[Goose]

Here's the damage I was talking about:


The gravel(?) between the cement ties is missing.  I'd think this means that something under the gravel burned through to some void.   This would allow the burning fuel to get down to the span's main structural component.  I presume that is some sort of steel structure.  The damage to that might not be as obvious as the deformed rail, but the heat could alter the strength of the steel. (Fire effects on steel;  fire effects on concrete)

I see what you mean, but that to me just looks like a bad tamping job near that tie. I agree the ballast doesn't reach the top of the tie, but I think it is still present. The ballast is about foot thick. There is no place for it to go. It is gravel, but it is pretty well packed (tamped) down. Underneath that there is a full deck wide concrete slab. That slab is rigid end to end. There are no voids. That is before you hit the so called "Ballast Deck" which is where the steel starts. I doubt much heat, let alone fire, got through there. This is from https://www.arema.org/files/pubs/pgre/PGChapter8.pdf. Take a look at figure 8-7 on page 333.

Obviously, it needs inspecting, but if they are running trains on the other track they have presumably done that and didn't see anything serious.

[Goose]

Here's the damage I was talking about:


The gravel(?) between the cement ties is missing.  I'd think this means that something under the gravel burned through to some void.   This would allow the burning fuel to get down to the span's main structural component.  I presume that is some sort of steel structure.  The damage to that might not be as obvious as the deformed rail, but the heat could alter the strength of the steel. (Fire effects on steel;  fire effects on concrete)

I see what you mean, but that to me just looks like a bad tamping job near that tie. I agree the ballast doesn't reach the top of the tie, but I think it is still present. The ballast is about foot thick. There is no place for it to go. It is gravel, but it is pretty well packed (tamped) down. Underneath that there is a full deck wide concrete slab. That slab is rigid end to end. There are no voids. That is before you hit the so called "Ballast Deck" which is where the steel starts. I doubt much heat, let alone fire, got through there. This is from https://www.arema.org/files/pubs/pgre/PGChapter8.pdf. Take a look at figure 8-7 on page 333.

Obviously, it needs inspecting, but if they are running trains on the other track they have presumably done that and didn't see anything serious.