Construction of the Olympic Park always had its legacy in mind, with the conversion to post-Games mode a key consideration.
The summer of 2012 will live long in the memories, as Team GB and Paralympics GB surpassed all expectations and the nation as a whole began to feel a little better about itself after hosting one of the most successful Olympics to date.
One of the main reasons London edged out its international rivals to win the right to host the 2012 Games was its emphasis on legacy, and a commitment to look beyond the competition. This applied as much to infrastructure and community building as it did to getting young people into sport.
“We don’t have a CLM. But we have taken much of the learning into this project”
Colin Naish, LLDC
With that in mind the Olympic Park Legacy Company - now called the London Legacy Development Corporation (LLDC) - was set up in 2009 to look at the transformation of the Park beyond the Games time.
Overseeing the park’s transformation into what is now known as the Queen Elizabeth Olympic Park is LLDC executive director of infrastructure Colin Naish.
“We’re clearing away temporary venues, connecting the park into its surrounding environs and completing permanent venues,” he says.
To convert the park into legacy use LLDC has awarded a £292M contract to contractor Bam Nuttall, with Mace as project manager.
But although there is no delivery partner for this project, Naish is keen to remember the lessons learned by CLM, the joint venture between CH2M Hill and Mace, when making the initial park construction programme a success.
“We don’t have a CLM,” said Naish. “But we have taken much of the learning into this project.”
Instead, the delivery function is split between Mace, as project manager, and Bam Nuttall as contractor. Many of the staff, including Naish, have transferred over from the Olympic Delivery Authority to the LLDC.
One of the things Naish has adopted from the Games construction programme is the use of the same reporting and management system, but scaled down to meet the smaller project, budget and timescale. “There’s a lot of learning legacy and the trick is to adjust the scale and make it appropriate to the next task,” he says.
The park will be reopened in phases coordinated with a series of festivals, with the first chunk - about half of the northern section - opening on 27 July, exactly a year after the opening ceremony.
The remainder of the northern section of the park will reopen by the end of 2013, while the southern section and the hub - an open space for concerts and events - will open by spring 2014.
Naish said opening up the park from the north was necessary so that Waterdon Road - running across the northern section of the park from north east to south west - could be built. This will become what is known as the Northern Retail Lifeline which runs through the site, connecting the Westfield shopping centre at Stratford to areas of London to the south and west.
“It’s a complex jigsaw,” says Naish. “Once we’ve got a large enough part completed then we open it to the public.”
From a high security, tightly controlled sporting amenity, the park is to slowly turn much greener and will connect into the adjacent communities.
LLDC gained access to park from the Games organiser Locog in stages after the Paralympic Games. It gained full access in October 2013.
Bam Nuttall project manager Doug Mills is overseeing the park’s conversion for the contractor. “We’ve split into four sections,” he says, “security and logistics, earthworks and landscaping, infrastructure and roads and venues.”
New infrastructure work includes reconfiguring about 9.5km of the road network and altering 30 bridges.
Many of the bridge structures were much heavier and wider during Games time to deal with crowd flows far larger than those required in legacy use. They will be scaled down, with some having sections removed. Much of the dismantled steel will be recycled and the concrete decks used as fill on the site, says Mills.
“We’ve now got a new legacy use for it so we’ve got to transform the stadium to reflect that ”
Colin Naish, LLDC
One bridge, known as T12, spans Stratford High Street. It will be relocated to the Olympic Park and replaced by a much smaller timber structure.
Green space in the North Park will be significantly extended, including the planting of 4,300 new semimature trees and 100,000 new shrubs. A new park hub is currently under construction close to the site of Basketball Arena.
For the South Park section, LLDC commissioned architect James Corner Field Operations to design a new public space along the lines of London’s South Bank.
Legacy venues remaining on the park are the Velodrome, the Copper Box indoor arena, the Aquatics Centre, the Olympic Stadium and Eton Manor. All have operators and will reopen for general use by 2014 - other than the stadium which will reopen in 2016.
Data store operator iCity will operate the Park’s media centre building from later this year, with new TV channel BT Sports already a tenant.
The stadium is the one area where the legacy impact has not been as smooth as hoped.
After much legal wrangling, football club West Ham United will be the main tenant, with LLDC and Newham council creating a special purpose vehicle to operate it.
Naish says the stadium reflected the design brief at the time, but this did not anticipate the needs of a Premier League football club as it was thought the stadium would be converted into a scaled down athletics venue.
“It was designed for its legacy use at that time,” says Naish, adding that in 2009 when LLDC was created it was to take down the temporary elements leaving a 25,000 seat athletics stadium.
“We’ve now got a new legacy use for it so we’ve got to transform the stadium to reflect that.” Naish also confirmed the park will meet its 20% renewable energy target by 2014. Much of its energy will come from the gas-fired combined cooling heat and power unit and biomass boilers which were built to serve games venues and the Olympic Village. Homes on the park will be connected to the district heating scheme which also served Games facilities, with additional renewable energy coming from other areas including photovoltaic cells installed on top of the multi-storey car park.
Five neighbourhoods will be built on the park. Contractor Taylor Wimpey and developer Quadrant have already signed up to develop the first plot, Chobham Manor. This additional neighbourhood will be on the site of the Basketball Arena and will offer around 850 homes, 70% of which will be family homes.
Redevelopment of the Park and surrounding area has been helped by the fact that the LLDC was turned into a Mayoral Development Corporation with wider planning and development powers.
“It assists enormously with our regeneration remit to bring this area up,” says Naish.
“The clearest thing is we have our own planning authority and our remit goes beyond the park and extends into the local boroughs to spread regeneration.”
Funding for the £292M contract to convert the park was from the original Olympic Delivery Authority budget, says Naish, but after that much of the investment for the other four plots will come from the developers on a “partnership basis”.
“We’re really confident we will develop the plots,” says Naish. “We’ve got outline planning permission and legacy community schemes which outline how they will be developed, and we’re looking at how we can accelerate those.”
Also in discussion is how and when each of the remaining four plots will be developed.
The Basketball Arena
One of the largest temporary venues to be dismantled is the Basketball Arena. Eight months after the games the arena is almost completely gone, with just the shell remaining.
The structure is very large at 114m long, 96m wide and 35m high, with the main steelwork trusses spanning almost 100m.
Surrounding the 1,000t skeletal steel frame is a 23,000m2 recyclable white PVC fabric skin.
Bam Nuttall took over the site in October and quickly began the dismantling operation. First to go were the seating and associated services.
“Starting with the west entrance of the arena we dismantled the seating in a clockwise direction,” says Bam Nuttall site agent Channari Penh.
The seating itself was provided by Locog, and 3,000 seats were relocated to Eton Manor and the remaining 9,000 returned to their owner, temporary seating company Slick Seating.
With the interior cleared, engineers then removed the PVC skin leaving the huge skeletal frame.
To dismantle the frame, two 250t crawler cranes will hold each roof truss in place while two 70t crawler cranes remove all the bracing and secondary steelwork.
Once the bracing and secondary steel is removed smaller cranes will move in to hold the column trusses, as they are not self-supporting. Engineers will unbolt the connections between the columns and roof truss before and lowering the columns.
The 70t crane will then return to help lower the nine sections of roof truss to ground level where they will be fully dismantled.
“This is repeated nine times as engineers work through the structure. Once that’s been cleared from the site it’s just the removal of any foundations,” explains Penh.
The foundation consists of a grid of temporary vibrostone columns and sheet piles, with the skeletal columns bolted directly on top.
Bam Nuttall is excavating down to 1m below ground level, and cutting off the top 1m of the columns. It will then backfill the whole space before handing the site over to contractor Taylor Wimpey and developer Quadrant in the summer. The steel frame and PVC cladding are currently for sale by owners Barr Construction for £2.5M.
One of most iconic venues left over from the Olympics is the Aquatics Centre, built by Balfour Beatty with steelwork subcontractor Watson Steel. During Games time two huge temporary seating wings were added to accommodate extra spectators, which means Zaha Hadid’s futuristic floating roof design can only be fully revealed in legacy mode.
“It was designed for legacy use in the first place and converted for the Games,” says Balfour Beatty project director Stuart Fraser.
The Aquatics Centre has 2,500 seats in legacy but required an additional 15,000 during Games time.
This meant construction of two giant temporary stands which are now being dismantled.
Fraser quips that dismantling the stands is just the “opposite of constructing it” but it is obviously much more complicated than that.
Fraser gained access to the site in October, just weeks after the end of the Games.
Although the structures - the Aquatics Centre and the temporary seating - are structurally independent, they are side by side and this affects the work.
“First of all we needed to protect the asset from the works and the Stratford winter,” says Fraser.
This involved putting up scaffolding and protective sheeting between the swimming pool and temporary stands.
“First job was to remove the seating then bleachers [the frame underneath the seating],” says Fraser.
Engineers are using four 150t to 200t cranes to dismantle the structure, with the roof girders coming first.
Then, using two 500t cranes, engineers will dismantle the main 100m long truss in a tandem lift.
The aim is to recycle the seating structure elsewhere. “We’re very confident we can find a home for the bleachers and the seating,” says Fraser. He is in discussions with LLDC to find a new home for them.
But he concedes most of the structural steel will be cut up and recycled. “I’d be very surprised [if it was sold]. I think most of it will be cut up,” he says.
Work to dismantle the main structural steelwork began in January and Fraser hopes it will be all removed by the summer.
At the same time engineers are beginning to install the glass panels that will allow natural light into the pool area - one of the key aspects of the design engineers have this week begun work on the mullions which house the glass curtain wall.
The glass panels are only supported from the bottom and fit into a 300mm deep and 300m wide slot in the roof.
“They cantilever [off the floor] into the roof void,” says Fraser
Each of the side glass walls is made up of 19 panels that are tailored to their location within the horizontal curve of the roof.
“Each one is different because the roof moves up and down,” says Fraser.
Once it has been fully fitted out in the summer LLDC will hand the Aquatics centre over to operator GLL.
The Velodrome forms the centrepiece of the Lee Valley VeloPark as LLDC adds a 1.6km outdoor road cycle circuit crossing the River Lee.