractor for the project was Multiplex of Australia. Project management was provided by Symonds. Structural engineers and consultants included SVE Franklin and Andrews; Nathanial Lichfield and Partners; Steer Davies Gleeve and Mott Stadium Consortium (Connell Wagner, Mott MacDonald, SKM, Weidlinger and M-E Engineers).

The original steel contractor was Cleveland Bridge, but it was eventually replaced by Hollandia. The mechanical and electrical contractor for the project was Emcor Drake & Scull, while the building services engineering was carried out by Mott MacDonald.

The original stadium demolition was carried out by Griffiths McGee. For the foundations of the new stadium, the piling specialist was Stent and the concrete specialist was PC Harrington.

Aurecon, as part of the Mott Stadium Consortium, was tasked with the structural engineering of the stadium’s arch and roof which involved ensuring the stability and strength of the architectural elements.

Controversy and events during construction

When the project first started, it was delayed for two years due to financial and political difficulties before eventually getting underway in late 2002. The stadium was supposed to be completed by May 2006 for the FA Cup Final, but the project was transferred to Cardiff as Multiplex was unable to complete it within the scheduled time and had to pay penalties. In December 2008, Multiplex sued the stadium designer Mott MacDonald for £253m claiming that it was denied access to key design information that led to increased steelwork costs.

A few construction problems were highlighted during the project. The first was a problem between Multiplex and the steel contractor Cleveland Bridge.

Cleveland Bridge walked off the job in 2004 shortly before the arch was raised because they did not believe they would be paid for materials and there were irrevocable difficulties between the two parties. The problems resulted in two high-profile court cases where the two companies sued each other for breach of contract (Multiplex sued for £45m and Cleveland Bridge sued for £22.5m to recover what it believed it was owed). In September 2008, Multiplex won the case and received £6m from Cleveland Bridge.

The second problem involved a temporary roof support rafter, which fell by more than half a metre in March 2006. The event resulted in the evacuation of 3,000 construction workers and delayed work while inspections and reports were carried out. The construction was resumed shortly afterwards.

Later, in March 2006, a third problem came to light. The sewers under the stadium had buckled due to ground movement. Remedial work started later on. The stadium was scheduled to be completed by late summer 2006, however, it was completed in March 2007 moving the scheduled sports events to another stadium.