rcktnut
Well-Known Member
Another bridge hit today: https://www.msn.com/en-us/news/us/b...ng-an-oil-spill/ar-BB1mrItE?ocid=BingNewsSerp
Quite a bit milder through.Another bridge hit today: https://www.msn.com/en-us/news/us/b...ng-an-oil-spill/ar-BB1mrItE?ocid=BingNewsSerp
I'm a CFI and commercial pilot. I follow Blancolirio channel on YT. He mainly does aviaition accidents. However, the parallels are there for the comparison, aviation to shipping systems. Liked his breakdown.
IMO one important thing was that they reset the two breakers that had just tripped rather than switching over to the other set, usually if a breaker trips there is a reason, and its likely to do it again...almost immediately, so I think that was a fail on the crews part. But I don't know ships...or aircraft for that matter, I do know a little bit about breakers though.I'm sorry, but I couldn't watch it after the first 2 minutes. All he was doing was reading the NTSB report, pretty much word for word. I know how to read, and already read it. He may know airplanes, but no, a ship is not at all like an airplane. The only thing similar in the electrical systems are they both involve the flow of electrons. The main engine of a ship is a slow speed diesel, which if I recall from my engineering class, is a little different from a turbo fan or jet engine. Maybe he did say something insightful later on, but I'm not optimistic.
Those details of crew actions may be laid out in the final report, which will be months or a year from now. My guess is that they may have opened some non-critical equipment breakers (fans, ac, reefers, etc.) on the way to closing those again. Typically, the engineers might then check a few obvious causes and troubleshoot before putting those other things back online one by one.IMO one important thing was that they reset the two breakers that had just tripped rather than switching over to the other set, usually if a breaker trips there is a reason, and its likely to do it again...almost immediately, so I think that was a fail on the crews part. But I don't know ships...or aircraft for that matter, I do know a little bit about breakers though.
Up front I don’t understand why the crew “manually” reset everything. This vessel surely had a control room with full remote control of the electrical system. But, moving on from there:
I don’t understand the operating configuration when leaving port, even if they had had some spurious loss of electrical in port (why didn’t that raise some eyebrows?). If DG3 and DG4 were online, I would have had HR2 and LR2 closed so that if the HVR bus tie opened, you would still have LV. In the configuration they had when leaving harbor, if any of HVR, HR1 or LV1 open, you lose all LV. And personally, when in a sensitive operation like leaving harbor, I would have had a DG on each side running, HVR closed, and both TR1 and TR2 energized with LVR open. That way, any single breaker opening would have almost no effect. Even three breakers opening would not have shut down the Main Engine.
I guess in the end, it comes down to why did the breakers open? Had someone been doing maintenance in the swbds? I need to hear that finding. But as I said, the configuration they were in was about as bad as it could be.
These guys were looking for a disaster. They did almost everything electrical wrong.
I would think that some of the crew members (especially officers) would want their own lawyers at some of these meetings as well. I wouldn't trust that my employer's lawyers wouldn't throw me under the bus at their earliest convenience.Well, we were all treated with different opinions and lore about how this bridge collapsed and even a "theory" or two about why, now we are starting to hear the battle about who and how it will be paid for. Apparently, the first meeting of the accountants and politicians occurred and there seems to be some differing thoughts on who will pay.
One burracrate said; "Oh, we can give you 90% but who's coming up with the rest?" The rest is about $200M. Of course some want that plumber down in Arizona to pay for the bridge along with a few of his buddies around the country, but not only do the Maryland and one Delaware (I think Delaware but the story always changes) want taxpayers to pay, they want to then charge those same taxpayers a toll to use the bridge they paid for...
The lawyers are lining up to get their share too. Seems there are a few players in the mix. The ship owner, the ship manager, the USCG, and most importantly, the Baltimore harbor pilots who were responsible for the ship. This fight will be the "mostest" fun!
Basically, the ships generators power everything. You can't have separate generators and switch boards for this, and for that. Not very efficient or redundant. Typically, and true here according to the report, there are 2 generators online during port transits, but 1 would usually be enough. So you have plenty of capacity. Then another is on standby and will start automatically if the others start losing power or if demand increases. That all seems to have been in place here. The big unanswered question is why did these breakers trip. We don't know that yet. Once those tripped, the rest cascades into loss of control of the vessel. If they had a little more time and distance, they could have recovered from this. A bad place for this to happen.@boatgeek and @Capt. Eric ... quick question on the electrical system. After Boatgeek's comment on the NTSB report, it seems like this whole problem started with some CBs popping on non-essential equipment....but, that were tied to critical equipment. It begs the question as to why aren't critical systems isolated from non-critical systems? Why is the ship's steering tied to some crew member's mini-fridge?
Those guys can't afford lawyers.I would think that some of the crew members (especially officers) would want their own lawyers at some of these meetings as well. I wouldn't trust that my employer's lawyers wouldn't throw me under the bus at their earliest convenience.
The initial blackout was from breakers tripping around the main high voltage-low voltage transformer, directly in the load path from the generators to critical systems. This part at least wasn't a case where something went wrong on the crew member's fridge and that cascaded up to critical equipment.@boatgeek and @Capt. Eric ... quick question on the electrical system. After Boatgeek's comment on the NTSB report, it seems like this whole problem started with some CBs popping on non-essential equipment....but, that were tied to critical equipment. It begs the question as to why aren't critical systems isolated from non-critical systems? Why is the ship's steering tied to some crew member's mini-fridge?
I would think that some of the crew members (especially officers) would want their own lawyers at some of these meetings as well. I wouldn't trust that my employer's lawyers wouldn't throw me under the bus at their earliest convenience.
There's no point in going after any of the crew civilly because they won't have enough money to be worth it. Nobody on that ship was a millionaire. The officers are probably ten thousandaires, but the crew probably aren't. It is very much in the company's interest to defend the crew from criminal action because if the crew is found guilty of criminal actions (which seems unlikely), it looks bad when the company defends itself from civil liability. And the company definitely wants to keep the crew on side because otherwise they can start saying things like "The central office told us to..." That kind of thing ratchets up the company's civil liability risk.Those guys can't afford lawyers.
6600VACBy high voltage you mean the native output of the generators, correct? What is it?
There's at least the bow thruster at 6600VAC. I don't know if there are any other loads on the high voltage bus. But yes, most everything else would be on 440VAC or below, fed by a pair of transformers. Since it's foreign flag, you'd expect loads above ~1 kW to be 440 VAC, and smaller loads like lights and receptacles to be 220 VAC. US flag would typically be 480 VAC for larger loads and either 208/120VAC or 240/120VAC for smaller loads.Then a giant stepdown transformer whose secondaries feed the 440V 3 phase ship-wide distribution?
I would guess that since this is foreign flag they'd use 50 Hz. US commercial ships are 60 Hz. The Navy may still use 400 Hz, but not in any of the (very few) projects I've been involved in. Those projects have all been small boats where we're trying to use COTS stuff as much as possible.Here's where I prove I'm out of date by 40 years - I remember tons of old USN surplus and most of it ran on a 400Hz powerline. Are modern ships still 400Hz today? Thanks.
I'm sure there is case law that speaks to harbor Capts roles in mishaps but it's interesting that US law requires US pilots be in used during transit of harbor activities. Even as a role of an "advisor", is suspect there is some culpability. The US Capts' actions after the crash (one of many) is a good example of knowing what to do in different scenarios.Finally, Bravo52 - note that pilots are advisors and are not responsible for a ship (with one exception, but that's a different subject). They will not have any culpability here, and in fact acted very well, and saved lives.
Terminology matters a lot here. The advisor is a pilot (who always* has a captain's license), but the captain is the ship's captain. The captain is always ultimately responsible for what happens on board. Pilots are required for local knowledge. The ship's captain may have 30 years of experience but may never have transited these waters before. The pilot knows the ins and outs of local weather, currents, tugs, etc.I'm sure there is case law that speaks to harbor Capts roles in mishaps but it's interesting that US law requires US pilots be in used during transit of harbor activities. Even as a role of an "advisor", is suspect there is some culpability. The US Capts' actions after the crash (one of many) is a good example of knowing what to do in different scenarios.
I think it's pretty likely that the carrier's management will be limited. The only good thing about that is that the ship and its cargo has some value after the accident. In a few cases that I've been involved in, the value after the accident was zero, so the shipowner had no liability.Ironically, it is likely the similar US law that may very well limit the liability of the carrier. Sadly, I suspect the personal injury lawsuits will be a lot easier to deal with than the liability associated with the bridge.
Thanks for the clarety. Lots of terms being used and it is important to get them right.Terminology matters a lot here. The advisor is a pilot (who always* has a captain's license), but the captain is the ship's captain. The captain is always ultimately responsible for what happens on board. Pilots are required for local knowledge. The ship's captain may have 30 years of experience but may never have transited these waters before. The pilot knows the ins and outs of local weather, currents, tugs, etc.
In defense of Juan Brown, he's a former military and current airline pilot, knows what he's talking about in most cases, and isn't afraid to say when he doesn't know something. That said, yes, a lot of what he does is just read the report, and he admits he doesn't know much about ships. If you find that not to your taste, perfectly understandable. FWIW I got something out of it.I'm sorry, but I couldn't watch it after the first 2 minutes. All he was doing was reading the NTSB report, pretty much word for word.
Breakers get less and less reliable the more they're activated, and as a natural aging process. That's why we have to pull, test, and often rebuild and recertify them with alarming regularity. My teams averaged about a thousand or so each year from small to huge main power breakers for USNS and a variety of civilian MSC vessels.It's still not clear from the report why the breakers tripped in the first place, but they had trouble the day before and swapped sides on the breakers; that seems to be have been an indication of a major latent problem still not understood.
OK, let's get into Pilots for a bit.Thanks for the clarety. Lots of terms being used and it is important to get them right.
Where Juan Brown excels is understanding NTSB reports. He may not be an expert on maritime crashes, but I would argue he is an expert on how to read NTSB reports and the culture that surrounds that agency. There are two types of "boards" in the Air Force. Accident Boards and Safety Boards. In very basic terms, Accident Boards are to find out what happened and assign fault. Safety Boards are similar in that they also discover causes but they are not attribution and for learning purposes only in order to better the force without fear of reprisal. Juan was trained in those areas and has an understanding of the process and how the NTSB conducts investigations. The good thing is it wasn't a "Dan Gryder" video...(that's a beer word).In defense of Juan Brown, he's a former military and current airline pilot, knows what he's talking about in most cases, and isn't afraid to say when he doesn't know something. That said, yes, a lot of what he does is just read the report, and he admits he doesn't know much about ships. If you find that not to your taste, perfectly understandable. FWIW I got something out of it.
It's still not clear from the report why the breakers tripped in the first place, but they had trouble the day before and swapped sides on the breakers; that seems to be have been an indication of a major latent problem still not understood.
If you go aground, you want to do it in mud. Even going really hard aground can end up with no damage to the hull.Well, more good news in that they floated the Dali and moved/moving it back to pierside. Should be there by now. "They" said there was no damage to the hull (other than the topside stuff) and it moved right off with the help of 6 tugs. The transit was supposed to take a total of 21 hrs to float it, move it off the beach (so to speak) and push it to the pier. The push part was supposed to take 2.5 hrs as they were moving 2.5 miles @ 1MPH.
Was anyone expecting damage? You can’t hurt that thing with a RPG!Well, more good news in that they floated the Dali and moved/moving it back to pierside. Should be there by now. "They" said there was no damage to the hull (other than the topside stuff) and it moved right off with the help of 6 tugs. The transit was supposed to take a total of 21 hrs to float it, move it off the beach (so to speak) and push it to the pier. The push part was supposed to take 2.5 hrs as they were moving 2.5 miles @ 1MPH.
Heh. It's amazing how much damage can be done to a grounded ship, even on a flat bottom. On a hard bottom, you can easily get a few thousand tons concentrated on a few tens of square feet of bottom. Bad things happen. Mud is good, since the ship sinks in and spreads the load. Sand isn't usually too bad. Gravel can get ugly.Was anyone expecting damage? You can’t hurt that thing with a RPG!
Wow 6 hours to abandon ship!!Heh. It's amazing how much damage can be done to a grounded ship, even on a flat bottom. On a hard bottom, you can easily get a few thousand tons concentrated on a few tens of square feet of bottom. Bad things happen. Mud is good, since the ship sinks in and spreads the load. Sand isn't usually too bad. Gravel can get ugly.
If there are large rocks, it gets even worse. I've been involved in a few salvage/repair efforts on vessels that landed on rocky shores. They all ended up with holes several feet into the hull from boulders sitting on the beach, and they hit at relatively low speed. When the Costa Concordia went aground at speed, a rock on the bottom folded up 1" bottom plate like it was a stick of gum.
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