Tell us about the early design brief
One of the events held at the ExCeL exhibition and conference centre was the table tennis. The centre’s temperature control systems are designed to keep large numbers of people comfortable. However, they use powerful jets of air which work well normally, but could easily knock a ping pong ball off course. Atkins’ engineers designed a system to keep thousands of spectators cool during the event without affecting play.
What inspired your design concept?
Engineers needed to measure air flow from any direction around the table. They chose a piece of equipment which was originally used to measure the impact of wind gusts on tilting trains to do this.
Did you know…
- Not a single ping pong ball was hit during the testing, instead engineers took 1,500 air samples from 1,000 locations – a total of 1.5 million measurements – to analyse the airflows around the table and arena.
How did it feel to be involved in such a large and important British project?
For Atkins, London 2012 was more than a celebration of sporting excellence. It was a celebration of the achievements of each and every one of the 1,000 colleagues who were part of our Olympic journey.
A project highlight for me was how London 2012 gave the engineering profession a chance to showcase its work, which often goes unnoticed. Atkins became the first official engineering design services provider to an Olympic and Paralympic Games, in part to show how interesting engineering design can be, but also to attract and retain the best international talent.
What challenges did you face along the way?
The International Table Tennis Federation (ITTF) required air velocity at the Games venue to be close to zero, not just at the level of the table but also 4m above, so the 2.7g ball does not get blown off course.
The table tennis was watched by up to 5,000 spectators in the arena, typically emitting 50–100 watts each. When this is added to temperature from the broadcast lighting and other equipment needed to transmit the event across the world, plus the summer weather outside which can be more than 25 degrees centigrade, engineers had to find a solution which keeps players and sports fans comfortable while reducing the fast-flowing air conditioning.
To control the temperature in the ExCeL, cool air is usually jetted out of large diameter nozzles in the ceiling. Because the ceiling vents are more than 10m above the venue floor a powerful jet stream is needed, which means the ball could easily be affected.
What about specific design challenges?
A team of 24 fluid mechanics engineers were brought in to use their knowledge and experience gained from analysing and testing the flow of fluids at oil and gas plants and power stations to keep the arena cool and minimise air flow.
The main engineering solution involved replacing sections of the metal air conditioning duct with large, fabric socks which allow cool air to leak out at very low speed. In addition, the grid over the air vents was replaced with ‘twist discs’ which have holes set at different angles so the air swirls out rather than shooting straight down.