A Mariner's thoughts on M/V Dali in Baltimore
Just speculation from a dude who's caused blackouts on vessels before...
Ok so I’m sure that by now you’ve heard that a container ship crashed into a bridge in Baltimore and knocked the bridge over.
I’ve wanted to comment many times on this event but could never quite find the words. Truth is, whatever I have to say is speculation and I don’t like to speculate on the causes of such events, especially when I’m no expert and when people have died because of the event but I do have a level of experience that may bring some clarity to what happened and this what I hope to achieve here. Just simple clarity to try and calm the noise down.
At the same time, there has been much said about the event and some of it is pretty wild so my motivation in writing about this event is more of trying to bring a level of reasonableness and understanding to the conversation.
As I’ve read through several posts and comments, it’s become apparent that ships are pretty much a mystery to most folks and I get it. Not many people in the US work in the maritime industry anymore and so I can understand much of the misunderstandings of what happens on ships and how they operate.
The thing is, a ship is a ridiculously complicated system of machines and electronics all working together (for the most part) in order to get a lot of stuff from one point on a globe to another across what can be the most harsh environment that people transit on the regular. Some of these ships are at the pinnacle of mankind’s technological achievements and most folks don’t even know they exist until something bad happens.
Deepwater Horizon is a good example of what I’m talking about here. Not many folks even knew that offshore drilling on that scale is a thing and then once the incident happen, “experts” came out of the woodwork to explain what went wrong. And most were wrong. We can’t know what happened until the investigations are conducted and the findings released and even then, those findings won’t tell the whole truth. They can’t because the investigations are carried out by people who have their own agendas, thoughts, and ideas who seek to explain how a highly complex incident happened to folks who don’t know how the thing worked before it went fubared while at the same time the people who are looking to understand the event have their own emotional filters, biases, and levels of understanding which cloud the way the event is viewed. The best we can achieve is a general level of understanding of the event.
Not only are these ships big, complex, and operated as cheaply as possible, they are minimally crewed by people from different nations who have their own lives and culture, but they also have to do their work with varying levels of competence and training and often without much support. Being a mariner is not an easy way to make a living and when a catastrophe happens, it’s all over the TV and interwebz for we armchair mariners to pick apart.
So… since I have spent most of my life reading and studying about ships and pretty much my whole working life as a mariner, more specifically as an engineering officer, I thought that I would throw out my own thoughts on the matter of the Bali allision.
So first allow me to give a little of my resume so that you can know where I am coming from in what I am talking about here.
I have worked as an engineer on offshore supply vessels for 16 years in the Gulf of Mexico. Prior to that, I served 6 years in the US Navy as an engineer. That’s 22 years in engine rooms, plus some experience in other mechanical trades and plant operations/maintenance.
Now… just to keep all of this in perspective, I have not worked on container ships nor have I sailed on anything the size of the M/V Dali. My purpose here is not to come across as an expert on ships or anything maritime related for that matter. In fact even had I designed and built the Bali by myself, I still wouldn’t claim to be an expert on this situation, but because of my work experience, I can bring some basic understanding as to what happened.
If you’re interested in a deeper dive into marine engineering, I have a series on various forms of propulsion. There are some links below that will take you to the parts that I have completed so far… Part 4 explains a little bit about the type of propulsion engines used on Bali.
Part three, High speed and medium speed diesel power
Part four, Slow Speed diesel engine power
Lets begin with a quick discussion of how the engineering plant works on a ship.
Disclaimer… I’m writing this on my phone and my sausage fingers are making it a little hard to type and move stuff around so this won’t flow quite as well as I would like. I apologize for this being a little disorganized… ok moving on.
When a propeller turns through the water, an interesting thing happens. A force is generated by something known as the paddle wheel affect, also known as propeller walk. This force will tend to push the bow of the vessel in the opposite direction from which the propeller is turning. If the propeller is turning clockwise, as viewed from the back of the vessel looking forward, then the bow of the vessel will be pushed to the left, or port side. The faster the propeller turns, the more effect the affect has on the vessel.
A vessel moving ahead will have less propeller walk than a when the vessel is moving astern, or backwards. This has to do with the way that water flows around the hull of the vessel. So when a ship is backing up, propeller walk will be more noticeable and is harder to correct for because the affect can’t be countered by the rudder but is countered by a bow thruster when the vessel is stopped or barely moving.
When a ship is moving along on it’s course, the helmsman is constantly moving the rudder to keep the vessel on course. Wind and current all affect what the vessel is doing and have to be constantly accounted for while the vessel is moving. The rudder, or rudders, never really stop moving and are always making small adjustments in order to keep the vessel on the intended course. The faster the vessel goes, the more affective the rudder will be.
Steering of the vessel is accomplished by the rudder. The rudder is only affective when there is water flowing over the rudder itself. This water flow is provided by the propeller and by the forward motion of the vessel itself.
There are various rudder configurations and method of operating the rudder but they all essentially work the same. Electric motors power hydraulic pumps which in turn operate the hydraulic system in the direction needed to turn the rudder for the helmsman. These hydraulic units can be really complex and in the case of a ship the size of the Bali, could require several hundred horsepower to operate.
There is usually a “backup” steering system that consists of hand pumps but these are not for steering but rather for positioning of the rudder for maintenance and in preparation for towing the vessel. These hand pumps operate at far to low a rate for them to be used for steering.
The steering machinery of the vessel is supplied by electrical power from two separate power sources so that in the event of an emergency, there is a redundant power source to supply the steering machinery.
Electrical power is generated on the vessel by diesel or turbine driven generators. Ships have mulitiple generators for redundancy and not all of them are needed all of the time. One generator is usually online with another in a stand-by mode in the event of emergency or in the event that more power is needed than the one generator can supply.
The electrical power is sent to switchboards where the electrical power is distributed through out the vessel. These switchboards are similar to the breaker panels in your house but combined with the ability to control the operation of the generators.
Control of the electrical plant is usually managed through a system known as the “power management system” or PMS. This is an automated system that can automatically start and stop generators as needed based on the electrical load of the ship. Typically, one generator is sufficient to operate all of the vessels equipment.
Container ships are a little unique with regards to their electrical power generating plant because they not only have to supply power to operate the vessel and keep the crew relatively comfortable, but the electrical plant also has to supply power to containers that are refrigerated. For this reason, M/V Dali had 4 generators.
There are two separate electrical systems on a ship, the normal system and the emergency system. Half of the ship’s critical equipment is supplied electricity by the normal system and the other half is supplied electrical power system. The emergency electrical power system typically supplies power to:
one start air compressor
one fire pump
one bilge pump
half of the interior lighting
electronics power supplies and backup battery chargers
half of the steering machinery’s hydraulic system.
Power for the emergency electrical system comes from two sources; the primary source is from the ship’s normal power generation system and the secondary source is from the emergency generator.
In the event that the ship looses electrical power from the ship’s normal generators, the emergency generator will (probably) start and supply power to the emergency circuit, but it takes time for that to happen.
From the time that power is lost to the time that the emergency generator comes on line and starts to do it’s thing, it could take up to a minute, which is a long time when something bad is happened. From my experience, the PMS usually gets a stand-by generator in service faster than the emergency generator starts and gets on line.
For safety and redundancy, the emergency generator is not located in the engine room. It is usually located in it’s own compartment and can be fairly far from the engine room. If the ship has a blackout and the emergency generator fails to start, an engineer has to leave the engine room and go to the emergency generator room to see what happened and start the emergency generator manually. This obviously adds more time to the response during a casualty to the engineering plant.
Just like everything else in this world, these vessels are controlled by electronic systems, which can have a battery back up, or UPS (uninteruptable power supply). In the event that power is lost to the ship, the UPS will keep the electronic systems running so that everything can be restarted when power is restored. These electronic systems are critical to the operation of the vessel and the power to operate the electronics usually comes from the emergency power system.
Main propulsion for most container ships is provided by a single, slow speed, direct reversible, direct drive engine. The engine is directly coupled to the propeller via a propeller shaft. When the ship needs to go forward the engine rotates the propeller in one direction and when the ship needs to go backerds, the engine is stopped and then started running in the opposite direction, which turns the propeller in the opposite direction.
Unlike a car engine, all of the pumps that the propulsion engine needs in order to operate are driven by electric motors. The fuel pump, 2 differnt lube oil pumps, and various cooling pumps are all operated electrically and so are the cooling pumps that operate separately from the engine in order to cool the cooling water and lube oil.
There are two types of fuel used on these vessels, diesel fuel and heavy fuel oil. These fuels are stored in separate tanks and are used at different times. Heavy fuel oil contains a high amount of sulfer and is used only once the vessel is in the open sea due to air quality regulations.
Fuel is stored in storage tanks until its ready to be used. The fuel gets transferred from the storage tanks to a settling tank, where any contamination is allowed to settle to the bottom of the tank. After a sufficient time, the fuel is transferred to a service tank using a fuel oil purifier.
Fuel oil purifiers can take just about every bit of everything out of the fuel, so fuel going to an engine is usually very clean, provided that the purifiers are cleaned regularly and operating properly.
So last bit that I think needs mentioning… the roles of the pilot and the captain of the vessel. I mention them because they are part of the story but are kind of obscure and thought worthy of mention.
A pilot is the person who is recognized as an expert on the port or river where they work. They know the port and are there to advise the captain on what to do in order to navigate the ship through whatever area they are going.
His sole job is guidance to the captain, though he does give orders to the helmsman the captain has the ultimate responsibility of what happens to the ship. If the captain doesn’t like what the pilot is doing, he has the authority to do what he needs to do in order to make the situation right.
So that concludes the brief discussion of how a ship works.
OK so here’s my view of what happened.
Dali was underway outbound from Baltimore when there was a failure in the electrical plant. Something caused the online generator to trip off line. There are several things that could’ve caused this to happen, some really simple and some highly complex, and the investigators will get to the root cause of the issue but suffice it to say, the ship lost power.
When the ship lost power, the propulsion engine shut down. Why did the engine shut down? Because the fuel pump, oil pump, and cooling water pumps are all electrically driven and so is the automation that runs the engine. When the engine lost oil pressure, because of the lube oil pump shutting down, the engine would’ve shutdown automatically or the automation may have shut the engine down.
The initial loss of power would’ve put the crew in a near panick, especially the engine department guys who would have to figure out what happened and get everything going again.
Power came back on with in a minute and I believe that this was from the PMS system auto starting an offline generator or the chief engineer getting the previously running generator back online. Either way, I don’t believe it was the emergency generator because the exterior lights came on and those are usually not on the emergency power circuit.
Following the restoration of ships power, the main engine appears to be restarted going astern judging by the fact that the ship was “rolling more coal” than a “tuned” Cummins bro-dozer passing a prius on the highway.
The heavy smoke indicates that the engine was working hard and also indicates that the electrical power was coming from the main generators and not the emergency generator. When the power was restored, the pumps “should” have come back on automatically which would’ve allowed the engineers to restart the engine relatively quickly. During recovery from a blackout, the stuff that is supposed to come back on automatically doesn’t always do that and must be reset.
With the engine running astern, the stern swung to the left (port side) because of the “paddle wheel affect” mentioned earlier. The stern swings to port and the bow swings to starboard while the ship was still moving forward.
At some point, the captain or the pilot order that port anchor be dropped, which is a standard procedure for this kind of thing. Watch cargos ships leaving a port and you will see crew members on the bow just in case something like this happens. I’m guessing that the order was given after the engine was started going astern and the vessel started to pivot to starboard and was done as a way of countering the pivot. Just a guess on my part.
Then the ship lost power again and I’m guessing that whatever cause the first power loss is what caused the second and it looked like the bow was starting come around back to the right. That leads me to think that the emergency generator was running at that point and supplied power to the steering machinery, but also could’ve been because of the dropped anchor pulling the bow to port.
Once the initial blackout started, the emergency generator would’ve started but it looks to me that an offline normal power generator started or the engineers got the initial generator reset and back online.
Once the ship impacted the bridge, there was another blackout but that is most likely from the jarring motion of the impact and/or bridge structure causing the generator breakers to open and the ship to go dark again.
And from then on, the rest of the story became part of the dopamine inducing news cycle and antisocial media feeds. As spectacular as the event was, the worse part of it all is that 6 people lost their lives and two men, the captain and the pilot, will forever be remember, by folks who have no concept of what they were faced with, because of the results of judgements that they had to make under extreme stress in short order without any guidance except for their experience, training, and decision making ability.
Our culture demands perfection from fallible people who are operating imperfectly designed and built equipment, and doesn’t seem to understand that sometimes things just happen and that are out of our control.
This ship suffered some kind of engineering casualty and appears that the crew did the best that they could do with how the understood the situation and sometimes the best that we can do just isn’t good enough to prevent something bad from happeneing. It’s life. It’s just the way it is.
Sorry if this one wasn’t one of my best. As stated earlier, I’m having to learn how to type this out on my phone and it’s a little bit more of a learning curve then I expected. Please feel free to comment, but do so in a respectful way. I don’t mind disagreement or challenges to my thoughts but I have no patience for rude and obnoxious comments.
As always, thanks or following along. Feel free to subscribe, like, share, or comment. It’s free and I have no plans to change that. Hope you have a blessed evening.
Fair winds and following seas,
Nate
In the great majority of disasters I've seen in the past 40 years, if you return 10 years later you cannot believe the improvement.
The initial impact of the hurricane, fire, flood, etc. is horrid, but something in humans responds to pick up the pieces and eventually make it better. So, too, with this disaster.
Thanks for explaining the ship operation and maintenance details.
Here are two resources you may like.
https://www.youtube.com/@wgowshipping
https://windward.ai/
Really enjoyed learning more about how ships work. I agree with you that those on the ship were in a very trying situation and no doubt will forever be haunted.