This week’s tragic events in Manchester will once again lead engineers to rethink how they design buildings to counter terrorist threats.
The impact of Monday’s bomb, set off in a crowded environment and aimed at causing maximum destruction, is something all engineers will be working to counteract in the design of structures such as stadia, arenas or stations.
These venues are often referred to as soft targets, their nature means it is simply not possible to protect them in absolute terms.
With each attack that takes place, alongside the latest intelligence, the goal posts move in terms of providing optimum protection. More low-tech devices such as knives, guns and cars are being used giving an accessibility to buildings and infrastructure which didn’t previously exist.
In light of this, engineers now have to respond to make sure they do as much as possible to limit their effect.
Arup associate director resilience security and risk David Cormie suggests three things engineers can do. The first is to use a site specific, risk based approach. Second is to understand the threat and design proportionately for it, and third is to include security measures into the design early. This means the design of the fabric of the building can add to its security, he says.
“We can look at the façade, the internal finishes to make sure they’re taking away from hazards rather than contributing to it,” says Cormie. “If we can use the building design work for us by protecting people, then that’s a win win situation.”
He also says flexibility is key. Structures are designed with a lifespan of 40 to 50 years, but threat levels can change on a weekly, monthly and yearly basis. Therefore being able to increase or decrease security with the changing demand should also be taken into account.
The initial moments after an attack are crucial and again good design can minimise the impact says Cormie.
“It’s very difficult to design a building to manage for that initial panic. But good security will protect people by being intuitive in getting people to safety quickly,” he says.
The behaviour of people in this state of stress is not to be underestimated and wayfinding, lighting and emergency access all need to be clearly designed to play their part.
“For marauding terrorist attacks there’s a lot more of a behavioural effect,” he says. “People are in a state of stress, they won’t be familiar with the building, they won’t know what’s going on and they won’t know whether they are running away or towards a threat.
“There’s quite a lot of behavioural psychology in designing a building for this situation. People do strange things when they’re in a state of stress and as designers we need to consider that in building design.”
Movement Strategies managing director Simon Babes agrees saying a combination of building design and having good operational plans in place is paramount. With this type of venue, drills are not practical and therefore having well trained staff to direct people to safety is more important than normal.
“I think it’s got to be people on the ground and using hand and arm gestures to provide very clear guidance,” says Babes. “Even an announcement over a PA isn’t very effective in a time of panic as it would be issuing a standard command to all areas, so it would be very difficult to rotate and give specific guidance to specific routes.”
Documents giving guidance for the design of buildings which might be at risk of an attack are currently being updated to reflect the changing nature of the threat.
And the tragic events this week in Manchester highlight how important it is to mitigate risks as much as possible.