Chief Makoi Video Transcript


On the 26th of March 2024, at around 0129 hours, the container ship Dolly collided with one of the pillars of the Francis Scott Key Bridge in Baltimore, causing the bridge to collapse. Based on the reports these past few days, this tragic incident has already caused at least six fatalities and, according to some analysts, could potentially incur total losses between two to four billion dollars.

By now, I’m pretty sure a lot of you have already watched various videos, commentaries, and reactions about this incident. We have seen footage of the ship moments before it hit the bridge. We already know that a blackout occurred, which led to the loss of propulsion. I’m pretty sure a lot of you have been wondering as to what could have caused this failure, which in turn cascaded into this catastrophe. We’ll dive into that, but before we do, just a disclaimer: the actual sequence of events in the engine room has not yet been made public. We only saw a bit of the timeline from what was recovered from the Voyage data recorder. So, I’ll analyze this based only on what I see from this footage, and I’ll try to make sense of it based on my knowledge and experience as a chief marine engineer. It’s just like doing an incident investigation and root cause analysis, which we, as the onboard management team, typically do whenever incidents happen on board.

Let’s take a look at the CCTV footage and check out the timestamp so we can analyze the sequence of events. So here we can see the vessel as it was approaching the bridge. As per the video’s timestamp, the blackout occurred at 32 seconds past 0124. There’s a slight difference in the time between the footage and the transcription from the VDR, so if I happen to mention a different time from what is shown on the CCTV, that just means I’m referring to a different source. Anyway, when a blackout occurs on board a ship, all of the machinery stops inside the engine room, the noise quickly dies down, except for the very loud and sometimes panic-inducing audible alarms, which will be persistent for about a minute or so as abnormal. Also, the engine room will suddenly go dark.

Now, as a ship’s engineer, those are the two things that you don’t want in the engine room, especially during maneuvering: darkness and silence because that means the ship is dead on the water. Whenever I’m on board a ship, when I’m sleeping, I actually get awakened if it suddenly becomes quiet. The noise and vibration from the running engines are actually the normal background. Now isn’t there a backup generator or something? Well, yes, but it’s a little bit more complicated than that. First, I need to explain a little bit about the marine power plant.

So basically, we have the main engine, which is the huge engine that provides propulsion power; in short, it’s the engine that spins the propeller and causes the ship to move. Now, the thing is, the main engine requires multiple auxiliary machinery to be running, like fuel pumps, lube oil pumps, cooling water pumps, and others, before it can be operated. And those pumps, those systems, they need electricity to function. For that, we have the generator engines, which provide electricity to the entire ship. For the purpose of this video, I’ll refer to them as the big generators. Typically, there are three generator engines on board, but for a container ship of this size, it probably even has four. I’m not sure for this ship, but what’s for sure is that the total electrical load requirement of the entire ship can be easily handled by at least two generators, with one extra generator on standby, ready to take over in case of failure. So there is usually no shortage of redundancies when it comes to electric power.

And then there is the emergency generator. It automatically starts in case of a blackout. SOLAS requires it to automatically start within 45 seconds of a power failure. It is located outside of the engine room and has its own fuel tank. However, it is driven by a smaller engine, and it’s dedicated to provide power to only a select group of machinery and lighting, all of which are powered through the emergency switchboard, which automatically disconnects from the main switchboard in case of a blackout. Now the equipment connected to the emergency switchboard serves the purpose of restarting the bigger generators, maintaining the operation of radar and navigation equipment, emergency and navigation lights, and of course, firefighting. The emergency generator doesn’t generate enough power to restart the main engine and restore propulsion. However, it provides power to the ship’s steering gear. Yes, once the emergency generator kicks in, the ship should be able to use the rudder, you know, to steer the ship. But more on that later.

And then there are also a few batteries, which automatically connect to the radios and other small emergency equipment, a few battery-operated lights, as well as UPS for computer-based devices like the EIS. Okay, so now that we have the basic idea of a marine power plant, let’s look at the footage again. As we have seen earlier, the blackout occurred at 32 seconds past 0124. So, as I mentioned, the emergency generator should kick in within 45 seconds as per SOLAS requirements. Here we see the electric power was restored at 31 seconds past 0125. That’s 59 seconds. Wait a minute, does that mean the emergency generator did not run and automatically connect on time?

Well, there were signs that it didn’t go online within the required time. If you look closely, for the entire duration that the lights were out, the nav lights were also out, and they never came on until all the other lights went on. The navigation lights are powered through the emergency switchboard, which is supposed to be powered by the emergency generator during blackouts. Also, according to the initial transcript of the timeline, the VDR stopped recording the ship’s data, except for the audio in the wheelhouse. It resumed a little over a minute later. Those are telltale signs that even the emergency power didn’t kick in within 45 seconds. What we’re seeing here, when the lights came back on, was probably just the emergency generators. I might be wrong, but I’m very familiar with the sequence when restoring power after a blackout, so I say there’s a big chance that that’s the case.

However, it’s also possible that they managed to restart the big generators and put them on load. That could also happen even without waiting for the emergency generator to kick in. Anyway, a few seconds later, after the lights came back on, you can see black smoke coming out from the stack. Initially, I thought this was from the main engine. I thought they were trying to do crash astern maneuvers, and the black smoke was the result of a poor fuel-to-air ratio because they canceled the load limits of the main engine, you know, to quickly increase the speed. However, it was only 13 seconds after the lights went on. I doubt they managed to restart the main engine that fast. There are a lot of things to reset before the main engine can be ready for operation. Well, it’s not impossible, but I seriously doubt they were able to. It’s more likely that the black smoke was coming from the big generators.

Anyway, assuming they were able to start the big generators and put them on load, this means they should have had the capability to restart the main engine. The problem is, at a speed of around 8 knots, it is very likely that the propeller was still spinning in the ahead direction due to momentum. Running the main engine in crash astern direction would be a bit tricky, and there will definitely be a few start failures before they get the engine running. It’s a matter of technique, but I’ve done it many times as part of a testing procedure years prior to the ship entering port. It should work as long as there’s nothing wrong with your main engine or fuel.

However, if we look at the AIS tracking, I don’t think they were able to run the main engine at all. Here’s why: by this time, the steering gear should be functional, even if they were still in emergency power mode. One of the steering gear motors would have already been functioning because it’s connected to the emergency switchboard. We can also see from the VDR timeline transcription that various rudder commands were given by the pilot at around this time. So that means the rudder was responding to the helm commands. Okay, so the steering gear was working at this time.

However, assuming they had use of the rudder, why didn’t the ship turn to safety? This kind of confirms that they weren’t able to restart the main engine because without propulsion power, the rudder won’t be able to turn a ship of this size effectively. To explain it simply, the rudder makes the ship turn by deflecting the water stream generated by the propeller. The force of that deflection creates a turning moment or torque around the ship’s center of gravity. So that, in combination with inertia, causes the ship to begin turning in the direction determined by the rudder position. The fact that they weren’t able to turn the ship is an indication that there was no propulsion.

So why was there black smoke coming from the stack? Where did it come from? Since the smoke appeared around 13 seconds after the lights went on, we can presume that it came from the big generators. I’m ruling out the auxiliary boiler automatically firing in this case, because it takes about a minute of pre-purging before it could fire. Presumably, they were trying to restore the main electrical power, which is logical because that’s the only way for them to be able to restart the main engine. But normally, there shouldn’t be any black smoke. In US waters, ships are required to use LSMGO or low sulfur marine gas oil, so it’s relatively cleaner compared to the black stuff that we normally use when the ship is out in the open sea. And even when ships use heavy fuel, there still isn’t supposed to be any black smoke under normal operating conditions. So why was there black smoke? This could possibly be one of the clues in finding out the root cause of the blackout.

Whenever ships are maneuvering into or out of ports, two generators are usually in service and at least one is on standby. Typically, one generator is capable of handling the essential electric loads needed to operate the main engine, but for safety, two of them are put on service to ensure that there is more than enough power available and that blackouts won’t occur while maneuvering. So, in case one of the in-service generator trips, the one on standby should be able to start and take over. But in case it doesn’t, the preferential trip will be activated on the main switchboard. This will shut down the non-essential machinery, you know, the ones not needed for maneuvering, like refrigeration and air conditioning, purifiers, blowers, and various other machinery. So, this preferential trip should be able to reduce the load enough that one generator is more than sufficient to maneuver the ship.

Now, for a ship to go on blackout while two generators are running means they both malfunctioned at the same time, or almost the same time. The two most probable reasons for this to happen are either fuel-related or switchboard-related. Either reason may explain why the standby generator didn’t automatically start and take on load. A switchboard malfunction, although possible, is quite improbable. For this, it is still possible, though, but it will involve a bit of, well, a lot of malfunctioning parts, or even human intervention, like someone doing electrical repairs on the main switchboard, which is a little bit unthinkable while the ship is maneuvering. I’m not ruling that out, though. It’s bad practice, but I’ve seen it happen before. It could explain why they weren’t able to bring the generators back on load, but it can’t explain the black smoke.

Now, the fuel-related reason seems to be more plausible in this case. Simply put, the fuel supply was suddenly cut off. I don’t think it would be something like clogged filters because that would happen gradually, and there are numerous failsafes for that, and it is easy enough to rectify. A sudden stoppage of the fuel supply would explain why both generators would shut down at the same time, as they share a common fuel line, and also prevent the standby generator from starting automatically. But since the ship was presumably using LSMGO, they might have been using the small flushing pump instead of the dedicated fuel oil booster pumps for the generators. The small pumps might not have had enough pressure, you know, to sustain the load on the generators. Or maybe someone mistakenly closed a valve or accidentally activated the quick closing valves or maybe even forgot to refill the fuel tank. It could happen. I’ve actually seen that before. There are many maybes, but the thing is, at some point, the fuel supply got cut off.

However, a simple closed valve is easy enough to rectify, and it shouldn’t have been difficult, you know, to restart everything from there. Now, there’s also the angle of contaminated fuel. Yes, that could also happen. In fact, the black smoke seems to be an indication that this might have been the case. There’s a possibility that they change over to a different tank, which had bad fuel or contaminated fuel, which could have caused the generators to stop at the same time. Or, and this one is a bit controversial, they tried to change over to heavy fuel oil too early, and something went wrong. That could also explain why the standby generator didn’t start and why there was black smoke afterward. Now, we can’t know for sure what specifically caused it, and I’m not accusing anybody of doing anything. I’m just trying to make sense of things because this could happen to any seafarer. It could happen to me.

Anyway, at around 0126, the pilot called for tugs in the vicinity through VHF. Now, looking at the footage, after over 1 minute since the light went on, it went dark again, but strangely enough, the navigation lights didn’t go out this time. This might have been an attempt to put the big generators on load, although black smoke was still coming out of the stack again. This is not normal as it indicates a poor fuel-to-air ratio or incomplete combustion, so it’s really strange since, prior to the blackout, there was no black smoke. So, at this point, the pilot gave the order to drop the port anchor since the ship was not responding to the rudder movements. As we can see, it didn’t have much effect.

At around 25 seconds after 0127, the pilot issued a radio call through VHF, reporting that the vessel had lost all power approaching the Key Bridge. So, since the lights went out again, we are assuming that even the emergency generator was, for some reason, disconnected. That means they don’t have any rudder control anymore because there’s no electricity supplying the steering gear motors. Anyway, after about 30 seconds, the lights went on again. Looking at the vessel tracking, the ship barely lost any speed and was already veering to starboard. At this point, collision was imminent.

At first, I actually thought the main engine was running astern at this point because the ship suddenly turned to starboard. This phenomenon is known as propeller walk, and the ship turned to starboard because it had a right-handed propeller. But, of course, after a thorough review of the footage, we know by now that they weren’t able to restart the main engine, which brought us to this fateful moment. At around 0129, the container ship Dolly collided with the Key Bridge at a speed of around seven knots, which caused the bridge to collapse.

After a major incident like this, we can easily assume that the crew morale is very low. The captain, being the overall in command of the ship, is definitely in a very stressful situation. But since the immediate cause was a blackout, the chief engineer would be up to his neck in crap and probably feeling depressed right now. You see, even if they were not the ones directly responsible for anything, it’s command responsibility. Unless there’s undeniable evidence that someone else did something wrong, the captain will always be in the spotlight. If it’s engine related, then the chief engineer will be too. Both of them will spend the next few months writing up statements, explaining what happened, how it happened, why it happened, and who did it. Presumably, they will be brought to court, so that’s another gloomy prospect that they won’t be glad to look forward to.

Looking at this tragic incident, we can expect that the reaction of ship owners will be to send their crew for additional training. But the thing is, there are already training courses using simulators that address this particular scenario. In fact, I used to handle the engine side of those scenarios back when I was teaching in maritime training centers. To be honest, what happened in Baltimore is almost exactly what happens every time we run those simulations, wherein a blackout occurs in an area with heavy traffic. It almost always ends up in a collision. It’s basically Kobayashi Maru, a no-win scenario, but without Captain Kirk cheating. Because realistically, if something like that happens, there won’t always be enough time to reset all the systems and restore power and propulsion. Our technology just isn’t there yet. The best we could do is to train the crew to retain their presence of mind and try to minimize the damage by acting promptly when faced with a similar situation.

Could they have done things differently to avoid a catastrophic outcome? Maybe. If the port regulations required tug assistance all the way out of the harbor, would that have made a difference? Definitely. But could have, would have, should have… One thing is for sure, though: prevention is better than a cure. No matter how much we want to spin this, we cannot deny that there were lapses on board the ship. I know it’s a hard pill to swallow, but it is what it is. Sometimes, even if you have been very meticulous in your work, things have a way of going wrong. There will be times when you will find yourself between a rock and a hard place, and the choices that you make will determine if you’ll come out of it unscathed or not come out at all. Thank you for watching, and see you on the next one.

Second Video Transcript.

A little over a month ago, I made a video analyzing the incident involving the container ship Dali, which led to the collapse of the Francis Scott Key Bridge. On May 14th, 2024, the National Transportation Safety Board released a preliminary report, which confirmed many of the probabilities that I discussed in my video. In this episode, we will go through the technical side of the report, and I will provide further explanations for some of the details, which hopefully will make things a bit more understandable.

First up, the Dali’s main propulsion system. In this part, they describe the basic layout and properties of the ship’s main engine and generators. As mentioned here, the main engine is a 41,480 KW, two-stroke, Hyundai-MAN B&W diesel engine, and as typical for cargo ships, the main engine is directly connected to a right-handed propeller. This means that in order to change the ship’s motion from ahead to astern, the engine needs to be stopped and then restarted in the opposite direction. Yes, the engine can run backwards, and this is done by reversing the cylinder firing order.

In order to run, the main engine needs functional support systems like the lubricating oil pump and cooling water pump. These pumps are driven by electrical power, so if a blackout occurs and these pumps shut down, it will also trigger the automatic shutdown of the main engine as this is a safety feature to prevent damage to the engine parts that could be caused by a loss of lubrication or cooling. In order to restart the main engine, these pumps need to be restarted first. We should note that the fuel pumps are also electrically driven. So in case of a blackout, the fuel pumps will also stop and eventually cause the engine to stop as well.

Next, the electrical power distribution system. The Dali has four big generators, each driven by diesel engines. Generators one and four are rated at 4400kW, and two and three are rated for 4000kW. They are all connected to a 6600 volt high voltage main electrical bus or main busbar. Just for clarity, in the maritime industry, voltages above 1000V AC are considered high voltage. Now, in the report, it might get confusing as they oversimplified the electrical diagram. So I made my own drawing to make the explanation easier. As you can see here, the high voltage main bus distributes electrical power to all systems on board a ship, including the reefer containers and the bow thruster, and the step-down 440 volt transformers. I colored the lines red to indicate the high voltage, or 6600 volt line, black for the 440 volt line, and blue for the 110 volt line.

This busbar can also be split using the bus tie breaker, which can be used to isolate two generators on each side, but under normal circumstances this bus tie is kept closed. As mentioned, there are two step-down 440 volt transformers which connect to the low voltage 440 volt switchboard. Breakers are located on either side of the transformers. They named it HR1 and HR2 on the high voltage side, and LR1 and LR2 on the low voltage side. Machinery in the engine room, like the steering gear and the lube oil and cooling water pumps we mentioned earlier typically use 440V, so they are all powered from here. Another set of step-down transformers, either 110 or 220V are also connected here for lighting and other smaller electric and electronic devices. The report didn’t specifically mention which voltage, but that’s not really relevant to the situation. This 440 volt busbar can also be split with the bus tie breaker, which is also in “closed” position under normal circumstances. With this configuration, it is possible to use just one transformer, either TR1 or TR2, with its associated breakers.

Then of course, there is the emergency switchboard, which is also connected to the 440 volt bus by a circuit breaker. This emergency switchboard supplies power to designated emergency machinery and emergency lighting. Once the system detects no voltage coming from this line, the emergency generator automatically starts, subsequently disconnecting the emergency bus from the 440 volt switchboard, and then takes electric power from the emergency generator by closing the circuit breaker.

Next we go to the events of March 26th. During departure maneuvering operations, generators three and four were in service and supplying electrical power to the entire ship. As I mentioned in my previous video, this is the normal procedure and two generators can provide more than enough power for this operation. Generators one and two were on standby and under normal circumstances would automatically start in case either of the running generators tripped. All three steering gear hydraulic pumps were also running, which is also the usual procedure during maneuvering in order for the rudder to turn faster. As I mentioned earlier, I’ll focus on the engineering side, so I’ll be skipping the other portions for now. At around 0125 hours, the Dali was 0.6 miles from the Key Bridge when the electrical breakers HR1 and LR1 tripped. This effectively caused the first blackout and shut down the 440 volt Busbar, which practically powered everything, including pumps, the steering gear, and lighting. Subsequently, since the oil pumps and other ancillary systems stopped, the main engine also automatically shutdown.

So at this point, the ship had no propulsion and no steering. Remember, in my previous video, I mentioned that the most probable cause would be either a fuel problem or a switchboard problem. Well, here it is. Switchboard problem. But I honestly think there’s more to this than just faulty components. Apparently, generators three and four continued running and were still supplying power to the high voltage bus. This is possible because without any electrical consumers, the generators didn’t need a lot of fuel pressure. So even without fuel booster pumps, it was mostly being fed by gravity since the gas oil tanks are usually located on the upper floors of the engine room. However, even if there’s power in the high voltage 6600 volt bus, the 440 volt is where everything critical is connected. And since there was no physical connection at that moment, there was no flow of electricity to almost all equipment. This included the ship’s bridge equipment, which caused the Voyage Data Recorder to lose vessel system data feeds, except for bridge audio. The VDR has its own backup battery, though, so recording wasn’t affected.

Now, according to the crew, the emergency generator automatically started and connected to the emergency bus shortly after the blackout. But as we have seen in the footage, the navigation lights remained off together with all the other lights for about 59 seconds. If the emergency generator did indeed run and connect shortly after the blackout, we would have seen only the nav lights turn on first, followed by everything else once power was restored. But more on this later. As I mentioned before, if the emergency generator did indeed run and connect, one of the steering gear pumps, in the Dali’s case, the designated emergency steering pump was the number three, would have been available for use. This means the ship can turn the rudder, although at a slower rate of movement. However, as I mentioned in my previous video and as mentioned in the report as well, without thrust provided by the propeller, the rudder would be less effective, especially for a ship of this size. In any case, power was restored after 59 seconds, and apparently it was being supplied by generators three and four, which never stopped running. This means the ship had access to all of its equipment and effectively had full electrical power. This means they had three steering gear pumps functioning, but even with all three and the rudder responding rapidly to the helm commands, there was hardly any effect since there was no propulsion. I’ve read some comments in the previous video saying I was wrong, saying that the ship can turn even without propulsion. Well, maybe for smaller ships. Yes, it’s possible, but we’re talking about a massive ship with comparatively a very small rudder here. So the report confirms that they weren’t able to turn the ship, even with a functioning rudder. Now, as it turns out, the crew manually closed the breakers HR1 and LR1, which reconnected generators three and four to the 440 volt transformer and Busbar, effectively restoring power to all systems. In the CCTV footage, black smoke started coming out of the stack around 13 seconds after power was restored. Now, even though we know that two generators were continuously running even during the first blackout, I still find it hard to believe that the black smoke was caused by the sudden influx of electrical load. These are big generators with 8400 kilowatt capacity between them. They are certainly more than enough to handle a few pumps in the engine room. Black smoke could be a possibility, but maybe only for a few seconds and not continuously, as we can see from the CCTV footage. This might have something to do with the second blackout. From here, the report mentions the pilot giving various orders and dropping anchor. So I’ll just skip that. At about 0.2 miles from the bridge. A second blackout occurred because the circuit breakers for generators three and four opened. This caused a total power loss for both the high voltage and low voltage systems. This time the trip occurred from the generator breakers and not the transformer breakers. This means there was something wrong with both of the engines as they happened at the same time. These breakers will usually trip in case of engine overspeed or slowdown. The report didn’t mention the cause, but I’m leaning towards slow down due to fuel issues. Whatever it is, it’s something common to the two running generator engines and fuel is the most likely suspect. Now, remember what I said about the emergency generator and the navigation lights earlier? Well, as you can see, the emergency generator was already running and connected at this time since the navigation lights remained on during the second blackout. In my previous video, I said I found this strange, but now it all makes sense. They just kept the emergency generator running even when the power was restored the first time. At this point, the ship still had functional steering because of the emergency generator. But even though the pilot ordered the rudder hard to port, it wasn’t having any effect. Now, since the running generators actually tripped this time, this activated the auto start for generator number two, which was on standby mode. Its circuit breaker DGR2 closed and restored power to the high voltage bus. The report mentioned that the crew still had to manually close the breakers HR2 and LR2 for the 440 volt transformer TR2. In any case, the crew was able to restore power to the 440V bus around 31 seconds after the second blackout. However, they were still unable to regain propulsion. Then, shortly after, the Dali hit the bridge. It was also reported that around ten hours before the incident happened, the ship experienced a blackout while in port. Apparently, the crew was doing maintenance on the exhaust gas scrubber for the running generator at the time, and as per the report, a crew member mistakenly closed an inline engine exhaust damper. Of course, this is going to trip the engine as the exhaust gas won’t have anywhere to go. It’s like having your car’s exhaust pipe plugged. Now why would they do maintenance on a running system? I find it difficult to believe that they would do this. Also, mistakenly closing a damper. There are plenty of fail-safes in place against this, but okay, mistakes can happen. In the report, it says that generator number three automatically started and connected to the high voltage bus. Then vessel power was restored when crew members manually closed HR2 and LR2 breakers for the 440 volt transformer and the 440 volt Busbar. Again, I find this strange. Normally, the auto start sequence of the standby generators should not require human intervention to restore power to the 440 volt bus. So in all these generator trips, why did they have to manually reset the breakers for the Transformers too? Is it really designed to work like that? Because in the ships that I’ve worked on, the transformer breakers never trip unless there’s a problem with the transformer itself. Or in the rare case of differential protection. Another strange thing. Generator three continued running for a short period, but insufficient fuel pressure caused the speed to decrease, which then caused the generator’s breaker to trip. This actually sounds very similar to the second blackout just before hitting the bridge. As I mentioned in my previous video, generators share a common fuel line. Insufficient fuel pressure will only happen if the fuel tank was empty or the fuel booster pumps were not running. So did they forget to switch the fuel pumps on? If I’m not mistaken, the fuel pumps are included in the automatic sequential start. So they should have turned on almost immediately after power was restored. But even if it did not. This is basic. It’s the first thing you switch on. As for clogged filters, they were using low sulfur gas oil at this time, which is a clean fuel. So we can rule that out. Anyway, the NTSB is looking into the breakers for transformer one, which is the HR1 and LR1 because these two were in service when the first blackout after departure occurred. It was reported that transformer number two and its breakers, HR2 and LR2, have been in continuous service for several months prior to the incident. Only during the blackouts in port did they switch to transformer one. So they’re may be thinking the root cause might be a faulty component in that area. Ships have an alarm monitoring system in the engine control console. The alarm history can be found there, and it is an invaluable tool that can help the investigators figure out the sequence of events that led to the breakers tripping. They just need to sort through all of the alarms recorded, and there will be so many alarms that will have the same timestamp in the event of a blackout since all of the systems will have failed at the same time. In any case, as I said in my previous video, the two probable causes of these blackouts are either fuel related or switchboard related. From what we can see now, we were right in that assessment. The cause is somewhere in the electrical switchboard. But as per the report, I’m getting the impression that there were fuel related and procedural causes as well. Although secondary. Only the specific details remain unknown at the moment. Maybe in the next few weeks new information might come out, but until then we can only guess. I saw a comment that said he has read the NTSB report, but didn’t understand what he was saying. So I hope this episode answered a few questions or at least gave more clarity to the report. Thank you for watching and