This recent tweet has by far the clearest footage of the aftermath, shot in daylight from the edge of the destroyed bridge deck; the actual extent of the destruction isn't fully apparent until the end.
Honestly somewhat surprised there isn't a Russian information blackout on this since it seems to me like a major logistic setback.
Yes, you can get “cantilevering”. When you remove the structural support at one part of the span, the segments of the span will react to their static gravity loading and this can cause them to flex and/pivot depending on their rigidity. You get one side pulled down by it’s weight which will then lift up the over side and a lot of bridges are not designed for a tension load lifting the bridge deck up, this can cause secondary failure points away from the primary damage and you can definitely see this effect if you look at photos/videos of other bridge failures.
I saw people arguing that the explosion must have come from below (eg a boat) because parts of the damaged doad deck had been lifted off the spherical bearings of the supporting piers/pylons. Is it possible this could also be attributable to the 'tension load lifting the deck up'?
That’s also an important thing a lot of people don’t think of! The kinetics of lightweight materials in the vicinity of an event like an explosion or other violent events is quite surprising. It often masks the underlying prevailing forces because the more visible things obscure our view.
Also, while some people on the bridges almost certainly died in the explosions, there's no actual gore (or any visible people at all, really) in the videos.
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https://twitter.com/Osinttechnical is covering this pretty well.
Russians are claiming it was a truck bomb and this is backed up by recently posted footage of the truck disappearing into a ball of doom.
Videos of the explosion(trigger warning: people are dying in these videos):
https://twitter.com/Osinttechnical/status/157863228417313177...
https://twitter.com/Osinttechnical/status/157863322104184422...
Update: Looks like it might have been a boat
https://twitter.com/Osinttechnical/status/157863387784927232...
This recent tweet has by far the clearest footage of the aftermath, shot in daylight from the edge of the destroyed bridge deck; the actual extent of the destruction isn't fully apparent until the end.
Honestly somewhat surprised there isn't a Russian information blackout on this since it seems to me like a major logistic setback.
https://twitter.com/JimmySecUK/status/1578639387843526656
The Russian media has been instructed to talk about this as a terrorist attack, the bridge is damaged and already being repaired.
I wonder if the t-word was chosen to suggest that the bridge wasn't a legitimate military target and portray the attack as an unlawful escalation.
Can single explosion collapse two parts so far away from each other or we're talking about two explosions?
If you look frame by frame, it doesn't look like explosion comes from those cars at all.
It looks more like military strike where bridge is hit quite far on the right hand side (or boat, whatever) - the explosion is clearly underneath.
Yes, you can get “cantilevering”. When you remove the structural support at one part of the span, the segments of the span will react to their static gravity loading and this can cause them to flex and/pivot depending on their rigidity. You get one side pulled down by it’s weight which will then lift up the over side and a lot of bridges are not designed for a tension load lifting the bridge deck up, this can cause secondary failure points away from the primary damage and you can definitely see this effect if you look at photos/videos of other bridge failures.
I saw people arguing that the explosion must have come from below (eg a boat) because parts of the damaged doad deck had been lifted off the spherical bearings of the supporting piers/pylons. Is it possible this could also be attributable to the 'tension load lifting the deck up'?
Oh absolutely, that sort of motion on the spherical bearings is exactly the sort thing I was talking about when I mentioned pivoting.
But it’s hard to be too much more specific without more information about the design of the bridge than I personally have
I meant more the first seconds of explosion where everything in the air moves doesn't indicate origin at the bridge itself.
That’s also an important thing a lot of people don’t think of! The kinetics of lightweight materials in the vicinity of an event like an explosion or other violent events is quite surprising. It often masks the underlying prevailing forces because the more visible things obscure our view.
I've never seen explosion which creates obscure counter intuitive trajectories.
Bridge must be one of the most open-space environments you can imagine.
If it's built badly enough, probably. And this is Russia and the bridge is hastily built political project.
Meaning we won't know without more data.
Boat tweet deleted as "too speculative"?
Also, while some people on the bridges almost certainly died in the explosions, there's no actual gore (or any visible people at all, really) in the videos.
Not much more speculative than the truck. Here is another view (can't vouch for the source):
https://twitter.com/L_Team10/status/1578642087284998144