One of my aunts was afraid of bridges and inclined planes. When I was around 7 we were going from my grandparent’s home in the valley to another aunt’s house on top of the hill. There have been so many floods in the river valley that there is an inclined plane that moves cars and trucks up in case of flooding and just for fun otherwise. The aunt afraid of inclined planes was with us when we finally got our ride on the inclined plane. She crawled into the foot well in the back seat until we drove off the platform, and she was genuinely terrified.
I think at this point the focus is on the electrical systems on the ship and the FBI and the manufacturer is being called to try to determine the cause of the failure. Bad equipment, incompetent staff, bad fuel, poor mantenance, who knows at this point? One report indicated over 6000 incidents of lost power among ships so likely not an isolated cyber attack. We shall see what is discovered, but quoting a wacko member of the public or using a cartoon to call theories into question is not helpful in discovering the main cause. But perfect timing happens by coincidence or not. I’m sure you agree.
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From an academic study on the optimal vessel speed taking into account safety, current, weather and water depth the author noted that the minimum steerage speed was 5 knots and
“The results of the calculation and experimental research of the case study clearly prove that the optimal speed of the PANAMAX container ship in the port channels and in the port water area is about 8 knots,”
Well, that’s one detailed and lengthy dissertation. The quoted area appears to be specifically related to the port of Klaipeda. And when they speak of optimal, that is taking into account a lot of factors like; fuel consumption, time of transit, emissions, etc. This is not necessarily addressing the transit past a bridge support that can be damaged by the ship if it loses control. This is in navigable channels and ports and those numbers relate to the above named port.
Earlier in the document, they address safety and the possible mitigations for those situations- including lower speeds and tugs. But those will not be corresponding to “optimal” conditions.
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Everything goes out. The engine does not power any of its own equipment needed for it to run. But it might have an oil pump powered from its own shaft, probably just to prevent engine damage as the engine will keep turning for a while after a power failure.
There may be only one main switch board. If some equipment like the rudder or some pumps trip the whole switch board, everything goes black and it has to be restarted.
I think they’re not designed to maintain reliable uninterrupted power and it is expected that manual control may be needed to bring things back after a failure.
I assume things are done to reduce costs and to the minimum that regulations require. Most of the time it is never an issue, until some situation like this. Losing power for a minute out in the ocean is not a concern.
It’s a difficult problem that these big ships have.
- To maintain safe steering, they need to be going 8 knots or so. I think someone said the minimum is 5. 9 knots should let them maintain speed to get through if the engine stops. That’s probably why they pick that speed.
- To be able to use tug boats, they would need to slow down a bit. 9 knots would be near top speed for the tugs so the tugs would be limited in what they could do at that speed. At a lower speed, the ship would be dependent on the tugs to navigate safely, and would be at risk if there was a problem with the tugs. This is probably the better solution though, since if a problem occurred with the tugs the ship could use its bow thruster or back up to stay clear of the bridge.
- Protecting the bridge is expensive.
Another factor:
Was Dali azipod, or conventional props & rudder?
The bridge will be a long time coming, but I’d say given the size of the mess, having it back open all of the way by this date is reasonably impressive.
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Single engine direct drive, no transmission, unable to go astern from fast ahead without slowing first. Single rudder with minimal redundancy. Single main electrical bus supplied by 1 to 4 generators. Main bus tripped out, generators never stopped running. Emergency bus supplied by either main bus (which tripped off) or emergency generator. Emergency rudder operates off the emergency bus.
I see they left big chunk of concrete on bow as ship left for repair facility. The shipyard obviously is better suited to fix damage. The cargo facility by key bridge is not setup to repair ships.
I’m surprised that the cargo wasn’t removed before moving the Dali to Norfolk since Baltimore was the original destination.
Do they ever unload part of the cargo at multiple ports? Maybe that huge concrete pillar is causing too much of a list forward for the containers to be safely removed.
I don’t know but according to the best commenter, they were concerned with the hull damage trying to take it all off, plus the height of the ship trying clear the big bridge on the way to Norfolk. The first port to unload everything, and then on to the next to either repair or salvage.
Whoever, ntsb, fbi, evidently removed a control panel to identify why it failed.
The NTSB preliminary report describes a scenario that doesn’t seem to make sense. They have high Voltage generators that power a high Voltage bus that powers the bow thruster. That is stepped down to 480 by one of two transformers (only one is used at a time generally). 480 is what powers everything else on the ship. The circuit breaker on that transformer tripped, and everything went dark. Then they say that the second partial blackout was caused by the high Voltage circuit breakers on the generators tripping. If something was shorted, wouldn’t the lower current breakers on the transformer trip well before the generator breakers? But I don’t really know how big the transformer is compared to the generators, so who am I to say. It seems like something on the 480 Volt bus was over loading the the bus and that caused breakers to trip. The emergency generator didn’t appear to come on during the first black out so maybe something on the emergency bus was the culprit. I wonder if the crew disconnected the problem circuit which allowed power to be restored.
I remember hearing a recording of the radio call where a ship that has lost its steering is mentioned.
This was all explained in detail by the best source, something like what’s going on with shipping on YouTube. The bus shut down the fuel or lube pumps which shut the engines down to prevent damage. The question was why the bus shutdown and was removed for failure evaluation. Faulty part.