Blowing in the Wind
Following the recent tragic accident at a Radiohead concert, FIRE correspondentTony Prosser (26/06/12)poses the question: are pop concerts structures a cause for concern?
The recent death of a stage hand at a Radiohead concert in Toronto is just the latest of many accidents involving temporary structures at outdoor venues. Thirty-three- year-old Scott Johnson was killed when the top part of the stage fell upon the drum technician on 16 June. A tragic individual accident or a reminder of the fragility and risks of what has become a burgeoning industry, particularly in 2012 with Olympic events taking part all across the UK.
Pop concerts have always had the potential for disaster and many famous bands have been involved in tragedies involving deaths of the public. The Rolling Stones Concert at Altamont, California in 1970 involved three accidental deaths and one murder. Eleven deaths occurred at Cincinnati during a gig by The Who due to poor crowd control in 1979. Europe has suffered its fair share of fatalities at concerts and outdoor events too - Rokhilde in Denmark in 2000 during a Pearl Jam set, nine people died of crush injuries and at the Duisburg, Germany, Love Parade in 2010, 21 died and scores were injured.
While the potential exists for large numbers of public to die in indoor events - such as The Station, Rhode Island Fire during the Great White set in 2003 with 100 fire deaths - outdoor events have in recent years raised their profile again due to a couple of incidents in the past year. In the most high-profile, a severe rainstorm and winds blew down tents at the Pukkelpop concert in Kiewit, Belgium last year. Lightning poles and a 15-foot video screen fell onto the audience leaving five dead and over 140 injured.
In the USA, as a result of previous occurrences of stage and canopy failures, a head of steam has started to build up over the issue. As far back as 2009, architects and structural engineers have been calling for standards that take into account wind load on temporary structures. The fact that there are so many different types of temporary structure, design, use and geographical location are just some of the reasons cited as being problematical and almost impossible to account for in all circumstances. As one engineer said on designing for fire, a fixed building is one thing but it is quite another to plan for a temporary structure each time it gets used.
A pragmatic alternative would be to set operational parameters which define safe operating margins. For example, setting wind speeds, above which the structure is not safe for use is a crude method but one that could be made fail-safe and ensure the safety of the public. Some responsible operators in the USA are now setting their own standards allowing clients to set their own wind threshold for giant screens - 40, 50 or 60 mph - and providing the correct amount of ballast to achieve stability.
Giant video screens will be proliferating across the UK as Olympic events are watched by thousands in public parks and venues. Of course, it should be expected that most members of the public would leave the event if severe weather breaks out during the British Summer, but then again, most events are free!
HSG 195, the Event Safety Guide ("Purple Guide") is the principle document used by most licensing authorities for pop concerts and similar events. In its 190 pages, it makes four mentions of wind including a single sentence: "All proper designs will have calculations to determine the balance of loading and scale of forces acting on the structure. Therefore, the designer should be able to provide…particularly for outdoor structures, details of the methods of transferring all horizontal forces, e.g. wind, back to the ground."
Providing that the design of the structure is "proper" and that the designer has used the correct method of wind loading, all should be well. Unfortunately, as fire and rescue services can testify, that, particularly in times of recession, one of the first things that disappear from organisations' agenda is health and safety. The failure to make that precise calculation of wind loading and stability could mean a compromising of the safety of the public. Fortunately, the UK has been free from many of the critical structural and organizational failures seen in the Europe and the USA. With probably the busiest time ever for event organisers in Britain, it is worth reminding ourselves that maintaining a good safety record is something that needs to be worked on and not taken for granted.
Write a Comment