NTSB Focus Dali Ship's Circuit Breakers | Bridge Collapse
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- Опубликовано: 20 май 2024
- You'll see updates from the unified command on the current salvage plan to clear the channel and free the stuck MV Dali Ship after it crashed into the Francis Scott Key Bridge in Baltimore, MD. There is also discussion from the NTSB on their investigation and focusing on the Dali ship's circuit breakers.
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NTSB website on Dali collision with Francis Scott Key Bridge: www.ntsb.gov/investigations/P... 
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I am a retired Merchant Marine chief engineer and radio/electronics officer. Before I retired I worked aboard container ships very similar to the Dali and used to go in and out of Baltimore years ago. The breakers on board a ship like the Dali are quite different from the ones you showed on your video but the cause of the problem may have been quite similar. Once, years ago, I was troubleshooting an electrical problem on a vessel with a 460 volt 3 phase breaker (3500 amps) that was tripping off at random. Everything looked fine visually and the current draw was below the breakers' trip current. I put a visual thermometer on the input and output contacts and saw 5 of them at close to ambient temperature but one was much hotter. Heat is what actually trips breakers. If they get too hot they will trip at a lower than rated current. All I did to correct the problem was to tighten up all the wire connection bolts on the breaker, after cutting the power first. When power was restored all the breaker tripping problems went away. What a lot of people don't understand is that on a ship, engine vibrations can loosen a lot of bolts and screws. I can't tell you how many times annoying problems that I had were fixed by just tightening up screws or bolts. It wouldn't surprise me if that was the only problem the Dali had. They probably loaded a whole bunch of reefers aboard the ship before departure and the load was up quite a bit and when the engine was running it caused some wire vibrations and the heat went up causing a breaker to trip. Power was interrupted going to the engines cooling, oil, and fuel pumps and the main engine tripped off. All the rest is history. It wouldn't surprise me if all the problems were caused by a loose connection on a main breaker somewhere that could have been fixed by a quarter turn on a bolt.
Had the same problem in miniature on my home panel some years ago. Breakers had a screw connection to the bus bar. Screws were loose - likely from day 1 - and the heat tripped the main breaker one day. Evidence of arcing as well. Neighbour had similar issue - dryer breaker case melted causing contact misalignment and opened the circuit. This breaker series is no longer available. Screwed connections as on large breakers need to be tight and periodically verified.
@@stevewolfe6096 Yes, the periodically verified part can be important. There were many times, while I was on a ship, sitting in port, when things were slow, when I would go around with wrenches & screwdrivers just tightening up bolts and connections. Once in a while I would encounter one that was obviously loose. I suspect that I prevented strange problems from happening at odd times doing that simple operation. Nothing worse than after a hard long day, being called up by someone on watch, saying that there was some kind of problem on the bridge, or down in the engine room and I would have to get up and do some troubleshooting. The only thing was that you had to be careful because sometimes what you were tightening would be a live circuit so you would have to be knowledgeable enough to know what to touch and what not to. There were time when I would break out my voltmeter and do a little testing first. You can usually detect a bad connection by measuring the voltage drop across it as well. I was sometime amazed by how a seemingly complex problem was fixed by just fixing a loose connection.
Add to it that on a ship you have salt water and the hull is flexing a bit too as well that when the ship rolls cables do move around a little. Not much, but over time it could also contribute.
But we'll have to wait to see what the investigation reveals. I don't rule out any cause - even human error.
I was on an aircraft carrier for 3 deployments . People don't understand what a beating a ship takes on the open seas and how one small event can escalate rapidly.
I understand the Battleship Washington was its worst enemy, as it broke crap all over the ship while firing those 16” shells…
It has been previously stated by a port worker that while the M/V Dali was in port loading/unloading cargo (Conex boxes) that as refrigerated containers were loaded on board and being plugged into the Dali’s house electrical system that circuit breaker were constantly tripping and causing generators to go down. The problem was so bad that the Dali had to run on shore power while attempts to diagnose and effect repair to the Dali’s electrical system/generator systems.
what is the upper level grid voltage on the Dali ship ? Do you know that ?
@@hardystrathe1713 The typical generator on a ship generates three phase 460 volts. That's the system used on most of the equipment on the ship. The only other main system is the bow thrusters. The generators fed a step up transformer that boosted the voltage up to about 8200 volts (3 phase) and fed three large cables that ran all the way up to the bow. There was another transformer on the bow that stepped the voltage back down to something like 1250 volts. It's been too long since I was on that ship so I don't remember exactly. The reason they did the voltage changes was to reduce the current on the long cables so they could be smaller. Higher voltage means more insulation, but less copper for the same amount of power transfer. This was on a car carrier ship (RORO) and the cables went thru the cargo hold so you could see them overhead. In that case I was troubleshooting a non working bow thruster. The problem turned out to be in the PLC on the bridge and was fixed by a simple board replacement.
I also was wondering about the report from a shoreside worker that the Dali was apparently having electrical issues while handling refer containers while at the berth in Baltimore. Who worked on the vessel's electrical system while at Baltimore? Did just the vessel's engineers correct the electrical issues or did they also employ local assistance? Who certified that the apparent electrical issues had been corrected prior to sailing from the berth? Will be interested to read the preliminary NTSB report being issued in early May per the NTSB spokesperson.
@@jamest-mk4qu The only certification that was needed could be provided by the chief engineer. I don't know if they employed any local assistance, but say the brought aboard a electrician to do something, he probably wouldn't be certified by the US Coast Guard. That's a completely different license. A ship's electrician and/or chief engineer wouldn't be certified to work on a shore electrical system and a shore side certified electrician wouldn't be certified to work on the electrical system aboard a ship. Those are the laws in place. I do remember, years ago, some local governmental official came aboard our vessel, while at the dock, and said one of the ship's systems wasn't up to the local code. That official was escorted off the ship while being told that any vessel system only has to comply with codes set up by the US Coast Guard. In some cases the local codes (like electrical) are incorporated in the Coast Guard codes, so are identical. However, in this case that wasn't true. Local officials should tell the Coast Guard, who always has the final enforcement responsibility. I can say that once we had a small engine room fire on a vessel that I was chief engineer on. We were sitting at the dock when that happened, while I was ashore. The fire department showed up and put the fire out. It was a Coast Guard rule that they could do that. When I got back aboard I talked to the firemen and they showed me what happened. It wasn't anything serious and the problem was fixed and we went back out on schedule.
@@ronjurgs9799 Agree with your comments but was just wondering if the vessel's owner's representatives had requested any advice regarding the apparent electrical issues from the equipment manufacturers technical representatives. Hopefully the NTSB representatives have looked into this as part of their on board investigation.
I like that Lady the way She talks. Very Professional! I have seen speak Her on some other previous disaster and the same.
In 2015,we have had a similar blackout and grounding on a large loaded LPG tanker coming out of Abu Dhabi ;vessel was caring 45000 MT of liquified Propane. Fortunately no damage/no major incident.
Root cause was incorrect settings/faulty AVR ( Automatic voltage regulator ) and incorrect settings/faulty OCR ( over current relays)
Vessel changed all this equipment .
Just an example on one ship where ventilation from a large laundry space was improperly designed. The issue came to light when an electrical panel that had been collecting lint and eventually caught fire. The lint was coming from a dry exhaust system when more than 2 dryers were working simultaneously. The system could not handle 3 dryers and had 5 installed. The exhaust would backflow into other spaces causing lint build up everywhere, but no one thought it was a serious issue until the fire. Further inspections turned up the top deck level exhaust vent that was supposed to have 3" wire mesh (only for personnel safety to keep a person from falling into 42" diameter duct) instead it had 1/2" wire mesh. The lint had been adhering to the wire causing partial blockage slowing exhaust speed. The outer perimeter of the duct had 4" reducing to just under 1" at the center. Issues can be cause by the least likely suspects.
Good to know, thanks.
@brunonikodemski2420
We had same problems with over heating breakers and distribution panels, where poor coordination was done. Sometimes this was caused by dust of debris coating the breakers or wiring. Several naval and desert projects. I had the job of solving and repairing these, and was horrified how bad the wiring and the breakers kickouts were done. This is still a problem between countries, where safety margins are NOT coordinated. NEC and Maritime rules are not the same, nor are the aircraft. We are seeing the same issues with solar installations, often catching on fire.
21 hours ago
The investigation into the distribution panel is more likely a "cause elimination" measure. The videos of the Dali show that it went totally dark all at once ... twice. This is NOT from 30 or 40 circuit breakers tripping all at the same time. Although similar to a home electrical system, the system on ANY large vessel is *three phase* with a floating ground to the generator. Although you can series connect two of the phases to increase voltage, each phase is a separate and independent electrical circuit. The ONLY way to cut power to the entire ship is at the generator itself or the three phase main cut-off that the generator feeds directly. The main cut-off is cut off in two ways, either manually or from two set safeties: 1. excessive high/low voltage 2: out of spec hertz rate. The hertz rate is dependent on a constant (governed) engine RPM. For a 60 hz system this is 62hz. A 50hz system has similar set points around 50hz ie; +/- 2hz on either side. If either set point is exceeded it drops the generator completely off line. If the ship is a single generator system, this kills ALL power to the entire ship instantly. The hertz rate ONLY changes if the motor lugs or if it surges. The motor will lug if the fuel is crap and clogging filters and injectors or from a clogged or failing air intake system (causes black smoke). The motor will surge if the RPM governor is suffering from hydraulic problems or sticking throttle linkage. Modern systems are RPM governed by electronic sensors with some type of servo operated mechanical or hydraulic linkage to the engine throttle. Unless the electronics take a holiday, lugging and surging are still caused by those same three mechanical problems.
Just keep in mind that in any incident at sea, the crew, the vessel owner, the vessel operator, and the voyage insurer are desperate to prove the fault was due to unavoidable circumstances. ... the fault of the ship builder or equipment manufacture. [edit] and in some cases they will hide facts from the investigators to prevent their own deficiencies discovered. Ask me how I know this.
Interesting comments @3DPDK. But they must still be generating electricity even now they are aground. I wonder how many times since the accident has the CBs tripped..? There are lots of engineers crawling all over the ship at present, even ones from Hyundai who were the makers of the Generators and Breaker Panels. They might have found the fault, and the NTSB will let us know in good time.
@@hiscifi2986 I actually agree with your final statement. With something like this investigators look into every claim made by the captain, engineer and crew. They have to to either confirm the claims or prove them wrong. Knowing that the NTSB is investigating the distribution panels doesn't automatically mean "ah-ha, see I told you it was the circuit breakers". My explanation is based on shipboard experience, that the way the lights go out on the ship as seen in the video could not have been from faulty circuit breaker panels that are scattered around the ship, but rather the generator itself went off line, or the main distribution panel in the engineering space took it off line, and that there are several reasons either of these can happen.
@@3DPDK Is there any single point of failure of a ground? Or is the generator so well grounded that is impossible?
Also, are the ship propellers direct drive or electric like a locomotive? In other words was this a propulsion problem or more a direction control problem?
@@DellAnderson 1. The floating ground in 3 phase is not like the center tap ground or neutral in single phase. The ground in 3 phase carries no load and is basically a 0 volt reference to the body of the generator. Even if the ground connection corrodes away, the generator will still put out the three independent phases.
2. The larger ships and some very big tugboats use the same diesel engine used on locomotives, an "EMD". On a train the engine drives a generator that drives an electric motor that drives the wheels. In most shipboard cases that I'm familiar with, the engine is linked to the shaft by way of a gear reduction transmission. In some, the clutches in the transmission are engaged by hydraulics usually pumped by the engine itself. If the motor shuts down, the hydraulic pressure is lost and the transmission disengages.
Steering on the other hand is usually accomplished using hydraulic rams driving the rudder(s) and in many cases the hydraulic pressure for that comes from electric pumps. Some vessels have an axillary or emergency steering hydraulic pump driven by the main engine, but this has to be manually engaged by the engineer.
The problem is that these systems and equipment can vary from one ship to the next. Arm-chair forensics is extremely difficult unless you know the equipment arrangement of that particular ship.
@@3DPDK Thanks, quite informative.
Jeff, your concerns about the still-missing construction workers and the plans to allow ships to transit over their vehicles and bodies struck me exactly the same way. Finding those lost souls' remains needs to be a high priority!
They did find one, likely the other 2 are close by, or washed out to sea.
@@SeanBZAexactly, we can't assume that there are any remains there. A lot of these youtube commenters think that they have enough access to facts to know better than the authorities.
They never said they weren’t going to try and recover the lost men before allowing shipping through. I just highly doubt that they would put it in a general information animation for the general public, I’m sure they would have spoken to the families and told them what they would try to recover their loved one’s first.
My thoughts are that they believe they will find the remains where they are clearing the temporary access channel, thus managing two things at one time. Otherwise, they would have opened a temporary channel elsewhere.
@@kathrynlitchfield7140 No real place to do that other than in the already dredged channel, as otherwise they need to dig out a massive amount of silt, which will take a year or more to do, and then find a close by place to dump that silt. Even before they start a 6 month environmental assessment, and a year waiting for paperwork. Existing channel already has dredging permits on file, just dig, and miss the gas pipeline buried somewhere there.
The lady refers to the electric power system and the circuit breakers. This is a very large area. The circuit breakers on a ship are very different to domestic CBs. It is not possible to add circuits to a ships CB. They also have overload protection. My guess, and that's all it is, is that the main electrical switchboard preferential trip failed to operate. There are rumours that there were electrical problems when the shippers were loading the fridge containers and had to provide their own power. If there was a fault on the fridge container supply system that circuit should have been cut off before it could affect the main CBs. There is a sequence of preferential cut out, with the essential circuits last, such as main engine lube oil pumps, the last to go.
(I'm a former Merchant Navy chief engineer, shipping company technical manager and marine casualty investigator.)
While you are fundamentally correct, the breakers involved are likely 250-2500a.
Having been a field tech working on these types of power breakers, I can attest that they typically have digital trip units that ARE quite accurate.
They will NOT trip below their setting (assuming that they are "good").
These breakers have multiple settings and a typical long-time trip will take anywhere from 30sec to 3min at GREATER than 150-300% of the setting.
Now, if the breaker tripped on Ground Fault, Short Time or Instantaneous they will trip in LESS than 1 sec.
So, this angle will take some time to investigate. If they trip units are digital, they will have a record of WHY they tripped.
Testing will be pretty straight forward, but they either need to be removed or the entire board which they are mounted in will need to be de-energized. THIS requirement will take time as I am sure the breakers in question are in boards partially or fully energized to sustain the ship in it's current situation...
I was a breaker and power distribution specialist electrician before I retired, the types of breakers that are likely onboard that ship are probably nothing like the household breakers you showed. They are going to be many, many times larger and probably not a molded case breaker. They would likely be anywhere from the size of a copy paper box up to the size of a washing machine and have a solid state trip device that is programmable. The settings for the trip devices should have been modeled by an electrical engineer using modeling software to custom tailor the trip characteristics to coordinate withe rest of the system to provide adequate over current protection without unwanted trips. Not doing this correctly or not maintaining the breakers and other system equipment could easily cause this type of event.
I agree that the breakers are not household 120V AC quality.....(120V household is an insane voltage using double the current of sensible 240V systems in sensible countries). I would be surprised if the onboard staff would be able to meddle with any programmes set in the electrical system - any issues being faced would almost certainly require the manufacturer support engineers logging in remotely. Well, if this is not the case, I would regard that as a major problem.
@@einfelder8262I live in a 240v sensible country, we use an electric kettle because we have 240v.
The circuit breakers in a ship's main switchboards are nothing like the domestic panel you showed. They are vastly more complex, with various levels of automation and control. The most sophisticated types have a small embedded computer in them, which is where you get into needing specialists from the manufacturer.
Yes ship power delivery is a lot more complex, and the panels are largely automatic, in that they will automatically assign load priorities, so will, as the load increases, drop off the less critical loads to limit current, and keep the main systems powered. Container power will be a less critical load, propulsion related power is priority, and then lighting, as that has lots of battery backed emergency lights for it, and then cargo and non essential loads. The power trips here were very likely from the generator sets dropping off line for some reason, or one of them dropped off line, at a load that needed them both to provide more than 60% of rated power, and the second one had an overload trip before the emergency generator could come on line, and the load controllers could not drop loads enough to keep main power buses on.
I stopped watching as soon as the idea of a domestic switchboard came up.
High N Dry have been called in because their circuit protection devices have no relation to old school thermal, magnetic or thermal / magnetic breakers.
Firmware version control, configuration and actual operation has to be confirmed against commissioning documents.
Reports indicate difficulty maintaining stable operation of the onboard electrical microgrid whilst docked in Baltimore. The cascade effects of fuel quality, AVR operation, protection settings etc., even down to Amortisseur winding and governor integrity will need to be tested and validated.
This woman is out her depth and so is Jeff.
Not a good video.
@@mikenewman4078She isn’t assessing the systems, she has the specialists from the company that makes them, she is just reporting to the committee on what they’re focusing on right now. She isn’t doing the investigations herself, she has the right people doing that. What’s wrong don’t you like strong capable women. You’re a dolt.
@@Sweetlyfe Agreed with your comment until you thought it necessary to make it a gender issue by putting words in his mouth. The "strength" of the woman in question is not relevant here, nor is her gender. And as you pointed out, neither is her (cap)ability to analyze these systems, as they have experts for that.
Yeah I think indeed what is in question is the large switchgear breakers and their controls. Nothing like residential distribution panels!!
The breakers in question are large electrically controlled breakers design to carry very large currents. There is an entire electrical specialty called coordination which determines which breaker trips when. For all the power from one end of the ship to the other, suggest it was on of the large main feeder breakers that was cycling. If all are set up correctly, these big breakers don;t just trio. Coordination looks at all the sensing device and makes sure the work together logically so any fault results in lowest level trips rather than the man.
Odds are that these big breakers have a UV, (undervoltage) trip so that the generators will not start into a load. they likely want to see the generated voltage up to normal levels before closing. All these coordination functions are usually controlled by a specialized PLC, Programmable Loop Controller design specifical for that type of use. Mist switchgear breakers and control, use a DC supply called station batteries. IGK, but I dbt that the on board engineer technicians are particular in depth on this type of control, which is likely why the called in the manufacturer experts. All this has to work together with the normal generators and emergency generators. This is fairly complex control. If I were to make abet the problem likely is in one of the sensing devices rather than an actual electrical fault, which would likely show itself with smoke and fire or other damage. But could also be a problem with generator regulation. Lacking any obvious physical damage, finding the exact reason for the trips can be a complex problem to troubleshoot.
Generally all this switchgear control equipment is maintained, inspected and calibrated on a regular time based schedule and is probably done by outside specialist rather than the maintenance tech on board, Unfortunately, this kind of work is often skipped or postponed if there are no operational problems. It is an area that often gets neglected. Whether it is on a ship or industry, the functionality is pretty much the same except that on a ship, they make their own power rather than have it supplied by a utility.
All that said, I think suggesting a similarity to to a residential distribution panel is way off base! Any problems at low level distribution panels will not knock out power to the entire ship!! The kind of breakers they are talking about are like in heavy industry and utilities. This is not the kind of thing the average person can relate to.
Corp of Engineers plans to open the channel to full depth by the end of May. So the 33' channel is over the wreckage buried in the mud. But they plan to remove all the steel and the concrete roadway to open it to the full 50some feet. I expect they will recover the vehicle containing the missing three workers during this. Though the bottom has 8 feet of mud, and I suspect that the vehicle is likely severely crushed under thousands of tons of debris. So this may not be easy.
Thumbs up for the great deal of respect you have for the ones still lost who must be recovered.
Thank you Jeff for excellent follow up info. You are my go to for the most comprehensive data on these terrible engineering fails. I’m not an engineer but I do ask and learn so much from you. Excellent analysis!
Glad to help
Homendy used the term "circuit breaker" to explain this in simple terms that most people will understand. however, we we are really talking about is a more complex electrical system & its associated power distribution. The Dali has 2 main generators, 2 aux generators and one emergency back up generator. each generator is creating thee lines of 120 VAC power at about each making 4500 Kilowatts of power. the lines of each generator have to be syncronized before all power is put on one common distrubution bus. From there, there are additional sub-panels that supply power to seperate sub systems, such as the main engine fuel pumps, lube oil pumps, etc.
Investigaors are likely focused on the merging of the those generators and that power distribution & management system. The electricity generated is more in like what you are going to find at power plant.
I was a USCG Marine Casulty Investigator & am a graduate of the US Merchant Marine Academy
John B Hall
LT, USCG, USMMA '95
Hi Jeff, I read a lot of good professional comments from your video yesterday. Seems like the NTSB is focusing it's attention in the right direction. One of the shorter comments that stuck out for me was that they were having electrical issues with the "reefer" containers right after they were loaded and plugged in. That was reported by the dock workers. Thanks.
The investigation of the circuit breakers could be just to rule them out as a source of the problem. Just because something is being investigated does not mean that it was the problem.
It was the problem. They were having trouble with it while docked.
They are investigating the CBs because they want to know which one tripped first. If it was the supply to the Refrigerated Containers, then maybe one of those containers has a problem, such as rodent damage to the wiring, causing a short circuit, with high currents flowing.
As the ship is still functioning, the generators will still be running, and maybe the fault conditions will re-occur.
+ It was mentioned that the powe tripping was caused by not having enough power to feed all containers and ship consumption and they were planing on alternating plugging in some during the trip !
@@hiscifi2986 Good to know, thanks.
For all Ship Power Generators (engines) to stop at the same instant has always been iffy. So yea, a massive electrical short taking down the system and CB trips as well as fault isolation - its called Circuit Breaker coordination and a fault can propagate to the Main CBs . Power was off for a minute initially, so the Backup Generator did not start or it faulted into a short that had not been cleared was well. Keeping in mind a lot of reefer units are carried on a Container Ship and it takes massive power to support those and its exposed above deck.
Very interesting. When she discussed the VDU and that they were unlike an aircraft blackbox and that information from the VDU was very basic I thought to myself, there is a major change coming to ships over a certain size and that update will have to happen soon. So by that I reckon, large ships will have blackbox that covers every function and position in all aspects of the vessel. Natrually, in time that will filter down to medium and small vessels too I would anticipate.
The breaker trip current depends on how long the load exists. The breaker is protecting the insulation on the wire from getting too hot. A short high overcurrent event will not trip the breaker. This allows motors, which can briefly draw twice the rated current while starting, to use wire suited for long term current, and to not have to oversize wire for that surge. In the US, continuous use (over three hours of continuous use) is limited to 80% of the circuit's rating, and a breaker should trip somewhat over 16A for a 20A circuit after three hours. The breaker doesn't typically instantly cool, so if the breaker is reset and the same 17A trip load is reapplied, it's not going to take another 3 hours to trip. However, in Europe, the breaker requirements there are not allowed to trip for continuous service at the full rated capacity of the circuit.
So, it depends on which standards the breakers and wiring were following as to what trip current the breaker should trip. Breakers also tend to trip more easily as they age, especially if they have been operated near their trip limit for much of their life.
Jeff, you are the best!!!
You give clear, concise explanations along with graphics which goes a long way towards helping us understand the subject at hand.
Thank you for another great video, for the education you've given me and all your viewers, and for the research and effort you put into each and every video.
Jeff is my number #1️⃣ go to for highly detailed information on engineering mistakes and disasters.
costco coming up tomorrow
Thanks Jeff, always appreciate your updates and engineering commentary.👍👍👍
Jeff we stumbled upon your videos a few days ago and are very impressed! SA number of days ago there was a short RUclips, someone was interviewing a lady dock worker who was saying the the Dali's circuit breakers were continually being tripped by the refrigeration containers aboard her. I can't seem to find it now.
Yes I saw that she was from a maritime insurer
Thank you Jeff 🥇for the great information 💯👍
While I don't have specific knowledge of the breakers used in container ship applications, a couple of basic principles to mention. One, breakers trip on a 3-dimensional curve with the variables of time, ambient temperature, and current. They are rated to hold some specific current at some specific ambient temperature for some period of time. A typical residential breaker (as you showed) rated 20 amps should hold 20 amps at 40C indefinitely (3+ hours). Tripping at 17 amps is not normal under any circumstances, that is an overheating or malfuctioning breaker. The other thing to mention is Ohm's Law. If resistance develops at an interface (breaker plugged onto bus, for example) that will cause a voltage drop = current times resistance. The impact on the circuit, current goes up or down, depends on the type of load. Electric motors (induction motors) typically draw *more* current when voltage sags. Resistive loads such as lighting will draw *less* current when voltage sags. The burning occurs due to power (at the point of resistance) = current squared times resistance. A small resistance, when the circuit is conducting a relatively high percentage of the rated current, can lead to a lot of heat (again power/heat varies with current *squared*) concentrated at the point where the breaker plugs onto the bus.
Stoked when your videos come out man!
I believe the breakers they are talking about is PLS controllers. They are far more complexed than the typical breakers you will find in a house. Their function is to control a process. Also in a ship’s switchboard they use high voltage. Normally 440 volt but also even higher. On my last ship we had 6000 volt systems and two separate switchboard rooms. And this was only for the engine room systems. In addition did we two separate switchboard rooms for the deck equipment. Being a ship built in 2015 I presume that Dali have something similar.
You are correct in the voltages. If they had a blackout it was on the 6.3kV but they should have been able to isolate one gen and restart. Thruster operation is problematic but they were in the main channel so if it was used it would be light load. A ground fault is a tricky problem but there are at least two 6.3 boards and a parallel before the sub LV boards. Cargo has its own. ?. However the emergency Generator did not start Why !!. regardless of the original problem I think we have operator intervention preventing backups from doing there work. As Ron says, "The ship is powered up now" Good post.
@@Woffy. I think the emergency generator started that is why they got some lights back after one minute of the first blackout. Why they got a second blackout is an interesting question but I think it’s related to the switchboard but was this caused by automation failure or was this caused by human error? I am certain that they were pretty upset in the engine room and might have done something stupid in the panic. The thick smoke is probably caused by auxiliary engines being restarted. As for the bow thrusters the need a lot of energy and at least two auxiliaries have to be running before you can use them. Besides the faster the ship moves through the water the less is the effect of them. Above five knots they will have no effect. In any case they were too close to the bridge when the accident happened and there was little they could do to prevent the collision. Murphy’s law at full display. As a turn of events I see that FBI now is involved in the investigation, something that indicates that there might have been some criminal negligence.
A old neighbor's grandpa told me everything we build can last forever if its properly maintained but you need to pay for it along the way. They don't put money aside to upgrade things as time goes by and you see the end results here.
Superb work Jeff, keep it up and thanks for posting.
Another great informative vid Mr Jeff. Thanks!
Great job as always Jeff! Don't need to go anywhere else for accurate updates on this accident.
I hate to point this out, but the upper Chesapeake is Blue Crab central. Baltimore is famous for it's steamed crab restaurants and all the crabs are caught locally. The bridge structure may be twisted enough to hold the bodies in place, but an adult Blue Crab can fit through a 4x2 inch hole. By the time they clear the rubble at the bottom of the channel, they are not likely to find any remains of bodies that have been down there for three to four weeks.
I am not understanding what your meaning. The crabs will eat the workers?
Yes
@@skycorrigan6511 Same for lobsters, and the best size ones are always found at sewage outfalls, eating off the stuff coming out.
@@skycorrigan6511 Sure. Why not. It's what they do. They eat dead animals and fish.
IIRC they seemed to have not been in a rush to get the Space Shuttle Challenger out of the water. Most stuff in the sea are meat eaters besides the crabs.
The shipping containers aren’t fed from the emergency board. It was the emergency board that went down and took out the main generators and the emergency generator also failed to start also indicating that the emergency board had a critical failure.
Power was restored from the normal service generators after 51 seconds rather than the limited power (including emergency lighting ONLY) that is fed from the emergency board.
Current guess - something went catastrophically wrong with the emergency power board and the surge tripped all the generators offline. I have seen this happen with vermin in industrial switchboards so that’s a possible explanation.
Now your not telling me that the ship is full of rates. I also heard that insulation on some electrical wires is made from soybeans and rats love to chew on it.
I don't buy this. The emergency board would not have been in use. The emergency generator was trying to fire up but was unable to as evidenced by the spewing of unburnt fuel out of the stack.
Keep in mind that the video most commonly being shown, recorded from south of the bridge was uploaded at 10x speed. To calibrate any time stamping, the green flashing light channel marker seen in the video between the bridge piling and the camera is supposed to flash once every 4 seconds. The period of the first blackout was more like 4 to 5 minutes
@@3DPDK The 51 seconds was from the voyage data recorder. That was when the first instrument data was restored as power came back up (it then went down again at least twice).
@@einfelder8262 The emergency generator is legally required to come online within 45 seconds and it feeds the navigation lights but not the ships normal lights. The fact the navigation lights AND normal lights came up together indicates the emergency board was failed.
3:16 They are probably clearing the limited access channel first because those vehicles are there. If the vehicles are there then they get a 2 for 1, You find the workers so they can be laid to rest properly and you clear a temporary access channel to get something moving.
This is so informative! Great job, fantastic reporting!🌻🌼🐝 Keep it up 🙌
Thank you! Will do!
Can't help but to say; "I TOLD Ya." It was Switch Board, electrical failure, overload I bet. As an Electrician Mate . Ship.
That makes no sense for a ship this new to have that kinda of failure unless its was poorly maintained
I understand your perspective, Mate, but a failed distribution panel doesn't cause black smoke in the stack. That's a problem in the motor driving the generator. It's still an electrical problem, but it's not in the panel.
Real problem is the total LACK of adequate protection for bridge supports! Federal, state & local officals act like shipping & vessel weight hasn't changed in 50+years! Not just this bridge location but most US port bridges! Egregious!
The panel you showed has the vertical flat tabs to connect the breakers to the bus, heating from normal currents can weaken the spring tension of the connection which may cause arcing between the breaker and bus tab. This created resistance which causes heating at the connection which continue to add resistance values and increases heating to levels which cause damage to the components. I have seen many of this type of panel fail in this way. Cheep to manufacture, expensive to replace.
Which is why so many of those model panels have been recalled over the years, as they get dangerous as they age. Not helped by the 110V mains, as that means you have to have high current flow for power use. Australia and NZ use the same thickness and dimension in the contacts on their plugs, but there you have a max current of 10A on most sockets, which is 2.3kW, while the USA runs 15A to get 1.5kW only, and if you need more you have to use a different plug, while Aus has a larger one, still fitting the 10A plug, that allows 15A, so allowing 3kW of power draw. The panels there generally do not catch fire.
Thank you Jeff for your insights.👍🏻
Jeff. Those circuit breakers they are probably talking about are the ones in the main switchboards (or emergency switchboard). The breakers are typically housed in cabinets at least 6 feet tall, with space inside for the breaker and the copper bus bars interconnecting them. Also housed (usually on the front panels) are the protection relays, metering and local control switches. In general, these installations are extremely reliable but a small fault in, say, a protection relay's electronics can cause a circuit breaker trip. There again, the protection relays might cause a trip due to an actual problem with the electrical load, such as a cable fault or a faulty motor - anything on the outgoing wiring. In large installations with multiple breakers, there needs to be careful design so that in the event of a faulty load, only the circuit involved is tripped out. If the so called "discrimination" between protection is set wrong, more than one breaker may trip, perhaps in turn causing a cascade of trips until everything is gone. Think the New York blackout of a few years ago...
Thank you for the update.
good solid and accurate reports as always.keep up the good work.
Thanks, will do!
Unless the current has moved them, I think the construction vehicles are exactly where you said.
I really appreciate these videos, Jeff. I agree about your deductions as to the location of the missing construction workers. I think the process of clearing that limited access channel means that they will recover the vehicles/bodies in that location as part of that effort. At least I hope that's the case. Keep up this valuable work 👍🏽
The lead investigator is an experienced marine engineer and former USCG inspector, I have no doubt in his thoroughness. I began to suspect - although without information, it is mere possibility - an electrical distribution issue after watching the video a few times. Most ships are equipped with 3 (some times more, rarely less) diesel generators. These can roughly be compared diesel railroad power units. Usually, it is customary to run all, or at least more than is needed, while maneuvering in port, so that if one is lost, the load is not dropped. For all power to drop like that, the problem is most likely in the distribution not the generation side, unless something significant happened that caused multiple power units to fail together or in quick succession. Also, understand, that unlike a diesel pickup, the main diesel engine relies on external power to operate, so loss of the load would typically cause an automatic shut down of the main. External power runs the fuel pumps and purifiers, lube oil pumps and purifiers and the cooling water circulating pumps.
All that said, I must make it clear, I was a mate, not an engineer, and could be proven very wrong in the end...
The people at dockside said that there were problems with the breakers. The Dali had too many refrigerator containers plugged in. That was blowing the breakers at dockside. This per staff at the dock.
Unless all the reefer breakers blew at once, I don't see how it would cause what happened. Does the main breaker in your house blow when you plug too many xmas lights into an outlet? No, just the breaker on that branch circuit blows. If they tripped all at once, the main generators could spike the system because they can't reduce their output fast enough. It's like running you car's engine hard in gear and then immediately throwing the transmission into neutral and watching the RPM go past redline. But I don't think that's what happened here. It feels like a fault in the emergency panel since all the critical loads like fuel and lube oil pumps and steering gear run off of that bus (normally power by the main generators through that bus), and the containers don't run off of that bus.
As I have said from the beginning of this disaster.... Lack of adequate pier protection is a major factor in this accident, regardless of what caused the power failure. You have to assume that things will go wrong, then plan to protect against such accidents. To not do so is reckless and negligent.
Great content!!
Good video thanks Jeff
Jeff you missed Chair Homendy's most profound statement. At 5:34 she says, "Our investigators are on scene. They needed the assistance of Hyundai who is the manufacturers of equipment in the engine room to DOWNLOAD DATA from the electrical power system and look at the circuit breakers" [emphasis mine]
Apparently there is a second data recorder, in the engine room. We are first learning about this now. All questions should be directed at obtaining a detailed explanation of this data recorder and its capabilities.
Thank you, keep working.
The NSTB animation shows that they will clear the bottom where the construction vehicles are in order to open the limited channel. So thy are concentrating on recovering the bodies assuming the vehicle went backwards as the span collapsed and not the other way. According to a worker at the container terminal the circuit breaks were tripping during the loading of refrigerated containers and connection to the ships generators to the point the ship had connect them to the dockside supply. In port and whilst maneuvering in the channel the ship relies on three diesel generators only switching to the main generator driven from the propeller shaft when at sea and its cruising speed is reached.
Hi Jeff, once again great Vlog regarding the Dali incident. From my Electrical experience, I would like to add that the study and behavior of Circuit Breakers is very complex and the subject of in depth projected analysis, in all electrical circuits the cables carrying the Current in the circuit should be designed so that the loads that are imposed on them, are within the design criteria of the current capability of the cable, the job of the Circuit breaker is actually to protect the cables, not just the load that they are powering. Thousands of Amps can actually flow in a circuit for milliseconds before the Circuit Breaker will sense and trip, the reasons for this are many fold, one of the reasons is to prevent nuisance tripping of the Circuit breaker. This can occur when the circuit is first placed under load and the quantity of electricity (Amps) has to in rush to the device to get it moving (AKA Electric motors) before the circuit can adopt the normal amperage draw during use. Your video was perfectly accurate, however the burning of that Breaker panel that you show looks like an Arching fault which as you correctly pointed out was probably the result of the Breakers being subjected to making and breaking there electrical contact within the panel. The Main incoming Circuit Breaker should have prevented the amount of Arching that appears to be present on your demonstration panel, but what is unknown, is the fact that the main breaker may not have been serviceable and is not shown in your Video.
USS Kansas City I was on breakers tripping loosing load and power to 1 circulation pump , ship goes dead. Emergency generator starts up and gets pumps going to start mains back taking time. I’ve suspected a breaker from the start
They started having electrical problems before the Dali left Port. Issues related to refrigerated containers popping breakers.
thankyou for your exlaination watching from uk
Most ships and trains are diesel / electric. A diesel generator produced electric that is used to power The azipods on a ship, and rotating these azipods independently with electric motors is how the steering of the ship is accomplished. Without the generator's electricity, the ship is no different than an unplugged appliance.
The breakers protect many separate circuits. If the main breakers were tripping as it appears, then a single circuit with its own separate protection couldn't have been causing the main ones tripping unless higher breakers were installed, or there was some other modifications. This would be something to investigate.
I speculate that the problem was caused by the generator itself. Likely poor maintenance being the cause.
Circuit breakers are only warranted to trip once at the rated new current. Trips beyond the first trip are not guaranteed due to possible damage caused by the first trip. Often the trip current will decrease as time goes on. Or the future tripping current will rise due to possible first trip damage. I have once investigated a tripped breaker which tripped due to a direct short. The heat generated by the short melted and welded together two of the three sets of contacts. Worst case scenario is a current of 17,000 amps on a 120v single phase breaker during a direct short.
It’s a surprising and refreshing change to hear someone from the Regime that doesn’t seem to suffer from breathtaking incompetence.
I had a new 1200 amp breaker fail on me the first time it was powered down & back up again. I could not get it to close even with power off. It certainly happens, it does make me a little more nervous seeing the electronics in them.
Good stuff, keep it up.
You are correct about the refrigerators. Compressors often require times-3 to times-10 surge to start, and this often kills a weak system. This is a "coordination" problem, well known to any electrical engineers.
8:15 By way of minor correction, as the resistance increases, current decreases -- but the heat generated per amp passed goes up drastically locally at the point of the resistance increase. I have to anticipate the breakers involved are nothing like domestic panel distribution panels, but are far more likely to be the sort of large industrial magnetic (as opposed to thermal) breakers which can be adjusted for precision operation at an exact amperage and allow time integrated (I^2*T) brief periods of higher amperages which still maintain safe branch conductor temperatures, so certain startup inrush conditions can be accomodated. These are "racked" into position by jackscrews which suddenly and forcefully accomplish the whole displacement needed for switching, to minimize arcs. The act of bringing such breakers into and out of operation "live" is usually done by fully arc flash suited personnel, or when deliberately tripping them locally under load as part of a test. They are just a different animal from the breakers in wall cabinets you showed.
Maybe they want to clear out where the people are first to find the people sooner.
I agree with your concern about finding & recovering the construction vehicles/personnel before opening the temporary lanes for traffic. Appears that business is more important than life.
Thank you Murph9000 my thoughts exactly , me be a ship board ELECTRICIAN FOR THE LAST 30 +YEARS! And the Circuit breakers can be up to 1000 amps 3 phase in which weight upward of 200 kilos , Thanks G
Breakers also get weak if they trip to many times. Or if there is corrosion.
Do they have an inspection after repairs are made in port before they're allowed to leave? I mean after working construction for a few years you'd get some inspections where they'd show up and talk about last nights football game or their fishing trip then rubber-stamp it as good without actually inspecting the work - your general had done it before so what could go wrong?-type of thing.
I hope I write this to coherently explain my opinion.
I think them currently working on examining the circuit breakers does not necessarily mean that their focus is that the breakers caused the outage, but rather their focus is the electrical system and the circuit breakers are the logical first place to investigate.
In other words, they are looking at the circuit breakers first to help determine where the failure in the electrical system failed, as opposed to (as I understood your interpretation) they are looking at the breakers because that's where they believe the failure may have occurred.
Thanks for all you're updates, and saddened to not see any of your state of the art animations in this video.
Thanks for the graghics!
Canada has 550 volt power supply in industrial use , and usually the electrician will use heat temperature gun aiming at each breaker to see if there are any problems . Depending on the temperature of the breaker , maintenance will be required sooner or later . All panels are closed at all time to prevent injuries to personnel due to explosions
Hey Jeff do you have any update on the titan?
Jeff, Do you get smart circuit breakers on ships,they are remotely controllable via a networkable connection to analyze data and manage loads,if so could they be hacked??
Didn't they say one or more refrigerated containers where tripping the power on the ship?
yes for days before it left dock
Can you explain inrush current? I mentioned this in one of your other videos, and I would like to hear your opinion on if this could of been a driving factor.
Refrigeration compressors turn on and off. I believe they have a high inrush current. The system could probably handle a constant state of all of them running, but not the inrush from all of them turning on at the same time.
Though I am only experienced with inrush current from a washing machine's electric motor.
9:00 issue with ships is the freezer unit containers are mobile, they are on Semi moving around the nation. Hence most have faults. Ships must redesign electrical systems to isolate power to these units independent of the ship's own systems. Ships are large enough to ensure this at current sizes.
This guy needs to do research. If he did do his research he would know that the ship is on top of a buried gas line and if the ship "was dragged" into the channel instead of refloating the ship then there would be a risk to the gas line.
While I'm not a ship's engineer, I'm an IT guy. Ive seen some guys debug issues using a FLIR camera. There are models that have a reasonable resolution that clip on the bottom of a phone and cost a few hundred bucks. A connection that is bad can be spotted without ever touching it because it's going to be hotter than the environment. Those IR cameras can spot a difference of 0.5 degrees, so a circuit that is on will show up, a broken one will be cold and one that is going to give you a headache in the future will outshine the others.
Edit to add: obviously, it will also allow you to spot a bearing going bad as well... :-)
Great video. The voice data recorder is one thing I would love to hear.
I saw a video somewhere of a woman who was working on the dock or something, she was being interviewed and mentioned the refrigerated containers causing trips in the panels.
It should also be noted, the Circuit Breakers shown are simple current draw. They get more complex as you go upstream to where they have a Microprocessor that has current settings for short term, long term, instantaneous as well as equipment ground fault settings, including timers. But, if they are not coordinated you can trip into the Main CB.
The lady is 100% right about the change in the vessels now navigating these waterways and the bridges are not adequately protected not even close!
A 49 foot draft thru a 50ft channel? Something aint right with that statement.
I spent 4 years as a deckhand on the JW Westcott mailboat on the Detroit river back around 1990ish. We delivered mail to all vessels up and down the river as they passed our station. 1000ft great lakes freighters could draft as much as 36ft. Detroit river channel averages 40+ foot. Never once do i remember a ship coming thru with just 1 foot clearance.
Its dangerous but not impossible
It's current draught is 12.2 meters, or roughly 40 feet. It would have had 10 feet of clearance in the channel.
It's a 12.2m draft from vesselfinder. So about 40 feet.
Yea, something isn't right. But this is a quote from Lt. Gen. Scott Spellmon, commanding general of the Army Corps of Engineers --- "A vessel the size of the Dali -- it is drafting about 48.5 feet when it comes into the port of Baltimore full. And I've told you the depth of this channel is 50 foot deep, so it's only about 12 to 18 inches of difference between the bottom of the vessel and the bottom of the floor."
Understanding of NAV per MV DALI is very important. From my observations, much focus needs to be on the FSK Bridge report (2021?) of being in 'Fair' condition. Seems the Bridge itself had been handling additional traffic loads that were not anticipated at construction... and my speculation is... the Bridge was in need of major maintenance which would have taken it offline... so it remained technically in 'fair' condition. As awful and devastating as this Containier ship disaster has been, perhaps a worse nightmare was not far ahead, meaning the Bridge might have in fact approached its useful life, and was heading for a collapse from fatigue. Trucking capacities are also sharply higher than forty (40) years ago. ie, the condition of the Bridge needs thorough investigation as well. The way the sections pulled apart, and so easily slipped off the outer pilings is alarming. Was pothole maintenance a full time activity... brings further speculation that the Bridge was subject to buckling and torquing throughout its life span. During the incident, the entire East side of the Truss lifted perhaps 40 feet in the air before crashing downward once the counter-balance broke off. Just some observations here.
Jeff, I am curious about flashes of light I saw at several places along the top of the bridge right when the ship hit the bridge. It looked as if there was even some smoke in the same areas as the flashes, perhaps even some explosions. Can you contact me please?
Why is it not mandatory that tugs be in attendance when large ships are navigating near bridges ????
Large frame breaker problems often are of two types: trip unit malfunction or overheating from poor connections. Also, a special systems protection might be installed in the form of an undervoltage coil - when these are in early failure stages what happens is nuisance tripping despite buss voltage being in normal range or... breaker just trips immediately every time closure is attempted. A UV coil is often a good investment where serving alot of motor loads. Motors always make rated power, and if voltage is low then amps will be high.... and that can become a dangerous situation. Replacing a coil means dropping the load, racking out the breaker to access the problem part. An hour repair maybe? But the problem at sea is dropping the load - thats vessel specific and loads have to be looked at for operational issues: fuel transfer, battery chargers, ventilation, cooling, ballast etc may be losing their backup or complete function. The absolute worst time to schedule any breaker repairs is... navigating an inland waterway.
Actual if you get bad contact (pitting/scorging) the resistance increase (and current decreases, not increasing as you mentioned). However on the spot of the added resistance and even with the decreased current you get an overheat situation that gives you that scorging problem because the overheating is way more than normal.
Thanks Jeff for putting together another great video about the bridge disaster. You would think with all these committee hearings, something is shady. The bridge was hit by a out of control ship. It was a wrong place, wrong time deal. Why make it seem like a Boogeyman is lurking.
+ Also ; my friend ; looking at the very recent photos of the Laly’ containers ; you can easily see that these containers are NOT lined up in an orderly way as they used to be at the beginning after the event ? They look now like they are very ready to go off in the water ? The Laly should’ve been secured not to tilt any further or not to flip even before touching its cargo or the debris on it ; one very effective way is by placing one or MORE strong ; maybe even military vessels almost as long as it or even longer on Laly’s sides forming a 90 degrees with it but tightly hard chained ( or even welded ) top and bottom , left and right , maybe also from front side and back one ; even if it is necessary to weld D rings on Laly’s top and bottom sides ; and even if they have to use portions cut of that bridge’s frame as adopters to achieve that .
I've got a feeling that in a couple more weeks those bodies will be gone if they're not already.
From what i have seen in the past in Houston extension cords were used to connect the refrigerated containers to the ships power.
No Mariner would leave anyone on the bottom of a channel. Nor would any of the entities involved in the clean-up/recovery. Kind of shocked you would cast any doubt on that. They will recover them when it's safe, and not until. But it will be done.
Manufacturers _always_ get involved. They have specific knowledge that sometimes even operators are not aware of. Marine engines also depend upon external power for subsystems like fuel delivery and cooling that “small” engines do not. But, “external” does not mean that they are running from the same bus as the hotel load keeping the reefers going. Critical systems like steerage, external lighting and engine restart and operation have their own dedicated power system.
1:48 the ship has run aground. That is the reason they are moving off the containers. The ship will list port unto the channel and may be topple one the bridge road is taken off. Depends how nicely or loosely it ran aground.
Scorching of the conductors does not increase overall current through the circuit. What it does is increase the resistance of the connection, causing the voltage drop across the connection to increase, therefore the power consumed to increase. That power is eliminated as heat. When the connection gets hot enough, either it starts a fire or the connection melts and becomes open, cutting the circuit.
This is why it's important to maintain good contact in all connections.
Exelent, thank you for not putting music over.
These breakers are large switch gears. They tend to get faulty after a few years. Many times the power quality can cause issues, if the power is off and on. The arching can look like bad welding. I like how direct Mrs. Homendy is! She did a very good job being direct and to the point. It is nice to see someone stand accountable!
It was most likely a multiple breaker short. Either from wiring that dislodged or water . Considering that the entire system failed, I’d put my money on water.
I would think they want to bring the workers up so when the question is posed to focus on them they also clear the channel at the same time. It actually makes sense to clear and search for remains at the same time.