Steam man, thank you for taking the time to respond to so many comments. It made reading through the comments useful. Others, please read through the comments. Most questions and comments have already been addressed. Note, most of seem to suspect the type of problem that we had to deal with in the past. It will be a wait to see the final report.
Let me join in here; really appreciate that chief Steam man takes the time to reply to many questions and also makes `hands-on´ videos showing engine room & machinery. Bit of a pity that YT software team doesn’t spend bit more effort by e.g. introducing more than one indent level which would help to structure conversations & threads in better way (and possibly avoid recurring questions 😉). But of course, primary YT target of the `comment section´ is to simply create `clicks & likes´ rather than `deep-dive forum discussion´… It’s remarkable once it comes to YT clips dealing with technical topics, there’s always a certain portion of comments where one can notice also experts sharing their knowledge & experience, which I really appreciate and enjoy. I could imagine this must also have been the spirit during the early days of the Internet (with DARPA being one the initiators as far as I know, possibly also other scientific institutions). Like here for the MS Dali incident, I believe it’s beneficial to share experience from maritime experts as well as pro’s from corresponding fields like US Navy chiefs, land-based power grid and aviation, plus safety experts. It’s important to take both mechanical and electrical perspectives into account. Yes, partly it’s speculating and also controversial due to different background & requirements from regulations. But best case everyone can pick up some beneficial insights & learnings, and if there’s differences, trying to understand why and where do they come from.
Fantastic information! Great to get an analysis from someone who actually understands the systems. Wish there was some sort of explanation that this was a preliminary NTSB report and not a final, from what I was understanding they have a good handle on what was happening that day, at least at a high level. Obviously they are still looking into the WHY those things occurred.
Great analysis. My hypothesis - First outage occurred because of TR2 differential protection operation for a transient fault in the transformer. Full electrical power was restored to ship by the manual close of the transformer breakers after about 60s. The emergency generator is expected to automatically start and come online with 45 seconds of the initial power outage but did not appear to do so. The emergency generator came online (and disconnected the emergency LV bus from the main LV bus) sometime after power was fully restored. The main generators LG3 & LG4 tripped causing the second (partial) blackout because of a re-occurrence of the low fuel pressure issue. As you say - lots of questions for the final report to answer. Give a thought to the engineering crew trying to manage this issue in their control/switchboard room. They would have been plunged into darkness, alarms going off all over the place and unexpected behaviour occurring.
Would they have been in darkness? My only experience with sea-going vessels was in the US Navy and we had lanterns all throughout the ship so that if we lost electricity those automatically came on (main electricity caused the lanterns to be open-circuit; when power was lost the switched closed and the lanterns came on almost instantaneously). Not sure how different the requirements are for a commercial motor vessel but I would have imagined something similar would be at play.
Good stuff! I understand electrical circuits but was unfamiliar with the design of these large ships. Love the information given and discussed here. Do drama either, thanks! Just the facts ma’am. 😊
I’m not a marine or electrical engineer. I’m curious what caused both the low and high voltage feed breakers to trip at the same time. Frequency out of tolerance? I would imagine if there was a fault to ground they wouldn’t be able to reset them because the fault would still be there. Then the EG breakers trip. Frequency out of tolerance? I would be looking at the controller for frequency synchronization of the generators. I suspect when they get the ship into dry dock they’ll pull the breakers out for extensive testing and tear down along with parts of the electrical control system. I’m also curious about the the coordination of the electrical breakers for not only fault but frequency. I’m also curious if the breakers operated based on internal safeties or by external command of the electrical control system.
Unfortunately the report doesn’t have the cause for breaker trips that’s a very important piece of the puzzle. But yes frequency or voltage out of order are very likely to have been the cause
Yes yes yes great point fountainvalley. I'd love to know how 2 mechanical piston driven generators are synchronized when they are not connected at the crankshafts
You can be sure that there are electronic (computer) controls that monitor voltage, frequency, etc. (plus relative phase for connecting multiple generators) to protect the system before connecting to either HV or LV buss. If the controls cannot remotely trip the breakers there are surely contactors that will open these these paths, and cut power to protect the equipment.
@@mark_osborne there are electrical/electronic components that synchronize the output of the different generators. The electrical output is synchronized not the physical diesel engines.
OK, I have a theory on the black smoke before the collision. In the blackout days before, the #2 generator was shut down due to closure of a damper. In a four stroke engine, if the exhaust is gagged, it will either blow up the exhaust piping, or the exhaust valves will float. The back pressure pushes down on the tops of the exhaust valves, and can make them float if the pressure is high enough to overcome the spring closing force. This can cause contact with the piston, and this can either hole the piston, bend the valve, or break the valve. If they caused damage to one or more cylinders and then didn't test generator #2, they could have sailed with a broken engine on generator #2. If they later tried to start generator #2, the disabled cylinders would put raw fuel into the exhaust, which would be seen as black smoke.
@@steamman9193 Absolutely! I've been very curious about the smoke. This could be one possible explanation. We'll have to wait until they look over generator #2.
@@sirenbleu 2 stroke diesels at least modern ones almost always have exhaust valves and ports for intake. But we were discussing generators which are almost always 4 strokes. There is no record released of the Dali main engine attempting to be restarted
2nd Comment: While this alone is not a full answer, I think it has merit. The system should be designed to allow this for critical maneuvering periods. The assumption is not best case, its worst case that at the wrong time you could loose propulsion (and or Power). The HV bus should be split with Tie Breaker HVR open. Then the HR1 and HR2 sides should be feeding parallel pumps be it fuel, coolant or lube such that a fault/failure on one bus or the other would keep the propulsion going. The Emergency Generator should be on line powering its area with LVR and LR2 open. That keeps at least the low speed ram on steering working regardless in the time frame you still have some speed to be somewhat effective.
I think failure to split the HV and LV buss will turn out to be the root cause of the failure. Operating with single buss leads to a system that has single point failures that can disable the ship.
As a Chief engineer, my thoughts would be......as pointed out, there is something wrong with the fuel system setup on the vessel.... wrong lining up or forgetting to line-up after maintenance could be a factor.... which in turn can lead to low fuel pressure in the system....tripping of DG breakers may be due low frequency where the tolerance maybe just 5%....low fuel leads to lower RPM of DG which leads to low frequency which may trip the breakers...
So what are your thoughts on this is related to securing the bow thruster and possibly a 3rd generator, then the other generators not being able to adjust to the load? I know it’s hypothetical but it fits very well
@@steamman9193 it's possible... unless we have the fuel system lines to guide us, we will have to wait for full report... but I strongly feel that something went wrong with frequency.... only reason being that the DGs were running, both blackouts were breakers tripping....why?? .
@@steamman9193 Using the opportunity to have 2 knowledgeable Chiefs in the conversation here; and just for my understanding since I’m quite interested in following all this tech-talk: I’d assume the bow thruster has been used for doing the 180° turn when leaving the pier. So does `securing it´ actually mean bringing it to a stop by controlled reduction of the motor’s RPM (thus also reducing load on the 6600V HV bus accordingly)? And 3rd generator might have been connected during the time when the bow thruster has been active to support with additional electrical power? More generally wrt manoeuvring using bow thrusters: will it make the ship turn around its centre of gravity (which is expected to be somewhere in the middle), also causing stern to move (I would expect this to certain amount except the situation when it is still fixed due to the pier)? Or will stern remain almost constant?
@@NRZ-3Pi10 I can’t comment on the maneuvering characteristics it’s outside my world. Every bow thruster ship I’ve worked requires 3 generators. Or is a separate diesel engine, but Dali was electric. That doesn’t mean it can’t be done with 2 especially due to Dali s very large main generators I just don’t have that information
Mr. SteaM: serious un-educated question. With the ship under way, would there be enough energy available with water passing the propeller to rotate the main shaft, and therefore continue to turn the engine? Does this type of engine have electric blowers to provide combustion air? Hypothetically the control system should know that the engine is not in a 'run' condition, Of course, we won't know what the programming logic is or what was overridden manually. Yet, I suspect it took time to re-boot the control system once everything went dark. just a controls / engineering technician here; musing. Thanks for taking the time to create these videos!
So can it turn by the water passing over the propeller? Absolutely! At what speed that happens is variable. Yes electric blowers under low load. But electronics shouldn’t need any kind of reboot time
Steam Man: I really like your information. You are the only one that is addressing this in detail. None of my comments is intended as tearing down. I also think we look at things and figure out how to improve them so that we have enough layers in the Swiss Cheese Model of failure that an event does not get all the way through. I am going to drop in a series of shorter comments. I don't think fuel had anything to do with the failure on Dali. My best guess is HR1/LR1 trip was either a transformer failure or a fault that went upstream through LR1 to HR1 and caused that initial trip. The other trips look to have been the Generator CBs reacting to whatever was causing the trip initially on LR1 and HR1. Depending on the protection settings and CB coordination, that can and does happen. LMSGO does have a lubricity, its sulfur content is vastly higher than land Number 2 diesel (US standard ULSD). Its a low sulfur diesel in name only just like Aviation Low Lead fuel had large amounts of lead, lower than it used to be but there. 0.10% sulfur vs the ULSGOs coming into the market from the automotive market typically have only 10 to 15 parts per million (ppm) sulfur, or 0.001% to 0.0015%.. Equally Marine has better cetane and worst case, if lubricity was too low then its added (which is what ULSD does). That said, the engine mfgs will ensure their equipment works with the lowest allowed lubricity (be it sulfur or additive). Road diesel engines worked fine with it.
I didn’t get into it in this video but I lean heavily on fuel being the main failure because of the heavy black smoke see in the accident videos. A normal breaker trip or engine starting shouldn’t smoke like that. And now that we have the report where the main engine was never started we now know it’s a generator
Thinking on this more a permanent electric fault should have presented itself obviously to the investigation team by now. Even an intermittent fault may have made itself apparent.
@@steamman9193 NTSB preliminary reports states DGR 3 & 4 kept running und thus also keeping HV bus alive. This suggests their fuel pumps connected to HV bus and still working, too. So no shut-down of the generators then; but at least drop to (very?) low-load condition. But when re-connecting TR1 (which might cause additional load in case of defect), that might be quite some heavy duty for DGR 3 & 4 then. That might explain heavy smoke (`black´ appearance to certain amount might also come from missing lighting on that side we see in the port cam video). In addition, like you've mentioned, could also be interesting how DGR3 reacted to this, considering the issues observed while in-port. If DGR3 struggles to support fully, `poor´ DGR4 would have to take all the load then, most likely even to `fight´ against DGR3 ...
@@steamman9193 I am going to have to print out the NTSB (I do have the Electrical Schematic). Smoke could be from the emergency generator starting or DG2. HR1 and LR1 would not open up due to generator issues, that is not their job. As you pointed out, they did open up a bit latter. But at that point they may be the most sophisticated breakers in the system left. Mine as I recall has 4 to 6 trip functions (two of those had to do with the Generator dropping off frequency or reverse power). But DG2 started, closed and ran. While I could see making a case for the 2nd outage being fuel it would not seem likely and DG2 seems to have kept running fine. I had cases where more sophisticated breakers with more settings (vs thermal) and or micro processor controlled tripped upstream leaving the downstream breaker still engaged (in one case it too tripped after a small amount of time but the upstream sensed before that fault first and opened.
@@steamman9193 That is one of my two electrical based theories. We don't know what the CB types and protections on HR1 and LR1 were (yet). A Transformer fault should not trip LR1, but it seems that is a possibility. I never had two high feature breakers one after another let alone across an Xformer bridge, so I can't say that a zark out of the Xformer would send a signal downstream. Equipment ground fault can be interesting and on a ship with its isolated grounding, more so not to mention the other faults.
The deep sea controllers we use for our em gennys monitor the fuel pressure at the filter housing, and this is recorded on the deep sea, so the information should be recorded as to if it was a fuel issue, I think it was more a phasing/syncing issue, running and restarting generators on various buses. The email gen probably was out of sync with the hv bus and caused the second trip. This would also explain why the em genny took so long to come online.
Thank you for posting video. Wondering if engineering team didn’t inadvertently introduce an issue during earlier power outage in port? Was the electrical system returned to the normal setup / lineup once the issue was resolved or was something locked out? PS - Think generators 1, 2, 3 and 4 are service by individual day tanks and require electrical power to run the fuel pumps to keep that day tank full. Wonder if second outage was just caused by fuel starvation?
Most likely all the generators get their fuel from a single service tank, but with redundant electric feed pumps. And no indication so far this was in any way related to the event, there should have been alarms associated with and discrepancy’s
I'm curious as well, been out the navy a while and this is making me think back on ring bus safeties hard. I know they won't be the same but I'm thinking some of the principles might be. I know trips would be designed to open breakers as close to the fault as possible to prevent taking down any necessary and still safely operating equipment. So if the hr1 and lr1 breakers to transformer 1 tripped it was prob an issue with the transformer? You would want this to trip before it could cause a problem that would trip up stream which we see as it does not cause the main hv breakers connecting the generator to the bus, dgr3 and dgr4 to trip. It could be a fault on the lv bus but in theory there would be breakers down stream closer to sub circuits and pannels supplying them and equip that should have tripped before tripping the transformer hence breaker pannels. That and tripping both to a piece of electrical equip was usually an equip fault if I remember correctly. But the crew manually closed hr1 and lr1 putting the transformer back on line. And in less than a minute dgr3 and dgr4 trip. This is also when smoke starts bellowing. could this be under volt or over throttle trips bc they could not supply some insane load bc of a fault in the reconnected transformer? I seem to remember there is a brief time after large breakers close that the trip is not "rearmed" bc an initial transient could re trip them. Again I'm almost 20 years out from my operator days. I deff get that insufficient fuel would cause rpm and torque to reduce resulting in and under power trip of then generators but would that cause all the smoke? Or was all that smoke dgr 2 coming on and loading hard? They also never say if dgr 2 shuts down or any other trips occur once they change to transformer 2 and dgr 2, but if it was fuk and the dgrs are on common fuel lines it should have dropped after a spell. If it was in the lv or hv bus it would have also eventually re tripped as the fault (if not in trnasformer1) would have not have been isolated. Im also surprised and curious about immeadiate actions why not split the bus and bring both transformers online bc there are some basicish (at least how we ran) indicators it might have been thr transformer. Also dont know how much civilian ships are set up and capable of runing split bus. I do get why, sort of, they never tried to restart the main engine. It doesn appear that they kept main power restored for any significant time so that they could. At 0125 they tripped, 0126 and seconds first restoration, then 0127 second trip, dgr 2came up but it took 30 more seconds to restore power to 440v bus using transformer 2 mere sends before impact.
Here’s something I’ve been thinking about since too if there was a piece of failed electrical equipment like a transformer it should have been discovered by now. My thought is there was an electrical load not seen since the accident and they haven’t been able to reproduce while stuck
Could you tell us what kind of GPM the various main engine pumps move? Ie the main engine oil pumps, cooling pumps and fuel pumps. I was surprised that the Oil Pumps would be on HV, cooling/coolant pumps on LV. As I understand it you would have a sea water pump(s) on one side for all the general cooling needs and then specific coolant pumps for the Main engine. Generators would have to run coolant to an intercooler and would those be internal to the engines or a separate pumps as well?
It’s not fair to compare to Dali because my main engine is much larger, and not all of this information is in 1 place but Main lube oil motor is 355KW. Cooling water pumps are 65KW each and absolute minimum of 1 salt water and 1 fresh water required. Those are 900 cubic meters/hour
Thank you for the video. I have a question regarding restarting the main engine. Could the main engine been restarted in the time frame? How long would it take to get the main engine back online ?
Unfortunately without being there no one can really know IF it was possible. But what is definite is even if they did re start the main it would have shut down again on each blackout
@@steamman9193 To start the engine both the HV & LV boards need to be powered. The EG could have powered the LV board and there may have been a small window where DG2 powered the HV board. This being before the HV2 & LV2 breakers were reset. After being reset the HV board would energise TR2 and generate LV power. I do not think that there was sufficient time between the second outage to restart the engine before impact; looking at the timeline the window was only 1:45. Also having just one of the main generators online may have not been sufficient to start the engine. DG4 & DG3 had tripped offline and DG1 was not running.
@@christopherrobinson7541 powering the main switchboard from the emergency switchboard is highly regulated against the way you are describing. It’s a complex system but the line you see in the drawing is to power another emergency switchboard from the main normally, it’s not a quick evolution to make it go the other way
@@steamman9193 I appreciate that the diagram shown is a simplification of the actual system. I was suggesting that at best, the emergency generator may have been able to supply some of the LV loads required to start the engine, whilst some of the main generators were on line to cover the engine HV loads. My main point is that at best there was a narrow window (1:45) during which the engine might have been restarted. Without detailed knowledge of the system, this period appears to be too short, especially if other main generators, in addition to RG2, needed to be brought online. Given the sequence of events it is not surprising that the engine was not able to be started.
I'm not a marine engineer. I'm curious what design requirements or compromises led to the coolant and lubrication pumps being on different electrical busses. If the HV bus is required to run the main engine anyway, why are the coolant pumps on the LV bus? Also, are the engine and pump control circuits powered by the HV bus or the LV bus?
I really don’t know why they did it for sure. Higher voltages require smaller wires aka save money on construction costs. Personally I wouldn’t put too much effort into any of this as I am highly suspect that there is nothing wrong with the switchboard and breakers at all. It’s far more likely there was a fault with the ships generators and the breakers opened because of that. Having different power or switchboard arrangements wouldn’t have changed that and the accident still occurred. That’s just an educated theory for now though until the final report
Not a marine guy but I've got to wonder about clogged fuel filters. If the pump is running and operating properly the next question is the condition of the filters. Thanks for the review, Chief.
Definitely an area to be investigated but I doubt the problem as the regular heavy oil they burn is much dirtier, plus each engine should have its own filtration so more than 1 becoming a problem at the same isn’t very likely
@@steamman9193 , I figured there was likely some separation and/or redundancy but I'm not a marine engineer. Thanks for the response and clarification.
So here's a question ... when LR1 and HR1 tripped, the crew reset them. What's the thought on resetting a breaker that tripped? Should they have switched to LR2 and HR2 until the cause for tripping was found?
That’s a missing piece of the puzzle. If they knew the trip was related to something else there’s no reason they couldn’t reset the breaker. Also the L1 tripping then H1 indicates the problem wasn’t with a single breaker
@@steamman9193 also consider, sitting there for five weeks now, they've been running on the left hand bus without any issues, albeit not operating the main engine. (the right hand bus, from the accident, is locked out by investigators and unavailable)
@@litz13there’s no where near the Electric load sitting there to gauge anything right now. I would want to load test everything that was on that day as it was
Steam man i have some thoughts i am curious of your opinion. I think the TR1 differential protection relay may have opened the breakers on both sides of the transformer as it is designed to do during an internal fault of the transformer. Immediately the crew should have tried to close in TR2 instead of TR1 again. Now i know that the diesel generators, unlike the main propulsion diesel engine, generally have gear driven oil and jacket water pumps. However, this jacket water is often cooled by either a salt water or a freshwater cooling loop driven by pumps that probably come off the LV board. So i wonder if the second trip happened due to the LV board being without power for some time and hese pumps not running causing the disel gens to overheat. Also i believe the fuel oil supply pumps are off the LV board so maybe that was the result of insufficient fuel pressure. I imagine the ntsb are looking at the fuel pressure as well as the cooling water temp trend graphs as well. Finally i am curious to ask why the crew doesnt run in an open bus tie arrangment while manuvering? It seems much safer to have gens on both sides online of the HV bus aith both the LV and HV ties open and both transformers energized. I worked on drill ships and we have 3 main electrical 11kv busses and our ties between them all were always kept open. Lastly, there should be some tie of ATS switch employed for the transformers that will automatically switch to the second transformer in a loss of power. What are your opinions on all this? Thank you i love all your videos chief
So I have doubts there is anything wrong with anything on the switchboard and the need to change anything with it. To put it simply if there was a definite fault there the crew would have immediately identified it to the inspectors as that would be a no fault of their failure. But we don’t have that and by now we should have if it existed. I’m not saying it isn’t possible just not likely
That isn’t my area of expertise but my understanding is bow thrusters are only effective at low speed. I don’t believe the status of it’s running is in this report to anylze
I’m not a marine or electrical engineer but am curious: why not run all four main generators and close LR1, LR2, HR1, HR2 to have redundancy at least while you're in restricted navigation? Would this possibly damage things or is it not done simply because it burns more fuel than needed and this stuff is usually so reliable that extreme redundancy isn't needed?
More reason than not to only run the number of generators required. Cooling, contamination, turbo charger loading. Etc etc. I don’t truly know why both transformers aren’t used I have never worked on a system like they have but I’d guess it has to do with synchronization or the inability to synchronize transformers
I'm not sure what type of fuel we are using now here in the UK fishing fleet, I wonder if it needs a percentage of clean engine oil added to it to bring it back up to a good standard
There are lubricity additives on the market I definitely recommend running something with these low sulfur diesel. I’ve also seen fuel chillers installed which thicken it and help with lubrication properties
Am I correct that 1] You have indicated that parts of the fuel transport system to the generators are or can be dependent on the lubrication in the fuel itself for long term operation? 2] If #1 is correct my suspicion that a cylinder or ball valve could expand then partially jam thus reducing fuel pressure is valid? 3] #2 being valid, design, age, maintenance, or exceeding published non-lubrication limits are all possibilities? The thought arises from my past in USN M-1a gunnery fire control system maintenance followed by a career as a Methods Analyst. Are such limits published and accessible, or is it an "Oh! Everyone knows that." situation. I have checked out ". . . injection control unit, problems from bad fuel" and "Diesel electric marine propulsion" on your Steam Man site. They have helped, but a video project illustrating this or similar shipboard fuel supply system, pointing out components that may be designed as fuel lubricated only, or partially fuel lubricated as you have done with the electrical would provide, I think, a good basis for understanding what you are communicating about the fuel part of the NTSB report.
I plan on doing a high pressure fuel injection pump video when time is right. Unfortunately the report lacks key information on zeroing in on the true cause. Basically the fuel injection pumps I’m focusing on are solely lubricated by the fluid they are pumping hence their susceptibility to wear and getting stuck and are an hours based overhaul or replacement item
Heavy fuel oil. Hfo it’s towards the bottom of what is left in refining crude oil very thick, and has to be heated to even pump but it lubricates parts very well and has more energy density aka more miles/gallon
@@steamman9193 `Chief´, can you help to double confirm, please? I'm aware HFO / MGO needs to be heated for pumping (like you wrote), up to temperatures around 40°C - 50°C. My guess has been around 80°C for injection, but Wiki tells even up to 130°C - 140°C (perhaps this partly comes along while increasing pressure up to 320 bar as per your other reply). Question also targets how heating is done and which bus used for power. I'd expect it is done both electrically as well as using heat from all the big diesel engines via their water cooling system? Good opportunity to expand my broad-band knowledge ...
@@NRZ-3Pi10 this is weeks worth of education. But I’ll try to simplify. Hfo has to be heated how high is based on test results of the fuel. I’m currently burning at 88C but I have had fuels at 155C. Do not heat diesel it gets to thin and wears parts out. Heating is typically done via steam
@@steamman9193 Thanks; also don't expect you to come back with lengthy reply like some of my comments, well, partly `novels` 😂. So steam can be created by oil burner, electric heating or from heat of the engine (but up to 155°C might be a challenge for the latter).
I have found no way to message or email you. So please forgive my being off topic. I think you would find the workings of the Mark-one-able [M-1a] gun fire control computer found on WW-2 destroyers mechanically fascinating. Covered in steel with portholes, about 4'w x 3'd x 3'h, and started by spinning very small crank. The thing actually ticked. Computation was by metal disks separated by a ball bearing. It was Fair shooting at socks towed by prop aircraft. Even attempting a lock on a MIG was a joke. but not a funny one when 10 miles off Cuba escorting one of our spy ships located in Havana harbor just after the capture of the USS Pueblo by N Korea. I am enjoying your sharing and wish you well in bringing together the age of steam with the age of UA-cam. Also motorizing that 4-8-8-2 Big Boy.
I am not a marine engineer, or indeed an engineer of any sort - just a pilot who is very interested in how these systems work and the various factors at play in how this accident unfolded. One of the minor things that has bugged me is this description of 6600v to the reefer containers, just doesn't seem right. So I Googled it- all the results I can find show standard reefer containers operating on 3 phase 440v, which makes more sense to me. So - my guess is the NTSB simplified the HV bus feed to reefer containers, and they are perhaps fed through their own dedicated T/R, or pair of them, from the HV bus. The alternative is that it's just an error in the preliminary report, and they are fed from the main LV bus, but are just pictured in the wrong place. And, as commented above, it does seem odd to me that the standard elec config in critical phases of the journey is to have everything tied together rather than split.... But I'm not a marine guy, so I'll defer to those with expertise on this matter.
@@cpazdzior so I don’t have the drawing but it’s likely the container reefers have their own transformers, it’s a better option. grounds in the marine industry are a big problem since the ship itself is grounded. There is a lot of focus on redundancy in the switchboard from non marine people, but we don’t have any indication that there was actually a problem with the switchboard. My theory is the problem is with the generators and they experienced multiple failures
Software engineer, so totally out of depth here!. Does LSMGO go through the same set of fuel purifiers as regular fuels?, is it implied the lower lubrication could impact flow rates through these?
It can there are gravity disks that can be changed for the lower specific gravity of the lighter fuel. Does it have to go through a purifier? Not necessarily it would still probably go through all of the same filtering equipment
Given the criticality during maneuvering watch, I wonder if there needs to be two fuel pumps and two water pumps on separate buses being fed by two different generators. That way if there's a problem on one bus it doesn't effect the other bus.
That’s a far more complicated question than on the surface. You would have to add additional components to regulate flow that would be subject to failure themselves so would it be better? Also in this case it would not have prevented the accident so now we are solving a problem that didn’t exist. I don’t believe the core failure exists with the busses or switchboards
Agree this issue with Generator 3 and “low fuel pressure” causing the second in-port blackout might also build a link towards the blackouts when Dali left Baltimore. This is especially considering the position of all the breakers as shown in the schematic block diagram as per status of departure March 26, with both DGR 4 and 3 supplying the entire HV as well as the LV busses. So if DGR3 faces issues like e.g. “low fuel pressure” again and there’s already high load on system, that might cause unfavourable and unwanted reactions. Let’s also keep in mind there was lot of smoke after first successful recovery of electrical power, indicating very high load. But more generally, even without this DGR3 issue while in-port, I wonder that the cross-tie breakers HVR and LVR have been closed during departure from Baltimore. I would have expected them to be open, thus starboard and port power supply systems being supplied and running independently (if this applies in similar way like what you’ve explained in your video “Dali size containership steering system …”). So e.g. DGR 4 and DGR2 active, but DGR3 on idle. This assumes there’s also redundancy in vital functions like e.g. fuel pumps for main engine and diesel generators, of course. If this is not standard and compulsory anyway, I could imagine this measure being one of the first “containment” procedures in restricted waters to be raised by the NTSB (and authorities world-wide). All 4 four generators almost have same power here. In any case it helps to reduce total load on each bus then. That would also apply for emergency procedure re-connecting the big diesel generators, too; rather than having all load again on a single bus only, where some single fail could cause overall overload and blackout of complete system accordingly. In restricted waters, considering the inertia of such a big vessel, every second counts. So better have the redundancy by main generators already active in best possible way then. Don’t get me wrong: this is not at all about somewhat judging and blaming the crew. It’s engineering approach, thinking and looking forward how to prevent such cadence of issues in future. Let’s use allegory from aviation with B-747 or A380 take-off going for long-haul flight. Nobody would think off having 1 engine completely switched off, another just on idle speed (especially both on same side) while the 2 remaining ones on the other wing to provide all the thrust plus power for hydraulics, electricity etc. (even if the engines have this capability) … Finally, highly appreciate that you (as well as Sal) keep following up on this topic and sharing your expertise here.
I’m not sure your aviation analogy works. Firstly, they had 1 of 1 propulsion engines online. Second, takeoff is the highest demand made of aircraft engines, as they go flat out to convert a static lump of metal i to something that is flying, before the runway runs out. In contrast, this ship was moving slowly as she navigated through somewhat difficult and restricted waters.
@@DanielsPolitics1 Sure, the analogy does not work when only taking the perspective of propulsion, of course. It does work if you compare 4 diesel generators with 4 jet engines, which also have the task to provide `auxiliary´ power for hydraulics, electricity etc. which is equally important for take-off and during flight. Next and very important analogy is safety & redundancy aspect wrt need for always having full control during the most critical phases of manoeuvring. In case of MS Dali, it’s not about maximum power in this phase, but having the required amount of energy available anytime (!), also in case of failures of single components. In confined waters, the criticality at low speed comes from reduced effectiveness of the rudder if there’s no additional water push (`wash´) from the spinning propeller, so ship movement is mainly governed by its speed and inertia, some amount of rudder, plus currents and effects from wind. NTSB preliminary report says Dali lost main engine and thus propulsion at “about 0125” and approx. 3 ship-lengths before the bridge, at a speed of ~ 9 knots (which means distance of 1 ship-length will be reached after ~ 66s, i.e. only slightly more than 1 minute). It is required that the emergency generator kicks in after 45s latest; video and VDR showed it took almost 1 minute. Means distance of Dali to the bridge was already only 2 ship-lengths when they had first possibility to get some reduced rudder control provided by emergency generator then - but also only 130s to close the distance to the bridge (if speed would remain constant). This is when precious time is lost due to not having redundancy already active. Note that I do not claim the crash into the bridge pillar could have been prevented safely, but split of electrical systems could significantly have reduced the probability at least (especially when main engine still running, providing sufficient propulsion for full effictiveness of rudder control). Further investigation might reveal that it’s combination of failures. One occurring at the HV-to-LV link via transformer TR1, perhaps another one related to DGR3 or it’s fuel system, with the latter possibly could even have been a central problem. If that’s the case, it would be real worst case since both sides of the system would have been affected. So all in all, the blackout obviously hit Dali at worst point in time, without any real chance to re-gain full control over its course as per the configuration of the electrical system (and potential issues with DGR3 or fuel system) … To close with the analogy: plane did neither make the take-off, nor come to a safe stop at the end of the runway.
@@NRZ-3Pi10 It's easy to synchronize 2 diesel generators but extremely difficult to keep 3 or more loaded the same. to add load to a generator that is lagging you must add more speed . like just a little. then the load changes and the system is out of balance again.
@@kennethchristensen7457 Fully understand larger load jumps or drops are generally quite bit of a challenge. But looking in 2 directions: if keeping 3 or more diesel generators synchronised is big problem in the confined environment of a ship, we end up in the question why system has been operating with HVR and LVR cross-tie breakers closed (there's some discussion wrt that with different opinions 😉). On the other hand, in land-based power-grids such `multi-site´ synchronisation is daily business. It's already required within e.g. hydro-power plant with several turbines & generators; and syncing also needs to be done with the power-grid.
@@steamman9193 the fuel supply stopped the same time the lights went out while the main engine kept turning causing the smoke cause the fuel wasn't lubing the piston or pistons, the timing is suspicious as well as the loss of power 24hrs previous that is new information, not to mention the gas pipeline the dollie has hit underwater that could have been disastrous, wouldn't a breaker have to be manually turned back on going to each transformer and have the contact points been inspected ? At the same time a train overpass is laying on the deck of a barge in Galveston
@@guytelfer1353 you need to go back through the report. The main engine stops and there is no record of it re starting. I’ve never heard of an engine that could billow black smoke when it’s off. And I don’t know where you are going with the rest of it
@steamman9193 someone mentioned a couple weeks ago that the main engine doesn't stop turning right away even if it's not getting fuel or loses electric because it takes a long time to slow down and stop and the propeller has come to a stop before restarting the motor, I'm just sharing conversations but I really don't give 2 shits 1 way or another any outcome to the situation it just looks like you clowns need all the help you can get especially when Biden turned his back on the situation after saying he was going to pay for it obviously he didn't know what he was saying again.
This low sulphuric fuel sounds like JP-5 used in military jets. The same type similar fuel is what are trucks on US highways are burning and has been a questionable fuel source on these vehicles for excessive wear of engine parts, that’s my 2 cents 😊
@@steamman9193 that's how it works in my trade too, 600 and under is low voltage ans 1000 and up is high voltage. But for me 480v is high enough to play with! That seems like really high voltage just to run lube pumps with. Not to mention you would always have to have 2 generators running at all times while under way to supply low and high voltage unless they do it with transformers, I guess I don't have any real understanding so I don't get the logic there...
@@shawnbeerens4292 the drawing shows transformers between the different busses that’s what the breakers that tripped are directly for. And there is a secondary that you probably wouldn’t run at the same time but as a backup
@@shawnbeerens4292 In my world it was 24 volt, 120/208 (3 phase) and 480 (technically 460 but 480 out of the main boards). I did a bit of work with 7500 volts under supervision of a HV rated (former lineman) instruction. Ungh. Dead 7500 line jumped a 3 inch gap just on induction through a couple miles of line). I had no issues with 480 but did not want to have to deal with 7500 (and that is weird to have a HV motor mixed with 440 motors as the insulation and isolation is extreme). BT I can see just due to the long run but not anything in an engine room.
Why is it normal to operate the ship with both the 6600 and 440 bus ties closed? It seems as if the overall system would be more fault tolerant to run one diesel generator on each side of the bus tie. Then a single fault with TR1 or TR2 and/or their associated breakers would not shut down all the auxiliary systems required to support the main engine. In my mind the bus ties would be a way to power up the "other side" of the bus after something like TR1 fails.
It’s the way this system is designed. I haven’t worked with a switchboard setup Like this. But before we go too deep down into how it should have been run i say wait until the final findings because i have significant doubts there were any problems with the circuit breakers it’s far more likely they worked as designed and were protecting the system from generation problems
This is the critical question. I wonder if the ship's "operating manual" documents a redundant mode with both buss ties open to be used in critical situations such as entering/leaving port or navigating canals. The configuration as shown in the NTSB document is probably the "open sea" mode where recovery time from single point failures is not time critical.
@@steamman9193 I understand your perspective and we definitely need to wait for the final report. As an EE who does lots of PLC programming and has worked on some redundant systems for large petrochemical plants, the topic intrigues me. I'm curious of the design philosophy behind the overall power distribution system and the bus ties. Like your channel. My son has sailed on the SS Curtis and will be sitting for Coast Guard exams to get 3rd engineer license in a few weeks.
@@dge283 almost definitely not. Bus tie breakers are very common HV and LV switchboards are not. Only once in my career has a bus tie breaker opened and it should have it was protecting the rest of the switchboard and essentially saved it.
@@steamman9193 chief makoi just did a video about the bus ties. I found it interesting. He states the bus ties are more for maintenance purposes and often bolted connections that are not easy to open/close.
Steam man, thank you for taking the time to respond to so many comments. It made reading through the comments useful.
Others, please read through the comments. Most questions and comments have already been addressed.
Note, most of seem to suspect the type of problem that we had to deal with in the past. It will be a wait to see the final report.
Let me join in here; really appreciate that chief Steam man takes the time to reply to many questions and also makes `hands-on´ videos showing engine room & machinery.
Bit of a pity that YT software team doesn’t spend bit more effort by e.g. introducing more than one indent level which would help to structure conversations & threads in better way (and possibly avoid recurring questions 😉). But of course, primary YT target of the `comment section´ is to simply create `clicks & likes´ rather than `deep-dive forum discussion´…
It’s remarkable once it comes to YT clips dealing with technical topics, there’s always a certain portion of comments where one can notice also experts sharing their knowledge & experience, which I really appreciate and enjoy. I could imagine this must also have been the spirit during the early days of the Internet (with DARPA being one the initiators as far as I know, possibly also other scientific institutions).
Like here for the MS Dali incident, I believe it’s beneficial to share experience from maritime experts as well as pro’s from corresponding fields like US Navy chiefs, land-based power grid and aviation, plus safety experts. It’s important to take both mechanical and electrical perspectives into account. Yes, partly it’s speculating and also controversial due to different background & requirements from regulations. But best case everyone can pick up some beneficial insights & learnings, and if there’s differences, trying to understand why and where do they come from.
Thank you for sharing! Great overview of the report. I admire your knowledge.
Thanks for highlighting & explaining the low fuel pressure
Lots of experts who have never set foot in an engine room . I was 10 years at sea with a Chief Engineer Certificate and this post is accurate
Fantastic information! Great to get an analysis from someone who actually understands the systems. Wish there was some sort of explanation that this was a preliminary NTSB report and not a final, from what I was understanding they have a good handle on what was happening that day, at least at a high level. Obviously they are still looking into the WHY those things occurred.
Great analysis. My hypothesis - First outage occurred because of TR2 differential protection operation for a transient fault in the transformer. Full electrical power was restored to ship by the manual close of the transformer breakers after about 60s. The emergency generator is expected to automatically start and come online with 45 seconds of the initial power outage but did not appear to do so. The emergency generator came online (and disconnected the emergency LV bus from the main LV bus) sometime after power was fully restored. The main generators LG3 & LG4 tripped causing the second (partial) blackout because of a re-occurrence of the low fuel pressure issue. As you say - lots of questions for the final report to answer. Give a thought to the engineering crew trying to manage this issue in their control/switchboard room. They would have been plunged into darkness, alarms going off all over the place and unexpected behaviour occurring.
Would they have been in darkness? My only experience with sea-going vessels was in the US Navy and we had lanterns all throughout the ship so that if we lost electricity those automatically came on (main electricity caused the lanterns to be open-circuit; when power was lost the switched closed and the lanterns came on almost instantaneously). Not sure how different the requirements are for a commercial motor vessel but I would have imagined something similar would be at play.
Very informative! Thank you!
That was excellent. Thank you.
Good stuff! I understand electrical circuits but was unfamiliar with the design of these large ships. Love the information given and discussed here. Do drama either, thanks! Just the facts ma’am. 😊
Thanks a lot for going over the reports.
I’m not a marine or electrical engineer. I’m curious what caused both the low and high voltage feed breakers to trip at the same time. Frequency out of tolerance? I would imagine if there was a fault to ground they wouldn’t be able to reset them because the fault would still be there. Then the EG breakers trip. Frequency out of tolerance? I would be looking at the controller for frequency synchronization of the generators. I suspect when they get the ship into dry dock they’ll pull the breakers out for extensive testing and tear down along with parts of the electrical control system. I’m also curious about the the coordination of the electrical breakers for not only fault but frequency. I’m also curious if the breakers operated based on internal safeties or by external command of the electrical control system.
Unfortunately the report doesn’t have the cause for breaker trips that’s a very important piece of the puzzle. But yes frequency or voltage out of order are very likely to have been the cause
Yes yes yes great point fountainvalley. I'd love to know how 2 mechanical piston driven generators are synchronized when they are not connected at the crankshafts
You can be sure that there are electronic (computer) controls that monitor voltage, frequency, etc. (plus relative phase for connecting multiple generators) to protect the system before connecting to either HV or LV buss. If the controls cannot remotely trip the breakers there are surely contactors that will open these these paths, and cut power to protect the equipment.
@@mark_osborne there are electrical/electronic components that synchronize the output of the different generators. The electrical output is synchronized not the physical diesel engines.
@@fountainvalley100 Interesting, I'd love to know more about this. This mechanical engineer thinks in terms of keeping both armatures in-phase
OK, I have a theory on the black smoke before the collision.
In the blackout days before, the #2 generator was shut down due to closure of a damper. In a four stroke engine, if the exhaust is gagged, it will either blow up the exhaust piping, or the exhaust valves will float. The back pressure pushes down on the tops of the exhaust valves, and can make them float if the pressure is high enough to overcome the spring closing force. This can cause contact with the piston, and this can either hole the piston, bend the valve, or break the valve. If they caused damage to one or more cylinders and then didn't test generator #2, they could have sailed with a broken engine on generator #2.
If they later tried to start generator #2, the disabled cylinders would put raw fuel into the exhaust, which would be seen as black smoke.
There is nothing to confirm or deny this theory
@@steamman9193 Absolutely! I've been very curious about the smoke. This could be one possible explanation.
We'll have to wait until they look over generator #2.
I believe the main engine on Dali is a 2 stroke engine.
@@sirenbleu Not the main, the diesel powered generators.
@@sirenbleu 2 stroke diesels at least modern ones almost always have exhaust valves and ports for intake. But we were discussing generators which are almost always 4 strokes. There is no record released of the Dali main engine attempting to be restarted
Excellent, THANK YOU!!!
2nd Comment: While this alone is not a full answer, I think it has merit. The system should be designed to allow this for critical maneuvering periods. The assumption is not best case, its worst case that at the wrong time you could loose propulsion (and or Power).
The HV bus should be split with Tie Breaker HVR open. Then the HR1 and HR2 sides should be feeding parallel pumps be it fuel, coolant or lube such that a fault/failure on one bus or the other would keep the propulsion going.
The Emergency Generator should be on line powering its area with LVR and LR2 open. That keeps at least the low speed ram on steering working regardless in the time frame you still have some speed to be somewhat effective.
I think failure to split the HV and LV buss will turn out to be the root cause of the failure. Operating with single buss leads to a system that has single point failures that can disable the ship.
As a Chief engineer, my thoughts would be......as pointed out, there is something wrong with the fuel system setup on the vessel.... wrong lining up or forgetting to line-up after maintenance could be a factor.... which in turn can lead to low fuel pressure in the system....tripping of DG breakers may be due low frequency where the tolerance maybe just 5%....low fuel leads to lower RPM of DG which leads to low frequency which may trip the breakers...
So what are your thoughts on this is related to securing the bow thruster and possibly a 3rd generator, then the other generators not being able to adjust to the load? I know it’s hypothetical but it fits very well
@@steamman9193 it's possible... unless we have the fuel system lines to guide us, we will have to wait for full report... but I strongly feel that something went wrong with frequency.... only reason being that the DGs were running, both blackouts were breakers tripping....why??
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@@sonishankar6008 agreed frequency or voltage tripped the breakers as they should have worked
@@steamman9193 Using the opportunity to have 2 knowledgeable Chiefs in the conversation here; and just for my understanding since I’m quite interested in following all this tech-talk:
I’d assume the bow thruster has been used for doing the 180° turn when leaving the pier. So does `securing it´ actually mean bringing it to a stop by controlled reduction of the motor’s RPM (thus also reducing load on the 6600V HV bus accordingly)? And 3rd generator might have been connected during the time when the bow thruster has been active to support with additional electrical power?
More generally wrt manoeuvring using bow thrusters: will it make the ship turn around its centre of gravity (which is expected to be somewhere in the middle), also causing stern to move (I would expect this to certain amount except the situation when it is still fixed due to the pier)? Or will stern remain almost constant?
@@NRZ-3Pi10 I can’t comment on the maneuvering characteristics it’s outside my world. Every bow thruster ship I’ve worked requires 3 generators. Or is a separate diesel engine, but Dali was electric. That doesn’t mean it can’t be done with 2 especially due to Dali s very large main generators I just don’t have that information
Mr. SteaM:
serious un-educated question.
With the ship under way, would there be enough energy available with water passing the propeller to rotate the main shaft, and therefore continue to turn the engine?
Does this type of engine have electric blowers to provide combustion air?
Hypothetically the control system should know that the engine is not in a 'run' condition, Of course, we won't know what the programming logic is or what was overridden manually. Yet, I suspect it took time to re-boot the control system once everything went dark.
just a controls / engineering technician here; musing.
Thanks for taking the time to create these videos!
So can it turn by the water passing over the propeller? Absolutely! At what speed that happens is variable. Yes electric blowers under low load. But electronics shouldn’t need any kind of reboot time
Steam Man: I really like your information. You are the only one that is addressing this in detail. None of my comments is intended as tearing down.
I also think we look at things and figure out how to improve them so that we have enough layers in the Swiss Cheese Model of failure that an event does not get all the way through. I am going to drop in a series of shorter comments.
I don't think fuel had anything to do with the failure on Dali. My best guess is HR1/LR1 trip was either a transformer failure or a fault that went upstream through LR1 to HR1 and caused that initial trip. The other trips look to have been the Generator CBs reacting to whatever was causing the trip initially on LR1 and HR1. Depending on the protection settings and CB coordination, that can and does happen.
LMSGO does have a lubricity, its sulfur content is vastly higher than land Number 2 diesel (US standard ULSD). Its a low sulfur diesel in name only just like Aviation Low Lead fuel had large amounts of lead, lower than it used to be but there. 0.10% sulfur vs the ULSGOs coming into the market from the automotive market typically have only 10 to 15 parts per million (ppm) sulfur, or 0.001% to 0.0015%.. Equally Marine has better cetane and worst case, if lubricity was too low then its added (which is what ULSD does). That said, the engine mfgs will ensure their equipment works with the lowest allowed lubricity (be it sulfur or additive). Road diesel engines worked fine with it.
I didn’t get into it in this video but I lean heavily on fuel being the main failure because of the heavy black smoke see in the accident videos. A normal breaker trip or engine starting shouldn’t smoke like that. And now that we have the report where the main engine was never started we now know it’s a generator
Thinking on this more a permanent electric fault should have presented itself obviously to the investigation team by now. Even an intermittent fault may have made itself apparent.
@@steamman9193 NTSB preliminary reports states DGR 3 & 4 kept running und thus also keeping HV bus alive. This suggests their fuel pumps connected to HV bus and still working, too. So no shut-down of the generators then; but at least drop to (very?) low-load condition. But when re-connecting TR1 (which might cause additional load in case of defect), that might be quite some heavy duty for DGR 3 & 4 then. That might explain heavy smoke (`black´ appearance to certain amount might also come from missing lighting on that side we see in the port cam video). In addition, like you've mentioned, could also be interesting how DGR3 reacted to this, considering the issues observed while in-port. If DGR3 struggles to support fully, `poor´ DGR4 would have to take all the load then, most likely even to `fight´ against DGR3 ...
@@steamman9193 I am going to have to print out the NTSB (I do have the Electrical Schematic). Smoke could be from the emergency generator starting or DG2. HR1 and LR1 would not open up due to generator issues, that is not their job. As you pointed out, they did open up a bit latter. But at that point they may be the most sophisticated breakers in the system left. Mine as I recall has 4 to 6 trip functions (two of those had to do with the Generator dropping off frequency or reverse power).
But DG2 started, closed and ran. While I could see making a case for the 2nd outage being fuel it would not seem likely and DG2 seems to have kept running fine. I had cases where more sophisticated breakers with more settings (vs thermal) and or micro processor controlled tripped upstream leaving the downstream breaker still engaged (in one case it too tripped after a small amount of time but the upstream sensed before that fault first and opened.
@@steamman9193 That is one of my two electrical based theories. We don't know what the CB types and protections on HR1 and LR1 were (yet). A Transformer fault should not trip LR1, but it seems that is a possibility. I never had two high feature breakers one after another let alone across an Xformer bridge, so I can't say that a zark out of the Xformer would send a signal downstream. Equipment ground fault can be interesting and on a ship with its isolated grounding, more so not to mention the other faults.
The deep sea controllers we use for our em gennys monitor the fuel pressure at the filter housing, and this is recorded on the deep sea, so the information should be recorded as to if it was a fuel issue, I think it was more a phasing/syncing issue, running and restarting generators on various buses. The email gen probably was out of sync with the hv bus and caused the second trip. This would also explain why the em genny took so long to come online.
There is no report of synchronization changes taking place to have caused the initial blackout. And unfortunately no fuel data in this report
Thank you for posting video.
Wondering if engineering team didn’t inadvertently introduce an issue during earlier power outage in port? Was the electrical system returned to the normal setup / lineup once the issue was resolved or was something locked out?
PS - Think generators 1, 2, 3 and 4 are service by individual day tanks and require electrical power to run the fuel pumps to keep that day tank full. Wonder if second outage was just caused by fuel starvation?
Most likely all the generators get their fuel from a single service tank, but with redundant electric feed pumps. And no indication so far this was in any way related to the event, there should have been alarms associated with and discrepancy’s
I'm curious as well, been out the navy a while and this is making me think back on ring bus safeties hard. I know they won't be the same but I'm thinking some of the principles might be. I know trips would be designed to open breakers as close to the fault as possible to prevent taking down any necessary and still safely operating equipment. So if the hr1 and lr1 breakers to transformer 1 tripped it was prob an issue with the transformer? You would want this to trip before it could cause a problem that would trip up stream which we see as it does not cause the main hv breakers connecting the generator to the bus, dgr3 and dgr4 to trip. It could be a fault on the lv bus but in theory there would be breakers down stream closer to sub circuits and pannels supplying them and equip that should have tripped before tripping the transformer hence breaker pannels. That and tripping both to a piece of electrical equip was usually an equip fault if I remember correctly. But the crew manually closed hr1 and lr1 putting the transformer back on line. And in less than a minute dgr3 and dgr4 trip. This is also when smoke starts bellowing. could this be under volt or over throttle trips bc they could not supply some insane load bc of a fault in the reconnected transformer? I seem to remember there is a brief time after large breakers close that the trip is not "rearmed" bc an initial transient could re trip them. Again I'm almost 20 years out from my operator days. I deff get that insufficient fuel would cause rpm and torque to reduce resulting in and under power trip of then generators but would that cause all the smoke? Or was all that smoke dgr 2 coming on and loading hard? They also never say if dgr 2 shuts down or any other trips occur once they change to transformer 2 and dgr 2, but if it was fuk and the dgrs are on common fuel lines it should have dropped after a spell. If it was in the lv or hv bus it would have also eventually re tripped as the fault (if not in trnasformer1) would have not have been isolated. Im also surprised and curious about immeadiate actions why not split the bus and bring both transformers online bc there are some basicish (at least how we ran) indicators it might have been thr transformer. Also dont know how much civilian ships are set up and capable of runing split bus. I do get why, sort of, they never tried to restart the main engine. It doesn appear that they kept main power restored for any significant time so that they could. At 0125 they tripped, 0126 and seconds first restoration, then 0127 second trip, dgr 2came up but it took 30 more seconds to restore power to 440v bus using transformer 2 mere sends before impact.
Here’s something I’ve been thinking about since too if there was a piece of failed electrical equipment like a transformer it should have been discovered by now. My thought is there was an electrical load not seen since the accident and they haven’t been able to reproduce while stuck
Could you tell us what kind of GPM the various main engine pumps move? Ie the main engine oil pumps, cooling pumps and fuel pumps. I was surprised that the Oil Pumps would be on HV, cooling/coolant pumps on LV. As I understand it you would have a sea water pump(s) on one side for all the general cooling needs and then specific coolant pumps for the Main engine. Generators would have to run coolant to an intercooler and would those be internal to the engines or a separate pumps as well?
It’s not fair to compare to Dali because my main engine is much larger, and not all of this information is in 1 place but Main lube oil motor is 355KW. Cooling water pumps are 65KW each and absolute minimum of 1 salt water and 1 fresh water required. Those are 900 cubic meters/hour
Thank you for the video. I have a question regarding restarting the main engine. Could the main engine been restarted in the time frame? How long would it take to get the main engine back online ?
Unfortunately without being there no one can really know IF it was possible. But what is definite is even if they did re start the main it would have shut down again on each blackout
@@steamman9193 To start the engine both the HV & LV boards need to be powered. The EG could have powered the LV board and there may have been a small window where DG2 powered the HV board. This being before the HV2 & LV2 breakers were reset. After being reset the HV board would energise TR2 and generate LV power.
I do not think that there was sufficient time between the second outage to restart the engine before impact; looking at the timeline the window was only 1:45.
Also having just one of the main generators online may have not been sufficient to start the engine. DG4 & DG3 had tripped offline and DG1 was not running.
@@christopherrobinson7541 powering the main switchboard from the emergency switchboard is highly regulated against the way you are describing. It’s a complex system but the line you see in the drawing is to power another emergency switchboard from the main normally, it’s not a quick evolution to make it go the other way
@@steamman9193 I appreciate that the diagram shown is a simplification of the actual system. I was suggesting that at best, the emergency generator may have been able to supply some of the LV loads required to start the engine, whilst some of the main generators were on line to cover the engine HV loads.
My main point is that at best there was a narrow window (1:45) during which the engine might have been restarted. Without detailed knowledge of the system, this period appears to be too short, especially if other main generators, in addition to RG2, needed to be brought online.
Given the sequence of events it is not surprising that the engine was not able to be started.
I'm not a marine engineer. I'm curious what design requirements or compromises led to the coolant and lubrication pumps being on different electrical busses. If the HV bus is required to run the main engine anyway, why are the coolant pumps on the LV bus? Also, are the engine and pump control circuits powered by the HV bus or the LV bus?
I really don’t know why they did it for sure. Higher voltages require smaller wires aka save money on construction costs. Personally I wouldn’t put too much effort into any of this as I am highly suspect that there is nothing wrong with the switchboard and breakers at all. It’s far more likely there was a fault with the ships generators and the breakers opened because of that. Having different power or switchboard arrangements wouldn’t have changed that and the accident still occurred. That’s just an educated theory for now though until the final report
Not a marine guy but I've got to wonder about clogged fuel filters. If the pump is running and operating properly the next question is the condition of the filters.
Thanks for the review, Chief.
Definitely an area to be investigated but I doubt the problem as the regular heavy oil they burn is much dirtier, plus each engine should have its own filtration so more than 1 becoming a problem at the same isn’t very likely
@@steamman9193 ,
I figured there was likely some separation and/or redundancy but I'm not a marine engineer.
Thanks for the response and clarification.
Is there any way that you can see the fuel issue causing the initial blackout by tripping the breakers on either side of TR1?
Absolutely if the generator isn’t getting the right amount of fuel it’s voltage and frequency can be off enough to trip breakers
@@steamman9193 Which I guess is why they wanted a team from the Japanese manufacture of the system to help gather info?
@@k53847absolutely after an accident you need an independent contractor to retrieve data
So here's a question ... when LR1 and HR1 tripped, the crew reset them.
What's the thought on resetting a breaker that tripped?
Should they have switched to LR2 and HR2 until the cause for tripping was found?
That’s a missing piece of the puzzle. If they knew the trip was related to something else there’s no reason they couldn’t reset the breaker. Also the L1 tripping then H1 indicates the problem wasn’t with a single breaker
@@steamman9193 also consider, sitting there for five weeks now, they've been running on the left hand bus without any issues, albeit not operating the main engine.
(the right hand bus, from the accident, is locked out by investigators and unavailable)
@@litz13there’s no where near the Electric load sitting there to gauge anything right now. I would want to load test everything that was on that day as it was
@@steamman9193 fair point. Presumably the investigator will eventually do that.
Steam man i have some thoughts i am curious of your opinion. I think the TR1 differential protection relay may have opened the breakers on both sides of the transformer as it is designed to do during an internal fault of the transformer. Immediately the crew should have tried to close in TR2 instead of TR1 again.
Now i know that the diesel generators, unlike the main propulsion diesel engine, generally have gear driven oil and jacket water pumps. However, this jacket water is often cooled by either a salt water or a freshwater cooling loop driven by pumps that probably come off the LV board. So i wonder if the second trip happened due to the LV board being without power for some time and hese pumps not running causing the disel gens to overheat. Also i believe the fuel oil supply pumps are off the LV board so maybe that was the result of insufficient fuel pressure. I imagine the ntsb are looking at the fuel pressure as well as the cooling water temp trend graphs as well.
Finally i am curious to ask why the crew doesnt run in an open bus tie arrangment while manuvering? It seems much safer to have gens on both sides online of the HV bus aith both the LV and HV ties open and both transformers energized. I worked on drill ships and we have 3 main electrical 11kv busses and our ties between them all were always kept open. Lastly, there should be some tie of ATS switch employed for the transformers that will automatically switch to the second transformer in a loss of power.
What are your opinions on all this? Thank you i love all your videos chief
So I have doubts there is anything wrong with anything on the switchboard and the need to change anything with it. To put it simply if there was a definite fault there the crew would have immediately identified it to the inspectors as that would be a no fault of their failure. But we don’t have that and by now we should have if it existed. I’m not saying it isn’t possible just not likely
Could you explain why they could not use the bow thruster for steering
That isn’t my area of expertise but my understanding is bow thrusters are only effective at low speed. I don’t believe the status of it’s running is in this report to anylze
I’m not a marine or electrical engineer but am curious: why not run all four main generators and close LR1, LR2, HR1, HR2 to have redundancy at least while you're in restricted navigation? Would this possibly damage things or is it not done simply because it burns more fuel than needed and this stuff is usually so reliable that extreme redundancy isn't needed?
More reason than not to only run the number of generators required. Cooling, contamination, turbo charger loading. Etc etc. I don’t truly know why both transformers aren’t used I have never worked on a system like they have but I’d guess it has to do with synchronization or the inability to synchronize transformers
I'm not sure what type of fuel we are using now here in the UK fishing fleet, I wonder if it needs a percentage of clean engine oil added to it to bring it back up to a good standard
There are lubricity additives on the market I definitely recommend running something with these low sulfur diesel. I’ve also seen fuel chillers installed which thicken it and help with lubrication properties
Am I correct that 1] You have indicated that parts of the fuel transport system to the generators are or can be dependent on the lubrication in the fuel itself for long term operation? 2] If #1 is correct my suspicion that a cylinder or ball valve could expand then partially jam thus reducing fuel pressure is valid? 3] #2 being valid, design, age, maintenance, or exceeding published non-lubrication limits are all possibilities? The thought arises from my past in USN M-1a gunnery fire control system maintenance followed by a career as a Methods Analyst. Are such limits published and accessible, or is it an "Oh! Everyone knows that." situation.
I have checked out ". . . injection control unit, problems from bad fuel" and "Diesel electric marine propulsion" on your Steam Man site. They have helped, but a video project illustrating this or similar shipboard fuel supply system, pointing out components that may be designed as fuel lubricated only, or partially fuel lubricated as you have done with the electrical would provide, I think, a good basis for understanding what you are communicating about the fuel part of the NTSB report.
I plan on doing a high pressure fuel injection pump video when time is right. Unfortunately the report lacks key information on zeroing in on the true cause. Basically the fuel injection pumps I’m focusing on are solely lubricated by the fluid they are pumping hence their susceptibility to wear and getting stuck and are an hours based overhaul or replacement item
Before the requirement to use low-sulfur marine gas oil, what did motor vessels use in port and coastal waters?
Heavy fuel oil. Hfo it’s towards the bottom of what is left in refining crude oil very thick, and has to be heated to even pump but it lubricates parts very well and has more energy density aka more miles/gallon
@@steamman9193 Sounds like “Bunker C”, the same stuff that merchant marine steamships used.
@@steamman9193 `Chief´, can you help to double confirm, please?
I'm aware HFO / MGO needs to be heated for pumping (like you wrote), up to temperatures around 40°C - 50°C. My guess has been around 80°C for injection, but Wiki tells even up to 130°C - 140°C (perhaps this partly comes along while increasing pressure up to 320 bar as per your other reply). Question also targets how heating is done and which bus used for power. I'd expect it is done both electrically as well as using heat from all the big diesel engines via their water cooling system? Good opportunity to expand my broad-band knowledge ...
@@NRZ-3Pi10 this is weeks worth of education. But I’ll try to simplify. Hfo has to be heated how high is based on test results of the fuel. I’m currently burning at 88C but I have had fuels at 155C. Do not heat diesel it gets to thin and wears parts out. Heating is typically done via steam
@@steamman9193 Thanks; also don't expect you to come back with lengthy reply like some of my comments, well, partly `novels` 😂.
So steam can be created by oil burner, electric heating or from heat of the engine (but up to 155°C might be a challenge for the latter).
I have found no way to message or email you. So please forgive my being off topic. I think you would find the workings of the Mark-one-able [M-1a] gun fire control computer found on WW-2 destroyers mechanically fascinating. Covered in steel with portholes, about 4'w x 3'd x 3'h, and started by spinning very small crank. The thing actually ticked. Computation was by metal disks separated by a ball bearing. It was Fair shooting at socks towed by prop aircraft. Even attempting a lock on a MIG was a joke. but not a funny one when 10 miles off Cuba escorting one of our spy ships located in Havana harbor just after the capture of the USS Pueblo by N Korea. I am enjoying your sharing and wish you well in bringing together the age of steam with the age of UA-cam. Also motorizing that 4-8-8-2 Big Boy.
Ebartonce@gmail.com there is a link somewhere on this UA-cam channel
what kind of motor with what sort of windings can run on 6600 volts? Would not Six KV arc to anything nearby?
Not sure how they build them differently but yes arcing is a challenge
motors above about 400 HP use high voltage
I am not a marine engineer, or indeed an engineer of any sort - just a pilot who is very interested in how these systems work and the various factors at play in how this accident unfolded. One of the minor things that has bugged me is this description of 6600v to the reefer containers, just doesn't seem right. So I Googled it- all the results I can find show standard reefer containers operating on 3 phase 440v, which makes more sense to me. So - my guess is the NTSB simplified the HV bus feed to reefer containers, and they are perhaps fed through their own dedicated T/R, or pair of them, from the HV bus. The alternative is that it's just an error in the preliminary report, and they are fed from the main LV bus, but are just pictured in the wrong place. And, as commented above, it does seem odd to me that the standard elec config in critical phases of the journey is to have everything tied together rather than split.... But I'm not a marine guy, so I'll defer to those with expertise on this matter.
@@cpazdzior so I don’t have the drawing but it’s likely the container reefers have their own transformers, it’s a better option. grounds in the marine industry are a big problem since the ship itself is grounded. There is a lot of focus on redundancy in the switchboard from non marine people, but we don’t have any indication that there was actually a problem with the switchboard. My theory is the problem is with the generators and they experienced multiple failures
Software engineer, so totally out of depth here!. Does LSMGO go through the same set of fuel purifiers as regular fuels?, is it implied the lower lubrication could impact flow rates through these?
It can there are gravity disks that can be changed for the lower specific gravity of the lighter fuel. Does it have to go through a purifier? Not necessarily it would still probably go through all of the same filtering equipment
Given the criticality during maneuvering watch, I wonder if there needs to be two fuel pumps and two water pumps on separate buses being fed by two different generators. That way if there's a problem on one bus it doesn't effect the other bus.
That’s a far more complicated question than on the surface. You would have to add additional components to regulate flow that would be subject to failure themselves so would it be better? Also in this case it would not have prevented the accident so now we are solving a problem that didn’t exist. I don’t believe the core failure exists with the busses or switchboards
It's going to be something down stream of the circuit breakers
I m leaning more towards generation problems and the circuit breakers worked as they should have
Agree this issue with Generator 3 and “low fuel pressure” causing the second in-port blackout might also build a link towards the blackouts when Dali left Baltimore.
This is especially considering the position of all the breakers as shown in the schematic block diagram as per status of departure March 26, with both DGR 4 and 3 supplying the entire HV as well as the LV busses. So if DGR3 faces issues like e.g. “low fuel pressure” again and there’s already high load on system, that might cause unfavourable and unwanted reactions. Let’s also keep in mind there was lot of smoke after first successful recovery of electrical power, indicating very high load.
But more generally, even without this DGR3 issue while in-port, I wonder that the cross-tie breakers HVR and LVR have been closed during departure from Baltimore. I would have expected them to be open, thus starboard and port power supply systems being supplied and running independently (if this applies in similar way like what you’ve explained in your video “Dali size containership steering system …”). So e.g. DGR 4 and DGR2 active, but DGR3 on idle. This assumes there’s also redundancy in vital functions like e.g. fuel pumps for main engine and diesel generators, of course. If this is not standard and compulsory anyway, I could imagine this measure being one of the first “containment” procedures in restricted waters to be raised by the NTSB (and authorities world-wide).
All 4 four generators almost have same power here. In any case it helps to reduce total load on each bus then. That would also apply for emergency procedure re-connecting the big diesel generators, too; rather than having all load again on a single bus only, where some single fail could cause overall overload and blackout of complete system accordingly.
In restricted waters, considering the inertia of such a big vessel, every second counts. So better have the redundancy by main generators already active in best possible way then.
Don’t get me wrong: this is not at all about somewhat judging and blaming the crew. It’s engineering approach, thinking and looking forward how to prevent such cadence of issues in future.
Let’s use allegory from aviation with B-747 or A380 take-off going for long-haul flight. Nobody would think off having 1 engine completely switched off, another just on idle speed (especially both on same side) while the 2 remaining ones on the other wing to provide all the thrust plus power for hydraulics, electricity etc. (even if the engines have this capability) …
Finally, highly appreciate that you (as well as Sal) keep following up on this topic and sharing your expertise here.
I’m not sure your aviation analogy works. Firstly, they had 1 of 1 propulsion engines online. Second, takeoff is the highest demand made of aircraft engines, as they go flat out to convert a static lump of metal i to something that is flying, before the runway runs out. In contrast, this ship was moving slowly as she navigated through somewhat difficult and restricted waters.
@@DanielsPolitics1 Sure, the analogy does not work when only taking the perspective of propulsion, of course. It does work if you compare 4 diesel generators with 4 jet engines, which also have the task to provide `auxiliary´ power for hydraulics, electricity etc. which is equally important for take-off and during flight. Next and very important analogy is safety & redundancy aspect wrt need for always having full control during the most critical phases of manoeuvring. In case of MS Dali, it’s not about maximum power in this phase, but having the required amount of energy available anytime (!), also in case of failures of single components.
In confined waters, the criticality at low speed comes from reduced effectiveness of the rudder if there’s no additional water push (`wash´) from the spinning propeller, so ship movement is mainly governed by its speed and inertia, some amount of rudder, plus currents and effects from wind.
NTSB preliminary report says Dali lost main engine and thus propulsion at “about 0125” and approx. 3 ship-lengths before the bridge, at a speed of ~ 9 knots (which means distance of 1 ship-length will be reached after ~ 66s, i.e. only slightly more than 1 minute). It is required that the emergency generator kicks in after 45s latest; video and VDR showed it took almost 1 minute. Means distance of Dali to the bridge was already only 2 ship-lengths when they had first possibility to get some reduced rudder control provided by emergency generator then - but also only 130s to close the distance to the bridge (if speed would remain constant).
This is when precious time is lost due to not having redundancy already active. Note that I do not claim the crash into the bridge pillar could have been prevented safely, but split of electrical systems could significantly have reduced the probability at least (especially when main engine still running, providing sufficient propulsion for full effictiveness of rudder control). Further investigation might reveal that it’s combination of failures. One occurring at the HV-to-LV link via transformer TR1, perhaps another one related to DGR3 or it’s fuel system, with the latter possibly could even have been a central problem. If that’s the case, it would be real worst case since both sides of the system would have been affected.
So all in all, the blackout obviously hit Dali at worst point in time, without any real chance to re-gain full control over its course as per the configuration of the electrical system (and potential issues with DGR3 or fuel system) …
To close with the analogy: plane did neither make the take-off, nor come to a safe stop at the end of the runway.
@@NRZ-3Pi10 It's easy to synchronize 2 diesel generators but extremely difficult to keep 3 or more loaded the same. to add load to a generator that is lagging you must add more speed . like just a little. then the load changes and the system is out of balance again.
@@kennethchristensen7457 Fully understand larger load jumps or drops are generally quite bit of a challenge. But looking in 2 directions: if keeping 3 or more diesel generators synchronised is big problem in the confined environment of a ship, we end up in the question why system has been operating with HVR and LVR cross-tie breakers closed (there's some discussion wrt that with different opinions 😉). On the other hand, in land-based power-grids such `multi-site´ synchronisation is daily business. It's already required within e.g. hydro-power plant with several turbines & generators; and syncing also needs to be done with the power-grid.
So the low voltage generator went out?
There is a transformer for the different voltages. Same generators
@@steamman9193 the fuel supply stopped the same time the lights went out while the main engine kept turning causing the smoke cause the fuel wasn't lubing the piston or pistons, the timing is suspicious as well as the loss of power 24hrs previous that is new information, not to mention the gas pipeline the dollie has hit underwater that could have been disastrous, wouldn't a breaker have to be manually turned back on going to each transformer and have the contact points been inspected ? At the same time a train overpass is laying on the deck of a barge in Galveston
@@guytelfer1353 you need to go back through the report. The main engine stops and there is no record of it re starting. I’ve never heard of an engine that could billow black smoke when it’s off. And I don’t know where you are going with the rest of it
@steamman9193 someone mentioned a couple weeks ago that the main engine doesn't stop turning right away even if it's not getting fuel or loses electric because it takes a long time to slow down and stop and the propeller has come to a stop before restarting the motor, I'm just sharing conversations but I really don't give 2 shits 1 way or another any outcome to the situation it just looks like you clowns need all the help you can get especially when Biden turned his back on the situation after saying he was going to pay for it obviously he didn't know what he was saying again.
@steamman9193 you need to go back and explain the smoke coming out the stacks because you haven't explained anything we've already heard
This low sulphuric fuel sounds like JP-5 used in military jets. The same type similar fuel is what are trucks on US highways are burning and has been a questionable fuel source on these vehicles for excessive wear of engine parts, that’s my 2 cents 😊
Hence why I sold my last diesel vehicle a few years ago and will probably not buy another one
🥴🥴
If 440/480 is low voltage what is high voltage?? 480 is high enough for me lol!
Marine industry 1,000v is “high voltage” most ships use 440/450 and 220v or 110v
@@steamman9193 that's how it works in my trade too, 600 and under is low voltage ans 1000 and up is high voltage. But for me 480v is high enough to play with! That seems like really high voltage just to run lube pumps with. Not to mention you would always have to have 2 generators running at all times while under way to supply low and high voltage unless they do it with transformers, I guess I don't have any real understanding so I don't get the logic there...
@@shawnbeerens4292 the drawing shows transformers between the different busses that’s what the breakers that tripped are directly for. And there is a secondary that you probably wouldn’t run at the same time but as a backup
@@shawnbeerens4292 In my world it was 24 volt, 120/208 (3 phase) and 480 (technically 460 but 480 out of the main boards). I did a bit of work with 7500 volts under supervision of a HV rated (former lineman) instruction. Ungh. Dead 7500 line jumped a 3 inch gap just on induction through a couple miles of line). I had no issues with 480 but did not want to have to deal with 7500 (and that is weird to have a HV motor mixed with 440 motors as the insulation and isolation is extreme). BT I can see just due to the long run but not anything in an engine room.
@@gregoryschmitz2131 7500 is WAY beyond my pay grade!!
Why is it normal to operate the ship with both the 6600 and 440 bus ties closed?
It seems as if the overall system would be more fault tolerant to run one diesel generator on each side of the bus tie. Then a single fault with TR1 or TR2 and/or their associated breakers would not shut down all the auxiliary systems required to support the main engine.
In my mind the bus ties would be a way to power up the "other side" of the bus after something like TR1 fails.
It’s the way this system is designed. I haven’t worked with a switchboard setup
Like this. But before we go too deep down into how it should have been run i say wait until the final findings because i have significant doubts there were any problems with the circuit breakers it’s far more likely they worked as designed and were protecting the system from generation problems
This is the critical question. I wonder if the ship's "operating manual" documents a redundant mode with both buss ties open to be used in critical situations such as entering/leaving port or navigating canals. The configuration as shown in the NTSB document is probably the "open sea" mode where recovery time from single point failures is not time critical.
@@steamman9193 I understand your perspective and we definitely need to wait for the final report.
As an EE who does lots of PLC programming and has worked on some redundant systems for large petrochemical plants, the topic intrigues me. I'm curious of the design philosophy behind the overall power distribution system and the bus ties.
Like your channel. My son has sailed on the SS Curtis and will be sitting for Coast Guard exams to get 3rd engineer license in a few weeks.
@@dge283 almost definitely not. Bus tie breakers are very common HV and LV switchboards are not. Only once in my career has a bus tie breaker opened and it should have it was protecting the rest of the switchboard and essentially saved it.
@@steamman9193 chief makoi just did a video about the bus ties. I found it interesting. He states the bus ties are more for maintenance purposes and often bolted connections that are not easy to open/close.