Thoughts about the ship that wrecked the Key Bridge

[PJMcK]

One detail I haven’t seen anywhere is the speed of the ship when it hit the bridge. The Dali displaces (basically weighs) 95,000 tons when empty. Although she can carry 10,000 containers, on this voyage there were 4,700 of them. I don’t know the cargo’s weight but when added to the ship’s size, that’s a huge chunk of mass. In this case, mass X speed will eventually be calculated for future bridge re-construction.

When sailing, I’ve encountered many ships of many different kinds. Their crews are generally professional and polite. They travel at a pretty good speed and in the open seas, 20-25 mph is pretty fast. It can take these ships as much as ten miles to come to a full stop! That’s how massive they are. Since the ship was still in the harbor, my guess is the Dali was moving around 5-10 mph, still a lot of energy to hit the bridge

My next thought is about responsibility. Who is at fault? The ship’s captain is responsible for the sea-worthiness of his vessel. If the reports of serious electrical problems prior to departure are accurate, why did the captain set sail? Was he under pressure from the ship’s owners? Did the owners skimp on maintenance? The pilot appears to have done everything as well as could be expected on a crippled vessel. Was the bridge design at fault? There weren’t any barriers around the piers that held up the bridge like there are on most bridges. (These fender systems actually help navigate to the center of the bridges’ transit points.) are there other inflection points to consider? I suspect the lawsuits will be plentiful.

In the end, bad luck played a role, too. If the ship had lost power five minutes later, it would have cleared the bridge and entered the Chesapeake Bay. It would still be a serious situation but in relatively open waters, tug boats could have come to the Dali’s rescue.

This was a terrible catastrophe and we’re fortunate that so few sadly perished.

[carpetbagger]

1. I heard 8 knots (9 mph). Nt

[woodsprite]

2. When it was in the channel it

Had picked up speed to 7.6-8 knots. When it hit the bridge, it had slowed down to about 1.8 knots. There is a maritime historian (Sal Mercogliano) that goes over this on his “What is going on with shipping” YouTube channel.

[Cattledog]

3. "No bridge pier can withstand being hit by a ship the size of the Dali".

Benjamin W. Schafer, Professor of Civil and Systems Engineering at Johns Hopkins University.

[Polybius]

9. It apparently grazed it though

It wasn't head-on.

[elleng]

4. 7-8 mph

It appears electrical problems were known for some time prior to 'departure,' which likely will be examined as time goes on.

https://www.democraticunderground.com/100218812409

[BigmanPigman]

5. The naval engineer sounds pretty skeptical

that this was all due to the power and propulsion turning off...
"They were already really too close. The unfortunate thing is they veered to the right," Perry said. "If they would have been in the channel with the rudder straight ahead, they would have continued drifting straight ahead and gone under the bridge."

I heard an engineer speak soon after it happened and he explained what he saw on the video and what is "normal" and if the ship went into reverse in an attempt to slow it down that could have made the ship go off a course a tiny bit instead of going straight. If they kept cruising it would have missed the bridge.

[Polybius]

10. Speculation is that the anchor made it veer right

Investigations will take a while though

[BigmanPigman]

11. That is what I heard

From the same naval guy. He said one had been dropped but he couldn't see the other side of the ship. He also wonders if it was dropped before or after the crash. But then after
I heard him someone else made a statement that no anchor was dropped at all.

Yes, it is going to be a big investigation. I have the feeling it'll be both the fault of the crew and the ship's maintenance.

[no_hypocrisy]

6. Communications between the captain and the owner of the vessel will need

to be examined. Especially what the owner's intentions were after learning about the prior electrical problems. Did the owner insist that the vessel continue its voyage despite knowing that repair was needed?

[maxrandb]

7. A couple of things

Catastrophic engineering failure could cause loss of rudder control, bow thrusters (if the ship had them), comms, etc. It's a nightmare.

It takes a long time for those ships to stop, reverse, or change course, and currents, tides and winds can even impact ships of this size. If you have a chance to see a cargo, or big Navy ship at anchor, you will notice that the winds and currents will cause those ships to swing around the axis of their anchor.

What I don't understand is the lack of tugs alongside. Maybe the new standard needs to be that tugboats remain alongside until ships are clear of major infrastructure.

[OAITW r.2.0]

8. The number of containers....

If this ship is capable of handling 10,000 containers, I don't know where you'd put them. It appears that the ship was fully stacked with containers, I can't believe they could put another 5300 containers on that ship.

[malaise]

12. You know it's thee efficiency of the workers following protocols

Why so few lives were lost.
Truth is 1970s bridges were not built for these massive cargo ships.