Thread by @GreggFavre

After my last tweet, I got a couple DMs asking firefighting related questions about the #NotreDameFire.

I -like most of you- are watching from a world away. But if you’re interested in some profession specific things I’d note/be concerned of, you can follow this thread.

The first issue is how old churches are built - heavy timber construction with large open spaces and very few (if any in a church like #NotreDame) fire stops.

A firestop is a passive fire protection system made up of various components and used to seal openings in buildings.

If the fire started high on the structure, there is a chance that Paris Fire can save the walls and unimpinged areas of the Cathedral.

But the roof has basically been surrendered at this point. The peak, the lack of access and fire spread means almost certain loss.

In firefighting there is something called a "trenchcut" that basically opens a large roof up from peak to gutter, allowing space to stop fire spread.

Given the peak of the #cathedral roof and advanced fire conditions, this is an unlikely option in the main area of the building.

Even if arial waterways (think hook and ladders with prepiped hoses) could reach the roofline, it is difficult to see how they would get an angle that would get water on the fire - its just too high.

So this means you have to put firefighters inside...

Inside is a whole other problem. The primary option is large 2.5" fire hoses.

These are heavy, difficult to maneuver and against a fire like this, largely ineffective.

This option also means placing responders on the inside as the roof is falling down around them.

And we aren't talking shingles.

This is heavy timber construction. Often 12"x12" in old churches, perhaps bigger in a #Cathedral this old.

Another concern is accountability.

Life safety is always the first priority, even in historic landmarks.

#NotreDame was undergoing a renovation. This means that there were more people there than normal.

Is the #Cathedral staff all out?
The construction workers?
Visitors?

If unaccounted for, where were they and how many? What does a rescue task force look like? How many responders do you place in additional harms way for unconfirmed reports?

I don't have these answers at a distance, but the responders on scene are asking them and forming plans.

And lets pause to remember how fires actually burn.

You need oxygen, fuel, heat and a chemical chain reaction.

If you take any one of these away (cool material, remove fuel or oxygen, or interrupt the CCR) the fire will go out.

Removing the fuel is a no go. Churches have no shortage of things to burn.

The heat that a fire this size is putting off is tremendous. Little options for interrupting that.

The chemical chain reaction is off to the races. That horse left the stable in the first five minutes.

That leaves the oxygen.

Unfortunately, even if the roof had not burnt off, churches are nearly impossible to control ventilation in.

Their design is to be open and airy. Great for Sunday worship, terrible for managing fire spread.

Finally, I'd be worried about construction materials not usually found in churches (since it was under renovation).

Things that can explode, things that don't like being hit with water, Hazardous materials that can run off / go airborne, etc.

Finally - especially this deep in to the fire - you have to be thinking about collapse of some or all of the structure.

The steeple and roof have to GO somewhere and its no guarantee that its straight down.

The walls of #NotreDame are stout, but if weakened by fire and roofing timbers could come down.

Are the streets in the collapse zone cleared? Of both onlookers and responder/trucks? Any other buildings threatened?

If a wall of fire comes down what the plan to fight THAT fire?

My gut (and experience) tells me that best case scenario her is something similar to Orthodox Cathedral of St. Sava Fire in NYC.

At least for the main part of #NotreDame that has been affected by fire.

Should be noted that while St. Sava is huge in its own right, it is dwarfed buy #NotreDame.

Depending on how hoses are placed, current wind conditions, responder access and water supply, damage could be significantly more, or less (- helpful I know...)

One thing that #NotreDame has in its favor - @PompiersParis are world class firefighters.

I saw their work when I served on a board for the @IAFC & they have as strong, dedicated and skilled responders as you'd find anywhere in the world.

And my thoughts are w/ them all today.

Finally, as a firefighter, as a Catholic and as a human this fire is heartbreaking.

#NotreDame is a beacon of both faith and the human spirit. I wish all on scene a safe evening and comfort in knowing their best effort was applied.

Thanks for following along.

This blew up a bit. I am glad so many of you found this informative.

I don’t have a SoundCloud, but I do have friends who are stepping to the line every day to do dangerous work.

If you chose to support @BackStoppers, we would be grateful.

backstoppers.org/donate/

A final note.

Asked on @fox5dc this am why an air tanker was not used.

This application is an inexact science. More importantly, water is HEAVY. It would be the equivalent of dropping 3 tons of concrete at 150 miles/hr.

Could have killed responders &/or collapsed the church.