Preventing the dangers of a crowd
Generally, at a celebration or an occasion, when a large number of people are gathered together in one place at the same time, a crowd is formed. Despite the happy nature of the occasion, crowds can be dangerous, which is why technology is leading the way to help battle the causes of crowd catastrophes and accidents. Crowds can cause suffocation and trampling, but calmer crowds can also be a persistent problem. When a group of people becomes a crowd, it becomes a fluid like movement that suffocates them by crushing their lungs or throwing them into the air.
Oasys software, crowd simulation technology experts, are using software that allows architects to design buildings that are safe for their users. Many firms are investing in technologies that analyse, evaluate, and provide data regarding the safety of a crowd. By law, event organisers are obligated to keeping crowds safe – so these technologies can be utilised efficiently within this endeavour. Dangers that are listed by the government are as follows:
- Crushing between people
- Crushing against fixed structures such as barriers
- Trampling
- Surging, swaying or rushing
- Aggressive behaviour
- Dangerous behaviour such as climbing on equipment or throwing objects
Identifying the dangers of a crowd
Believe it or not, trampling is not the main cause of death within crowds – in fact it is more often the movement of people that can become a powerful force, and in some cases, it can be up to a force of over 4500 Newtons, or 1,000lbs. Objects that are supposed to protect a crowd can also become a potential hazard, as steel railing can be bent and cause injury to passers-by. These types of pressures can cause compressive asphyxia, a leading cause of suffocation within a crowd and the most common cause of death.
Whilst some people think a ‘stampede’ is most likely to cause a crush, it is actually something small such as a trip or fall that can cause a knock-on effect through the crowd. This occurs within a crowd that has 6 or more people per square meter. Technologies that analyse motion on mass are therefore used in these situations where crowd footfall can be analysed to minimise the risk to those within the crowd.
It is crucial that a potential threat and the extent of it is analysed to pre-empt the dangers that the crowd could be faced with. Pre-emptive technologies can be used to help avoid future disaster because it can spot dangers before they happen. For instance, in 2003 70 people were crushed while trying to escape from pepper spray that was being used to break up a fight. This may not have happened if technology could have established that this wasn’t enough space per square meter for people to leave the building safely.
Examples
There are several reasons why a crowd can be lead into a disaster:
Reaction to perceived threat: A riot by English and Italian fans in 1985 at a European Cup Final in Brussels led to a flight by spectators trying to escape the violence, which led to 38 deaths by asphyxia. Over 437 people were injured.
Lack of communication: In 1981, Greek football fans were killed when they tried to leave a match in Athens stadium, finding the gates locked. The rear of the crowd had no way of knowing this was the case and continued to press forward, causing 24 deaths.
‘Craze’ behaviour: in 1989, 96 people were killed and more than 170 injured at Hillsborough Stadium in Sheffield, England. A larger than expected fanbase was trying to enter the stadium, which caused police to open gates to relieve crowd pressure. Instead, the crowd surged into the stadium, crushing fans into enclosed terraces.
How to prevent the dangers of a crowd?
Preventing disasters in a crowd is exceptionally difficult, as it can be complicated to control all factors that could lead to a disaster. However, there are some factors that you can try and control to try and prevent the risk of disaster. The density of a crowd is the first immediate problem to tackle. Setting a specific limit of guests can help alleviate the dangers associated with crowd density, but this can often be an unrealistic method at larger events such as religious gatherings.
Communication is key – when dealing with a large number of people, it can be difficult to communicate important information different points within the crowd. Placing barriers to try and create movement paths can cause their own problems, as barriers may actually lead to accidents rather than prevent them. Simple barriers like rope or posts may be less dangerous. The use of stewards to help promote communication is a recommended measure as they can prevent the issue that comes from a communication breakdown between the head and body of a crowd.
Exit strategies should be in place to keep control of crowd surges. This is something to consider when building a new venue that will host big events and occasions. At a large event, a timed exit, where people from different levels exit at different slots of time, is another popular prevention method.
Technology is also helping fight against crowd crushing and other dangers. Using tools like MassMotion, those in charge of buildings or crowd control should first run simulations to test the stresses of pedestrian flow and crowds. These tools can help in evacuation planning, giving an unparalleled insight into the unique spectacle of crowd movement.
Sources:
http://www.bbc.co.uk/programmes/b00x53wd