This is a place to collect some data and images related to the Baltimore Scott Key Bridge being dropped by the MV Dali ship. It has come about since Canadian Friend has an assertion, based on a video from far away with a long telephoto lens, that somehow the track indicated by the AIS system is not correct.
It is my assertion his claim is an error. That the AIS Data is ACCURATE, the ship must be in the dredged channels (and nowhere else since the 50 foot draft of the ship is about double the depth outside of the channels), and that the long telephoto lens compresses the apparent distances and makes the ship look flatter, hiding the actual motions in the film behind a perspective illusion.
So here’s some data to help illustrate things. These have C.F.’s claims and assertions on them. They are his creation sent to me in email:
CF baltimore ship bird eye 2b with drawings and notes
CF baltimore ship bird eye 3 with drawings and notes
At this point, we swap over to my interpretation of things.
From this video: https://www.youtube.com/watch?v=N39w6aQFKSQ
posted in this comment by C.F. https://chiefio.wordpress.com/2024/03/05/w-o-o-d-5-march-2024-super-tuesday-tds-eu-pokes-the-bear-zinc/#comment-169621
I’ve taken a few screen shots.
A detail to notice in the left AIS Track panel: The indicated length of the ship, that green rectangle with a pointy bow in the channel, is clearly about the same or a bit longer than the width of the channel. That is accurate. The ship is just under 1000 feet long, and my “thumb measure” using the map is that the channel is about 750 feet wide. The ship can not go sideways in the channel, and can not leave the channel (more on that below, but outside the channel is about 1/2 the needed depth).
The right side is the view that C.F. fixates upon. It is a long telephoto lens, located far away near or on shore (not where he speculates). He “sees” a ship going left to right as he “can see the windows on the side”. BUT, notice you can also see the front of the ship… The brightly lit area is the FRONT, and dead in the middle is the central light. In reality, you are seeing this ship from about a 45 degree angle and you are seeing BOTH the front and the side. You are NOT seeing the ship “from the side”. But telephoto perspective flattens depth so both the front and the side look to be in about the same plane. In reality, that front is about 160 feet wide, and that “side” is about 1000 feet long. Yet look at it. The side measures about 3 x the front. That’s only about 400+ to 500 feet (measured via my little finger nail ;-)
You can not see, that in 3-D, the ship extends out of the picture to the rear by a LOT. It “looks like” it is just moving left to right in a flat plane. That’s the telephoto perspective flattening depth. It is used a lot in portraits and in view cameras for pulling distant items “close” to near items into a more ‘painting like’ perspective.
In the background, you can see a bunch of cranes with lights. That’s the Dundalk Marine Terminal on the far side of the bay and “upstream” from the bridge (map below). This can locate the approximate location of the camera as a line from Dundalk through the impact point will lead to the camera location. Also note the “telephoto perspective distortion”. Lights at Dundalk look large while the giant ship looks smaller in comparison, and all of them look closer together.
https://en.wikipedia.org/wiki/Perspective_distortion
Compression, long-lens, or telephoto distortion can be seen in images shot from a distance using a long focus lens or the more common telephoto sub-type (with an angle of view narrower than a normal lens). Distant objects look approximately the same size – closer objects are abnormally small, and more distant objects are abnormally large, and hence the viewer cannot discern relative distances between distant objects – distances are compressed.
And the far end of a 1000 foot long boat will seem closer and flatter than reality…
WGOWS AIS Track & Ship View
Further down, I cite another video in my comment here:
https://www.youtube.com/watch?v=DoPRz7wk3WY
It has a close up of the shot. At about 8 minutes he comments that the “Formast Light” has come on. That’s the large light center of the bow of the ship. Again, note that you can see both the side and the front of the ship. It is still in the shipping channel that travels at about a 45 degree angle to camera, but 90 degrees to the bridge. Your perspective is a quartering view from the front & side with a long telephoto lens. Notice how the ship does not look nearly as long as it really is.
https://en.wikipedia.org/wiki/MV_Dali
Length 299.92 m (984 ft)
Beam 48.2 m (158 ft 2 in)
Draught 15.03 m (49 ft 4 in)
[…]
Dali is propelled by a single low-speed two-stroke crosshead diesel engine coupled to a fixed-pitch propeller. Her main engine, a 9-cylinder MAN-B&W 9S90ME-C9.2[11] unit manufactured by Hyundai Heavy Industries under license, is rated 41,480 kW (55,630 hp) at 82.5 rpm. Her service speed is 22 knots (41 km/h; 25 mph). For maneuvering in ports, Dali has a single 3,000 kW (4,000 hp) bow thruster. Electricity is generated onboard by two 3,840 kW (5,150 hp) and two 4,400 kW (5,900 hp) auxiliary diesel generators.
It is really 6 times as long as it is wide, yet the photo looks more like 3:1.
Note that the bow thruster will need electricity to run, and that was what they didn’t have when the lights went out… so both propulsion and maneuvering were compromised.
Dali just as lights come on
Were we seeing this “from the side” it would look a LOT longer and the bow would look a lot shorter, or be hard to see at all. Clearly this is a front corner point of view. Matching the map that shows the channel at a 45 angle and presenting that point of view.
This image is just at the moment of impact. Notice that you can still see some of the side. The channel is still passing on the right side (so the camera is outside the channel toward the shore and looking north toward Dundalk).
Dali at impact
Slightly outside the channel at this point (the water depth increases a lot at the bridge and beyond) and “on the rocks”. Then the bridge falls down.
Here’s some maps / charts. First, an overview:
Overview Baltimore Chart
There will be close-ups of some parts further down. Here you can now orient to the whole area. You can get a very detailed copy and scroll around on it here:
https://www.charts.noaa.gov/PDFs/12281.pdf
I’m going to show screen captures of some bits of it. But notice that the camera is most likely to the left side of the channel (as you look upstream) and a long ways down the page (long telephoto) and that puts it close to the shore, or on shore, on that south side of the water. Somewhere south of Hawkins Point and perhaps as far down as Stoney Beach; but I suspect it may be the private piers near the spoils dumping area. In any case, near land, not out near the channel.
I’d gone looking for “Webcams” in about that area, but found none. So I suspect it is some kind of private or government camera. Here’s a view of the spoils dump area just south of the bridge out point:
Bridge To Spoils Area
That, or slightly further down, gives about the right angle to still see a bit of the side of the ship, and a lot of the nose, after the impact. Here’s some more of the area along that shore, note that Stony Brook is at the center bottom.
Stony Brook & Shore
OK, now lets look at the harbor bottom a little. Here’s the area where the ship is under power approaching the bridge area:
Channel approaching bridge
Notice that any excursion outside the channel puts you around in about 25 foot of water. The ship was in that channel, which is what the AIS Data shows. This conformance of the actual depth per the charts, the vessel draft requirements, and the AIS Track confirms that the AIS was reporting correct data.
Here’s the area of the bridge and impact. I remind that measuring the channel (with thumb width) and comparing it to the legend, said that the channel is somewhat less wide than the Dali is long, so most likely with impact at one side and the ship stern rotating toward the other side, it wedged in between the two sides of the channel (which would explain the lack of movement with tides and currents…)
depths at bridge
I noticed a caption upper right that says “cable and pipeline area”. That’s going to complicate the recovery / salvage…
The camera will be almost due south (and a little West toward shore) from the impact point. Notice that the channel is clearly going at a strong angle away to the upper left / lower right. The apparent left to right motion in the video is in fact left / rear to right / front at about a 45 degree angle, but the telephoto perspective masks the “coming at you” aspect / angle a lot; and makes it less apparent than the “going left to right” motion.
For anyone wanting the scale, here’s those images (or get them off the link):
Chart distance scale
And a couple of words about the channels:
About the channels
I have a few more images, but it is approaching 3 AM and I need sleep. Note that many / most of the images can embiggen if you click on them.
Hopefully this makes it clear that the camera is nearer the south shore than out in the water somewhere. That the ship NEVER leaves the channel until it hits the bridge and stops. That the ship can not “go sideways” in the channel as it is too long. That the telephoto perspective compressing fore-aft distances is what creates the illusion of a plane “left to right” motion when it is really as much “coming at you” on a 45 degree angle. And that the AIS Data correctly tracked all of this, and the track map is what happened.
Musings from the Chiefio 
Some comments from Karl Denninger on this at https://market-ticker.org/akcs-www?post=251017
He also sees no nefarious stuff here, just an unfortunate accident, though of course it may have something to do with the fuel used to run those engines.
Interesting is that the main engine won’t run without an electrical power supply, and it doesn’t have a generator geared to the main engine to generate its own electricity – instead you have a couple of motors driving generators. Should really be OK with two such generators, but if the fuel is waxing and clogging the filters then that would knock out both.
I’d expect the inquest into this to be pretty reliable, since there’s no obvious fault to be applied to any political figure.
@Simon:
Nice link. What he calls “torque effect and rotation of the water column” is what I call (and is often called… and is taught in the class my boat partner took) “prop walking”. I like that he confirms most props are right handed, and I note that Dali was a single prop vessel (all of that confirming my conclusion that she had some rudder to port to counter the starboard prop force when accelerating out of the harbor; and that power-out would have that “rudder to port force” no longer countered by the prop torque). So at power-out, the ship would start a slow turn to starboard (to the right and toward the right side of the channel / bridge impact point).
His conclusions match mine (and match the physics of boats, and match the experience I’ve had docking in a current and matches…):
I note that the bow thruster is about the same total kW demand as one of the generators (3 vs 4 kW range), so add in any significant other demand and you exceed one generator. My guess would be attempting to start the main engine AND engaging the bow thruster at the same time would overload one generator; so hopefully they were on separate generators…
He also notes the electrical dependence of “modern” Smog control first safety and reliability second… designs. IMHO it is most likely the case that fuel gelling (wax deposition / falling out of solution) clogged up something in the engines and caused the loss of generator power. This is presently a KNOWN ISSUE all over the place; so more exotic explanations are far less likely until this is ruled out.
In other words, Smog Laws caused this accident until proven otherwise.
As I noted in this comment here: https://chiefio.wordpress.com/2024/03/05/w-o-o-d-5-march-2024-super-tuesday-tds-eu-pokes-the-bear-zinc/#comment-169642
and cited this source: https://shipandbunker.com/news/world/581135-feature-vlsfos-the-concerning-fuel-management-issues-so-far
While I’ve not piloted boats, I have piloted an airplane. The concepts are similar. This is an accident, after one or more mechanical failures, to me. Could sabotage contribute? Yes, but I’d not be surprised if the sabotage was emission rules affecting the fuel whose tanks may have only been minimally heated, if at all. I have read NTSB reports after airplane crashes. I’d like to read the NTSB report from this, if it is released.
@CDQuarles:
I think air pilots get sensitized to fuel issues and cold since it effects the engines a lot and at high cold altitudes that can be fatal. It is my opinion that the folks running diesels (on land or sea) are learning the same things, but now via “hard knocks”.
I ran into it when BioDiesel was being pushed and a lot of Diesels “had issues” especially in the cold. ”Wax” coming out of solution in 40 F or lower temperatures and clogging up the fuel filters.
In the link above to “shipandbunker” they have a marvelous graph showing how wide the range is between WAT (Wax Appearance Temperature) and WDT (Wax Disappearance Temperature). In other words, where the fuel starts throwing wax deposits at your fuel filter and how hot it must get to re-dissolve that wax.
WAT looks to range MOSTLY from about 20 to 40 C. (68 F to 104 F) but with some as high as 60 C (140 F). Basically, with this new VLSFO fuel, your fuel can start sludging up with wax on any temp cooler than a nice spring day, and for some batches as hot as Death Valley in August.
Then, to get that wax gone again, WDT ranges from about 55 C to 70 C (131 F to 158 F) with some spikes up at 75 to 76 C (167 to 170 F). Given that the water and air were in the 40 F range when the ship was docked, I think that matters.
It takes HEAT, and a lot of it, to keep many hundreds of tons of fuel hot in a hull sitting in cold water. That usually comes from the engine “waste heat”, but… many US Ports are now mandating that you run from “shore power” and not from your on-board ship engines / generators because of “Smog Laws & Muh- Climate Change”.
So my best guess is that folks are depending on the large mass of fuel to stay warm in port, long enough to get the cargo swapped, and then get the motors going again; but that is just rolling dice in cold weather. Then, once wax crystals form in the fuel, it must get a LOT hotter to remove them, and that just doesn’t happen (or took way too long).
So depending on “lot of fuel” and length of time in port AND WATER TEMPERATURE, you get engine not wanting to run / fuel starvation issues.
This is likely to be worst in ships coming from a warm area (China, Singapore, India) to a cold area (north Europe, North USA, Canada) as they get there fine, but then wax up the fuel while sitting idle in a very cold port.
That’s my best guess as to what is going on, and why.
Basically, Politicians have no clue about any of this and make crappy engineers, while they mandate Stupid Stuff at whole industries; then do not know they caused the problems so blame the managers & actual engineers who are just trying to cope with these really stupid mandates (for the notional “fix” of what are actually non-problems).
Just tossing it out there to share the experience I had.
I watched and read several descriptions last night of the ship being off course about 2 minutes before impact, veering sharply towards the bridge, cyber vulnerabilities etc…
This was one of them I found entertaining. Albeit there were a few points I pondered. None from the dude with the fake white glasses (who would wear those anyhow?)
I still remain a denier, again.
Enjoy the hype and mostly unjustifiable Black Swan speculative propaganda :-)
“The TRUTH is coming out in the Baltimore bridge collapse” General Mike Flynn | Redacted News (youtube.com)
Seeing is believing. But seeing can be tricky.
This is good:
Here’s an interesting video that uses a simulator. (9-ish minutes)
RECAP: How did The Dali Ship crash into Francis Scott Key Bridge? – YouTube
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Thanks for the analysis. Being unfamiliar with ships and airplanes — I’ve learned new things from this post.
@John H.:
You are most welcome. Ships are a whole lot different than anything folks commonly encounter, and the bigger they are the more different they are.
Like some ships (and perhaps the Dali) have a prop directly attached to the engine by a fixed prop shaft. There is no “reverse gear”. To go into reverse, you run the engine backwards…
The sheer mass of these things is beyond the scale most folks comprehend. It is like a train that takes a few miles to stop, and then “protesters” sit on the rail road tracks and are surprised when it doesn’t stop but runs over them. (one “protester” lost a leg that way…). Except the ship is many many times heavier and takes a lot longer to change directions or stop.
Some new ships are now being outfitted with giant electric motors in pods that hang under the vessel and can be turned, so they can move in any direction. There are very few of these and they are quite expensive; most ships are made to go one direction, forward, with at most a little bit of turning ability at speed. Tugs are used out of necessity when these are in a port. Seeing one kind of ship move does not tell you what another class of ship can do (or can’t do…)
I was, frankly, surprised and a bit shocked to find out that my “new” boat can not handle AT ALL Like my old boat. I was used to just “driving it around” with the rudder and using the prop wash to turn just about anywhere any time. (Bayliner Buccaneer with a BIG short rudder almost all in the prop wash area). My “new” boat is only about 9 feet longer, but has a longer deeper rudder that is narrower, so mostly doesn’t respond nearly so fast to prop wash and is slow to turn if moving slow. It is a pain to get it into the berth when the tide is moving under the docks as the deep keel wants to go with the tide and the “rudder authority” is quite low when going slow enough to dock. I practiced a bit in the bay and you can “hit the gas” and the boat just doesn’t turn much at all until it gets moving.
After a few of that kind of experiences, you come to understand just how different the handling can be even in two boats that look very similar and of similar mass.
Oh, and watching cargo ships navigate in the San Francisco Bay taught me a lot about what they can, and can not do. On one occasion I was out mid bay and the weather got bad. Winds AND heavy Mist / Fog. I decided to reef the main, which required dropping it and hand tying reefs. I was in the middle of doing that when a horn went off and a HUGE cargo ship came out of the fog headed right at me. OK… I know he can’t stop and can’t turn out of the channel… so turned the key, put full throttle on, and motored out of his way pronto (and with some pucker factor). The fog was thin enough that I had what felt like about 30 seconds to get it done, but was likely a minute. At about 6 feet / second, that got me between 180 and 360 feet off his line of approach. Enough but … Things you learn… like don’t reef in a shipping channel in poor visibility ;-)
In Theory, sailing ships have right of way over power ships, but… “Most Afraid Captain yields right of way” made sense to me ;-)
Related to this is https://reason.com/2024/03/27/the-obscure-protectionist-law-that-will-slow-clean-up-of-the-baltimore-bridge-disaster/
Back in 1906, a law was passed to stop foreign dredgers working in US waters, so the US dredgers didn’t need to compete against better technology. Not surprisingly, this meant that the US technology didn’t develop as well. “Might be carp, but it’s this or nothing”. Today, this means that the dredgers that can be legally used will not be the quickest available, or the highest capacity, so clearing the harbour will take longer.
Also maybe related:
Reconciling the three lights in the background is hard for me to do….
Find the right hand brightest light … get the (rough) alignment for the camera … go from there.
Done.
Or, red bridge light almost aligns with light coming through left (undisturbed) pier.
The camera was SW of the channel and SW (mebbe S10degreesW) of the impact. Seems odd, but it appears that camera was in water and not on the west bank (could be wrong here).
See also both arches above the left undisturbed pier for perspective.
Finally, the left side pier gap is in line with the bridge, and we are looking through it from the west … not the east.
video link: https://www.youtube.com/watch?v=kz9pc6_ZiIM
There are two places in this video which are of interest.
01:23 chart of the new (shallower) detour channel being laid out.
and which shows the Dali’s current position (it hasn’t changed) — but what is interesting is how very slightly it was off-course. A lot of the ship is still in the proper channel. Which is to say — that channel was practically touching the bridge pier, the unprotected bridge pier.
Going into speculation here, but the ship was on a straight-line course for a long time already when they lost power. If they Did Nothing At All when they lost power, they would have coasted right under the bridge, in the proper channel. So, did somebody panic and do something stupid?
06:00 in that video, he comments that the NTSB has announced there will be no further press conferences. Nothing to see here, move along.
YMMV – “If they Did Nothing At All when they lost power, they would have coasted right under the bridge”
Earlier, it was pointed out that the screw adds some sideways force, and that thus to go straight they’d have needed the rudder to add in some thrust the other way. If the electrical power fails, then the main engine stops and the rudder can’t be changed because the hydraulics are down too. Assuming that the rudder was set to provide some right-turn to counter the screw, that would become the only vector active with the main screw stopped but the ship still moving forward. Thus “doing nothing” (because the power failed) resulted in a right turn.
Thus looks to me that there isn’t really much to see here. They had a problem keeping the electrical generators running because the fuel was waxing up, and the generators failed at exactly the wrong time, after which there was no chance of stopping the collision. It was unfortunate, and will cost a lot to put right again, but not some nefarious plot. The base cause was really the rule change on using low-sulphur fuels, and that they are currently pretty variable in their wax-point.
You could argue that they shouldn’t have left port when they were having some problems in keeping the generators running, but maybe they thought they’d fixed it. Looks to me that the filter-clogging isn’t that predictable, so they might also have passed the tests they ran, only to fail later if the bunker-fuel tanks or lines cooled slightly.
“If they Did Nothing At All when they lost power, they would have coasted right under the bridge”
I stand by that, except they said the wind was strong. I don’t know from which direction it was blowing, but that ship was a huge sail, so that could be a factor. Also, river and tidal currents, but these would generally not be from the side.
Prop walk when in reverse is big for small boats. For 1000 foot boats, I don’t know. I doubt it would have been a factor here if they did nothing and coasted forward.
New information. The ship did not have a head-on collision with the bridge supports, it was more of a grazing, glancing blow. The side of the ship broke one of the four concrete legs of that support, and then the containers pushed the bridge span. If it was just a few feet to the side it would have missed the bridge.
In other words, that bridge was a push-over. Sorry.
I’ve set this video to start at the key point.
Press 0 to run it from the beginning.
@YMMV:
There were 2 significant forces pushing the course to starboard (right). One was the prop walk force to port (left). This was countered with some small rudder to starboard. On loss of power AND rudder control, this slowly turns the ship to starboard (and that rotational force would require rudder to PORT to neutralize the rotation). The other is wind. In the video, at the moment they try to start the engine and you get the black smoke plume, it blows fairly stoutly off to starboard rear.
So that big stack of containers, taking wind on the port forward, also acts as a sail to turn the ship to starboard.
Now it didn’t take much. Maybe 6 degrees? To shift the course from “right through the middle of the channel” to “grazing the edges.
As to what would happen if “they did nothing”? Well that’s exactly what they did do until the very last moments. Again, in the video, you can see that just before impact after the lights come back on: the bow starts to move to port. Just too little and too late to avoid the crash.
There’s a reason large ships depend on tugs in port: They simply can not change direction nor speed very fast at all, and fighting wind, currents and inertia in close quarters requires changing speed, direction and cancelling inertia fast. This includes rotational inertia. So you use tugs. Large Ships measure changes in 10s of minutes to hours. Close quarters require changes in seconds to small minutes.
Heck, even my small boat, attempting to dock, has required some “go arounds” as rudder authority was too little for the rate of change needed if I was not lined up right for the ambient wind, currents, and such. ”Hanging the prop” (putting it in full reverse) takes a good fraction of the boat length to stop it if going more than a few knots, so nosing into the dock is done at 1 to 2 knots. And even then, sometimes “doing nothing” means that the 4 knot current shoves me into the dock (what fenders are for ;-) or away from the dock and tossing lines to the shore crew may or may not let them stop it.
Basically, wind and currents WILL change where your boat goes, and “prop walking” will do it too. Part of the art of docking is to learn how to predict all that.
Then, like an airplane, you do not just put the rudder in a direction and “go there”, but use the rudder to impart a force. That force can counter another, or if unopposed it put in a rotational momentum around the center of mass. Now you need to use opposite rudder to stop that rotation (or wait a long time for a nice big keel to do it.. if you have a nice big keel). So an unopposed set of rudder to starboard and wind will cause an increasing rate of turn (“falling off the wind”) until opposed with opposite rudder.
What I saw was a ship adrift with a little starboard rudder plus wind pushing to starboard doing exactly what I’d expect. A mild starboard turn.
@Simon:
While I think it is most likely a fuel issue (related to cold VLSFO) it is also possible that it was just some kind of generic “electrical issue” causing breaker trips.
The ship has several large-ish Diesel Generators, and while those are usually highly reliable and will run for decades: It is suspicious that all of them went off-line together (common tripping from a common electrical cause? Or common fuel cause? Or common human error? Hard to say with certainty, but odds are all we have at this time).
Reports are that it was having “electrical issues” for several days in port. Without knowing what they were or what all was done about them, that doesn’t add more information than “maybe don’t sail in a ship with problems”.
Wind speed and direction at the time of the Dali allision was light, 10 knots, gusting to 12. The data was collected at two points on that bridge, one of those is gone now. The data is available for 45 days.
Station FSNM2 – 8574729 – Francis Scott Key Bridge NE Tower, MD
https://www.ndbc.noaa.gov/station_page.php?station=fsnm2
Station FSKM2 – 8574728 – Francis Scott Key Bridge, MD
https://www.ndbc.noaa.gov/station_page.php?station=fskm2
Wind direction 150°T (the two stations have slightly different readings)
I see no operational difficulty with this wind speed or direction.
Even in a stronger wind, it is not obvious that it would cause the ship to change heading, since the wind area seems balanced. Nor cause sudden drift, remembering how heavy that ship is.
I’m going for rudder issues. Sudden rudder issues.
Full moon , outgoing tide and the secondary channel current outflow, position in the primary channel, need accounted for too. There are some dynamics at play there.
@YMMV,
10 knots of wind Is enough to push a boat around pretty good. Remember it is basically sitting on a slick slippery surface. The center of wind pressure is unlikely to ever be exactly at the center of mass AND the center of hydraulic pressure on the hull.
@Ossqss:
Also remember that toward the end they dropped, and were dragging, the port bow anchor. As the ship turned a bit crosswise / to starboard in the channel, the stern swings out and the center of that force ends up slowing the bow and letting the stern swing even more (to the extent center of mass is port side of the attachment point of the anchor – center of force of the anchor chain attachment – it puts a torque force turning the ship to the starboard (right).)
Frankly, given the complexity of the mix (anchor dragging, wind, currents, tides, prop walking forces – and their sudden absence, prop wash area of rudder, unknown rudder position, rotational momentum, linear momentum, eventually grounding forces, and more) all you can really say is “What the record shows it doing, is what it did”.
I regularly think I’ve got one set of control forces on my boat, and find it doing something different from what I expected. A bit of wind, or a shift of current as a tide rushes around some ground structure, or just changing the prop speed; and the boat gives me some surprises… or just slapping into a wave at an angle and I’m on a different heading…
EM – I’d figure that the fuel supply (and associated problems with filters clogging) would be common to both generators, so would be a reason for both failing.
Yep, seems they had some problems with generation in port, but it’s a fair bet that they had found that they could get the generators up and running again in a few minutes so it would have been treated as a nuisance rather than a consequential problem. It became a major problem really because of the precise timing of the failure and the conditions at that time (wind, tide). I’d doubt if anyone really considered that that result of a short power-out would happen.
We’ll have to wait for more data on what the electrical problems really were, but it looks to me that they were considered to be minor problems that could be quickly fixed if they happened. Your link on the waxing-up implies that many people are getting the same problems, so they wouldn’t delay setting sail until they had a perfect fix because obviously no-one has a perfect fix yet.
Otherwise, since YMMV points out that the reverse-thrust was almost enough to stop the collision, if they’d got the generator running again just a little faster the bridge may not have come down.
The video TTN posted above is instructive.
Some Notes On Dali Downs Baltimore Bridge | Musings from the Chiefio (wordpress.com)
I see all sorts of things in that earliest video that appear to show something convincing about the Dali’s movements and the impacts. Then I watch the video again and I don’t see what I just saw but something else entirely that is just as convincing. For example, sometimes I see the Dali moving towards the support and it seems I’m watching the Dali from the rear. Watching again, I see the Dali from the side moving left to right. Watch again and I’m clearly seeing the Dali from the front, viewing the ship from a starboard angle.
The only view that I trust to be something that doesn’t fool the brain is the early daylight images of the aftermath taken from a drone or helicopter. It shows the Dali T-boned the bridge at almost, not quite, but almost 90 degrees. The axis of the fallen bridge across the bow of the Dali is almost, not quite, but almost at 90 degrees to the long axis of the ship. The channel is pretty much at 90 degrees to the bridge as near as I can make out.
Any explanations of the Dali’s movements have to be consistent with the final outcome of the Dali being at near 90 degrees to the bridge and at 0-degrees (close enough for government work) to the channel.
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The question I see being argued is whether or not the strike was deliberate and orchestrated by one or several of the TLAs or a terrorist act or was it an accident caused by a series of mechanical and/or human failures.
My plan is to watch what happens to 21 merchant sailors, 1 captain, and a pilot and pilot-in-training. If they all suddenly “didn’t k!ll themselves” and there is no one left to tell the tale, I’ll go with nefarious TLA actions. If that bunch lives reasonably long lives and are tied up for years in courts and boards of inquiry, then it was all a series of unfortunate events that led to the tragedy.
And here’s a question to ponder. If planned and executed by a TLA or terrorists, why pick the 9th-busiest port in the US? Why not go for one of the top three? There are some good answers as to why not, such as other ports have multiple routes in and out so a single incident can’t gum up the port. And perhaps any bridges over the channels at other ports have the protective barriers so taking out a bridge isn’t an option. But still, why the 9th busiest if it was a planned act?
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My favorite bit of speculation is that the ship is owned by the family of Mitch McConnel’s wife and the – yes – accident would cost the family $billions. So the investigation will be muddied up AND dragged out until no one is left who even remembers the incident. Then the report will be filed away in a crate in some warehouse right beside the crate holding the Ark of The Covenant.
@H.R.:
Unless one spends a lot of time in the study of the effects of “perspective”, especially in photos and more especially using different focal length of lenses; photos and movies can be more misleading than informing.
For this type of accident, while the Far Far Away Telephoto Perspective entertains along with letting you see the lights go out, and come back on; it confuses more than it illuminates.
So THE Best, bar none, way to understand the motions during the accident is a straight down view based on AIS Data. This is what will be used in any investigation, in working out the accident timing and dynamics, and in planning the recovery. For the simple reason that the system is very robust and very accurate (since $Billions to $Trillions of ships and shipping depend on it working correctly and accurately).
The ship appears to be headed almost 90 degrees to the bridge because it is. Then it appears to end up at a very slight angle because it does. About 6 degrees. It may have been as much as 12 degrees off as it approaches the pylons, but got a few degrees back in the last minute when power came back on and the got a little bit of steering authority; but too late.
The latest imaging (sonar / underwater and perhaps some lidar) shows the ship grounded in the mud. I’d postulated the stern might be wedged against the opposite side of the channel. That was in error and based on the video (which I knew would be misleading…). At only single digits of divergence, it is not enough abeam to the channel to jam in it or to reach the other side.
What it did do was leave the channel as it hit the bridge and has about 2/3 bottomed in the mud. The stern sticks out only a modest amount into the deep channel.
“What’s happening in shipping” interviewed a prior Port Captain and they discussed a different container ship that was aground and got pulled back into the channel. They had to remove the containers to get it light enough and off enough of the mud, then the 2nd Tug pull got it moving. They then speculated that this ship being more heavily laden will take a bit more. So expect that once enough of the downed bridge Is removed, a large crane will start unloading containers onto shuttle barges and sent off somewhere else. (They mentioned a company that currently shuttles containers between a couple of ports, including this one; so that a giant container ship can have cargo for both, but dock and unload at only one).
It looks like they are working to open at least 2 shallow alternative channels (11 feet deep) so that barge and tug traffic can get moving. Then I’d expect to see a lot of barges getting priority containers (from the dock, other ships, or even Dali) moved out of that port and on to others. Right after that, I think getting the wreckage out of the deep channel will be a priority, and then refloating Dali and nursing it to a dock or repair station. I THINK there was mention of potentially dredging one of the alternative channels to make it a bit deeper (like 20 feet) as there was discussion of where to put the “spoil”.
There’s going to be a lot of dredge and crane traffic and work, 24 x 7, to get the junk out of there as fast as possible. There’s a large area that used to be Bethlehem Steel (now renamed) nearby that can handle steel and cement recycle, so the barge run to get it to a recycle facility is quite short. At some large $Millions of loss every day the channel is closed, folks will be willing to toss a LOT of money at getting it back open.
This one I think:
https://www.youtube.com/watch?v=l-DAZqTZCb8
At any rate, speculation about sabotage or attack is not indicated by what is known.
The ship had ongoing electrical issues while in port. (IMHO this tells me the Captain is likely toast as the lawyers will find that “A prudent man” would not sail until those were proven gone for months /sarc;) Then the ship had clear electrical issues while underway and lined up to hit the bridge.
Most of the forces I can identify will put a starboard turn to the ship on loss of electrical power.
The ship lost electrical power, and in about 1 minute had a starboard turn of course, then hit the bridge after a 2nd power outage that prevented any steering.
No reports of things blowing up or crew acting strangely.
No reports of computers failing to respond to commands when power was present.
Basically, no actual evidence at all of anything beyond a failure of electrical power from a system having known failures leading to the expected total loss of steering authority. And AIS Data shows the deflection from expected course to be down around 12 degrees max (and very reasonable) while the ship ends up aground at about 6 degrees off course (also very reasonable).
BIG ship, small hole, dodgy control while doing a relatively fast 8 knots and a known failure mode happening at just the wrong time, but what would be the right time given the very few minutes from leaving dock to reaching the bridge? Any time it was in motion would be a mess, just a different scale of mess.
Where is a good place to find the AIS data in tabular form?
It should have a lot of info in it that I haven’t yet seen, such as rate if turn.
An even better source of data would be the ship’s voyage data recorder (VDR), although from published comments, it is lacking some instrument data. Even hearing the bridge audio would be good. As far as I know they have not shared that, although they did say there were rudder commands issued.
Even this needs to be clarified: everybody says the ship lost power. Does that mean the lights went out, or that the genset failed, or that the main engine failed, or all of the above?
This video by a chief engineer explains a few things, including prop walk. His opinion is that none of the engines failed, it was just a breaker panel issue, and that trying to slow down by putting the engines astern was the thing that caused them go off the course down the channel. He also wonders about the low-sulfur fuel issue. There is a lot we do not know.
https://www.youtube.com/watch?v=BEzDh4RwpaM
E.M. wrote: “So THE Best, bar none, way to understand the motions during the accident is a straight down view based on AIS Data.”
Yup. I wrote the above for those who don’t trust the AIS data. My point being that if you discount the AIS data, and clearly you cannot trust what you see in the accident video as TTN’s video illustrates, then you have to start with the clear images of how it all ended up and explain how it got there.
The best explanation is that there was a ‘drift’ to starboard in the straight-down-the-channel course whether or not one believes the AIS data that shows that.
Now as to why the ‘drift’, that is still up in the air because only a few facts have been released, such as the Dali had power problems while docked. Best I know, what those problems were has still not been explained in any detail. But there’s no argument that the Dali was having problems even before setting out.
I have been reading a lot of “it was a TLA wot dunnit” or terrorists. So far, none of the usual suspect terrorists have taken credit, which they would certainly do if they could. And the only way we’ll ever know if it was some really clever, planned TLA op is if by amazing coincidence, the 20-some people involved start committing su!c!de with two bullets in the back of their head while their hands were cuffed behind their back. That would be a strong indicator of a TLA op ;o)
‘Twas an accident, but factual details aren’t forthcoming. I am willing to consider that if Mitch’s wife’s family was tied in, there would be some stonewalling and coverup to mask that involvement. If there is any conspiracy to the whole mess, a coverup of that tie-in would be a good candidate as to why we are not getting details.
Otherwise, the NTSB is withholding the details “to avoid fueling speculation.”
Suuuuuure. Withhold information. That’ll put a stop to all the speculation. 🤣🤣🤣
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Or… you can accept Mayor Pete’s explanation that the bridge was racist and we can all just move along now. Yeah… Racist bridge… That explains everything. WAFI!
@YMMV:
I don’t know where to get the raw data.
@H.R.:
The biggest issues with AIS Data are related to 2 things.
The device can be configured to lie about who you are, or turned off entirely.
The data has a finite lag (that is a few seconds for large ships or more for small pleasure boats – class of AIS used determines.)
So it is possible for the ship to have turned more “sideways” than the AIS Data shows IF it does it very briefly and then turns back, and it is possible for the speed to be off some if the ship is rapidly changing speed. I’d expect that “at impact” the AIS Data still showed a forward speed for a couple of seconds, for example. Or it might be more “sideways” in the channel for a second or two and then swing back, and that could be missed (and IMHO likely was for about a second per the video, then again we know the video is highly misleading….)
There are minor issues with things like jammers in war zones, fraudulent GPS signals broadcast in war zones (spoofing GPS), and the potential for loss of GPS signal (from equipment failure, or metal obstructions where they don’t belong – unlikely on a commercial ship)
FWIW, commercial ships in the Red Sea Area are doing the AIS “turn off” or “change identity” things to try to avoid Houthi missile attacks. But for this accident, we have AIS Data from start to end.
One question I have is just “did it have a drop out when the power fails happened?”. They were basically “long blinks” and it is possible that the system is designed to “absorb” them and interpolate. I don’t know, that’s just speculation on my part. But it would make sense. IF you have a 100,000 ton ship in a place and the AIS drops for 5 seconds, you don’t want it to just disappear off the navigation charts of the other ships around. You want them to know if they are headed right at it, or even where it was 5 seconds ago… My guess would be that with small ship (low end) AIS having a 10 second interval, the software is set up to expect up to a 10 second “skip” for any ship / boat (and maybe longer).
I’ve just not cared enough to “dig here!” on the details inside AIS intervals and dropouts. But it ought to be done (and aligned with the video…) But that’s a job for the investigators, not a couch potato… ;-0
A strong outgoing tide with a full moon from a nearly perpendicular channel flowing into the main channel near the bridge will have influence on a powerless boat’s inertial movement. Just my 2 cents on the mystery’s, mystery.
NOAA Chart – 12281_Public
“IF you have a 100,000 ton ship in a place and the AIS drops for 5 seconds, you don’t want it to just disappear off the navigation charts of the other ships around.”
True, but the responsibility for that is with the receiving end. For small boats, many/most/all? MFDs can do a lost target alarm.
Sending out an extrapolated AIS message would be a lie, dangerous physically and legally. But if your own AIS receiver and MFD wants to do that, that’s okay as long as it is clear what it means.
All large vessels also have multiple radars, and there should be a shore based port control radar too. I haven’t seen any mention of those. So I think we can take the AIS data as real. We just don’t know the intermediate points. Those are probably available from the onboard navigation equipment. Probably someone has collected that and not shared it.
good find: NOAA Chart – 12281_Public
Also take a look at the US Coastal Pilot book, volume 3, chapter 15, page 339
for advice to mariners entering that harbor. (already updated)
https://www.nauticalcharts.noaa.gov/publications/coast-pilot/files/cp3/CPB3_WEB.pdf
And there should be a link somewhere to online tide tables.
This interactive chart can go back one month.
https://tidesandcurrents.noaa.gov/noaatidepredictions.html?id=8574680&units=standard&bdate=20240324&edate=20240327&timezone=LST/LDT&clock=12hour&datum=MLLW&interval=hilo&action=dailychart
Tide was negligible, so the currents should also be negligible.
Here’s another video from an expert who has access to new facts.
and read the comments for alternate expert opinions.
Another ship, another loss of power, but this time no bridge down.
https://www.gbnews.com/news/us/major-container-ship-loses-power-new-york-verrazzano-bridge-baltimore-disaster
Could be something that happens quite often, and we just don’t hear about it unless some major damage is caused.
@Simon:
It happens a LOT more now that the Political Class has decided to play Fuel Engineer and mandate fuels for which the ships were never designed… and don’t like.
Having fuels (as noted above) that throw wax blobs at the fuel system at normal ambient temperatures in much of the world most of the year…
Just like they screwed up a lot of cars and trucks when they first mandated taking the sulphur out (that was important to maintaining rubber seals at full size…) or pushed Bio-Diesel in cold climates (that also waxes up and clogs fuel filters when at freezing or below). A lot of Northern School Busses failed in winter until they figured that one out. (Note: I was, and am, a big fan of BioDiesel and “funny fuels” in Diesel engines. I’ve run a LOT of them. I’m just not a fan of “one size fits all mandates” by politicians who have no technical skill or clue at all and end up breaking things that were working fine.)
That the (now mandated) VLSFO can throw wax blobs at temperatures as high as 70F or more pretty much assures a lot of failures in cold weather. At least until folks figure out to heat THE ENTIRE FUEL SYSTEM above the wax dissolution point (about 190 F) for both the main propulsion unit AND all the aux generators (that are necessary for having the main engine run – all the oil pumps, fuel pumps, controls, etc. are powered by the aux generators…)
A LOT of good stuff in this video (by a Chief Engineer of big ships) that includes the startling fact that big ships are designed with a way too small rudder so even at 7 knots the rudder does nearly nothing IF / WHEN the prop wash ends. Yes, they depend on the prop wash to have effective rudder authority. Sigh…
Covers the dependency of the main engine on the aux generators, so if you lose them, you lose main engine AND rudder authority.
EM – yep, that waxing problem stuck out from the data as being a major hassle. To be certain that there’s no waxing you need to keep the whole system hot, and previously that wasn’t necessary. Thus looks like a lot of ships will have the same problems keeping their engines going all the time when using low-Sulphur fuel in port. I’d suspect that the need to keep the whole tank of fuel (maybe a few hundred tons) and all lines at 190°F might lead to other problems and risks of fire.
Similar fuel problems with alcohol in motor fuels, where things like chainsaws and mowers last around 2 years because the carburettors fail (both from corrosion of the alloys and damage to rubber bits), and even if you empty them out at end of season and store them dry you don’t get that much more life. The manufacturers know this, so they sell special alcohol-free fuel at around 5-6 euros per litre.
Some things are just a bad idea.
The wax problem.
https://www.wilhelmsen.com/globalassets/imo2020/whitepaper-3_wax-formation-in-vlsfo_042021_lr.pdf