The 10mph travel speed under heavy escort seems like car crashes wouldn't be fatal.

The Dali hit the Key Bridge at under 10 mph.

The kinetic energy of a 415000 kg object going 4.5 m/s is about equivalent to a 2000 kg object going 65 m/s = 145 mph.

Something that big in water trying to stop vs something on the ground with lots of friction contact with the ground is two entirely different things.

I'm way less concerned about this thing hitting something moving at 10mph than I am someone else driving their thing into this bigger thing. It would have to be a massive thing to budge it.

Oh sure, I don't mean to imply that this "Super Load" poses a threat to major infrastructure. I was simply pointing out that "under 10 mph" is not necessarily a guarantee of safety, and that very massive objects are tricky to handle in lots of ways, mostly due to inertia and balance.