Confirmed:
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My experience is more on the order of what KC described above. Spinning reserve also refers to the margin of what is available for on line generators. So having 2 on line running at say 50% or even more and others ready to be started (ie assigned a start order number and “seen” by the automation as ready) with power management system itself in auto mode is what I would consider typical.
Where would you have this running DG at? Idle? Synchronous speed? Then you get into the fine point of an individual power management systems. Some would not allow that. Even if the logic allowed an engine to be running in my opinion that would not be a significant advantage over properly maintained DG sets and power management in auto. It is then available for “normal” start or “emergency” start and the reaction time would not be much different than having a DG running.
None of this would help if it turns out there is a common problem with the prime movers though. For they would fail off the bus and the ones coming on would presumably fail after that if say gross fuel contamination/supply issues.
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But if two generators are operating and connected then when maneuvering are they paralleled and tied to a common buss or each operating on their own separate buss? If paralleled, then if one trips off or shuts down then as long as the common buss doesn’t get buried by load then there should not be a black out. If operating on separate busses then are critical systems for propulsion and steering being run from each buss (two pumps for steering, lube, fuel, cooling circ. online and operating)?
In this situation where going black is not allowable then why did this ship go black when and where it did? Was this simply not a concern for them?
Both running SSDG would be on the same bus would be my understanding. But getting further out of my area of expertise.
That said; just before the bridge is not the right spot to be altering the set-up.
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yea - the actual events ( issues at the dock, decision to sail, going dark for a minute, regaining power) would not raise any major major concerns - it all just happened at an absolutly awful moment in time.
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Don Jon is heading down with a fleet of tugs I would assume with the the Chesapeake 1000 crane barge
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Wonder where the Golden Arches that are usually hanging out in Sabine are. That thing might be helpful.
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Makes sense. Not surprised they were called in. Side note. Very little I’ve seen about Incident Command / Unified Command structure in this case. They always have a PR section yet briefings are coming from individual agencies so far - least what I have seen. Somewhere in Baltimore is a unified command set up in a big room with sections for spill response, salvage, insurance rep, owners rep, etc yet haven’t seen anything about that. Am I just watching the wrong news? Anyone heard anything about incident command.
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Might be. This is basically “wreck removal” task which Don Jon definitely knows how to do.
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lets wait for the report on the DP3 pipelayer in OZ that has had 2 total losses of propulsion, if man can make it, man can cock it up
We are talking about a ship with one engine and one rudder and it all goes wrong at the wrong time, why are we surprised.
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I’m not sure what you are asking here. “Why” is what everyone is speculating about. But do you really think crews are not concerned about blackouts?
For other engineers - I was only chief of one container ship and it was much smaller than the Dali. It did not have a split bus and carried many fewer reefer containers. So do ships of this size have separate busses just for reefer containers? Is that “splittable”? Would power management load shed that with trouble on main bus?
Split bus was only a recovery or maintenance feature to me. Maybe the navy does differently. I can’t see running around like that. Even with a ring bus, bus ties are usually all closed. Only upon fault (or set up for M&R) would it start separating. Not sure I understand why concern with split bus concept other than “searching for solutions” and “what should have beens” at an early stage.
Another SOP to reduce risk while maneuvering in restricted waters is to have the M/E (main engine) on heavy fuel oil (HFO) while having the SSDGs on diesel oil (DO).
Would switch the SSG to HFO at the start of the ocean passage, after the pilot got off.
EDIT: This is not correct - ships are required to shift from heavy oil to diesel before entering the ECA.
I thought they used MGO in port ( emission issue) till it became low sulphur then with so many propulsion losses they said ok you choose?
The ship I’ve been working on has a bus tie breaker. One side of the bus was the main switch board with Gen 1 and 2. The other side was the reefer transformers with gens 3 and 4.
This ship was also 6600v from the gens, so two separate transformer banks to go from 6.6kv to 440v. And they each had a breaker before and after.
We were having electrical issues as well and once trying to replicate the problem in port, the bus tie breaker opened. With zero volts on the reefer side the automation started the #3 Gen and put it online. It happened fast, less then 30 seconds maybe.
With regard to EDG, I’ve been pondering if it ever came online by itself. I don’t think all the deck lights would be on the emergency bus. When you watch the video look at the stbd nav light. Nav lights are on emergency bus.
When the ship blacks out it’s dead for a full minute, no nav light. Then it seems full power is restored. A minute later the lights go out again, but the nav light stays illuminated and a light that might be the access to the house.
I don’t think I’ve seen the EDG take longer then 30 seconds to take over the emergency bus when testing and the CFR states it should be less then 45 seconds.
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MGO might be a more precise way to say it but depending on what part of the world you’re in the same fuel could be called MGO or DO.
Don’t see “MGO” used in the States that I recall.
It seems like the gCapt knowledge pool on slow speeds is much shallower than I realized. I’ve been working slow speeds since 2007 with a 5 year hiatus into the world of medium speeds that ended almost 10 years ago. I’m just shy of a decade as a senior engineering officer. Based off of the ships I’ve been on, I’m comfortable making some generalizations with the caveat that there are always going to be the outlier ships that I haven’t experienced that don’t go with the generalizations.
While I’ve never been on the Dali and don’t know the exact arrangement of the machinery space I can speak some on the common designs and setups of shipboard engine rooms. Power generation in the engine room can be broken into two main components: Electrical generation and Propulsion. On a ship such as the Dali there will be several generators powered by medium speed diesel engines for electrical generation and typically one slow speed to provide propulsion.
The electrical system is commonly broken into the Main Bus and Emergency Bus. The Main Bus is the majority of machinery on the ship. The Emergency Bus will power critical machinery but is not necessarily set up to preserve propulsion. Under normal operation, all power for the Main Bus and Emergency Bus will come from the ship’s generators. The generators are typically sized so that the full ship’s load can be carried with one or two generators, with additional generators available for extra consumers. On a container ship, these extra consumers may be ventilation fans, refrigerated containers or thrusters. While maneuvering the ship into or out of port, I want to have at least one more generator online than I need. This provides a buffer in the event that a generator fails as there’s already a generator online and running that can shoulder the load and reduce the risk of a blackout.
There is a smaller Emergency Diesel Generator (EDG) on board. In the event that a blackout occurs, the EDG is supposed to automatically start and provide power to the Emergency Bus. It’s not a big generator and you aren’t going to be able to run larger pumps with it. You will have the ability to use a fire pump, a steering gear pump, emergency lights, automation and wheelhouse electronics and various other small consumers. It’s meant to be an emergency backup that allows us to fight a fire, continue steering or bring the ship back from a blackout. I can walk onto any ship with a functional EDG, start it off of battery power or a hydraulic hand pump and get the ship to the point to where I can start one of the larger generators.
Separate from the electrical system will be your main propulsion. The most common setup for container ships, ROROs, bulk carriers and many tankers is a single slow speed main engine. These engines range considerably in size depending on the cylinder bore and count. The largest are pushing over 100,000hp. I’ve been working mostly on the smaller ones in the 15,000 to 20,000hp range but they’re all fundamentally similar, they just vary in the size of the components. As implied by the name, a slow speed operates at fairly low RPMs. The fastest I’ve personally seen could do 120rpm. The low speed allows for directly connecting the propeller to the main engine via a shaft and eliminates the need for a reduction gear. One quirk of the slow speed is that in order to change the ship’s direction, from ahead to astern for example, you must first stop the engine and then restart it in the opposite direction. On older engines this was done by shifting the camshaft forward or back to move onto a different set of camshaft lobes. On newer engines the camshaft has been replaced with hydraulic actuators and solenoid valves that allow for a wider range of adjustment of the engine parameters.
One issue that arises when you stop an engine is that anything driven by the engine also stops. Lube oil and cooling water pumps, for example, need to be kept running. This means that most of the ancillaries needed to actually operate the engine are not driven by the engine, they are powered from the electrical bus. This is typically the pumps needed for lubricating and hydraulic oils, the high and low temperature cooling water circuits, the fuel system and the compressors needed for the compressed air systems. I have never seen any of this equipment on the Emergency Bus, nor have I seen an EDG large enough to power all of this stuff. The gist of it is that you’re almost certainly going to lose propulsion when you blackout a slow speed propulsion plant.
So, what happens after the blackout? Well, hopefully the EDG has kicked on and your automation is still up and running (this is typically on a UPS as well as the Emergency Bus). As mentioned earlier, the EDG should have some of the basics up and running within a minute. The automation should be trying to bring the next standby generator online while the EDG is going through its start cycle. How long this takes can vary from plant to plant, machine to machine. I’ve seen engine rooms where a certain generator in standby would start and come online faster than the emergency. Once all of the lights are back on, the automation should next begin starting the essential pump motors sequentially. The goal is to bring things back online without overloading the generator by starting too much too quickly. Sometimes it works great and you can go from blackout to back up and ready to start propulsion in about a minute. Sometimes it doesn’t go great for any number of a variety of reasons. Just in my personal experience, I’ve had two blackouts caused by accidental activations of the quick closing fuel system valves (one human error, one mechanical failure). I’ve seen blackouts caused by an update in the automation, faulty overspeed devices, accidental activation of the emergency stop, hitting the stop button on the wrong generator, opening the circuit breaker on the wrong generator, improperly adjusted high temperature shutdown switch, a broken tube going to the lube oil pressure switch, faulty wiring, water in fuel, bacteria in fuel, an improperly set up governor, a plugged lube oil strainer, a plugged fuel strainer… the list can go on and on.
In the case of the Dali, we know she blacked out. If the EDG came on she should have been able to maintain steerage but it does appear that for whatever reason she continued turning to stbd. The stbd turn could also have been caused by the helmsman turning the wheel to the right instead of turning to the left (which is shockingly common). We know she was able to restore power briefly. I can’t tell if it was enough to actually get the main engine restarted. There is a large puff of smoke visible in the video but the video isn’t clear enough for me to tell if that’s coming from the main engine or generator exhaust. The lights go on, the lights go off. Are these lights on the E-bus or main bus? We don’t know but I suspect the main bus.
Was the engine room attended or unattended? I don’t know for sure in this case. Based off my experience it was most likely attended. I would have a very difficult time flipping the UMS switch and heading out while under pilotage. None of the companies I’ve worked for would permit this. As CE, it’s usually myself and the duty engineer in the engine room at a minimum. I’m usually down there from 1 hour notice until about an hour after the ship gets up to sea speed after dropping the pilot.
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There would be a lot of bitching if ships were running heavy oil in the harbor! I thought that was illegal now???
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What I am asking is if these ships operate in pilotage waters where critical systems are protected against loss of a single generator or if the engineers operate with belief that the PMS will work exactly as designed to prevent what occurred? Load shedding does fail and a common buss can be buried if a single generator trips offline or shuts down leading to a blackout like we witnessed. To have one gen isolated to its own buss feeding all critical pumps would seem to be the only safe way to ensure a ship transits under a bridge and leave what is not critical like reefers or thrusters on their own buss so as not to endanger losing everything?
Also, why can’t breakers to reefer transformers be opened during critical transit periods? The boxes wouldn’t warm up during the 30min needed to get out of a harbor.
Great post- thanks for taking the time to share that. A mate not an engineer, but almost exactly as I remember it. As a mate, I really really want the rudder back. If I have steerage way I can bleed speed, and in a worse case senecio I can chose what I am going to hit, and do so with a lot less force.
Too early to know, but this might be down to just awful timing- the 20-40 seconds of carrying right rudder way have been to much to overcome with the distance left to the bridge
Back to that 2 second decision to go full ahead or full astern.
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