Stadium's retractable seating pushed and pulled by hand
The Olympic running track where Bolt, Ennis and Farah struck gold during London 2012 will be out of bounds to athletes for nine months every year.
The £154m cost of converting the Olympic stadium into a new home for West Ham includes retractable seating over the running track. But unlike other venues, the seats will not be fitted with a hydraulic or electrical mechanism.
Instead, they'll be pushed and pulled into place by a team of stadium workers. The process will take up to seven days. That means the track is likely to remain covered throughout the football season from August to May.
A warm-up track, with seating for 300 spectators, will be built next to the stadium and is likely to become the main focus for grassroots and community sport. Officials at the London Legacy Development Corporation said the manually-operated retractable seats would be cheaper to build and maintain.