Anons, StructuralFag here, with commentary on the ND fire.
I don't know what Ausfags do with wood in Oz, but this sounds like bullshit:
“Once these massive timber structures start to burn, they almost never can be stopped,” said Jonathan Barnett, an international fire safety authority at Basic Expert in Australia. “We focus on their masonry walls and forget all the massive timber within.”
Comes from this NYT article:
https://www.nytimes.com/interactive/2019/04/15/world/europe/paris-notre-dame-fire.html
Anyway, this is in direct conflict with the French architect saying he couldn't believe the timbers burned up so hotly and thoroughly.
This forced me to dig deep into the memory banks. Heavy timber construction is not something you come across very often in my neck of the woods (kek), so there may be something I'm not considering here, and I certainly don't have the specifics of the timber members on ND, but here ya go, from the American Wood Council:
"The superior fire performance of timbers can be attributed to the charring effect of wood. As wood members are exposed to fire and the wood begins to burn, a char layer is formed. The char layer acts as an insulator and protects the core of the wood section."
https://awc.org/codes-standards/publications/tr10
"The excellent fire resistance of heavy timber framing has been demonstrated in many building fires over the years. Building codes recognize its superior performance by allowing larger sizes for buildings of this type. Heavy timber construction is also recognized in fire insurance rating schedules through lower rates."
https://www.awc.org/pdf/codes-standards/publications/wcd/AWC-WCD5-HeavyTimber-ViewOnly-0402.pdf
When designing anything wood, we follow the AWC code, so they ain't no shills, anons. I agree with the French architect, it stinks.