When the hallway is on fire and the only option is the stairs behind you, I really doubt you'll care about the space 'wasted' on them.
And in response to Grenfell, the argument is tenants don't like fire drills; just wow. Eventually everyone forgets the reason for regulations...is there a named law for this phenomenon?
A dozen extra staircases wouldn’t have done much to save people in Grenfell tower. They were instructed to stay in place, because when building regulations are followed, that’s the safest place to be. The problem with Grenfell was that building regulations had been violated, at which point, all bets about safety are off.
I could see a layperson like me thinking “yeah, thick concrete and fire doors; you’ll never need to fully evacuate”. I would expect architects, fire marshals, city planners, and other experts to see the obvious problem with this. Or at least one of them. It’a a single building. How do you build a plan around never needing to evacuate the place? It seems straightforward and appropriate to support a full evacuation strategy.
Is “stay in your flat while the building burns down around you” a common fire safety plan in the UK? Because that seems scary as hell. And also negligent.
Apartment doors, walls and floors can withstand many hours of continuous burn. The building would never be on fire, at worst you’d have one apartment or one floors public areas on fire before it’s put out. If my apartment was on fire, no alarms would sound in the building, only within my apartment, it doesn’t matter to my neighbours.
There’s certainly scenarios in which you might need to evacuate, like a bomb threat, but we are speaking about internal fire, in which case there’s more danger in hundreds of people fleeing in panic down stairs (whether that’s 1 stair case or 2) than staying inside.
> Apartment doors, walls and floors can withstand many hours of continuous burn.
24 stories of Grenfell were engulfed in an hour - the fire bypassed the doors, walls and floors, by going up the outside.
> The building would never be on fire
The entire building was on fire. 72 people died.
> The problem with Grenfell was that building regulations had been violated, at which point, all bets about safety are off.
Mistakes get made. Hence redundancy, like two staircases. If you're going to design for 'no mistakes ever made' then don't bother with any fire systems as a fire is a mistake in the first place.
It's so not criminal that plenty of hi-rises in the UK still have flammable cladding. If it were criminal, the people who put it on there would be in prison.
The correct approach is to design for the biggest common mistakes, not for all mistakes ever. We already do this for floods, earthquakes, wind load, etc.
Trying. Because the UK government absolutely does not give even a single fuck. Housing is a shitshow everywhere. (A symptom of completely bonkers politics in general.)
> there’s more danger in hundreds of people fleeing in panic down stairs (whether that’s 1 stair case or 2) than staying inside.
Is there? I’ve never seen people panic when a fire alarm goes off. Maybe if the fire alarm is going off as the building is filling with deadly smoke people would panic. But then that seems appropriate (or at least better than sitting and waiting to die of smoke inhalation).
Pretty sure the Grenfell situation would have ended better by having everyone evacuate. And yes, the incompetent cladding work makes that a special case. But a huge amount of our codes are for a special case. Every so often it saves 70 lives.
The problem isn't only a potential panic. While the people are evacuating, how does the fire brigade get to where they need to combat the fire in the apartment?
This is sort of a comical response. The building is engulfed in flames and plan is to keep the stairwells clear.
If the concrete and fire doors are doing their supposed job, then the fire brigade can just wait. If the concrete and fire doors are not doing their job, then getting people out is far more important than getting the fire brigade in.
> If the concrete and fire doors are doing their supposed job, then the fire brigade can just wait.
Wait until the people in the apartment on fire die? (Either it starts in an apartment, or a common are which would block the escape of inhabitants living on there or higher)
I’m struggling to understand the scenario you’re describing. So the alarm goes off because an apartment is on fire. In response to this, everyone else waits until the fire brigade shows up to attempt to exit? I’m pretty sure if people are going to evacuate, they’ll do this in response to the alarm, and not wait and block the stairs. Also I’m pretty sure the fire brigade can tell them to get the out of the way to get up the stairs if necessary. How narrow are these stairs anyway? And why did everyone not evacuate before the fire brigade showed up?
I just find the “apartment on fire, but everyone is blocking the stairs so the fire brigade can’t get to the burning apartment” scenario to be far fetched. Are there documented cases of this? Because there is at least one documented case of people sheltering in place and the building burning around them.
I never feared fire when living in a high rise, and never had to evacuate except for drills. But here’s a recent counter example where shelter-in-place can go wrong. https://www.thestar.com/news/2021/toronto-fire.html
It does seem to be the norm for the UK: “In the United Kingdom... residential buildings are designed with a stay-in-place firefighting strategy as opposed to simultaneous evacuation, and regardless of building height, maximum occupancies determine staircase width, resulting in many tall buildings serviced by a single stair core. On June 14, 2017, one such building, the Grenfell tower, was engulfed by the deadliest residential fire in the United Kingdom since the Second World War and cost the lives of 72 people. Subsequent inquiry determined that the negligent use of combustible cladding and insulation caused the rapid spread of the fire up the building exterior. The tower consisted of a 24-storey concrete structure with a single central exit stair, for which the shelter-in-place evacuation policy was sustained for more than 80 minutes before a general evacuation was ordered.”
In 2001 when the Twin Towers came down, people were trying to desert the building. Is there an analysis that shows they would have been just as safe in their offices?
The South Tower had one remaining stairwell survive impact and 18 people were actually able to evacuate from above the impact zone, which is actually pretty impressive when you consider that the impact was on floors 77-85, and the people who called emergency services were told to stay in place. One of the survivors was actually only 20 feet (6 m) from the left wing. https://en.wikipedia.org/wiki/Stanley_Praimnath
That being said, a lot of fire codes and related legislation had to be updated in the wake of 9/11. Among the many other dumb things:
* the stairwells were all extremely close to each other. In the North Tower they were 70 ft (21 m) apart and in the South Tower they were 200 ft (60 m) apart, which is probably why one stairwell survived in the South Tower and none did in the North.
* stairwells were only surrounded by drywall instead of concrete, which is another contributing factor to why so many of them were rendered inoperable. If you're not familiar with drywall, you can literally punch a hole through it with your arm.
* stairwells were built with a 44 inch width because it was assumed that the average person had a shoulder to shoulder width of 22 inches (55 cm). This slowed down evacuation a lot.
* the fire code was incorrect. the building was only half full but took much longer to partially empty than a full evacuation of the full occupancy tower was projected to take. so codes were revised.
* there were not enough stairwells according to code. but how might this be? well, the owner and constructor, the Port Authority of New York and New Jersey, is a federally created entity, and so is not actually subject to local fire codes. (This last point wasn't actually addressed; they're still not actually required to follow NYC fire codes, but they did at least do so for the new iteration of the towers.)
* In a previous attack on the WTC, people were evacuated from the roof, but since that incident the roof doors were locked to prevent base jumpers from gaining access.
These things correlate though. Sure, sometimes we get misses like child car seats, but more often than not outrage-induced regulation manages to make things better.
Most residential detached multi story houses only have one staircase. If government forced me to give up one bedroom and build an extra staircase, so that I have a slightly higher chance of survival of a very unlikely event, I’d be fucking pissed.
I don't think we are talking about modifing existing buildings or small homes, they are talking towers and large units - a lot of places still count jumping out a residential second floor as an exit, so you'd probably be fine.
Being on the 7th story is very different from being on the 2nd story. If the staircase was to catch fire right now it'd be like a 6 meter jump down the window, maybe less if I manage to lower myself by hanging off the edge. I can land on my legs and I'd risk breaking an ankle or something like that at worst, not ideal but I wouldn't burn to death.
> think of all the wasted space and weight having 8 exit doors on a airplane
If we could choose to fly on the same plane with 4 doors that would give us more legroom and get us to our destination in less time, I believe a lot of us would make that choice.
Eh? More legroom? Leg room is determined by the airline, not the plane.
If there were fewer doors there would me more seats, and the weight of the seat, passenger, and luggage would far outweigh the weight saving on the door.
No, the limit of airplane speed is the speed of sound, as you get very close to that aerodynamics changes greatly. While you can make a plane go faster it is rarely done.
A giant heavy emergency ballistic reserve parachute system (currently used on smaller planes) is a much better analogy than 8 doors, which don't change the equation that much. Let's waste 20% more fuel to be able to recover from the rare all engine failure.
yeah. it is. but only in the same way that the prohibition of tetraethyl lead merely subsidized a slightly smaller amount of brain damage for relatively few children at the significant cost of the cheapest anti-knock agent known to mankind
seriously, who is pushing this weird anti-fire-code agenda and why is it in slate
The journalist was lazy. The only 'statistics' offered is a graphic from the lobby against 2nd exits...that website's home page says:
"This website is a tool to make sense of the wicked problem of the second egress in Canada and prepare a building code change."
It is super biased, and the bigger issue is that it is impossible record what-if situations like how many minor US fires could have been major tragedies if they had a single stair instead of two, and firefighters could tackle a fire from two sides.
Just looking at one of their sources even states that rapid smoke/fire in stairways and vertical opens is a significant portion blocked-escape deaths
Trapped-by is not the same as "would have been saved by a second egress", if the fire traps you in your room for example. It has all structure fires.
This whole fire (and building) safety code problem is that it's driven by superstition instead of data. It mandates certain solutions instead of outcomes. (Eg. the railing spacings to prevent kids from being able to fall through.)
Many developed countries have similar outcomes without the same strictness of code, plus housing is so overregulated in so many ways it's no wonder that many people argue for shifting the set-point in these trade-offs in order to help more people to have housing.
Of course ideally society would address poverty so there trade-off between safety and other aspects would be just academic.
And in response to Grenfell, the argument is tenants don't like fire drills; just wow. Eventually everyone forgets the reason for regulations...is there a named law for this phenomenon?