Once the big build was completed on the Olympic Park, the final stage of preparing venues could get underway: installing overlay.
Overlay is all the temporary equipment and material needed to get venues ready to host an event – such as seating, tents, cabins, toilets, fencing, temporary power, flags, banner, PA systems, lighting and rigging. For London 2012, this includes more than 200,000 seats, enough tents to cover the whole of Hong Kong, and enough toilets to service the entire population of Malta.
A complex challenge
The nature of overlay means it’s all temporary – London 2012 hires the equipment, it’s installed in venues, then is removed and goes back into the supplier’s stock after the Games. In some existing venues, London 2012 has worked with venue managers to install permanent facilities, which will benefit venues in the long term – for example, toilet facilities or fences. In these cases, the overlay has been purchased rather than hired.
Work started in October 2011, with technical Ceremony installations in the Olympic Stadium, and will continue until shortly before the Games start. In the case of completely new builds like the Riverbank Arena and Greenwich Park, overlay takes around four months to install.
The Olympic Park represents a particular challenge due to its scale and complexity – around 60-70 overlay projects are required there to get it ready.
Using London as a backdrop for the Games
London 2012’s vision was to use the city and its surroundings as the backdrop for the Games – creating venues in stunning, iconic locations such as Horse Guards Parade, The Mall and Hampton Court Palace. This itself posed some specific challenges in terms of overlay – and required suitably innovative solutions.
At Greenwich Park, for example, the arena deck has been built on stilts – minimizing the impact on the ground beneath and reducing the site’s environmental impact by doing away with the need for materials to fill the space under the deck.
In central London, the number of people attending events and the logistics of building the venues in busy tourist spots has also posed a unique set of challenges. At Horse Guards Parade, there is just a 36-day period to erect the huge arena between Trooping the Colour and the start of the Beach Volleyball competition.
Removing the overlay
After the Games, most of the overlay will be taken down and cleared away by the end of October 2012. But there are a number of venues – particularly on the Olympic Park – that will take longer to decommission. These will be completed by the end of the year. For venues such as Greenwich Park, which requires grass and ground reparations, works will be fully finished and the park returned to its former state by early 2013.