1400 cars engulfed in multi-story carpark fire

[ScottyUK]

https://news.sky.com/video/car-par-blaze-leaves-trail-of-destruction-11191692

Thankfully no lives lost in the fire itself.

Quite apart from the scale of the vehicle loss, I'm a little surprised by the severity of structural damage to the car park itself. The floor looks to have only a single layer steel mesh reinforcement, and large areas of floor have simply burnt away. Is this kind of damage expected in a fire of this type?

 

[berkshire]

Scotty,
I noticed the story in todays Daily Express , with an editorial that sprinklers would have confined the blaze, and wondering why none were fitted.
B.E.

You are judged not by what you know, but by what you can do.

 

[3DDave]

I wonder how much plastic fuel tanks contributed to this fire. I saw a video of a street car fire where the leaking fuel from one car ran down the gutter to ignite the next car in line, forming a domino effect.

 

[zeusfaber]

I may hear more about this soon. My daughter was there handing out bacon butties to the evacuees from the nearby hotels.

A.

 

[dik]

Time for a review of code requirements for storage garages (aka parkades) due to the larger amounts of combustibles in construction of autos.

Dik

 

[cooperDBM]

The floor seems to be formed of double tees, which would be common. The thin top flange is only reinforced with mesh for transverse bending. The stems which you can still see in place contain the main reinforcing, prestressing strand. I'm surprised to see the stems hold up so consistently. Perhaps FRP strands?

 

[EdStainless]

Perhaps not enough heat to effect the tension strands deep within the "T"s.
The structures around here that I park in don't have sprinklers as such, but a form a deluge system.
Part of the reason may be that it is very cold here in Milwaukee and a spray would just be snow flakes in a fire.

How much burning sludge was running out of the structure?
Those cars on the top that look intact are probably totals as well, I am guessing that wire insulation and under car plastic/rubber parts are shot.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube

 

[Ingenuity]

I'm surprised to see the stems hold up so consistently.

Me, too.

Perhaps FRP strands?

What makes you think that? FRP has a glass-transition temp of about 180F. I would think they used regular 7-wire steel strand, with adequate concrete cover etc.

 

[dik]

CooperDBM:

Not likely FRP; this material is generally more susceptible to heat degradation.

Dik

 

[cooperDBM]

Thanks Ingenuity/dik, I know little about FRP or fire. Just surprised that the steel held up so well. Given the loss of the top flange I wouldn't have thought the cover to the strands remained intact.

 

[JStephen]

On the sprinklers- is that even done in a unheated structure? Seems freezing would be a major problem there, assuming a somewhat cold climate.

 

[davidbeach]

Sprinkler lines can be charged with glycol or they can be dry systems. In both cases the water is released into the pipes once a head fuses and the pressure drops.

 

[ScottyUK]

We routinely provide sprinkler / deluge protection to plenty outdoor assets like transformers, petrochemical pumps. Freezing isn't a problem because the discharge pipework is a dry system until the deluge is actually released. I think the case for sprinklers is stronger for occupied structures such as London's Grenfell Tower which was destroyed in the tragic fire of 2017. It will be interesting to see the recommendations from the Public Inquiry into that event.

 

[EdStainless]

I have talked to facilities people here in Milwaukee. The garage that I park in is attached to a building by walkways and it has a dry deluge system in it. He said that at the time that his one was built the city didn't require it, but the insurance company strongly urged them to install it (I am sure that they told them the difference in rates).

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube