This is the speed up video of the event. It just gives me some weird itching in the suspicious bone.

If you know ships and care to explain that behavior, you have the comments section at your disposal.

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By Miguel.GFZ

Semi-retired like Vito Corleone before the heart attack. Consiglieri to J.Kb and AWA. I lived in a Gun Control Paradise: It sucked and got people killed. I do believe that Freedom scares the political elites.

13 thoughts on “The accident in Francis Scott Key Bridge… I don’t know.”
  1. Ship loses power twice. Right before impact, it does appear to attempt to steer away, but that much mass needs time to change course.

  2. That ship lost power at least twice. You can see, after the first power failure, that they are attempting to turn the ship to go under the tallest span.
    Once the rudder is over, it will stay over until commanded to do something else. When the power fails the last time, the rudder stays over and the ship continues its turn until it is facing the south main support.
    The power comes on, you can see the ship straighten and start to turn to the port, away from the support. Things continue to go wrong, and it runs into the support and the bridge comes down.
    Having driven over that bridge many times, it is high, scary and an important bypass over going through the tunnels or around the north of the city. Some cargo cannot use the tunnels, so they must now go an extra 20ish miles, if I recall correctly, around the north of the city.
    Finally, this will have a huge impact on moving cargo in and out of the US. Baltimore ships a lot of stuff.

  3. From what I have read, the ship lost power and was a steer-by-wire system. When power goes, so does control. My dad had a steer-by-wire car that lost power in motion on the highway and he lost steering and braking at highway speed. He went onto the grass and the only thing that stopped him was physics.

    Steel bridges are structures that are engineered to hold the load across the entire span of the bridge. If you take out one support column, the entire bridge will collapse. The ship hit the support column and the whole thing went down.

    1. A pure drive by wire system in a car? I didn’t think that was legal. My Ram has EPS, but I still have a mechanical connection to the wheels and the EPS is just the power assist.

      1. Same here. Hydraulic power assist works similarly. I know of no car with purely electric or hydraulic steering. Now a ship that size simply cannot be anything else.

    2. The question that comes to mind: why didn’t the ship have adequate redundancy on the power buses that feed safety critical systems like the rudder? Airplane designers know to do that. Don’t shipbuilders? Or is the problem that we’re dealing with a “flag of convenience” ship, one where the registering nation has no requirements at all other than “the mordida has been paid”?

      Check out the audio here — the calmness of the cops is quite amazing. I’m not used to that level of “the right stuff”.

  4. The ship definitely lost power at least once, possibly twice. When ships lose power, they lose everything, including steering. When power goes down, the rudder is basically locked in whatever position it was in at that moment.
    Even if the rudder was dead-center, the current can still cause a ship to drift, and if the rudder wasn’t dead-center when power goes down, well… that’s Not A Good Thing.

    From what I’m reading, it looks like the crew may have attempted to either stop the engine or put the engine in reverse to slow or stop their forward momentum once they got power back, but doing that could have exacerbated the loss of control. They definitely dropped their port anchor, possibly their starboard too, but the port anchor apparently dragged along the bottom and didn’t set until it was too late.

    As for the collapse itself, like j.KB said above, all of the weight was resting on the primary support columns. Lose one of those and the whole thing goes down.

    This is definitely a tragedy that will have major economic effects on Baltimore and the entire country, but as of right now it looks like an unfortunate accident.

  5. Not going to talk about the ship steering, but I am not without knowledge of power systems. Especially critical ones, like those controlling massive vessels.
    When there is some kind of power failure, there are automatic resets that kick in. This is why you will normally see the power flicker on and off once or twice before a blackout. The system trips a breaker, automatic switches re-route the power somewhere else on the grid, and hopefully only a small area loses power. Sometimes the damage is enough for a large area to lose power.
    My guess is, the power cut off, and the bridge put the rudder controls over to one side, making a right turn essentially. But, nothing happened (no power) and the ship kept going straight. Notice how the ship seems to continue on a straight course, under the high part of the bridge. Right up until the power comes back up.
    Then the rudder cut over, turning the ship starboard. Did the pilot realize it straight away? I cannot say. But, by the time they realized the bridge support was in their path, it was likely too late to change course back.
    Then power cut off again.
    Actually, had the power system not automatically reset, the ship might have glided under the bridge in the channel. The backup system might be the cause of this crash.

    1. There is an increase in smoke from the funnel starting as the power comes up again the first time, which fits with that. Presumably the engine was put full astern at the same time as the rudder was put over.

      1. Remember that for a rudder to have any effect, it has to have water flow past it. So as soon as you put the engine in astern the rudder is basically a useless appendage just hanging there unless you have considerable sternway on. The reason the the smaller tugs in the ICW and rivers can do what they do with 800 or 900 ft of tow in front of them is because they have what are called flanking rudders. These tugs have 2 sets of rudders, 1 set aft of the screws as normal, but then another set forward of the screws, so that when they reverse one engine to bend the tow around a corner it has immediate effect

  6. Okay I’ll try not to make this a novel; 99% of single screw vessels are right hand turning as viewed from aft. Now unless there is a kort nozzle [a shroud around the wheel, ducted propeller] which is doubtful; a propeller not only has action fore and aft but beam to beam, due to the rotation. So if you put a single screw vessels in reverse it’s not only going to try and slow you down but to drag the stern into the direction of the rotation, which being right hand rotation in reverse would be to port. Note the turn could also be to the rudder position at the loss of power but if they backed down the ship did exactly what you would expect, started to slow and the stern went to port. Hope that helps. PS – 40 years in the oil patch as an AHTS Master

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