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Baltimore Francis Scott Key Bridge collapse
Posted by
tom66
on 26 Mar, 2024 08:28
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Looks like a major disaster, with many people in the water, after a ship collided with the bridge structure and the bridge collapsed.
https://bbc.co.uk/news/live/world-us-canada-68663071Fortunately, fatalities are going to be lower just because of the time at night but multiple vehicles and at least a work crew have gone into the water, so almost certainly several will have died. It's not clear if anyone on board the ship was injured.
Going to be an expensive day for the marine insurers. I thought bridges like this were designed to resist the collision of a ship? Is this a design fail? The bridge is, or was, roughly 50 years old, so it's within the range of time that you'd expect considerations like this to have been made.
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#2 Reply
Posted by
rsjsouza
on 26 Mar, 2024 08:50
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What an unfortunate event... The video of the collapse is very impressive - the bridge crumbles as if it was made of paper.
Bridges that collapsed after collisions have happened before and I wouldn't be surprised if negligence or corruption related to its maintenance were critical factors in this case.
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#3 Reply
Posted by
Whales
on 26 Mar, 2024 09:07
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That brings up an interesting question: are those bridges designed to survive single-ship impacts like that? We'd hope so, but I wonder if it's actually a requirement.
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#4 Reply
Posted by
guenthert
on 26 Mar, 2024 09:12
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I'm pretty sure that with a massive enough ship sailing fast enough, one could take down any bridge. I'd think for that reason, there will be limits to what ship and how fast may approach such a bridge. Were those limits exceeded?
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#5 Reply
Posted by
watchmaker
on 26 Mar, 2024 09:48
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What a thing to wake to! We lived just outside Baltimore for 40 years. Sad for the victims, sad for the firemen (FIL led the response to a stadium escalator collapse). Some USN preposition ships there, port does handle mainly cars (that now screws things up). City/county/state cannot handle the loss of revenue and jobs.
The Mates and Pilots school is also in Balmer ((hon) and this will a classic case study.
Yeah enough mass at any speed will take down a structure with a direct hit. Which this appears to have been. Pilot lost his card unless he had a heart attack.
Holy shit!
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#6 Reply
Posted by
Ian.M
on 26 Mar, 2024 10:22
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See
NOAA chart 12281 The main span's piers were in 30' - 35' of water (+ tidal range), and the channel is dredged to 50'. They were protected by
dolphins either side. To add enough extra dolphins to 'ship-proof' the bridge would be rather expensive, ballpark estimate on the high side of $100 000 000 USD, just for the dolphins and associated protection works, which is at least double the total annual revenue of the port authority, and a significant fraction of the city's budget which is already forecast to have a $180 000 000 annual deficit for the next decade.
The insurers will pay out (eventually) for the cleanup and a depreciated cost for the bridge, and the city and port authority will have to pick up the rest of the tab unless they can get a federal grant. Ain't nobody going to be happy, as port fees and local taxes will have to go up.
@Watchmaker,
Even if the pilot had a medical issue, unless the ship was found to have suffered a critical systems failure, e.g. loss of both throttle and rudder control, Pilot lost his card FULL STOP, either due to responsibility for the incident or by being medically unfit. At this point (absent such a failure) the pilot and ships' bridge officers on watch are essentially unemployable in any similar role, probably for the rest of their lives. '
Take an oar and walk inland ...'
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#8 Reply
Posted by
tom66
on 26 Mar, 2024 10:49
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Yeah, that's terrible. Looks like the ship pilots would have been able to do nothing about that, and would have been aware of it the whole time... Makes you wonder if this is going to be down to whomever maintained that engine/power system last.
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#9 Reply
Posted by
soldar
on 26 Mar, 2024 10:50
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That brings up an interesting question: are those bridges designed to survive single-ship impacts like that? We'd hope so, but I wonder if it's actually a requirement.
I think this comment shows a lack of understanding of the scale and proportions of the entire thing. It is pretty much impossible to build that bridge in a way that it could withstand being hit by a mass of, say, 100,000 tons, 150,000 tons etc, going at speed. And it makes no sense, economic or otherwise.
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#10 Reply
Posted by
vk6zgo
on 26 Mar, 2024 10:54
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That brings up an interesting question: are those bridges designed to survive single-ship impacts like that? We'd hope so, but I wonder if it's actually a requirement.
The Tasman bridge in Hobart was hit by a ship in 1975 & several spans collapsed, with the loss of 12 lives.
The pillars on each side of the navigation channel were designed to take a ship impact, but the others where the ship hit weren't.
The "Lake Illawarra" which brought it down was by today's standards, relatively modest in size.
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#11 Reply
Posted by
iMo
on 26 Mar, 2024 11:18
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From the video above - interesting how fast the ship changed its direction after the first power outage. I would expect the rudders of such a ship will stay in the "last good" direction after the outage.
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#12 Reply
Posted by
jonpaul
on 26 Mar, 2024 11:21
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Possible circidian effect on captian of ship at 01:30?
Impact on commerce at the Baliomore port?
Jon
PS: An old is dierect desendent of Francis Scott Key, composer of our National Anthem.
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#13 Reply
Posted by
Circlotron
on 26 Mar, 2024 11:44
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That brings up an interesting question: are those bridges designed to survive single-ship impacts like that? We'd hope so, but I wonder if it's actually a requirement.
The Tasman bridge in Hobart was hit by a ship in 1975 & several spans collapsed, with the loss of 12 lives.
The pillars on each side of the navigation channel were designed to take a ship impact, but the others where the ship hit weren't.
The "Lake Illawarra" which brought it down was by today's standards, relatively modest in size.
Remember it well.
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#14 Reply
Posted by
watchmaker
on 26 Mar, 2024 11:54
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Mykid (Structural PE) just told me there was a repair crew on the spans. Fuck. Coulda been her.
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#15 Reply
Posted by
NiHaoMike
on 26 Mar, 2024 13:11
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From the video above - interesting how fast the ship changed its direction after the first power outage. I would expect the rudders of such a ship will stay in the "last good" direction after the outage.
Is the ship steer by wire? I would expect that most ships are hydraulically steered and in any case, there would be redundant systems like on aircraft.
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#16 Reply
Posted by
tom66
on 26 Mar, 2024 13:18
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From the video above - interesting how fast the ship changed its direction after the first power outage. I would expect the rudders of such a ship will stay in the "last good" direction after the outage.
Is the ship steer by wire? I would expect that most ships are hydraulically steered and in any case, there would be redundant systems like on aircraft.
I'm also wondering why they were so close to the bridge pier. I'd have thought you'd aim for the middle of the bridge and in the event of a power failure you'd just drift through the middle of the bridge. It looks like they were quite off course and then simultaneously lost power, a bit of a Swiss cheese event. I know very little about maritime navigation, but it does seem a bit odd that they even ended up in this position in the first place.
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#17 Reply
Posted by
Andy Chee
on 26 Mar, 2024 13:35
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From the video above - interesting how fast the ship changed its direction after the first power outage. I would expect the rudders of such a ship will stay in the "last good" direction after the outage.
Is the ship steer by wire? I would expect that most ships are hydraulically steered and in any case, there would be redundant systems like on aircraft.
Remember that in order for the rudder to have any effect, the ship needs to be moving relative to the water, or in other words the ship’s propellers must be providing some thrust.
If the ship is moving at zero speed relative to the water i.e. drifting with the current, the rudder does nothing.
In aircraft terminology, if airspeed is zero the aircraft has stalled.
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#18 Reply
Posted by
Ian.M
on 26 Mar, 2024 13:36
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The main span of the bridge was 1100 feet. MV Dali is approx 160 feet wide, and IRCPS ('COLREGs') Rule 9 states a vessel proceeding along the course of a narrow channel or fairway is obliged to keep "as near to the outer limit of the channel or fairway which lies on her starboard side as is safe and practicable.", so it would be normal practice under a bridge span wide enough for two vessels to pass, to aim for a point that's considerably off-center.
The vessel would have been carrying considerable way, and in water much shallower than the beam, would require at least six ships lengths to stop from typical manoeuvring speeds, assuming full astern was available, and there was enough lateral searoom to accommodate the severe slew to one side that is typical of a single screw vessel going hard astern. If the engine failed, low speed steering would be compromised by the lack of forced water flow over the rudder.
Re: WatchfulEye's video link: The observed thick smoke from the funnel implies the engines were rapidly commanded to full speed, and no pilot or watch officer in their right mind would go full ahead towards a near hazard in restricted waters. Its likely that the slew into the bridge pier was mostly due to going full astern with insufficient distance to stop. Dammed if you do, dammed if you don't.
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#19 Reply
Posted by
NiHaoMike
on 26 Mar, 2024 13:59
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The main span of the bridge was 1100 feet. MV Dali is approx 160 feet wide, and IRCPS ('COLREGs') Rule 9 states a vessel proceeding along the course of a narrow channel or fairway is obliged to keep "as near to the outer limit of the channel or fairway which lies on her starboard side as is safe and practicable.", so it would be normal practice under a bridge span wide enough for two vessels to pass, to aim for a point that's considerably off-center.
I wonder if that would get revised to aiming for the center as long as there's no traffic in the other direction, to give more room for error.
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#20 Reply
Posted by
Ian.M
on 26 Mar, 2024 14:07
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No, but its common practice to put markers on a bridge span and have a harbour regulation that vessels shall pass between the markers, which effectively has the same result of excluding non-emergency navigation near the piers.
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#21 Reply
Posted by
TimFox
on 26 Mar, 2024 15:11
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The last news report I heard on the radio (9:30 CDT on March 26) said that the container ship had suffered a total loss of propulsion.
The ship notified authorities about the possibility of impact, who were able to reduce the number of people at risk on the bridge before the ship hit it.
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#22 Reply
Posted by
guenthert
on 26 Mar, 2024 15:34
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The main span of the bridge was 1100 feet. MV Dali is approx 160 feet wide, and IRCPS ('COLREGs') Rule 9 states a vessel proceeding along the course of a narrow channel or fairway is obliged to keep "as near to the outer limit of the channel or fairway which lies on her starboard side as is safe and practicable.", so it would be normal practice under a bridge span wide enough for two vessels to pass, to aim for a point that's considerably off-center.
I wonder if that would get revised to aiming for the center as long as there's no traffic in the other direction, to give more room for error.
For the landlubbers: starboard is right side, the ship hit the left pylon.
As far as change of rules is concerned, I could see a demand for ships exceeding a 'safe' size be required to be towed into port by tugs, rather than sailing under own power.
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#23 Reply
Posted by
soldar
on 26 Mar, 2024 16:28
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I have sailed my own sailboat on the Chesapeake for quite a few years and know the area well although my main sailing was in the southern part of the Bay. Lots of stories and memories. I used to love sailing at night.
There can be some strong tidal currents, more so on the southern part, much less so in Baltimore Harbor. I used to know the tides and currents pretty well and use them to my advantage.
As a curiosity, those channels leading up to Baltimore Harbor are marked by "ranges"
https://en.wikipedia.org/wiki/Leading_lights
Leading lights, also known as range lights in the United States, are a pair of light beacons used in navigation to indicate a safe passage for vessels entering a shallow or dangerous channel; they may also be used for position fixing. At night, the lights are a form of leading line that can be used for safe navigation. The beacons consist of two lights that are separated in distance and elevation, so that when they are aligned, with one above the other, they provide a bearing. Range lights are often illuminated day and night.
Two lights are positioned near one another. One, called the front light, is lower than the one behind, which is called the rear light. At night when viewed from a ship, the two lights only become aligned vertically when a vessel is positioned on the correct bearing.
The span of the bridge is wider but the width of the dredged channel is about 220m (700') so when the ship hit the bridge it was already outside the channel and had hit the bottom which probably slowed it down considerably.
Remember the ship that got stuck in the Suez canal? Those large container ships are huge!
If the dredged channel is 220 m wide you have 110 m in each direction and if the ship is about 50 m in beam then it only has 30 m clearance on each side. That is about 1/10th of the length of the ship.
In the attached photo I have marked the edges and center of the channel and what width the ship would be taking.
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#24 Reply
Posted by
TimFox
on 26 Mar, 2024 16:53
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Edited from an AP news item (11:24 AM CDT) with further details.
BALTIMORE (AP) — A container ship lost power and rammed into a major bridge in Baltimore early Tuesday, causing the span to buckle into the river below and plunging a construction crew and several vehicles into the dangerously cold waters. Rescuers pulled out two people, but six others were missing.
The ship’s crew issued a mayday call moments before the crash took down the Francis Scott Key Bridge, enabling authorities to limit vehicle traffic on the span, Maryland’s governor said.
The ship struck one of the bridge’s supports, causing the structure to collapse like a toy. It tumbled into the water in a matter of seconds — a shocking spectacle that was captured on video and posted on social media. The vessel caught fire, and thick, black smoke billowed out of it.
With the ship barreling toward the bridge at “a very, very rapid speed,” authorities had just enough time to stop cars from coming over the bridge, Maryland Gov. Wes Moore said.
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#25 Reply
Posted by
David Hess
on 26 Mar, 2024 17:10
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Even if the pilot had a medical issue, unless the ship was found to have suffered a critical systems failure, e.g. loss of both throttle and rudder control, Pilot lost his card FULL STOP, either due to responsibility for the incident or by being medically unfit. At this point (absent such a failure) the pilot and ships' bridge officers on watch are essentially unemployable in any similar role, probably for the rest of their lives.
It looked like the ship had power failure, and then power failure of the backup system if all of that smoke was from a backup diesel generator.
https://twitter.com/CheeseEaterAnon/status/1772585380291784719
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#26 Reply
Posted by
Ian.M
on 26 Mar, 2024 17:28
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I doubt that much smoke would come from a backup generator start. Usually you get a puff of white smoke from totally unburnt fuel till it fires, then the governor kicks in and throttles back to match the load so not much black smoke. OTOH if you suddenly throttle up a big diesel running at low speed under load to emergency full throttle, you will get *LOTS* of black smoke, especially if the engine isn't fully warmed up yet. Whether that was with the engine initially making RPM for 8.5 knots, or was immediately after an engine restart; and whether it was a desperate attempt to get flow over the rudder, or going full astern to take way off, will no doubt come out in the NTSB report.
Meanwhile here's some preliminary analysis from a
shipping industry expert:
For the landlubbers: starboard is right side, the ship hit the left pylon.
Not from the ship's point of view. The ship was proceeding to seaward, but the video is looking landward, so left side pylon in the video is right (starboard) side as seen from of the ship. They'd only match if the video was from astern of the ship.
Note that COLREGs rule 9 (part) "as near to the outer limit of the channel or fairway which lies on her starboard side as is safe and practicable." may not actually be to starboard of the channel centerline if no other vessel is approaching in the opposite direction. Depending on tidal/current and wind conditions, and the ship's manoeuvring characteristics, keeping port of the centerline to allow additional room to starboard may be prudent.
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#27 Reply
Posted by
cosmicray
on 26 Mar, 2024 17:57
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The MV Dali was departing Baltimore, under it's own power, with two harbor pilots on board. Something happened to the power plant (still unclear) and the ship veered off course. Might have been the rudder, or might have been it got caught by the tide without any way to oppose it. There were 7 or 8 people on the bridge repairing potholes, and an unknown number of vehicles.
This reminds me a little of the ship collision in 1980, with the (old) Sunshine Skyway Bridge (across the entrance to Tampa Bay). That accident occurred during a strong rain squall, and the ship had one harbor pilot on board. One (of two spans) collapsed during that accident.
Prayers for everyone.
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#28 Reply
Posted by
BrokenYugo
on 26 Mar, 2024 18:30
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My only question is how many months/years did this ship have this problem, or some actionable sign of an issue that should have been corrected but instead was allowed to snowball. Every disaster is a long chain or large pile of bad decisions, I'd be shocked if this was the first time it acted up.
I'm sure it will come out in the report, it always does, too bad the people who need to read the reports apparently don't.
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#29 Reply
Posted by
BILLPOD
on 26 Mar, 2024 19:02
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Does Boeing have a a ship building subsidiary
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#30 Reply
Posted by
tom66
on 26 Mar, 2024 19:10
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Apparently the ship radioed a MAYDAY into the port authority and the bridge was closed to traffic before the collision. This can be seen in the footage, before the ship strikes there is a pronounced gap in traffic.
That is fantastic on the part of the bridge operators, either quick thinking or a well rehearsed safety drill. Either way, they likely saved countless lives with this action. Sadly the construction crew stationed on the bridge didn't seem to be aware of the danger, or if they were, they didn't get out in time. You can see the trucks go down into the river when the collapse happens.
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#31 Reply
Posted by
mariush
on 26 Mar, 2024 19:38
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Yeah... they tried but couldn't get the ship to stop or turn fast enough
The guy in the video below says they black smoke is the engines running in emergency full reverse and he says the ship also dropped one anchor trying to stop the ship but the anchor was dragging along, and possibly that anchor contributed a bit to ship changing direction a bit but it was in theory a correct move in such scenarios
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#32 Reply
Posted by
floobydust
on 26 Mar, 2024 19:42
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They'd stopped traffic on the bridge but the road crew was still there I guess.
My heart goes out to the dead, crew fixing potholes at 1:30AM on the bridge. What a job to have.
The MV Dali had prior problems and crashed once at an Antwerp dock, it's 9 years old. Who knows how well maintained these container ships are.
The excessive stack smoke might be from the engine not fully supported (air pumps) when the backup generator is running?
The Bow motor really needed to work but sure didn't.
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#33 Reply
Posted by
tooki
on 26 Mar, 2024 21:08
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A friend of mine in Maryland texted me about this about an hour after it happened. Crazy.
I used to commute across that bridge daily.
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#34 Reply
Posted by
Bud
on 26 Mar, 2024 21:29
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The first thing that came to my mind watching the moment of collapse is the rightmost section of the bridge that also collapsed. Perhaps was not the best bridge design if the entire bridge collapsed because of one section was damaged.
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#35 Reply
Posted by
guenthert
on 26 Mar, 2024 21:35
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[..]
For the landlubbers: starboard is right side, the ship hit the left pylon.
Not from the ship's point of view. The ship was proceeding to seaward, but the video is looking landward, so left side pylon in the video is right (starboard) side as seen from of the ship. They'd only match if the video was from astern of the ship.
And I was sure it was. I saw only the webcam video on youtube ("lifestream") and mistook the lights in background for the port. An aerial view clears things up:
https://www.fox5dc.com/news/aerial-videos-photos-baltimore-francis-scott-key-bridge-collapseMy bad.
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#36 Reply
Posted by
nctnico
on 26 Mar, 2024 21:51
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That brings up an interesting question: are those bridges designed to survive single-ship impacts like that? We'd hope so, but I wonder if it's actually a requirement.
I think this comment shows a lack of understanding of the scale and proportions of the entire thing. It is pretty much impossible to build that bridge in a way that it could withstand being hit by a mass of, say, 100,000 tons, 150,000 tons etc, going at speed. And it makes no sense, economic or otherwise.
Still, the bridge could have been constructed/designed in a way that only 1 or 2 sections collapse in case of a pylon getting damaged. Now all 4 sections of the bridge collapsed.
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#37 Reply
Posted by
bdunham7
on 26 Mar, 2024 22:09
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OTOH if you suddenly throttle up a big diesel running at low speed under load to emergency full throttle, you will get *LOTS* of black smoke, especially if the engine isn't fully warmed up yet.
This ship has a low-speed direct-drive two-stroke engine that would have required a complete stoppage and reversal of the engine itself. AFAIK they typically will always be fully preheated with a boiler so it wouldn't be cold, but a full-power reversal/startup would certainly generate some pretty copious smoke. The heavy fuel they use doesn't help. Looking at that video I think you may be right in that reversing their single screw violently changed their direction, although I certainly wonder what the rudder issue was. I guess we'll wait for the reports to come out.
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#38 Reply
Posted by
tom66
on 26 Mar, 2024 22:32
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The first thing that came to my mind watching the moment of collapse is the rightmost section of the bridge that also collapsed. Perhaps was not the best bridge design if the entire bridge collapsed because of one section was damaged.
Still, the bridge could have been constructed/designed in a way that only 1 or 2 sections collapse in case of a pylon getting damaged. Now all 4 sections of the bridge collapsed.
This type of bridge is not redundant. A single lost section is catastrophic. This is common to most suspension and truss bridges of this scale. It is quite hard to imagine how you could build such redundancy into a bridge like this without fundamentally changing its design into something like a cantilever bridge which would require substantially more material.
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#39 Reply
Posted by
bdunham7
on 26 Mar, 2024 22:41
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I think this comment shows a lack of understanding of the scale and proportions of the entire thing. It is pretty much impossible to build that bridge in a way that it could withstand being hit by a mass of, say, 100,000 tons, 150,000 tons etc, going at speed. And it makes no sense, economic or otherwise.
It's pretty common to have islands of large fill around the piers. The island can be mostly underwater as it is sufficient to have the ship run aground before it gets to the bridge itself.
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#40 Reply
Posted by
EEVblog
on 26 Mar, 2024 22:45
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Thread from bridge designer Matt Dursh
https://twitter.com/MattDursh/status/1772605870599238112Bridge design for vessel collision. A🧵
The main span of the Francois Scott Key Bridge is 1300 ft. It also has 185 ft of clearance, making this a massive bridge.
This type of bridge is considered complex.
Baltimore is in for a long haul before replacement. Here is why.
We design modern bridges for ship impact, but this was not always the case.
In 1980 the Sunshine Skyway Bridge also collapsed from vessel strike.
The photo below is the original Skyway. Similar bridges and identical failure.
The Skyway collapse changed bridge design.
The Baltimore bridge collapsed because it got hit by container ship. What failed first?
It appears the bow of the ship made contact with the vertical columns that supported the truss superstructure, causing it to have a cascade failure.
This bridge was going to fail from this event. It simply was not designed for an equivalent static force that is well over 3 million pounds.
The container ship, assuming the navigation channel is centered, veered over 500 feet off course.
Why did the whole thing fall?
The whole truss fell because this is a continuous bridge.
This means that the 3 span unit behaves as as one. If one span fails, the maximum dead loads redistributes.
This provides benefits to load resistance and is how we design modern bridges for this.
How?
Modern bridges deal with vessel collision two ways.
The first is to use a dolphin.
This is a mass of rock, sand, and steel that serves to stop the vessel before it makes contact with the bridge.
Likely the new bridge replacement will use a dolphin as one method.
The second is to design the bridge to take the vessel strike and resist the event.
This is a massive undertaking with a central focus: don't collapse.
We will see localized failures, but maintain global stability.
This load could be well over 3 million pounds.
To resist that much load to stop a vessel, we need a flexible bridge and a lot of foundations, such as piling or drilled shafts.
Typically this is more foundation needed than to simply resist earthquakes, hurricanes, and every day loads.
So where do we go from here?
Baltimore is going to be without a critical bridge for a long time.
Tampa's Skyway bridge took 7 years, but this will be done sooner, hopefully much sooner.
What needs to be done? Well, a lot.
Can the approach spans be salvaged?
The approach spans are likely fine.
But are they tall enough to support the new main span? Does the bridge need more vertical clearance?
Officials will nees to ask... do they fully replace the bridge in full, or attempt to reopen sooner with only the main span?
The main span is not easy to design or build, unless they make a decision to go to a smaller span bridge (less than 375ft).
But that comes with new challenges particularly with how close the piers will be to the navigation channel.
There are many things left to talk about here, but on a plane now.
I specialize in bridge design of long bridges over navigable waters.
Thanks for reading and happy to answer all questions.
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#41 Reply
Posted by
bdunham7
on 26 Mar, 2024 22:45
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Here's a photo of the bridge with the intended path in green and the actual path in red. Not particularly accurate, just a rough hand drawing. Quite the sharp turn and very unlucky.
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Indeed, very unlucky.
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#43 Reply
Posted by
coppice
on 26 Mar, 2024 22:52
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It's pretty common to have islands of large fill around the piers. The island can be mostly underwater as it is sufficient to have the ship run aground before it gets to the bridge itself.
All the modern big bridges have those islands around the piers. They will certainly lead to a modest sized ship running aground in a fairly harmless way. Whether they are effective against a really big container ship is another matter.
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#44 Reply
Posted by
EEVblog
on 26 Mar, 2024 22:54
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Apparently the ship radioed a MAYDAY into the port authority and the bridge was closed to traffic before the collision. This can be seen in the footage, before the ship strikes there is a pronounced gap in traffic.
That is fantastic on the part of the bridge operators, either quick thinking or a well rehearsed safety drill. Either way, they likely saved countless lives with this action. Sadly the construction crew stationed on the bridge didn't seem to be aware of the danger, or if they were, they didn't get out in time. You can see the trucks go down into the river when the collapse happens.
Yes, really fantastic effort here if that's the case.
There wouldn't be any local "bridge operator" who could run out with witches hats and signs though right? Are there electronic signs they can just switch on warning people instantly? I pressume so.
Very sad about the construction crew and anyone else caught up in this.
EDIT: Yes, they have electonic signs.
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That brings up an interesting question: are those bridges designed to survive single-ship impacts like that? We'd hope so, but I wonder if it's actually a requirement.
I think this comment shows a lack of understanding of the scale and proportions of the entire thing. It is pretty much impossible to build that bridge in a way that it could withstand being hit by a mass of, say, 100,000 tons, 150,000 tons etc, going at speed. And it makes no sense, economic or otherwise.
The San Francisco Bay Bridge was hit by a ship similar in size to the ship that hit the Key Bridge and the damage to the bridge was minimal. This was an ecological disaster due to the collision spilling 50,000 gallons of bunker oil into the bay, but no injuries on the bridge or on the ship.
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#46 Reply
Posted by
soldar
on 26 Mar, 2024 23:11
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Still, the bridge could have been constructed/designed in a way that only 1 or 2 sections collapse in case of a pylon getting damaged. Now all 4 sections of the bridge collapsed.
That makes no sense. It is a single bridge, designed and built as a whole. It is not three bridges.
In any case. If the channel span falls it makes no difference: the channel is blocked and the vehicular deck above is blocked. The result is the same: both the maritime channel and the road above are unusable.
This is a one in a billion occurrence. If the ship had lost power a minute earlier it would not have reached the bridge and if it had lost it a minute later it would have been past the bridge.
In my estimation removing the wreck of the bridge is the most urgent task so that maritime traffic can be restored. We shall see how long that takes but I am generally quite impressed by how quick the feds deal with this kind of thing.
Vehicular traffic still has a tunnel under the Bay a bit farther north and another bridge a bit to the south so, while inconvenient, it is not terribly bad.
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#47 Reply
Posted by
tom66
on 26 Mar, 2024 23:12
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Apparently the ship radioed a MAYDAY into the port authority and the bridge was closed to traffic before the collision. This can be seen in the footage, before the ship strikes there is a pronounced gap in traffic.
That is fantastic on the part of the bridge operators, either quick thinking or a well rehearsed safety drill. Either way, they likely saved countless lives with this action. Sadly the construction crew stationed on the bridge didn't seem to be aware of the danger, or if they were, they didn't get out in time. You can see the trucks go down into the river when the collapse happens.
Yes, really fantastic effort here if that's the case.
There wouldn't be any local "bridge operator" who could run out with witches hats and signs though right? Are there electronic signs they can just switch on warning people instantly? I pressume so.
Very sad about the construction crew and anyone else caught up in this.
EDIT: Yes, they have electonic signs.
Imagine being that one guy who blew past the 'STOP DO NOT ENTER' sign because "ehhh I can make it"...
A system like this is installed in a tunnel in Sydney, not sure if anywhere else uses it for a bridge. Tunnels justify its use more often due to their greater risks (I imagine daylight vs dark tunnel makes it more difficult too).
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#48 Reply
Posted by
EEVblog
on 26 Mar, 2024 23:16
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They had two minutes warning:
https://www.bbc.com/news/live/world-us-canada-68663071Ship hit bridge two minutes after mayday call
The pilot steering the Dali made a mayday call to authorities roughly two minutes before the ship collided with the bridge, Baltimore County Executive John Olszewski has said.
We also have some new details about what happened onboard, with BBC's US partner CBS News saying multiple officials confirmed the Dali crew had tried to drop an anchor to stop the ship.
It's not clear if they were able to successfully deploy the anchor.
For those wondering why tug boats were not guiding the Dali, it's because tugs are not required to escort ships under the bridge.
They are used mainly to get ships in and out of the docking station in the Port of Baltimore.
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#49 Reply
Posted by
EEVblog
on 26 Mar, 2024 23:19
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Imagine being that one guy who blew past the 'STOP DO NOT ENTER' sign because "ehhh I can make it"...
A system like this is installed in a tunnel in Sydney, not sure if anywhere else uses it for a bridge. Tunnels justify its use more often due to their greater risks (I imagine daylight vs dark tunnel makes it more difficult too).
That has been activiated quite a few times in Sydney. Tall trucks getting stuck are not that uncommon, and you don't want cars piling up in the tunnel due to exhaust. IIRC they have a height detection system now and that water barrier activiates automatically if a tall truck tries to enter.
Of course, worst case activiation would be a harbour tunnel leak.
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#50 Reply
Posted by
soldar
on 26 Mar, 2024 23:32
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The San Francisco Bay Bridge was hit by a ship similar in size to the ship that hit the Key Bridge and the damage to the bridge was minimal. This was an ecological disaster due to the collision spilling 50,000 gallons of bunker oil into the bay, but no injuries on the bridge or on the ship.
Well, yes, but... In this case they built the bridge the way they did and I assume they had their reasons. Probably cost was a major consideration. Probably today it might be done quite differently. To make a large enough island to protect the supports you might have had to widen the span of the bridge more than was considered economical or practical at the time of it's design.
I mean, I tend to trust the people who designed it because they had the knowledge and information. I try not to second guess unless the flaws or faults are blatantly clear and obvious.
At the time the engineers thought it was a reasonable compromise and the fact that it has gone for so many decades without this accident kind of supports their choice. It is a one in a million chance and if it did not happen this time the bridge would most likely have served its life without a similar thing happening.
Engineers have to make choices with how to best use the budget they are given and after any accident there will be those who will say it could have been prevented if only they had spent more on this or that. It is just not economical to try to prevent everything that could possibly happen. Note also that the ship was already outside of the dredged channel and running aground (and slowing down).
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#51 Reply
Posted by
NiHaoMike
on 26 Mar, 2024 23:40
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Any info on how the steering system of the ship works? I'm surprised it doesn't have enough redundancy to prevent this, in particular a backup turbine (analogous to the RAT on an aircraft) powered by the momentum of the ship itself.
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Any info on how the steering system of the ship works? I'm surprised it doesn't have enough redundancy to prevent this, in particular a backup turbine (analogous to the RAT on an aircraft) powered by the momentum of the ship itself.
So am I.
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#53 Reply
Posted by
soldar
on 27 Mar, 2024 00:17
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Any info on how the steering system of the ship works? I'm surprised it doesn't have enough redundancy to prevent this, in particular a backup turbine (analogous to the RAT on an aircraft) powered by the momentum of the ship itself.
I guess it is most probably hydraulic and I think an emergency engine and pump would make more sense. I live next to a hospital and as soon as the electric power fails an emergency generator starts automatically. On a ship that size I would expect a standby system that guarantees the proper working of all essential functions. It may be that the ship did have them but they were not adequately maintained.
I am always surprised by how emergency systems are not functional when needed. Like when there is a fire in a crowded place and the emergency exits are locked and people die.
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#54 Reply
Posted by
cosmicray
on 27 Mar, 2024 00:33
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The Skyway collapse changed bridge design.
The Sunshine Skyway Bridge (entrance to Tampa Bay) came down in 1980. The FSK Bridge (that collapsed today) was built during the 1970s, so before the Skyway lessons were learned. The Sunshine Skyway Bridge (the current one) has dolphins surrounding the support columns. We live and we learn. The original Skyway Bridge lasted about ~25 years (originally there was a single span, then a second was added). The FSK Bridge survived for ~50 years. Properly taken care of, it might be still standing, other than for the vessel collision.
I grew up around Tampa Bay. The original SSB scared me. The new one is much better, but it's still a long way down to the water.
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#55 Reply
Posted by
cosmicray
on 27 Mar, 2024 00:40
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In my estimation removing the wreck of the bridge is the most urgent task so that maritime traffic can be restored. We shall see how long that takes but I am generally quite impressed by how quick the feds deal with this kind of thing.
Vehicular traffic still has a tunnel under the Bay a bit farther north and another bridge a bit to the south so, while inconvenient, it is not terribly bad.
US Army Corp of Engineers has been tasked with restoring the shipping channel, which includes the removal of the wreckage. I'm assuming they will be working with the owner of the ship and the port of Baltimore, to have the ship carefully withdrawn from the accident location.
Somewhere today it was mentioned that hazardous cargo that could cross the bridge, may not be allowable in the tunnel. So that is a complication that needs to be sorted out.
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#56 Reply
Posted by
soldar
on 27 Mar, 2024 00:52
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US Army Corp of Engineers has been tasked with restoring the shipping channel, which includes the removal of the wreckage. I'm assuming they will be working with the owner of the ship and the port of Baltimore, to have the ship carefully withdrawn from the accident location.
Somewhere today it was mentioned that hazardous cargo that could cross the bridge, may not be allowable in the tunnel. So that is a complication that needs to be sorted out.
I had not thought of hazmat but in the big scheme of things those vehicles can go around. Still, it the Key bridge being out of service will mean additional traffic on the other bridge and the tunnel and may lead to traffic jams, etc.
I would think getting the ship out of the way is the easier part and removing the wreckage of the bridge is more complicated. Or maybe not. I suppose the first thing is to get everything out of the channel and not necessarily out of the water.
I wonder how hard aground the ship is. I am reminded of the Evergrande ship that went aground in the Suez canal and they had quite a hard time getting it afloat again.
As for the wreckage of the bridge, I suppose it can be cut up so it is easier to move. Still, quite a task.
But clearing the channel and making it navigable again is, in my view, the most urgent task with great difference. Lots of ships are waiting to get out and to get in and waiting idle costs money.
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#57 Reply
Posted by
EEVblog
on 27 Mar, 2024 01:18
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Well, yes, but... In this case they built the bridge the way they did and I assume they had their reasons. Probably cost was a major consideration. Probably today it might be done quite differently. To make a large enough island to protect the supports you might have had to widen the span of the bridge more than was considered economical or practical at the time of it's design.
I mean, I tend to trust the people who designed it because they had the knowledge and information. I try not to second guess unless the flaws or faults are blatantly clear and obvious.
At the time the engineers thought it was a reasonable compromise and the fact that it has gone for so many decades without this accident kind of supports their choice. It is a one in a million chance and if it did not happen this time the bridge would most likely have served its life without a similar thing happening.
That would be my guess as well.
Engineering is the art of practical compromise.
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#58 Reply
Posted by
soldar
on 27 Mar, 2024 01:35
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That would be my guess as well.
Engineering the art of compromise.
Also, safety is a relative and changing concept. In the late 19th century, in the age of sail, it was considered quite normal to lose a sailor or two on a long voyage. they climbed the rigging and accidents were common. If a sailor fell on deck he was probably dead or maimed for life. If he fell in the water the chances of recovering him were slim... even if they tried and many times they didn't because it might be considered too risky with little chance of recovering him.
Up into the 1930s building bridges and other structures the risk of death was just considered part of the job. No safety equipment and no real accident prevention. It was a very different mentality.
Today we build a tunnel and it is two tunnels plus one or two service tunnels, etc. And build with much greater safety in mind. The culture has changed. Electrical appliances and installations from 60, 80, 100 years ago were extremely dangerous by the standards of today.
It is easy to see how the mentality of safety in general has changed in developed nations. Just go to some third world countries and you still see a mentality that any money or effort expended in safety and prevention is money and effort wasted.
Safety costs money and it is good if you can pay for it. The richer we become the more safety we can afford. Which is good.
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#59 Reply
Posted by
soldar
on 27 Mar, 2024 01:40
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I notice an electric line running parallel to the bridge and the pylons are well protected by caissons. Still, they are in shallower water, farther away from the dredged channel. If they were hit by a ship that size I doubt they would survive.
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#60 Reply
Posted by
BrianHG
on 27 Mar, 2024 01:49
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Closeup view of crash. The ship appears to have it's power go off and on 3 times up to the crash...
Areal reconnaissance the next day.
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#61 Reply
Posted by
EEVblog
on 27 Mar, 2024 01:53
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Safety costs money and it is good if you can pay for it. The richer we become the more safety we can afford. Which is good.
But there is still going to be practical compromise at some point, that six sigma does only get you so far.
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#62 Reply
Posted by
fourfathom
on 27 Mar, 2024 06:12
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The San Francisco Bay Bridge was hit by a ship similar in size to the ship that hit the Key Bridge and the damage to the bridge was minimal. This was an ecological disaster due to the collision spilling 50,000 gallons of bunker oil into the bay, but no injuries on the bridge or on the ship.
That was a mere side-swipe or glancing blow -- not a head-on crash. The Bay Bridge pylon gouged the side of the hull. Up close the Bay Bridge pylons are rugged-looking but I doubt that they could withstand a bad direct collision.
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#63 Reply
Posted by
Jeroen3
on 27 Mar, 2024 07:02
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The regs say the ship should have steering back within 45 seconds by emergency power.
Looks like it takes more than a minute for power to recover.
These ships have massive power plants. Looks like they have four ~4 MW generators. They're big, I worked on some.
And depending on the amount of reefers they're running multiple generators are in parallel all the time. I'm not sure if they can run the main engine on emergency power alone, that is typically only to get one of the four others running.
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#64 Reply
Posted by
EEVblog
on 27 Mar, 2024 07:38
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In Tasmania they stop traffic when a large ship goes under:
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#65 Reply
Posted by
EEVblog
on 27 Mar, 2024 07:40
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The regs say the ship should have steering back within 45 seconds by emergency power.
Looks like it takes more than a minute for power to recover.
These ships have massive power plants. Looks like they have four ~4 MW generators. They're big, I worked on some.
And depending on the amount of reefers they're running multiple generators are in parallel all the time. I'm not sure if they can run the main engine on emergency power alone, that is typically only to get one of the four others running.
I heard on an interview with an expert on large ship navigation that the port thusters at full power can overload the generators and cause a complete loss of power.
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#66 Reply
Posted by
tom66
on 27 Mar, 2024 08:36
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The regs say the ship should have steering back within 45 seconds by emergency power.
Looks like it takes more than a minute for power to recover.
These ships have massive power plants. Looks like they have four ~4 MW generators. They're big, I worked on some.
And depending on the amount of reefers they're running multiple generators are in parallel all the time. I'm not sure if they can run the main engine on emergency power alone, that is typically only to get one of the four others running.
I heard on an interview with an expert on large ship navigation that the port thusters at full power can overload the generators and cause a complete loss of power.
That seems like poor design. Surely those thrusters should be electronically limited when on emergency power, or the circuit breaker to the thrusters should trip before killing the generator too. The last thing you need in a situation like this is losing electric power as well as steering, as it will disorient you at night.
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#67 Reply
Posted by
Jeroen3
on 27 Mar, 2024 08:43
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The regs say the ship should have steering back within 45 seconds by emergency power.
Looks like it takes more than a minute for power to recover.
These ships have massive power plants. Looks like they have four ~4 MW generators. They're big, I worked on some.
And depending on the amount of reefers they're running multiple generators are in parallel all the time. I'm not sure if they can run the main engine on emergency power alone, that is typically only to get one of the four others running.
I heard on an interview with an expert on large ship navigation that the port thusters at full power can overload the generators and cause a complete loss of power.
Yes, to operate thruster they will need more than 1 generator, often 3. Thrusters are awful for generators. They can take all the load in several seconds, and then also dump it. Wiki says the thruster is 3000 kW. That's challenging.
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#68 Reply
Posted by
dietert1
on 27 Mar, 2024 11:46
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Maybe the reason for the curve the ship took was trying to run it into the dolphins. It's terrible the ship passed all the dolphins and got stuck exactly at the bridge pillar. The pillar should have been in the "shadow" of the dolphins.
Regards, Dieter
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#69 Reply
Posted by
soldar
on 27 Mar, 2024 12:31
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Maybe the reason for the curve the ship took was trying to run it into the dolphins. It's terrible the ship passed all the dolphins and got stuck exactly at the bridge pillar. The pillar should have been in the "shadow" of the dolphins.
Regards, Dieter
What? This makes no sense at all.
There were no dolphins.
The ship was out of control. If they had any control they would have gone under the bridge.
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#70 Reply
Posted by
bdunham7
on 27 Mar, 2024 14:11
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There were no dolphins.
There are, visible here in Bing maps and in my earlier photo. Oddly they aren't visible in Google maps satellite view.
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#71 Reply
Posted by
ejeffrey
on 27 Mar, 2024 15:24
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That would be my guess as well.
Engineering is the art of practical compromise.
Also the size of container ships has probably increased since the bridge was designed. It doesn't sound like the bridge was designed to take a large direct impact in any case but even if it was designed for a typical ship from the 60s and 70s, it might not have been enough. You try to plan ahead when you design a major civil engineering project but you can't necessarily plan for every thing that could happen in 50 years.
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#72 Reply
Posted by
fourfathom
on 27 Mar, 2024 15:26
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Any info on how the steering system of the ship works? I'm surprised it doesn't have enough redundancy to prevent this, in particular a backup turbine (analogous to the RAT on an aircraft) powered by the momentum of the ship itself.
On any vessel with a rudder, there needs to be water flowing past the rudder for steerage. At low speeds, this flow is provided by the propeller. Once that flow diminishes the rudder becomes ineffective (especially with the relatively small rudders you find on large ships). And if you are trying to back up, a working propeller can no longer force water over the rudder, making steering even more difficult. In this case you get "prop walk" caused by the asymmetrical water flow around the propellor (the top side is close to the hull, the bottom side is not), and this pushes the stern sideways more than the rudder can compensate for. I believe we saw this in the video. Also, apparently they were dragging an anchor (ships anchors are generally too small to be of much use in this type of situation), and this also made any rudder steering control much less effective.
Some ships have propellers on steerable pods, bow and stern, and/or bow and stern thrusters (mounted for sideways maneuvering thrust) but I understand that this ship only had one propeller (screw) and a rudder.
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#73 Reply
Posted by
switchabl
on 27 Mar, 2024 17:31
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Some ships have propellers on steerable pods, bow and stern, and/or bow and stern thrusters (mounted for sideways maneuvering thrust) but I understand that this ship only had one propeller (screw) and a rudder.
As well as a single 3000 kW bow thruster according to Wikipedia.
https://en.wikipedia.org/wiki/MV_Dali#DescriptionNot likely to have any relevant effect at 8 kts though.
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#74 Reply
Posted by
fourfathom
on 27 Mar, 2024 18:14
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Some ships have propellers on steerable pods, bow and stern, and/or bow and stern thrusters (mounted for sideways maneuvering thrust) but I understand that this ship only had one propeller (screw) and a rudder.
As well as a single 3000 kW bow thruster according to Wikipedia.
https://en.wikipedia.org/wiki/MV_Dali#Description
Not likely to have any relevant effect at 8 kts though.
I was not aware of the bow thruster -- should have checked first. Thanks!
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#75 Reply
Posted by
tooki
on 27 Mar, 2024 18:22
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Apparently the ship radioed a MAYDAY into the port authority and the bridge was closed to traffic before the collision. This can be seen in the footage, before the ship strikes there is a pronounced gap in traffic.
That is fantastic on the part of the bridge operators, either quick thinking or a well rehearsed safety drill. Either way, they likely saved countless lives with this action. Sadly the construction crew stationed on the bridge didn't seem to be aware of the danger, or if they were, they didn't get out in time. You can see the trucks go down into the river when the collapse happens.
Yes, really fantastic effort here if that's the case.
There wouldn't be any local "bridge operator" who could run out with witches hats and signs though right? Are there electronic signs they can just switch on warning people instantly? I pressume so.
Very sad about the construction crew and anyone else caught up in this.
EDIT: Yes, they have electonic signs.
In addition to the electronic signage, there is the toll booth area on the east approach (for both directions) that could have stopped westbound traffic. But additionally, due to the roadwork being done, there were apparently traffic flaggers present. I don’t know whether they were the ones who actually stopped traffic.
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#76 Reply
Posted by
soldar
on 27 Mar, 2024 19:13
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There were no dolphins.
There are, visible here in Bing maps and in my earlier photo. Oddly they aren't visible in Google maps satellite view.
I believe they are intended more as navaids as they have lights and they are not really placed as dolphins and they are not massive enough to serve that purpose for any large ship.
They would be useless for a ship that size. I suppose they could serve to stop small speedboats or such.
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#77 Reply
Posted by
soldar
on 27 Mar, 2024 19:19
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Some ships have propellers on steerable pods, bow and stern, and/or bow and stern thrusters (mounted for sideways maneuvering thrust) but I understand that this ship only had one propeller (screw) and a rudder.
This YouTube channel shows time lapse videos of cruise ships arriving and departing Miami and... not a single tug.
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#78 Reply
Posted by
tooki
on 27 Mar, 2024 19:39
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Also the size of container ships has probably increased since the bridge was designed.
Not “probably”. A better word is “dramatically”. The Dali is a roughly 10000-TEU ship. (TEU = twenty-foot equivalent units) That’s 4x the size of the biggest container ships in existence when the Key Bridge’s construction began in 1972. And a fraction of the size of the biggest ships today, which currently top out at 24,000 TEU!
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#79 Reply
Posted by
nctnico
on 27 Mar, 2024 19:42
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Some ships have propellers on steerable pods, bow and stern, and/or bow and stern thrusters (mounted for sideways maneuvering thrust) but I understand that this ship only had one propeller (screw) and a rudder.
This YouTube channel shows time lapse videos of cruise ships arriving and departing Miami and... not a single tug.
I don't think that is a fair comparison. Cruise ships hop short distances from harbour to harbour including relatively small harbours. Freight ships OTOH travel much longer distances and are much more cost sensitive so it makes sense to equip a ship with the minimum necessary features. Keep in mind that what isn't on a ship, can't get broken
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#80 Reply
Posted by
soldar
on 27 Mar, 2024 19:47
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I don't think that is a fair comparison. Cruise ships hop short distances from harbour to harbour including relatively small harbours. Freight ships OTOH travel much longer distances and are much more cost sensitive so it makes sense to equip a ship with the minimum necessary features. Keep in mind that what isn't on a ship, can't get broken
Um... I wasn't comparing anything. Only pointing out that thrusters exist and can be used usefully.
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#81 Reply
Posted by
tom66
on 27 Mar, 2024 20:17
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Also the size of container ships has probably increased since the bridge was designed.
Not “probably”. A better word is “dramatically”. The Dali is a roughly 10000-TEU ship. (TEU = twenty-foot equivalent units) That’s 4x the size of the biggest container ships in existence when the Key Bridge’s construction began in 1972. And a fraction of the size of the biggest ships today, which currently top out at 24,000 TEU!
I am curious how much of an improvement such container ships are. Ultimately the TEU-per-day figures are what matter for a port.
I would presume the reason they exist is they have better fuel economy, and fuel is the biggest operating expense for a ship like this. Are they better in other ways, such as overall logistics capacity? Or, would it be better to have more smaller ships?
If it is a case where these ships offer, for instance, 5% better fuel consumption per container-km, it could be argued that society is bearing the cost of these ships in other ways (Suez Canal blockage would not have been possible without the Ever Given for instance, 20kTEU capacity) and governments should be thinking carefully about this.
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#82 Reply
Posted by
soldar
on 27 Mar, 2024 20:25
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There are, visible here in Bing maps and in my earlier photo. Oddly they aren't visible in Google maps satellite view.
Also visible in earlier Google Earth photos
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#83 Reply
Posted by
bdunham7
on 27 Mar, 2024 20:31
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I believe they are intended more as navaids as they have lights and they are not really placed as dolphins and they are not massive enough to serve that purpose for any large ship.
They would be useless for a ship that size. I suppose they could serve to stop small speedboats or such.
Hmmm, small speedboats? The reinforced concrete part that is out of the water is over 5 meters in diameter and presumably there is much more below the water. They are placed over 50 meters from the main bridge piers. I'm pretty sure that would stop a medium, or even a large speedboat! But since the Dali bypassed them entirely, we'll never know for sure. I'm betting that if even a large cargo ship hit them at a shallow angle as they anticipated, it probably wouldn't reach the bridge piers. But without knowing the subsea profile around those, its hard to say.
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#84 Reply
Posted by
floobydust
on 27 Mar, 2024 20:46
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That would be my guess as well.
Engineering the art of compromise.
Also, safety is a relative and changing concept. In the late 19th century, in the age of sail, it was considered quite normal to lose a sailor or two on a long voyage. they climbed the rigging and accidents were common. If a sailor fell on deck he was probably dead or maimed for life. If he fell in the water the chances of recovering him were slim... even if they tried and many times they didn't because it might be considered too risky with little chance of recovering him.
Up into the 1930s building bridges and other structures the risk of death was just considered part of the job. No safety equipment and no real accident prevention. It was a very different mentality.
Today we build a tunnel and it is two tunnels plus one or two service tunnels, etc. And build with much greater safety in mind. The culture has changed. Electrical appliances and installations from 60, 80, 100 years ago were extremely dangerous by the standards of today.
It is easy to see how the mentality of safety in general has changed in developed nations. Just go to some third world countries and you still see a mentality that any money or effort expended in safety and prevention is money and effort wasted.
Safety costs money and it is good if you can pay for it. The richer we become the more safety we can afford. Which is good.
I say nope. Profit is priority #1. Engineering is not so important. Ref. Boeing.
It's a toll bridge that makes a shit ton of money $56M last year. They even sell bonds. It's a big fat cash cow. I'm sure it's paid for itself a few times over its lifetime.
Could they not afford tugboat escorts? Upgrades would not useful, no bridge can withstand a fully loaded container ship nailing it.
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#85 Reply
Posted by
.RC.
on 27 Mar, 2024 23:32
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In a previous life I had a bit to do with cargo ships.
The number that broke down or had inoperable things like bow thrusters was surprising. It is probably why they were mostly registered in some third world country.
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#86 Reply
Posted by
JustMeHere
on 27 Mar, 2024 23:52
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Apparently the ship radioed a MAYDAY into the port authority and the bridge was closed to traffic before the collision. This can be seen in the footage, before the ship strikes there is a pronounced gap in traffic.
That is fantastic on the part of the bridge operators, either quick thinking or a well rehearsed safety drill. Either way, they likely saved countless lives with this action. Sadly the construction crew stationed on the bridge didn't seem to be aware of the danger, or if they were, they didn't get out in time. You can see the trucks go down into the river when the collapse happens.
Yes, really fantastic effort here if that's the case.
There wouldn't be any local "bridge operator" who could run out with witches hats and signs though right? Are there electronic signs they can just switch on warning people instantly? I pressume so.
Very sad about the construction crew and anyone else caught up in this.
EDIT: Yes, they have electonic signs.
In addition to the electronic signage, there is the toll booth area on the east approach (for both directions) that could have stopped westbound traffic. But additionally, due to the roadwork being done, there were apparently traffic flaggers present. I don’t know whether they were the ones who actually stopped traffic.
The police stopped the traffic. This is well documented. (
https://www.foxnews.com/video/6349808520112). Also there are no toll booths on this bridge (
https://www.google.com/maps/place/Francis+Scott+Key+Bridge,+Maryland/@39.2298883,-76.5108951,319m/data=!3m1!1e3!4m6!3m5!1s0x89c80052ddeb3cad:0xf3fb8c8f100a3e9e!8m2!3d39.2323329!4d-76.5063164!16zL20vMDR2Njgw!5m1!1e4?entry=ttu)
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I say nope. Profit is priority #1. Engineering is not so important. Ref. Boeing.
It's a toll bridge that makes a shit ton of money $56M last year. They even sell bonds. It's a big fat cash cow. I'm sure it's paid for itself a few times over its lifetime.
Those cargo ships, as .RC. also confirms, are the epitome of favoring profits over anything else, being extremely polluting and transporting cheap goods all over the world that are of dubious quality and manufactured in dubious conditions for a bottom-low cost.
So really, I don't know how we can even be surprised.
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#88 Reply
Posted by
vk6zgo
on 28 Mar, 2024 00:20
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In a previous life I had a bit to do with cargo ships.
The number that broke down or had inoperable things like bow thrusters was surprising. It is probably why they were mostly registered in some third world country.
Back in the 1950s/60s the regulation of such things in Australian ports was very strict, to the point of harshness.
Ships suspected of not meeting the safety standards, (usually back then, those registered in Panama), would undergo a "snap" inspection.
If they didn't meet the requirements, they were asked nicely to fix things, & in the meantime they could not leave the port.
The "Sheriff's Officer"
* would nail (in reality, tape) a notice to the mast, officially arresting the ship.
If they still didn't fix it, the fines started to apply.
*Yes, Virginia, we do have Sheriff's, but they don't lead posses chasing "owlhoots", they are "Officers of the Court", who in turn have minions who do such things as arresting ships.
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#89 Reply
Posted by
floobydust
on 28 Mar, 2024 00:22
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[...] Also there are no toll booths on this bridge [...][/url])
"All eight Maryland Transportation Authority (MDTA) facilities are all electronic (cashless). With All Electronic Tolling (AET), drivers do not stop or slow down to pay tolls. Instead, they are collected through E-ZPass, Pay-By-Plate, and Video Tolling...."
source {mysteriously offline for a while now}
I wonder if this disaster is out of the woods? The ship is stuck on top of the concrete pier, full 1.5M gal of fuel, has a history of structural damage from crashing into a dock years ago. Yeah good luck there. At least it's not on fire.
It's said the ship had electrical problems for two days
while docked and they're suspecting contaminated fuel as another problem.
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#90 Reply
Posted by
Someone
on 28 Mar, 2024 00:47
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At least it's not on fire.
Yet/so-far.
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#91 Reply
Posted by
johansen
on 28 Mar, 2024 01:41
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I would presume the reason they exist is they have better fuel economy, and fuel is the biggest operating expense for a ship like this. Are they better in other ways, such as overall logistics capacity? Or, would it be better to have more smaller ships?
If it is a case where these ships offer, for instance, 5% better fuel consumption per container-km, it could be argued that society is bearing the cost of these ships in other ways (Suez Canal blockage would not have been possible without the Ever Given for instance, 20kTEU capacity) and governments should be thinking carefully about this.
I don't think the ships are going to get much bigger than they are now, because at some point the lowest natural resonance frequency of the largest boats, which is already on the order of 1 second.. results in a problem where the waves can split the ship in half. bigger ship would require more steel which means your improvements in hull speed are offset by the ratio of dead to full load.
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#92 Reply
Posted by
JustMeHere
on 28 Mar, 2024 02:08
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I would presume the reason they exist is they have better fuel economy, and fuel is the biggest operating expense for a ship like this. Are they better in other ways, such as overall logistics capacity? Or, would it be better to have more smaller ships?
If it is a case where these ships offer, for instance, 5% better fuel consumption per container-km, it could be argued that society is bearing the cost of these ships in other ways (Suez Canal blockage would not have been possible without the Ever Given for instance, 20kTEU capacity) and governments should be thinking carefully about this.
I don't think the ships are going to get much bigger than they are now, because at some point the lowest natural resonance frequency of the largest boats, which is already on the order of 1 second.. results in a problem where the waves can split the ship in half. bigger ship would require more steel which means your improvements in hull speed are offset by the ratio of dead to full load.
The size of the ships are limited by canal locks and the bridges it will encounter. The ship class is often incorporated into the name. Ex: Panamax 366m. 400m.appears to be the current size limit. These ships cannot enter the Panama Canal though .
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#93 Reply
Posted by
JustMeHere
on 28 Mar, 2024 02:18
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I don't think it's a question of cost vs safety. It's a question of mass. The more mass added to a bridge means the more additional mass that is needed to stop the bridge from collapsing under its own weight.
At some point making the bridge stronger adds more weight to the point the bridge can't be made any stronger. (My university roommates were civil engineers, and I remember discussing this exact subject with them.)
Space flight has the same limitation. Say it takes 2 kg of fuel to lift 1 kg of fuel. (Don't know the exact numbers, but I've heard 2-1 works.) This is why on orbit refueling is a big step to mankind moving past Earth.
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this is why the nostromo had a self destruct on it
I wonder if these ships will be robotic one day (or have a escape helicopter) and have a rapid scuttle command to sink them to save lives.
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#95 Reply
Posted by
AlfBaz
on 28 Mar, 2024 02:40
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It's been 20 plus years since I worked on ships that came into our local port so treat this info with a grain of salt.
I have worked on, maintained and fault found all of the gear mentioned below
Most large vessels have three main alternators driven by 3 separate diesel engines. Each alternator is somewhere in the vicinity of 600kW and up and run on heavy fuel oil, the same as the main engine.
This fuel at room temperature is a tar like substance and is heated to decrease its viscosity. It is then run through centrifugal separators to get rid of impurities prior to being fed to the engines
Under normal electrical load conditions only one alternator powers the main switchboard.
There are 2 methods of bringing a second or third main alternator on line. Automatically or manually. Both methods are the same just controlled by hand or actuators.
The alternator to be brought on line is started, its governor is adjusted to bring the frequency of the alternators’ output up as close as possible as the one already on line.
At this stage, fine adjustments are made to the speed to get the three phases in sync using either the three old school synchro lights or simply an analogue meter whose 12 o'clock position corresponds to phase alignment.
As the needle or lights come around slowly to the synchronized position it is connected to the main bus.
At this stage, depending on what you want to do the load sharing is adjusted by increasing or decreasing the governors whilst at the same time watching the frequency.
For example if you want to bring an extra alternator online you would start the diesel, synchronize and connect it to the bus. Once connected you increase the governor speed which has the effect of increasing that generators load and decreasing the load on the existing one. If the line frequency starts getting too high then you decrease the speed of the alternator with the most load.
Most of the ships at that time didn’t have autonomous load sharing, we did start to introduce these systems onto some vessels but that’s another story.
Ships that had bow thrusters needed two geny’s on line. Namely to handle the start up current but consequently as a safety measure, should one trip off.
All of the bow thrusters I had seen had variable pitch propellers and had to be at zero pitch before they could be started. Some were DOL others employed old school resistance starters with the latter method having massive inline resistance starters or slipring motors with resistors in their rotor circuits shorted out in stages
They all have an emergency alternator that runs on normal diesel fuel that have a substantially lower kW rating and start automatically when power loss is detected on the main buss. These were also air start.
When the emergency alternator is running only a small subset of essential equipment is powered and the main generators can't be switched onto the main bus until the emergency geny is ofline
In addition to emergency AC there are large banks of single cell batteries stacked up to create an emergency 24VDC supply for navigation, radios etc.
Some vessels had more than one bank for DC supplie for other various systems. One example of this was for a vessel that had three internal gantry cranes used to move and store large 30 tonne slabs of steel with large electro magnets. A large bank of AGM batteries making up 110VDC were used in the event of loss of power to ensure a slab wouldn’t detach.
In the steering flat where the top of the rudder comes into the ship, there would be a series of hydraulic rams actuated by a large pump and indeed had a backup. The port and starboard pumps. In fact there is very little equipment on a ship that doesn’t have 2 of everything.
If that vessel had a bow thruster it would explain why all the deck lights turned on and off as with the emergency geny, only a few would have turned on but the bow thruster certainly could NOT be run off of it so they would have been attempting to put the main genys back online which presumably tripped when attempting to restart the bow thruster.
Having worked on many overseas ships they were often poorly maintained with a lot of safety stuff spragged out. Many times when surveyors were called onboard to inspect dodgy vessels, they would be laid up and barred from going to sea until rudimentary safety gear was repaired.
Speculating here, but if they were attempting to restart the bow thruster any number of issues would certainly cause the generators to trip off
edit: typo bow thruster can not be run from emergency generator
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#96 Reply
Posted by
NiHaoMike
on 28 Mar, 2024 04:51
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Given all the difficulty of having to match phases, wouldn't HVDC make more sense nowadays? And/or just stick to hydraulics for the big mechanical stuff?
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#97 Reply
Posted by
AlfBaz
on 28 Mar, 2024 06:00
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Most ships don't carry an electrician any more let alone EE's. So having complex systems out in the middle of the ocean needs simpler systems which facilitate farming style bodges.
I recollect one vessel coming into port where the ctrl system wouldn't, for some reason or another, allow some motor contactor to energize. I opened the front enclosure door and a lump of timber fell out as they'd jammed it in there to keep some pump motor running till they got to shore
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#98 Reply
Posted by
tooki
on 28 Mar, 2024 07:44
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#99 Reply
Posted by
tooki
on 28 Mar, 2024 07:49
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At least it's not on fire.
Yet/so-far.
Why would you expect this to happen, given that no indications so far point towards anything even distantly fire-related. The Dali is now at rest, and ships at rest don’t normally just burst into flame.
The two sources of smoke initially reported by some have since been explained: the black smoke is from the engines, and the “smoke” at the point of impact is concrete dust, isn’t it?
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#100 Reply
Posted by
SeanB
on 28 Mar, 2024 08:03
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Also to point out that those shipboard lights are high pressure sodium lights, which take 3 minutes to restrike when the power is interrupted. Cheap iron core and superimposed pulse starters will not strike a hot tube, until it has cooled down a little, when it will restrike, in about 3 minutes. I would also say the ship owners would also not buy dual tube lamps, where they have 2 arc tubes in parallel in the glass envelope, and which will, if there is a single power dip, have the other tube light up and run, as these cost double the price of the cheap Chinese Ya Ming lamps they likely buy by the case lot. The lights going out is a good indication of power loss, but the relight shows the hot restrike time, and they all coming on nearly at the same time says they were all from the same batch, and all had similar running hours on them, as the restrike time varies greatly with age, and from batch to batch. The only way to have hot restrike is to buy more expensive ballasts that can provide the 5kV plus needed to strike the tube, which needs the wiring to be insulated to the socket, and the socket to be rated for 5kV without flashing over, plus the tubes need a different E40 base design with a wider glass insulator.
No LED lights, the power supplies fail badly, even those designed for rough service use, and do not mix well with salt water ingress, while the magnetic will carry on till the core rots away. Also easy to relamp, as all you need to carry up in a small sling bag is a spare lamp, a new ignitor, a can of WD40 for the rusted fasteners, and some pliers and screwdrivers to open the fixture, which mostly use simple spring clips to allow tool less lamp changes. LED you have to use a rope and pulley to first lower the old one down, and then pull the new one up, and need 2 people up there, and 2 on deck, to do this. Lamp just needs one person and possibly a deck watcher for the crew of 3, doing 3 at a time in an area. Plus also 5 minutes per lamp, excluding the climb, and power does not have to be cut either.
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#101 Reply
Posted by
Someone
on 28 Mar, 2024 08:42
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At least it's not on fire.
Yet/so-far.
Why would you expect this to happen, given that no indications so far point towards anything even distantly fire-related. The Dali is now at rest, and ships at rest don’t normally just burst into flame.
The two sources of smoke initially reported by some have since been explained: the black smoke is from the engines, and the “smoke” at the point of impact is concrete dust, isn’t it?
Mostly in jest, but grounded ships have subsequently caught fire in the past so its not implausible.
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#102 Reply
Posted by
Circlotron
on 28 Mar, 2024 11:50
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And a fraction of the size of the biggest ships today, which currently top out at 24,000 TEU!
That's twelve thousand large truck's worth! Yowsers!
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#103 Reply
Posted by
floobydust
on 28 Mar, 2024 18:45
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At least it's not on fire.
Yet/so-far.
Why would you expect this to happen, given that no indications so far point towards anything even distantly fire-related. The Dali is now at rest, and ships at rest don’t normally just burst into flame.
The two sources of smoke initially reported by some have since been explained: the black smoke is from the engines, and the “smoke” at the point of impact is concrete dust, isn’t it?
Cargo manifest shows 56 containers of hazardous (764 tons) mostly corrosives, flammables, "Class 9 including lithium-ion batteries" according to the NTSB Media Briefing 2.
Containers are flattened, crushed. Some in the water, some are leaking. There's around 4,700 on the ship.
It's not a static situation, tides up and down and things have to be moved, torched cut as they clean up the mess.
I would say there is a fire risk- but putting it out is the impossibility if one starts. The bow has a huge hole in it.
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#104 Reply
Posted by
tooki
on 28 Mar, 2024 18:57
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At least it's not on fire.
Yet/so-far.
Why would you expect this to happen, given that no indications so far point towards anything even distantly fire-related. The Dali is now at rest, and ships at rest don’t normally just burst into flame.
The two sources of smoke initially reported by some have since been explained: the black smoke is from the engines, and the “smoke” at the point of impact is concrete dust, isn’t it?
Mostly in jest, but grounded ships have subsequently caught fire in the past so its not implausible.
I said ships do not
normally catch fire, not that it's impossible.
And it's not grounded, mind you. The ship is afloat.
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#105 Reply
Posted by
tooki
on 28 Mar, 2024 18:58
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Cargo manifest shows 56 containers of hazardous (764 tons) mostly corrosives, flammables, "Class 9 including lithium-ion batteries" according to the NTSB Media Briefing 2.
Containers are flattened, crushed. Some in the water, some are leaking. There's around 4,700 on the ship.
It's not a static situation, tides up and down and things have to be moved, torched cut as they clean up the mess.
I would say there is a fire risk- but putting it out is the impossibility if one starts. The bow has a huge hole in it.
Definitely not impossible. But no reason to assume it's a likely outcome.
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a container full of massagers might turn on and cause the entire situation to shake apart
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This fuel at room temperature is a tar like substance and is heated to decrease its viscosity. It is then run through centrifugal separators to get rid of impurities prior to being fed to the engines
One theory that I've seen, that sounds plausible, is that contaminated fuel clogged the fuel filters for the generators, causing the generators to stop. Perhaps the ship didn't have centrifugal separators, or the separators didn't filter out enough impurities to prevent clogging the filters.
The bunker oil used as fuel on ships like this one is the dregs of the petroleum refining process and often contains gunk that may be problematic.
All of this should be easy enough to figure out as the ship is still intact and presumably there's data logging that will point to the cause of the problem.
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#108 Reply
Posted by
tooki
on 28 Mar, 2024 19:44
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All of this should be easy enough to figure out as the ship is still intact and presumably there's data logging that will point to the cause of the problem.
Yep. The NTSB has already taken the data recorder. However, we may end up disappointed with what it contains, or rather doesn't.
This is what the
NYT reported:
Jennifer Homendy, the N.T.S.B. chair, says the agency has long wanted more data to be recorded on ships’ voyage data recorders. She described the apparatus as recording only basic data, far less than is the case with the recording devices — or “black boxes” — on commercial airplanes.
N.T.S.B. officials said the voyage data recorder on the ship was a newer model, with additional features, but is still “very basic” compared to what would be on a commercial airplane. It does not, for example, record power distribution data, they said. However, it does record the ship's location, rudder commands and audio.
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#109 Reply
Posted by
tom66
on 28 Mar, 2024 21:14
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It should be easy enough to examine parts of the engines, generators, fuel and fuel system to determine the likely fault. Chances are, if they powered the ship up in this configuration they'd be able to replicate the fault too, if it's related to a problem that exists there rather than crew misoperation.
It sounds like from another NTSB report that the data recorders are only operational when the main ship power is running, so they likely only recorded data when things were operating correctly. The audio recorders, however, do operate off backup batteries, and so they've retrieved the audio from the ship's bridge for the duration of the incident.
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#110 Reply
Posted by
Someone
on 28 Mar, 2024 22:55
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At least it's not on fire.
Yet/so-far.
Why would you expect this to happen, given that no indications so far point towards anything even distantly fire-related. The Dali is now at rest, and ships at rest don’t normally just burst into flame.
The two sources of smoke initially reported by some have since been explained: the black smoke is from the engines, and the “smoke” at the point of impact is concrete dust, isn’t it?
Mostly in jest, but grounded ships have subsequently caught fire in the past so its not implausible.
I said ships do not normally catch fire, not that it's impossible.
And it's not grounded, mind you. The ship is afloat.
Equally I'm not saying it will catch on fire in the future for certain. yet/so-far both leave either possibility for the future and literally mean "up to the current time".
As to grounded, if it cant move as its tangled in things sitting on the riverbed, that mass/agglomeration of which the ship is a part is grounded.
Wikipedia references bringing the goods:
https://maritime-executive.com/article/bridge-s-weight-is-pinning-container-ship-dali-to-the-bottomIn a reversal of the usual order for a major marine salvage operation, the U.S. Army Corps of Engineers (USACE) and its contractors will make the first big move in getting the wrecked container ship Dali out of Baltimore's ship channel.
Dali's bow is technically aground in the channel, said Vice Adm. Peter Gautier at a press conference Wednesday, because of the vast weight of the steel bridge span resting on top. The ship is pinned to the bottom and cannot move.
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#111 Reply
Posted by
Andy Chee
on 28 Mar, 2024 23:40
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And it's not grounded, mind you. The ship is afloat.
Not with the weight of a broken bridge span sitting on the deck of the bow!
I’ll be fascinated with the salvage operation. Much like the refloating of Costa Concordia, they’ll have to be careful about weight and buoyancy shifts.
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let people claim containers as salvage and it will be gone in 3 days
However the value of a good failure analysis could benefit us for the next 100 years if they figure out every detail and determine how to make improvements
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#113 Reply
Posted by
Andy Chee
on 29 Mar, 2024 01:49
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Once enough debris has been manually cleared from the ship’s bow, the ship refloated and towed away, the remaining bridge span elements, both above and below water, will probably be broken down into smaller pieces by demolition explosives.
The bridge is way too big to cut apart with plasma torches or oxygen lances.
The ship itself is also probably destined for scrap metal yard.
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#114 Reply
Posted by
floobydust
on 29 Mar, 2024 01:54
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Keep the ship for collateral - some 1851 law which was cited by the Titanic’s owner in a Supreme Court case 1912, could limit the payout.
Titanic law could help ship owner limit liability in Baltimore bridge collapseEstimates are $2B to repair/replace the bridge, $0.1B to free the ship and clean up the mess. Biden is talking like the Feds will give the money, but I have to ask why the US taxpayer is ultimately on the hook, as well as the many years of cranked up toll pricing we know will result. OUCH.
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#115 Reply
Posted by
Andy Chee
on 29 Mar, 2024 02:06
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Keep the ship for collateral - some 1851 law which was cited by the Titanic’s owner in a Supreme Court case 1912, could limit the payout. Titanic law could help ship owner limit liability in Baltimore bridge collapse
Estimates are $2B to repair/replace the bridge, $0.1B to free the ship and clean up the mess. Biden is talking like the Feds will give the money, but I have to ask why the US taxpayer is ultimately on the hook, as well as the many years of cranked up toll pricing we know will result. OUCH.
Recouping the costs from the “at fault” parties, will probably take a long time in courts, longer than if the US government financed the rebuilding from the start.
The US government can always recoup the costs later.
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#116 Reply
Posted by
xrunner
on 29 Mar, 2024 02:06
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Oh yea Money Money Money (I'm humming the song from Dark Side of the Moon in my head at the moment). Of course we have lessons learned from the collapsed bridge, so they'll design the new one to withstand such a crash better. Maybe more lanes? How about restaurants and shopping areas at the entrances. The list goes on ...
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Oh yea Money Money Money (I'm humming the song from Dark Side of the Moon in my head at the moment). Of course we have lessons learned from the collapsed bridge, so they'll design the new one to withstand such a crash better. Maybe more lanes? How about restaurants and shopping areas at the entrances. The list goes on ...
I think you should put them on the bridge. Like the original london bridge.
I think you are going here with your idea.
You could buy all sorts of services on it. From the late seventeenth century there was a greater variety of trades, including metalworkers such as pinmakers and needle makers, sellers of durable goods such as trunks and brushes, booksellers and stationers.[18]
How about a drive through chapel?
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let people claim containers as salvage and it will be gone in 3 days
I know it's just tongue-in-cheek, but just for the sake of the idea, how would people salvage all this in 3 days right in the middle of the river with no bridge?
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how would people salvage all this in 3 days right in the middle of the river with no bridge
canoes
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#120 Reply
Posted by
floobydust
on 29 Mar, 2024 03:58
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Given $xx million to get this ship out of the way, how are we doing it? FAST
Use Thug Technology® - wait for high tide, maybe a Supermoon - startup the ship's engine and nail it in reverse!
Use TNT and blow up that pier!
I could borrow my uncle's tugboat, maybe call up his friends and get their tugs pushin' too.
Remember the Suez Canal incident March 2021?
Ever Given ran aground. It's over 2x GT as big as the
MV Dali (but similar engine power, odd). Call up
SMIT Salvage has a huge crane and tugs.
Bloomberg storyThe Francis Scott Key bridge also
got nailed in 1980 by (smaller) container ship named the Blue Nagoya. Good to know nothing was changed.
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how would people salvage all this in 3 days right in the middle of the river with no bridge
canoes
Yes.
(Just for some figures, a 400m container ship holds an average of 20,000 TEU (
https://en.wikipedia.org/wiki/Twenty-foot_equivalent_unit ), it's hard to give an equivalent weight of course, but it's usually about 20T per TEU.
So, that's about 400,000T for the whole ship. And, of course, in containers piled up on several layers.
All that in 3 days on some canoes.
)
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#122 Reply
Posted by
mfro
on 29 Mar, 2024 07:17
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Stick a $10000 tag on each container and they will be gone by tomorrow.
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I think they would form a fleet of various boats from all over the place in american east coast to take it on anything they can
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#124 Reply
Posted by
Jeroen3
on 29 Mar, 2024 08:21
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Given all the difficulty of having to match phases, wouldn't HVDC make more sense nowadays? And/or just stick to hydraulics for the big mechanical stuff?
Yes and no. Matching phases is easy, we're doing for decades. The gear is there, you can buy DEIF, Woodward, Deep Sea controllers for it. Standard gear. DC is not standard. It requires inverters, and those are complicated and dangerous. They require complex control theory and software. Where you can manually keep spinning copper in check if you have to.
However it is attempted. DC busses or having a few drives on DC bus is attempted at some ships. I know of a large ferry and some youghts but inverters do not play not nice with good old spinning copper and iron. Plagued with problems and breakdowns.
Inverters can do things generators cannot keep up with, not engine wise, not control wise and not due to reactances, complicated physiscs.
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I think they would form a fleet of various boats from all over the place in american east coast to take it on anything they can
There are things that are physically difficult. Various boards all over the place? That would be a major safety hazard, that's just insane.
And you can't lift those containers like that, they are all tightly placed next to one another and on top of one another. That needs major means to do it effectively and safely.
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Speaking of figures, if I didn't mess up my calculations, at the speed the ship was estimated to move when it hit the pillar and with its estimated mass, the energy must have been something the equivalent of the explosion of between 500kg and 1t TNT. Just to get an idea.
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#127 Reply
Posted by
jpanhalt
on 29 Mar, 2024 10:17
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Sunrise in Baltimore: 6:55 AM:
Oh, say, can you see
By the dawn's early light
What so proudly we hail'd
At the twilight's last gleaming?
Whose bright containers shined
Through the perilous night
O'er the river's banks we watched
And the Dali was still there.
Inspired by FSK and quoted in part.
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#128 Reply
Posted by
xrunner
on 29 Mar, 2024 10:58
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how would people salvage all this in 3 days right in the middle of the river with no bridge
canoes
Didn't the ancient Egyptians move multi-ton obelisks on simple wooden boats?
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#129 Reply
Posted by
langwadt
on 29 Mar, 2024 11:31
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This fuel at room temperature is a tar like substance and is heated to decrease its viscosity. It is then run through centrifugal separators to get rid of impurities prior to being fed to the engines
One theory that I've seen, that sounds plausible, is that contaminated fuel clogged the fuel filters for the generators, causing the generators to stop. Perhaps the ship didn't have centrifugal separators, or the separators didn't filter out enough impurities to prevent clogging the filters.
The bunker oil used as fuel on ships like this one is the dregs of the petroleum refining process and often contains gunk that may be problematic.
All of this should be easy enough to figure out as the ship is still intact and presumably there's data logging that will point to the cause of the problem.
coastal areas and ports are sulfur emission controlled areas, so there they run bunker A which is basically diesel
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#130 Reply
Posted by
switchabl
on 29 Mar, 2024 12:14
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Keep the ship for collateral - some 1851 law which was cited by the Titanic’s owner in a Supreme Court case 1912, could limit the payout. Titanic law could help ship owner limit liability in Baltimore bridge collapse
Estimates are $2B to repair/replace the bridge, $0.1B to free the ship and clean up the mess. Biden is talking like the Feds will give the money, but I have to ask why the US taxpayer is ultimately on the hook, as well as the many years of cranked up toll pricing we know will result. OUCH.
The article makes it sound a bit like it is some loophole in an old, forgotten law. But in fact the principle of limited liability has been a central element of maritime codes internationally for centuries and it comes up in almost all major shipping accidents.
Now, many people do think that this doesn't really make sense anymore in a world where LLCs and huge insurance companies exist and shipping isn't nearly as dangerous as it used to be. But any attempt to change this unilaterally might prove hard to enforce. E.g. the owner of the MV Dali is based in Singapore which is a member of the International Convention on Limitation of Liability for Maritime Claims.
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coastal areas and ports are sulfur emission controlled areas, so there they run bunker A which is basically diesel
Sometimes they run cleaner fuel when in port and switch to the dirty stuff when at sea.
Even the lowest grade bunker fuel is lower in sulfur than it used to be. In fact, that change has contributed to global warming because higher sulfur emissions tended to mitigate warming.
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#132 Reply
Posted by
langwadt
on 29 Mar, 2024 15:11
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coastal areas and ports are sulfur emission controlled areas, so there they run bunker A which is basically diesel
Sometimes they run cleaner fuel when in port and switch to the dirty stuff when at sea.
yep, and if they are going to shut down the engines. Don't want things to cool down with the thick fuel that needs to be hot
Even the lowest grade bunker fuel is lower in sulfur than it used to be. In fact, that change has contributed to global warming because higher sulfur emissions tended to mitigate warming.
yes, the global limit was lowered to 0.5% from (afair) 3.5% in 2020, I think in ports and coastal areas it is ~0.1%
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#133 Reply
Posted by
coppice
on 29 Mar, 2024 15:16
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Even the lowest grade bunker fuel is lower in sulfur than it used to be. In fact, that change has contributed to global warming because higher sulfur emissions tended to mitigate warming.
The response to this seems to be that we now need to throw more crap into the atmosphere to replace the crap we've just removed. Welcome to clown world.
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#134 Reply
Posted by
xrunner
on 29 Mar, 2024 16:27
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The largest crane on the Eastern seabord has arrived at the bridge. That may well be, but it doesn't seem large next to the wreckage.
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#135 Reply
Posted by
delfinom
on 29 Mar, 2024 17:49
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The largest crane on the Eastern seabord has arrived at the bridge. That may well be, but it doesn't seem large next to the wreckage.
* Largest water borne crane the army corps of engineers has access to
Also the photo is not even correct, they took a photo of another crane that got moved closer to the wreck.
This is the crane that's called in:
https://www.donjon.com/ches1000.htm
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That crane looks precarious. It's hard enough working with big cranes near the limit of their load capacity on solid ground--doing it on a floating barge adds another element of difficulty.
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#137 Reply
Posted by
floobydust
on 29 Mar, 2024 19:35
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Is this an example of decaying infrastructure or misplaced pride?
That crane barge built in 1972, max. 1,000 short tons (within 63ft), Donjon's stuff is all very old but with upgrades apparently.
It looks not enough to deal with the mangled steel trusses, and having to cut it up into nice little pieces will take a long time.
Just phone up a professional salvage company that has real cranes and foot the bill. The port needs to be open ASAP.
"U.S. Army Corps of Engineers (USACE) is deploying more than 1,100 personnel to Baltimore..."
It's going to be impressive, they don't mess around- but you still need good tools for the job.
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#138 Reply
Posted by
mariush
on 29 Mar, 2024 19:51
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I was wondering how feasible would be inflate some thick things with air or something and tie the to the metal of the bridge and then cut small segments of that bridge and drag the segments to the river sides while they float.
Maybe even something like filling shipping containers with ping pong balls or something and welding them shut... cheap flotation devices with mounting points at the corners to attach to the bridge.
I'm thinking the surface of the bridge would be the hardest to lift out the water and remove it, I imagine they'd have to cut strips and lift it with the crane.
I guess river's too deep for a boat like this to work :
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Is this an example of decaying infrastructure or misplaced pride?
That crane barge built in 1972, max. 1,000 short tons (within 63ft), Donjon's stuff is all very old but with upgrades apparently.
It looks not enough to deal with the mangled steel trusses, and having to cut it up into nice little pieces will take a long time.
Just phone up a professional salvage company that has real cranes and foot the bill. The port needs to be open ASAP.
"U.S. Army Corps of Engineers (USACE) is deploying more than 1,100 personnel to Baltimore..."
It's going to be impressive, they don't mess around- but you still need good tools for the job.
they need to make better boats because fuck the cost going on the tax payer. You can probobly make a better bridge but someone is just gonna make a bigger boat. Its way cheaper to make the boat and it effects way less people if they improve the boat rather then improving the bridge.
Why should we have to build crazy bridges, when there is a over seas non American manufacturer that probably caused this problem by putting copper clad wire in a generator to keep his costs down?
Like we are gonna end up eating off brand ramen to protect the right of Marsk to use alibaba inverters and crap like that. I don't think the infrastructure is failing.
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#140 Reply
Posted by
langwadt
on 29 Mar, 2024 20:16
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Is this an example of decaying infrastructure or misplaced pride?
That crane barge built in 1972, max. 1,000 short tons (within 63ft), Donjon's stuff is all very old but with upgrades apparently.
It looks not enough to deal with the mangled steel trusses, and having to cut it up into nice little pieces will take a long time.
Just phone up a professional salvage company that has real cranes and foot the bill. The port needs to be open ASAP.
"U.S. Army Corps of Engineers (USACE) is deploying more than 1,100 personnel to Baltimore..."
It's going to be impressive, they don't mess around- but you still need good tools for the job.
they need to make better boats because fuck the cost going on the tax payer. You can probobly make a better bridge but someone is just gonna make a bigger boat. Its way cheaper to make the boat and it effects way less people if they improve the boat rather then improving the bridge.
Why should we have to build crazy bridges, when there is a over seas non American manufacturer that probably caused this problem by putting copper clad wire in a generator to keep his costs down?
Like we are gonna end up eating off brand ramen to protect the right of Marsk to use alibaba inverters and crap like that. I don't think the infrastructure is failing.
what a weird nonsensical rant..
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whats decaying about the infrastructure? It was a fine bridge. Probably would have passed inspection for 50 years more. It is the ship that was having problems even by its service history. A boeingesque problem?
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Worse than Boeing, IMO, although (usually) less of a problem as there are no passengers.
The reliability and maintenance of those cargo ships are disastrous, from what I've heard.
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#143 Reply
Posted by
David Hess
on 29 Mar, 2024 20:49
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whats decaying about the infrastructure? It was a fine bridge. Probably would have passed inspection for 50 years more. It is the ship that was having problems even by its service history. A boeingesque problem?
The ship has been in service for a while, so a maintenance problem is more likely than a design or manufacturing problem. It could have been contaminated fuel so we will have to wait for the investigation and report.
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#144 Reply
Posted by
soldar
on 29 Mar, 2024 22:05
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what a weird nonsensical rant..
Especially when pretty much everybody agrees America's infrastructure is in bad state of decay and in serious need of update, repair, improvement and maintenance.
A search for
America, infrastructure, decay brings up dozens of pages, including the White House.
https://www.businessinsider.com/asce-gives-us-infrastructure-a-d-2017-3https://www.csis.org/analysis/united-states-broken-infrastructure-national-security-threathttps://www.whitehouse.gov/cea/written-materials/2021/11/15/the-time-is-now-to-modernize-u-s-infrastructure/And, in any case, the prevention of accidents, in general, is a multitude of layers, of redundancy.
That bridge today would be built with a breakwater and other better measures that it had when it was built fifty years ago.
Accidents happen. They happen in American built ships. They happen in American navy ships. They happen.
Blaming the whole thing on a foreign built component is misplaced.
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#145 Reply
Posted by
tom66
on 29 Mar, 2024 22:48
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Given the last disaster of similar scale in the USA was almost 50 years ago, it could be argued that a one-in-50 year event is not worth spending billions of dollars on (across all possible bridges on entry to ports in the USA).
Whilst tragic that six lives were lost, it is clear that the port authority and bridge operator had reasonable mitigation for this type of disaster by being able to close the bridge to traffic quickly. The cost is mostly economic, and even if it costs $2 billion to rebuild this bridge, it would probably not be worth spending, for instance, a further $2 billion on reinforcing remaining bridges.
I would like to see maritime law changed to make the insurers liable for these costs, though. It's not okay that the federal government has to pick up the tab for incompetent maintenance, or contaminated fuel.
Edit: corrected amount, brain fart
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#146 Reply
Posted by
soldar
on 29 Mar, 2024 23:01
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I would like to see maritime law changed to make the insurers liable for these costs, though. It's not okay that the federal government has to pick up the tab for incompetent maintenance, or contaminated fuel.
Where do you get the idea that the insurers are not liable?
https://edition.cnn.com/2024/03/28/business/who-ends-upholdingthebagfor-the-baltimore-bridge-collapse/index.html
Insurers footing the bill
The Dali ship is owned by Grace Ocean Private, a Singapore-based company, and insured by the Britannia Protection and Indemnity Club.
Britannia is one of the dozen marine insurance member clubs under the International Group of P&I Clubs, a consortium that provides marine liability coverage for 90% of ocean freight and pools liability claims among members. (The International Group of P&I Clubs did not respond to CNN’s request for comment.)
These insurance companies are backed by insurance companies of their own – a type of business known as a reinsurer.
Around 80 different reinsurers provide around $3 billion in coverage to the Dali’s insurers, according to Moody’s analyst Brendan Holmes. Since the losses will be spread across so many insurers, it’s unlikely to bankrupt any of the companies or cause a major bump in insurance prices, he said.
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#147 Reply
Posted by
tom66
on 29 Mar, 2024 23:19
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I would like to see maritime law changed to make the insurers liable for these costs, though. It's not okay that the federal government has to pick up the tab for incompetent maintenance, or contaminated fuel.
Where do you get the idea that the insurers are not liable?
The post above by @floobydust suggests they might be on the hook for a maximum of the ship's value + cost of cargo transport. So probably north of $100mn, but well short of the cost of one replacement bridge.
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#148 Reply
Posted by
floobydust
on 29 Mar, 2024 23:49
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whats decaying about the infrastructure? It was a fine bridge. Probably would have passed inspection for 50 years more. It is the ship that was having problems even by its service history. A boeingesque problem?
I meant the infrastructure to deal with modern shipping accidents - such as newer, VLCC tankers, big container ships, scuttling or on fire etc.
It's all fine letting these ships in/out of ports and on your waters, but at the same time you need to invest in the equipment to deal with their calamity, and not be caught with your pants down.
Coast Guard, U.S. Army Corps of Engineers (USACE) etc. doesn't have the equipment and it looks like neither do American salvage companies. We'll see how that crane barge from New Jersey does.
edit: It's the largest crane in the Eastern Seaboard.
edit 2: I was right, nobody makes a crane like this for general purpose unless...
"The crane originally was built as the Sun 800 in 1972 to help construct the Hughes Glomar Explorer, a deep-sea vessel used by the CIA in a secret mission called "Project AZORIAN" to recover a Soviet nuclear submarine that sank in the Pacific Ocean during the Cold War {1968}, according to the Engineering News-Record."
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#149 Reply
Posted by
soldar
on 30 Mar, 2024 00:18
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I would like to see maritime law changed to make the insurers liable for these costs, though. It's not okay that the federal government has to pick up the tab for incompetent maintenance, or contaminated fuel.
Where do you get the idea that the insurers are not liable?
The post above by @floobydust suggests they might be on the hook for a maximum of the ship's value + cost of cargo transport. So probably north of $100mn, but well short of the cost of one replacement bridge.
Regardless of the liability, I would advise not legislating in the heat of the moment and pondering things very carefully. Legislating too quick makes for bad laws.
All countries, including the USA, have many ways of limiting liability because it is considered to result in a benefit to society in the big picture. Limited liability corporations, bankruptcy laws, etc. might seem unjust in specific cases but they benefit society as a whole.
Governments already pay for infrastructure out of taxes because it results in economic activity and development and well being.
If the government required every business to have unlimited insurance coverage then many businesses would have to shut down because it would not be affordable.
I do not know but maybe if the USA required too much insurance or other requirements for ships and other forms of freight then that would result in much higher shipping costs or even in some ships or companies just refusing to go there.
It may well be that the USA considers the cost of rebuilding a bridge every few years more affordable than putting very onerous requirements on ships.
Legislating in the heat of the aftermath often makes bad law and has unwanted consequences.
Laws have to be considered and crafted very carefully and even then they often backfire.
The Jones Act requires vessels transporting freight within American ports to be American built and crewed. The ostensible purpose was to protect the American shipbuilding industry. In fact it totally backfired.
https://www.cato.org/publications/policy-analysis/jones-act-burden-america-can-no-longer-bearI would advise to tread slowly and carefully and consider changes with great care.
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#150 Reply
Posted by
JustMeHere
on 31 Mar, 2024 04:00
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Check out this video on how those engines work.
So the smoke is not likely the ship being "slammed" into reverse. You just can't do that with these engines. You basically have to stop the engine and restart it, and that takes a long time.
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Some analysis:
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#152 Reply
Posted by
guenthert
on 31 Mar, 2024 08:05
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[..]
It may well be that the USA considers the cost of rebuilding a bridge every few years more affordable than putting very onerous requirements on ships.
[..]
The monetary cost perhaps, but the loss of live (even if just minuscule when compared to car traffic) won't be very popular.
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#153 Reply
Posted by
EEVblog
on 01 Apr, 2024 02:26
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#154 Reply
Posted by
langwadt
on 01 Apr, 2024 02:31
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Wow, the response time of the pilot on board was incredible.
30 second after losing power the first time he was calling to get the bridge closed, and it was within 2 1/2 minutes.
https://twitter.com/cfishman/status/1773733488295882896
afiau the only reason they actually managed to close the bridge so fast was that police was already there because of the work being done on the bridge
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Wow, the response time of the pilot on board was incredible.
30 second after losing power the first time he was calling to get the bridge closed, and it was within 2 1/2 minutes.
https://twitter.com/cfishman/status/1773733488295882896
afiau the only reason they actually managed to close the bridge so fast was that police was already there because of the work being done on the bridge
Yes.
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#156 Reply
Posted by
soldar
on 01 Apr, 2024 08:20
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#157 Reply
Posted by
AlfBaz
on 02 Apr, 2024 21:25
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This fuel at room temperature is a tar like substance and is heated to decrease its viscosity. It is then run through centrifugal separators to get rid of impurities prior to being fed to the engines
One theory that I've seen, that sounds plausible, is that contaminated fuel clogged the fuel filters for the generators, causing the generators to stop. Perhaps the ship didn't have centrifugal separators, or the separators didn't filter out enough impurities to prevent clogging the filters.
The bunker oil used as fuel on ships like this one is the dregs of the petroleum refining process and often contains gunk that may be problematic.
All of this should be easy enough to figure out as the ship is still intact and presumably there's data logging that will point to the cause of the problem.
coastal areas and ports are sulfur emission controlled areas, so there they run bunker A which is basically diesel
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coastal areas and ports are sulfur emission controlled areas, so there they run bunker A which is basically diesel
Sometimes they run cleaner fuel when in port and switch to the dirty stuff when at sea.
yep, and if they are going to shut down the engines. Don't want things to cool down with the thick fuel that needs to be hot
Even the lowest grade bunker fuel is lower in sulfur than it used to be. In fact, that change has contributed to global warming because higher sulfur emissions tended to mitigate warming.
yes, the global limit was lowered to 0.5% from (afair) 3.5% in 2020, I think in ports and coastal areas it is ~0.1%
Contaminated fuel causing this issue is highly unlikely. If it were, the ship would of stayed blacked out. The fact that power was reenergised in short times indicates an electrical fault
Main engines are always stopped in port, ALWAYS
Main Engines are designed to run on heavy fuel oil (HFO) you can't change fuel on the fly and the cost of running a vessel on anything approaching diesel would be prohibitively expensive and need a completely different engine.
Then there' the matter of being able to carry the volume of any fuel other than HFO to be able to make the voyage.
The fuel oil tanks are at capacity when setting off.
If it were feasible to change the fuel type you would need the ship to drop anchor and change out major engine components.
Simply throwing a valve from one fuel to another is not what would happen you would have to clean out the cylinder liners and the scum deposits internally would require waiting for the main engine to cool down, remove heads and possibly liners and pistons and having people climb into the scrubbers to clean them out.
You have to remember that fuel ignition is caused by compressing the fuel air mixture, causing it to heat up and the fire. There is no "spark plug" that determines when it fires.
The firing point is determined by the stroke of the piston and bore diameter.
Not to mention the different operating temperatures caused by using different types of fuels. This alone would require fundamental mechanical engineering properties of the engine to change as heat exchangers would need to be different based the different heat generated from different fuels
As for who's fault this is, I would be looking at the port authority who allowed a vessel to navigate past what is an intrinsically flimsy bridge to move through this area without tug boats. Sure bow thrusters are installed to mitigate tug cost but it is electrical equipment which is prone to fail without notice and to not have a backup for this the outcome could be predicted by anyone who has the slightest idea of what hazard analysis is.
Given the power generation is at the back of the ship and bow thrusters are at the front of it and the typical length of a ship is 300-400m, voltage drop on startup is huge.
I have seen some vessels employ large transformers to increase the generated 415 3 phase voltage to 3.3kV to reduce the cable size feeding the bow thruster motors but I am not entirely sure this is standard practice.
Haven't seen any concrete evidence this vessel even has a bow thruster. If it doesn't then certainly a port authority issue for not using tug boats to manoeuvrer the ship out of the harbour.
Lets also not forget that when pilots are on board they're captaining the ship so the responsibility is on them not the master
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#158 Reply
Posted by
langwadt
on 02 Apr, 2024 23:33
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This fuel at room temperature is a tar like substance and is heated to decrease its viscosity. It is then run through centrifugal separators to get rid of impurities prior to being fed to the engines
One theory that I've seen, that sounds plausible, is that contaminated fuel clogged the fuel filters for the generators, causing the generators to stop. Perhaps the ship didn't have centrifugal separators, or the separators didn't filter out enough impurities to prevent clogging the filters.
The bunker oil used as fuel on ships like this one is the dregs of the petroleum refining process and often contains gunk that may be problematic.
All of this should be easy enough to figure out as the ship is still intact and presumably there's data logging that will point to the cause of the problem.
coastal areas and ports are sulfur emission controlled areas, so there they run bunker A which is basically diesel
*********************************************************
coastal areas and ports are sulfur emission controlled areas, so there they run bunker A which is basically diesel
Sometimes they run cleaner fuel when in port and switch to the dirty stuff when at sea.
yep, and if they are going to shut down the engines. Don't want things to cool down with the thick fuel that needs to be hot
Even the lowest grade bunker fuel is lower in sulfur than it used to be. In fact, that change has contributed to global warming because higher sulfur emissions tended to mitigate warming.
yes, the global limit was lowered to 0.5% from (afair) 3.5% in 2020, I think in ports and coastal areas it is ~0.1%
Contaminated fuel causing this issue is highly unlikely. If it were, the ship would of stayed blacked out. The fact that power was reenergised in short times indicates an electrical fault
Main engines are always stopped in port, ALWAYS
Main Engines are designed to run on heavy fuel oil (HFO) you can't change fuel on the fly and the cost of running a vessel on anything approaching diesel would be prohibitively expensive and need a completely different engine.
Then there' the matter of being able to carry the volume of any fuel other than HFO to be able to make the voyage.
The fuel oil tanks are at capacity when setting off.
...
they a change over to the cleaner fuel (Marine Diesel Oil) in coastal areas, changing from hot HFO to cold MDO it takes a while and of course has to be timed to use as little MDO as possible
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#159 Reply
Posted by
ZigmundRat
on 03 Apr, 2024 00:39
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#160 Reply
Posted by
floobydust
on 03 Apr, 2024 22:08
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I wonder if the ship's engines work or were they damaged when the smoke was going on? It's a huge engine 3 stories 82 RPM typ.
They plan to unload that ship. "Coast Guard Rear Adm. Shannon Gilreath said... planning to remove undamaged containers off the ship but has been held up by weather..."
edit: oh, the ship is grounded, water too shallow where it sits.
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#161 Reply
Posted by
soldar
on 04 Apr, 2024 08:53
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Well, the ship has to be grounded because it left the dredged channel and so unloading the containers helps with getting the ship afloat again .. and with getting the containers on their way.
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#162 Reply
Posted by
RJSV
on 04 Apr, 2024 18:35
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I've heard cost figures, in the past (...>> 20 years ago) that one container generally has goods valued at some 1 million dollar, of course in rough terms.
Some percentage, in the case here, are going to be expensive logistical crises, especially when causing long wait times. Consider a manufacturing line, that has to wait for container of 4 dollar parts, like a door handle for automotive factory line.
Do you wait, some weeks or months, to finally receive shipment, or, as purchasing agent, just contract out a duplicate order? One alternative leaves (you) with an Xtra 'million' dollars worth of extra stock.i
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#163 Reply
Posted by
guenthert
on 05 Apr, 2024 08:55
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I've heard cost figures, in the past (...>> 20 years ago) that one container generally has goods valued at some 1 million dollar, of course in rough terms.
I'm sure the value varies wildly. Given that end customers pay just in the order of $2k for a container to be shipped across the Atlantic, you can expect the value to be a multiple of that. If you're lucky, you fetch the container some multi-millionaire shipped his art collection with or the one used to smuggle cocaine, but you're more likely to fetch the one full of cheap Chinese made cloth hangers.
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#164 Reply
Posted by
Ice-Tea
on 05 Apr, 2024 09:37
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Main engines are always stopped in port, ALWAYS
Main Engines are designed to run on heavy fuel oil (HFO) you can't change fuel on the fly and the cost of running a vessel on anything approaching diesel would be prohibitively expensive and need a completely different engine.
I'm not entirely sure I completely understand what you're arguing here, but you can't run HFO in pretty much any port or coastal zone. A changeover to DO is always performed. You're right that it isn't on the fly, it does take some time, but the procedure is pretty standard. In addition, you don't want HFO in the tubes, pumps and injectors when you shut her down. There's tracing steam on pretty much all lines but starting up the engine with HFO is always a PITA regardless.
You have to remember that fuel ignition is caused by compressing the fuel air mixture
Eh, no. You heat up and compress the air (without fuel) and then inject fuel in the hot air. These are diesel engines, not petrol.
Not to mention the different operating temperatures caused by using different types of fuels. This alone would require fundamental mechanical engineering properties of the engine to change as heat exchangers would need to be different based the different heat generated from different fuels.
Not at all. The heaters have a regulation loop based on the measured viscosity of the fuel. As a result, HFO will be heated to 120°C or so and DO to 30°C by the same machinery.
As for who's fault this is, I would be looking at the port authority who allowed a vessel to navigate past what is an intrinsically flimsy bridge to move through this area without tug boats.
Comes down to cost, obviously, but even then it is somewhay debatable if tugs would have been able to do much.
Haven't seen any concrete evidence this vessel even has a bow thruster.
Aside from every bit of documentation out there and, well, common sense?
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#165 Reply
Posted by
Kleinstein
on 05 Apr, 2024 09:58
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A fuel problem is well possible to cause the engine to fail / stall. It could be as simple as an air bulble or a clogged filter that has a switch over to an alternate filter to allow cleaning on the fly.
The smoke plume is likely from restarting the engine. From the analysis (the speed of the ship did drop from that point on) this was with reverse direction, trying to slow down the vessel. This may have been the final large mistake, as this also caused the ship to turn and really get the wrong direction. With just the engine stoped, chances are they could have still passed the bridge, even with lost control over the rudder.
Using tugs may not be much safer: with such a large ship the tugs have limited control, once the ship has any useful speed. With tugs a broken line could as well cause a similar desaster if this happens at the wrong time and with some wind.
For improved safty it would be more having better backup for steering, so that a loss of control is less likely for the large vessels.
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#166 Reply
Posted by
m k
on 05 Apr, 2024 12:50
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You have to remember that fuel ignition is caused by compressing the fuel air mixture
Eh, no. You heat up and compress the air (without fuel) and then inject fuel in the hot air. These are diesel engines, not petrol.
Sulzer?
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#167 Reply
Posted by
langwadt
on 05 Apr, 2024 13:00
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You have to remember that fuel ignition is caused by compressing the fuel air mixture
Eh, no. You heat up and compress the air (without fuel) and then inject fuel in the hot air. These are diesel engines, not petrol.
Sulzer?
MAN B&W
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#168 Reply
Posted by
David Hess
on 05 Apr, 2024 18:03
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The smoke plume is likely from restarting the engine. From the analysis (the speed of the ship did drop from that point on) this was with reverse direction, trying to slow down the vessel. This may have been the final large mistake, as this also caused the ship to turn and really get the wrong direction. With just the engine stoped, chances are they could have still passed the bridge, even with lost control over the rudder.
Apparently depending on the tide, there is a significant cross-current at that point in the shipping channel, so without steerage they were doomed.
Using tugs may not be much safer: with such a large ship the tugs have limited control, once the ship has any useful speed. With tugs a broken line could as well cause a similar desaster if this happens at the wrong time and with some wind.
Tugs are basically useless for handling an emergency like this, unless they want to be part of the emergency. The bow thruster is also useless for something like this.
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#169 Reply
Posted by
JustMeHere
on 05 Apr, 2024 18:39
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A fuel problem is well possible to cause the engine to fail / stall. It could be as simple as an air bulble or a clogged filter that has a switch over to an alternate filter to allow cleaning on the fly.
The smoke plume is likely from restarting the engine. From the analysis (the speed of the ship did drop from that point on) this was with reverse direction, trying to slow down the vessel. This may have been the final large mistake, as this also caused the ship to turn and really get the wrong direction. With just the engine stoped, chances are they could have still passed the bridge, even with lost control over the rudder.
Using tugs may not be much safer: with such a large ship the tugs have limited control, once the ship has any useful speed. With tugs a broken line could as well cause a similar desaster if this happens at the wrong time and with some wind.
For improved safty it would be more having better backup for steering, so that a loss of control is less likely for the large vessels.
Watch the engine video that has been posted. It takes about 10 minutes to reverse a marine engine.
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#170 Reply
Posted by
JustMeHere
on 05 Apr, 2024 18:45
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Contaminated fuel causing this issue is highly unlikely. If it were, the ship would of stayed blacked out. The fact that power was reenergised in short times indicates an electrical fault
Main engines are always stopped in port, ALWAYS
Agree. With low engine speed, electrical blowers will be feeding most of the air into the engines.
If the engine is directly connected to the shaft then there's no way it can stay at the dock with the engine running. I guess it could, but not a good idea.
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Bound to happen, a very slight base, no surrounding bumpers .....
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#172 Reply
Posted by
NiHaoMike
on 07 Apr, 2024 13:37
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#173 Reply
Posted by
soldar
on 08 May, 2024 10:24
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How Bridge Engineers Design Against Ship Collisions
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#174 Reply
Posted by
floobydust
on 09 May, 2024 00:09
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The demolition plan is to free up the cargo ship using explosives, to get the big bridge span piece off the top of the ship. The ship's crew gets to stay on board.
Regarding the Dali engine exhaust smoke, I did find this. It was a valid engine room command back in the day of steamboats in the Civil War.
Some of my projects could use one of these lol. Stop Making Smoke!
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#175 Reply
Posted by
floobydust
on 14 May, 2024 23:08
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NTSB Marine Investigation
Preliminary Report May 14, 2024 is out, with good info on what happened (but not the cause).
I thought it strange the LV transformer TR1 primary and secondary breakers tripped at the same time. Redundant system but was brought up a bit uh odd and too late.
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Interesting read.
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#177 Reply
Posted by
tom66
on 14 May, 2024 23:24
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"The road maintenance inspector had been walking the length of the bridge
when the ship struck it. He ran north and made it to the nearest surviving span before
the rest of the bridge collapsed."
Hell of a story. I'd buy a lottery ticket if I were him.