Francis Scott Key Bridge collapse in Baltimore

So, having spent some time navigating the NJ back bays on small craft, there is this thing that happens when you are in a channel and you cross a junction with another offshoot channel. It's not intuitive because the opposite happens than what would be expected.

I'll use left and right instead of port and starboard to be less confusing.

You're in a channel, piloting your boat along and an intersecting channel from the right comes up. When you hit that intersecting channel, the boat will want to start veering towards the right. That's counterintuitive because people see channels as a flow and they aren't. There isn't a current coming out of the channel.

What happens is, when you are in the channel, your bow wave pushes water out of the way and off to the sides. This creates a rippling pressure wave that travels down each side of the boat, evenly. If your draft is shallow enough, the intersecting channel doesn't really affect you except maybe bouncing over some oblique waves. If you draft enough that your hull is deep enough to be in the channel, the intersecting channel will affect you. See, that bow wave travels down the sides and if you watch a wake, you see it bounce back at the opposite angle that it hit the shore or pier or bulkhead or whatever with. The channels sides will do the same thing. If you are in the center of the channel, your bow wave is bouncing water off the channel sides at an equal rate and if your boat is long enough, the reflected waves are hitting your hull. But they are hitting each side evenly so they are canceling each other out. But they also make it more difficult for a boat that is in the channel to leave it if it is drafting enough to have the hull below the top of the channel sides.

When the channel comes up on the right, you now lose the wall of the channel on the right and your bow wave on the left is now reacting to your hull more than the right because the right side bow wave is no longer hitting the channel side and has a longer distance to be reflected back to your hull. This changes the pressure balance and means there's more pressure on the left side of your hull now. This is why the boat wants to veer towards the intersecting channel. This is easily correctable and only happens briefly and you just power through it with minor correctional moves on the rudder(s) and/or prop(s).

In the videos, the ship loses power for whatever reason. Once it loses power, it is still moving forward but there's no longer enough water flow over the rudders to be effective at turning. When you look at the map of Baltimore Harbor, the Curtis Bay Channel intersects the main channel just before the FSK Bridge. It would be on the starboard side of the ship and that was the direction it started veering when the power went out.

When the power came back on, it seemed like it was trying to correct but, like I said before, leaving the channel is hard to do because of those wave pressures. It's even hard to turn in the channel sometimes, especially at low-tide when the channel isn't as full of water and your ship sits lower in it. You have a significant amount of force to overcome to maneuver and if you are already off course, you have to overcome the correction before your maneuver around an obstacle can start to happen. The shipped seemed to be in that stage when it lost power a second time. It veered into the bridge support hard when it lost power the second time and that is, quite possibly, due to it hitting the lacking dolphin and the side of the channel. That would pretty much do the same thing as sticking a paddle in the water on one side of a moving canoe. You will draw the bow of the boat to the side of the resistance whether it's a paddle in the water or hitting the side of a channel.

With roughly 100K tons of inertia, that's a lot of junk to stop and turn.

Also, on ships that large and long, the rudders don't do much without the props spinning. So even if the rudders were turned, they would not have been turned towards starboard, they would have been turned towards port and if the engines did come back up and start pushing water over the rudders, it would have veered to port and run aground. It never did which makes me think that once the power went out the first time, it never regained propulsion and a collision was a sure thing at that point.

This guy's video actually illustrates what I'm talking about quite well.

https://youtu.be/TlIhoxIxM30?si=qJjmFx-Zp2Em0s_h