This, 100%. I forget the specific numbers but regardless, the kinetic energy of a thing with that much mass, even moving at a very slow speed, is off the charts. Designing a bridge or protections for a bridge to survive that would at a minimum be cost prohibitive, if even possible with today’s materials and construction technologies.

Doesn't mean that nothing can be done. https://www.ntsb.gov/news/press-releases/Pages/nr20250320.as...

> The NTSB found that the Key Bridge, which collapsed after being struck by the containership Dali on March 26, 2024, was almost 30 times above the acceptable risk threshold for critical or essential bridges, according to guidance established by the American Association of State Highway and Transportation Officials, or AASHTO.

> Over the last year, the NTSB identified 68 bridges that were designed before the AASHTO guidance was established — like the Key Bridge — that do not have a current vulnerability assessment. The recommendations are issued to bridge owners to calculate the annual frequency of collapse for their bridges using AASHTO’s Method II calculation.

Letters to the 30 bridge owners and their responses https://data.ntsb.gov/carol-main-public/sr-details/H-25-003

This is essentially the same thing that happened with Fukushima Daiichi. The organization running it failed to respond to new information.

Energy doesn't mean squat without a time component over which it's dissipated.

Stopping a car normally vs crashing a car. Skydiving with a parachute vs skydiving without a parachute.

For something like ship vs bridge you have to account for the crunch factor. USS Iowa going the same speed probably would've hit way harder despite having ~1/3 the tonnage.

Nah, we definitely can.

Plan the bridge so any ship big enough to hurt it grounds before it gets that close. Don't put pilings in the channel. It's just money. But it's a lot of money so sometimes it's better to just have shipping not suck.

Alternatively, the Chunnel will almost certainly never get hit with a ship.

> Plan the bridge so any ship big enough to hurt it grounds before it gets that close.

Have a look at the trajectory chart that I posted upthread and tell me how in this particular case you would have arranged that.

Yet another idea: if a ship's motors fail, have a ship ready that can push it in the right direction, in time. Probably need 2x the amount of horsepowers to make up for lost time, but it's not impossible.

Yes, that's called a tug and in plenty of harbors a vessel of this size would not be permitted to do close quarters maneuvers without the mandatory assistance of one, or in this case more likely two, tug boats of a certain minimum size relative to the size of the vessel.