Why do Fire Doors Open
Posted on 25th January 2023 at 14:08
Imagine the scene.
You are watching a movie with a hundred or so other people when suddenly the fire alarm rings.
Calmly, people gather their possessions and start to head to the exits...
You are the first to arrive at one of the exits and push at the door.
Nothing happens…
You realise that the door needs to be pulled open.
No problem, right?
Wrong.
On your first attempt, the door opens against your foot and instantly closes again.
You try to open the door again but by this time you have a increasingly panicking crowd gathering behind you…
They start to surge forwards which makes it impossible for you to open the door as they push you against it.
The more they panic, the more they push while the fire and smoke come closer and closer…
This tragedy played out in real life in a theatre in Chicago in 1903.
The theatre was packed full for a matinee performance when a stage lamp ignited some of the set.
The audience headed for the 27 exits but found most locked (to stop people without tickets entering) and the rest only opened inwards onto dangerous fire escape ladders.
600 people died (mainly women and children) and more than 250 were injured in the deadliest single building fire in US history.
The tragedy was that most of these deaths were avoidable – many were crushed underfoot by panicked crowds, others died trapped by iron gates or from the unfinished fire escape ladders.
As a result of this disaster, Carl Prinzler, a hardware salesman, determined that the tragedy should not be repeated.
He eventually created what is now known as the ‘panic bar’ which stops people entering but also lets those inside exit quickly.
Over a hundred years later and his design is still a common sight in many public buildings.
And that is why fire doors tend to open outwards…
Stay safe out there.
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