The first 30m-long steel section of the roof compression truss has been lifted into place, taking the height of the Stadium to almost 37m above podium level.

A 1,350-tonne super lift crane has been assembled in what will be the field of play to lift each 85 tonne, 15m-high section and hold it in place while it is bolted to the top of the 27m-high roof support columns.

The remaining 27 sections of the roof truss will be lifted into place over the next nine months with the aim of completion by October this year.

The ODA also released an online document today, updating against the ten milestones published last June. The 'big build: foundations update' document shows that good progress is being made on the milestones which aim to be achieved by July this year. This includes a commitment to complete the Aquatic Centre foundations, construction of seven bridges and work begun on the IBC/MPC and Velodrome foundations.

ODA Chair John Armitt said: 'The construction of the roof starts to give a real indication of the height of the structure and people can start to see for themselves how the Olympic Stadium will look during the Games.

'This is a very complex engineering and construction project and we will still face challenges over the next year but we have made a very strong start on the construction of this flagship venue.'

The steel terracing supports which will hold the upper tiers of seating are nearing completion on the South and West stands and work will now begin on the North and East stands.

There are currently over 500 workers on the Olympic Stadium site. This will increase to around 700 as the internal fit-out work starts and trades are required such as electricians, brick-layers and plumbers.

Notes to editors:

Pictures of the columns and time-lapse footage of their construction can be downloaded from:
http://mm.gettyimages.com/mm/nicePath/locog?nav=pr120886980

In July 2008, the ODA published 10 milestones that it planned to achieve by 27 July 2009. Today the ODA has set out the progress made at the half-way point to July 2009 in an online document which can be downloaded from:
http://www.london2012.com/documents/oda-publications/big-build-foundations-update.pdf

Construction started in May 2008, site three months earlier than originally planned, and was witnessed by Prime Minister Gordon Brown.

Olympic Stadium facts & figures:

- 33 buildings on the Olympic Stadium site have been demolished

- Over 800,000 tonnes of soil has been taken away to help create the construction platform for the Stadium - enough to fill the Royal Albert Hall nine times over

- The Stadium is highly sustainable, containing around 10,000 tonnes of steel - the lightest Olympic Stadium to date

- The total Stadium island site covers an area of 40 acres – five times the size of the Houses of Parliament

- The Stadium is 53m high - taller than Nelson’s Column (50m)

- The Stadium roof covers an area of 24,500 sq metres - the equivalent to three and a half football pitches.

For further information please contact the Olympic Delivery Authority Press Office on +44 (0)203 2012 700.