Francis Scott Key Bridge in Baltimore collapses after ship struck it

[Gadfly]

New fear unlocked.

The bridge over the Houston Ship Channel is 175ft above the water. Now, every time i have to drive over that hump, I have to worry about an eight second drop to my death. Or, I survive the drop, only to drown in that nasty ass ship channel water. Crap. At least only have to cross it maybe 10 times a year.

[Borderland]

My question is why aren't tugs used for safety in areas where something like this could happen. I see tugs on ships in Puget sound but not sure what the protocol is.

[Lester Polfus]

My question is why aren't tugs used for safety in areas where something like this could happen.

Because it would add to the cost of all the cheap shit we buy on Amazon.

[Lester Polfus]

@Stephanie B, you were a black shoe, right? What would a warship do if propulsion was lost in a case like this where you’re in fairly shallow waters?

Not Stephanie, but I did plenty of time on Special Sea Detail.

The main focus on a US Navy or Coast Guard vessel is to stay “left of bang” and not become a vessel “not under command” at such a critical moment. My Coast Guard cutter had four engines. Two were big diesels and two were Pratt & Whitney gas turbines similar to what’s on a commercial airliner. The vessel also had twin screws with variable-pitch propellers and twin rudders. We also had a bow prop that dropped down out of the bottom of the ship that could be used for low-speed maneuvering.

The ship was highly maneuverable and could stop in a VERY short distance from a full bell by changing the prop pitch. When we practiced a crash stop, we had a safety briefing ahead of time and everybody had to be braced because you could no shit get your neck broken flying across a compartment.

When maneuvering in restricted waters, both diesels were online, and the two gas turbines were ready to be started fairly quickly.

The ship could be steered from the main helm, either bridge wing or the aft part of the ship. We could use the rudders in conjunction with the variable pitch props to spin a 378’ ship in a circle like a kid doing donuts in a Waffle House parking lot. If ALL That shit broke, we could steer the ship with a chain fall hooked up to the rudder shaft.

Also, in restricted waters, we had people standing on the bow ready to drop either or both anchors if things really went to shit. We could go from snapping photos of the harbor we were pulling into to dropping anchor in a few seconds on command if we had to. There was a crew of about 140 people, and we trained constantly for things to go wrong.


Contrast that to the M/V Dali, which has a crew of 24, a single-engine, and a single, fixed pitch screw. The rudder is very small compared to the size of the vessel. Even if everything is working correctly, they take a very long time to make even minor course corrections, and stopping distance is measured in miles. There are lots of single points of failure. If the engine quits or there is a problem with the steering gear, it’s basically a giant, low-speed, unguided projectile. The vessel HAS anchors, but I don’t know how quickly the crew can drop them. I’m also not sure how the physics works out trying to stop a vessel that size by dropping anchor.

The crew is trained to a minimum acceptable standard, and I’ve seen civilian mariners lose their shit at fairly minor things that would just be a day ending in “y” to a Coastie who was six months out of boot camp.

I’m not the least bit surprised this happened. I’m just surprised it doesn’t happen more often.

[Chance]

The first thing through my mind when I saw that video was, "Thank fuck that wasn't rush hour." It's a tragedy as it is, but at least it happened when traffic was minimal.

And I'm not surprised at the speed of the collapse. Bridges like that are big physics equations: you pull a string and everything reacts immediately. Perhaps someone with a civil engineering background can comment.

[43Under]

Cargo ships are bigger than they have ever been. A loss of power would mean loss of control then the river is in control. Bam.

That is a through route. As RJ observed this is going to create one heck of a traffic problem in the area for years. No quick fix.

Worse than the vehicular traffic impact will be the impact on shipping. The port of Baltimore will be closed until the wreckage of this bridge is removed. That looks like it'll take a while.

[Lester Polfus]

The first thing through my mind when I saw that video was, "Thank fuck that wasn't rush hour." It's a tragedy as it is, but at least it happened when traffic was minimal.

And I'm not surprised at the speed of the collapse. Bridges like that are big physics equations: you pull a string and everything reacts immediately. Perhaps someone with a civil engineering background can comment.

Yes. I saw the light traffic on the bridge and thought that it was a really lucky break at the time of day. It sounds like some transportation workers got the traffic shut down, too. if this had happened when the bridge was bumper-to-bumper it would be casualties in the hundreds.

Longer ago than I care to admit, I was part of some “What happens when a big ass ship hits a bridge” exercises. You essentially can’t design a bridge to withstand an impact from that kind of mass. Upthread TGS mentioned building breakwaters around the bridge piers. That’s the answer because then the ship runs into giant piles of rock, and not the bridge structure itself. Not all shipping channels are amenable to that kind of retrofit, even if there were the political and economic will to make it happen.

[Stephanie B]

@Stephanie B, you were a black shoe, right? What would a warship do if propulsion was lost in a case like this where you’re in fairly shallow waters?

If all control has been lost, I'd drop the anchor. Even losing propulsion, there's backup generators for stuff like steering. But once steerageway was lost, drop the anchor.

[Borderland]

We had a bridge collapse on I-5 just north of where I live. The superstructure was hit by truck with a trailer that was over the height limit. Several vehicles went into the river but nobody died. IIRC correctly the bridge was 75 years old and folded up like an accordian. Infrastructure replacement is still being neglected on many bridges in this state. I believe the term the DOT used was functionally obsolete, not meeting current design standards.

So how old was that bridge? Why did it not have walls protecting the piers? That's pretty common for bridges around here. Astoria bridge over the Columbia R.

[Stephanie B]

Yes. I saw the light traffic on the bridge and thought that it was a really lucky break at the time of day. It sounds like some transportation workers got the traffic shut down, too.

I heard through the grapevine that the ship sent out a Mayday, warned that they might hit the bridge and the cops were able to stop most of the traffic.