39 Comments

Great explanation. I know everyone wants to call it sabotage but weird accidents do happen. I have much more confidence in your analysis than many of the others I’ve read!

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I'm nobody...but I completely agree with your explanation and in particular the influence of bank suction and the bad luck of "last rudder position" during power failure and the influence of the presence of the Curtiss Bay channel. Nice that you had the opportunity to experiment in a simulator.

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"We need a full investigation of why the power went out and why it took so long for backup power to be restored."

That's for sure. And if we don't get it that would surely be circumstantial evidence that "something is happening here, but you don't know what it is, Mr. Jones".

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Excellent explanation.

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Bank suction.

Something new I had not considered.

Thank you for the dose of humility!

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Did you know that there were supposedly 2 other bridges that were struck that day? The Valleyview Bridge in Ohio and the Indian River Bridge in Delaware. Now today there has been another one in Oklahoma. I don't believe in coincidences and certainly not 4 that resemble the same incident so closely related in time!

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One was a mulch fire under the bridge, one was the ocean breaching over a dune barrier.

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If this were the only strange thing that had been happening over the last four years, I would buy this explanation. But this is one of WAY TOO MANY STRANGE THINGS FOR IT TO BE A MERE MISTAKE.

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Yeah it doesn't look good. I understand why people are inclined to believe this is an attack - and it very well could be.

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My husband was a navigator in the navy, USNA graduate, masters from MIT. My instincts said, "Something is wrong with this picture". As a trained navigator, he said, "There was no way this would happen just because they temporarily lost control, as they had to turn INTO that area of the bridge support." From either perspective - there is no way this wasn't planned...

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I think your husband is correct. They did turn into the bridge. The question is, was it intentional or did it happen because the rudder got locked in place once the power went out. We see the turn start commencing during the first power-outage. It's not possible to turn the ship without power to steering, so the helmsman already had to have the wheel turned before the power went out.

I can tell you from years of experience driving ships through harbors that it's very common to have ten degree rudder inputs left and right while transiting a harbor channel in order to follow a course.

The part that concerns me is not the turn into the bridge, but the fact that they were unable to correct the turn when power came back on the second time. I would think that once power came back, they would already have the wheel turned over hard to port.

As another poster said, it appears that they may have never regained steering control.

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Did they know that the yaw moment *applied* would appear to be an attempt to avoid a collision, to the untrained eye, but would instead result in a collision?

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Good work everyone. What was the wind speed and direction? What was the tidal current speed? Was this ship coasting out to sea on the tide flow? Dropping anchor and the ship moving over it may have helped pull the bow to starboard in that video. "The question is, was it intentional . . . ?" Need more data before convicting the ignorant.

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Winds calm to six knots from the south, current was a few hours from slack tide, probably a 1 knot outflow if I had to guess, ship appears to have lost power then restarted engines, port anchor was dropped which would pull the bow to port.

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Yes, to port under normal conditions. In this case, it seems that the ship could have passed over the anchor and chain to get pulled from under the forward hull from starboard position of the overtaken and dragging anchor. Thanks greatly for the current and wind.

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The ship turned continuously to starboard right up until just moments before impact. I don't think it's possible that the ship passed over the port anchor chain in a way that would pull the bow to starboard.

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OK, do you see the anchor drop at second 3:59 in the video, or is that something else? Wikipedia had the accident timing posted. 01:27:04 Pilot orders port anchor be dropped; issues additional steering commands. Coincide video timing with Wikipedia posted timing of events. The stern could be moving over the anchor chain into the collision. It looks like a low budget lack of love for ship shape.

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Timeline

This timeline is based mostly on NTSB's preliminary timeline of events from the ship's VDR and the MDTA Police log.[93][94][95]

Time

(a.m. EDT) Event

00:39 Dali departs Seagirt Marine Terminal[96]

01:07 Dali enters Fort McHenry Channel[96]

01:24 Dali underway at a heading of ~141° at ~8 knots (9.2 mph; 15 km/h)

01:24:32 The lights go out on Dali[54]

01:24:59 Total power failure; propulsion is lost. Multiple audible alarms; VDR ceases to record ship systems, but continues to record audio

01:25:31 The lights on Dali come back on[54]

TBD Verbal rudder commands are recorded by VDR

01:25:40 Dense black smoke begins to pour from Dali's funnel[54]

01:26:02 VDR resumes recording ship systems

01:26:37 The lights go out again on Dali[54]

01:26:39 Pilot requests tugboat assistance, the first signal of distress

TBD Pilot association dispatcher informs the MDTA duty officer of Dali's lack of steering

01:27:04 Pilot orders port anchor be dropped; issues additional steering commands

01:27:09 The lights on Dali come back on again[54]

01:27:25 VHF mayday: Pilot reports total blackout and that Dali was approaching the bridge, the second signal of distress

01:27:53 MDTA duty officer dispatches units to close the bridge

01:28:09 Last moving vehicle leaves the bridge[54]

01:28:49 Dragging anchor, Dali at ~7 knots (8.1 mph; 13 km/h) first allides with the bridge

01:29:00 Dali continues dragging anchor; first sounds of allision recorded by VDR

01:29:27 MDTA reports collapse of bridge

01:29:33 Sounds of collapse cease

01:29:39 Pilot reports collapse of bridge

01:29:51 All vehicular approaches to the bridge reported shut down

Thank you Wikipedia.

Impact force 170,000,000 newtons = 38,000,000 lb ft

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Because the ship is continuously turning to starboard until right up to the collision, it's not possible that the port anchor chain played a role in turning the ship to starboard. It would have slowed the turn to starboard and assisted with the turn back to port. By the timeline, it doesn't appear that steering was ever regained, which is very unusual. Steering should have been regained during each time the lights came back on, even if it was just under the power of the emergency generator.

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Another engineer commented that when starting the engines in reverse the propellor would have a paddle wheel effect driving the stern to port pivoting the bow towards the bridge.

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That depends on which direction the screw is turning. It can have that effect, but that effect can also be countered by some rudder input.

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It's a shame that there was a loss in the recordings . . .

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I'm guessing that no bow thrusters could have been applied with enough thrust force to the starboard bow to move her back on track to the port side glide path. She is large and in charge without stern rudder direction and screw rotations of counter rotating efforts. Too much confusion.

Time clock to impact ran to "0" ,

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Yeah bow thrusters are electric and take a full load on the generators to run. They don't work on the standby generator. And even if they had power to run the bow thruster, it's not effective when the ship is moving beyond three knots or so because the water is just blowing past the thruster to quickly for it to work effectively.

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With as much as these ships cost to build and with more safety items developed for top side innovations readily accessible to crew. Maybe the time has come to reinvent the bow thruster for maximum mobility in harbor use for high winds docking or just moving the bow at a much quicker rate. I'm sure it's been discussed. Million dollar yachts have them.

Great explanations on what may be the crux of missing the target lane to open sea. A+

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The question then becomes, how much of this did "they" know?

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“If a nefarious actor was intending for the ship to hit the pier of the bridge, knocking power out to the ship is the last thing you’d want to do. Without steering, there’s no way to intentionally direct the ship into the bridge.”

This is an important point. However - if they wanted it to look like an accident, they succeeded. If the target was not hit, it was just malfunction with a near miss.

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I'm willing to wait for a report on what caused it. Not that I trust the NTSB at all, but without any evidence, this looks like an accident to me. I've actually been on a warship that has lost power just like this ship did while at sea. It can happen.

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Now I keep wondering WHY it lost power? What causes that? I heard..dirty fuel? Or can someone mess with programming....leave a bug...virus....? Thanks for your expertise. You answered lots of basic questions for us landlubbers.

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That's the million dollar question. Could it be a hacked virus? I mean anything is possible. These ships aren't tied to the internet though. Hacking the power system on a ship would be a pretty impressive feat if someone was able to do it. You'd likely have to get physical access to the ship's computers to pull it off. Again, I think the difficulty of hacking the ship means it's more likely this was some kind of accident.

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It was mentioned that ships use low sulphur fuel in US waters and cheaper stuff in the open ocean. Changer over difficulties?

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Fuel contamination is definitely a top culprit, but that is also easily tested for. The longer this goes on without the NTSB saying what happened, the worse it looks. They need to figure out what happened and tell us.

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Except…didn’t the ship undergo some sort of maintenance while in port? If so, this would enable someone to mess with programming…??

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Anything is possible, but ships are constantly undergoing maintenance in port, especially older ships like Dali. It's more likely that the they broke something than it is a hacker maliciously attacked the computer system.

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Thank you, Michael.

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Is that another boat sitting to the right side of video, under the other bridge support pillar?

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No, that's a protective barrier. There are four of them, one in front and behind each bridge pier.

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