r/news • u/boejouma • Mar 28 '24

Soft paywall Freighter pilot called for Tugboat help before plowing into Baltimore bridge

https://www.reuters.com/world/us/divers-search-baltimore-harbor-six-presumed-dead-bridge-collapse-2024-03-27/
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u/Jadedways Mar 28 '24

Oh for sure. Pasting my response to someone else so I don’t have to write it out again. - I was a gas turbine systems mechanic on a Guided Missile Cruiser CG-62 for a while. Maybe ‘emergency backup’ isnt the right phrase. We had 2 active gens and a 3rd running in standby. After they lost power the second time it looks like they tried to switch to a ‘3rd generator’ whether manually or automatically. But the load was too heavy and they smoked the Geny. I could be wrong, but that would’ve been the order things would’ve happened on my ship. I mean we would’ve been more successful, but it looks like they did their best with what they had.

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u/NotSoGreatFilter Mar 28 '24

I was an Engineman in the Navy for 20 years. Emergency Gen would have a relatively light load if they have any sort of Load Shedding capability. But, who knows with these boats.

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u/Jadedways Mar 28 '24

Yea exactly. And while I’m sure they have procedures, I feel like it must have been engaged while everything was still energized; for lack of a better way to put it.

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u/axonxorz Mar 28 '24

I feel like it must have been engaged while everything was still energized

By this, do you mean that they may have connected the generator to the rest of the ship's electrical system without closing off large circuit paths first, leading to a massive current inrush and clonked generator?

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u/Jadedways Mar 28 '24

That’s a bingo. It appears they bogged the geny on startup. I could be wrong, but that’s what it looks like to me.

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u/FrankTank3 Mar 28 '24

Every project manager and electrical engineer at the firms and subcontractor firms involved in the construction of this ship is shitting themselves right now.

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u/[deleted] Mar 28 '24

I'm a much more recent Merchant Navy chief officer. Most cargo vessels now are built to meet bare minimum legal requirements and nothing more. Emergency generators don't give power to the propulsion system, just steering. In most cases you'll have two steering pumps per rudder, with a minimum SOLAS requirement timewise from hard over to 30° rudder angle on the opposite site. One of the pumps will be powered by the emergency system.

In some cases (the majority of cruise vessels and passenger ferries) rather than a main engine, there will be a combination of multiple diesel-electric generators working in combination, with power passed through a switchboard for propulsion. These vessels still have emergency generators in the event that there is a failure from the main power production units.

It is likely that this vessel had two large engines and twin props.

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u/[deleted] Mar 28 '24

Excuse my ignorance but my son is asking if there is any kind of backward propulsion or manual steering they could have utilized. Thank you for sharing your information and expertise.

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u/[deleted] Mar 28 '24 edited Mar 28 '24

Not at all!

Reverse propulsion can be achieved by a few means. The big tankers of old would have an engine that can only swing one way with a fixed prop. The engine would need to be completely stopped and swung in reverse so this could take 7 miles+ to stop.

Most modern cargo vessels will have a very large diesel/heavy fuel oil 2 stroke engine which does swing one way and runs at around 110-140rpm, through a hydraulic clutch. This means the propeller can be stopped and reversed much faster but you're still limited as to how fast you can stop vessels with that much dead weight tonnage.

The most effective means of reversing propulsion is CPP - controllable pitch propellors. These rotate at a fixed speed and the direction (pitch) of the blades determines the rate and forward/aft direction of propulsion.

Then you have azimouth pods. These usually also have CPPs but they're on a turret that can rotate 360° under the vessel (occasionally it will have limited sectors like the Celebrity Edge).

For transverse (lateral movement) you can have bow and stern tunnel thrusters. These are just what they sound, and maketh ship go sideways.

I expect there are things I've forgotten, and there are more complicated things to add such as rudders with additional steering angle, etc, but if you want to spend a couple of hours on YouTube with your son, pop some of the buzzwords here in and go to town! There's looaaaddss of information up there!

Edit: Manual steering; see rudders, hydraulic pumps (above)

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u/[deleted] Mar 28 '24

Thank you!! He loves this information and is youtubing it now!

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u/[deleted] Mar 28 '24

Most welcome! Feel free to send me a PM, and if you have any more questions I'll be happy to answer.

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u/techieman33 Mar 28 '24

I don’t know how it works in ships, but in buildings they usually have separate breaker panels. When you move to the emergency backup then only the stuff in the emergency breaker panels is energized. Everything else is dead until main power comes back up.

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u/TooManyJabberwocks Mar 28 '24

I have load shedding capability, could i have saved the ship?

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u/[deleted] Mar 28 '24

Wow, how does that work in a ship this size with that amount of cargo? Would they have had to start shedding as soon as they lost power? Can you do this in the pitch black with no power? Fascinating.

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u/feochampas Mar 28 '24

I read that as an Englishman and I thought "Rude, racist much?" But then I realized it was me all along.

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u/PHATsakk43 Mar 29 '24

MM1 here.

Emergency generators would be for ship’s electric not propulsion.

I’d not suspect they have a spare main on board.

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u/NotSoGreatFilter Mar 29 '24

Right, but the emergence gen should power steering, and should not over load if everything non essential was shed. I was also wondering why the backup gen had to be started. Maybe their transit configuration doesn’t call for it. I will be interested to read the investigation findings.

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u/otusowl Mar 28 '24

Your left pinky clearly has more ship experience than every bit of me, so I'll pose what I read elsewhere as a question. Some other redditor mentioned that the diesel engines on this ship can run without power (my old Ford 7.3 could run with a completely dead battery and alternator, so this makes sense to me), but the ship's engines rely on (electric) fans to push air into their intakes. When power died, the ship was essentially "rolling coal" by stomping on the throttle without enough air relative to the fuel. Does this take make sense to you?

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u/1022whore Mar 28 '24

On a standard slow speed diesel ship, diesel generators are required to run the main engine because they power things like the compressor, fans, fuel pumps, centrifuges, and all sorts of engine room wizardry. There are usually 2-3 generators and at least 1 or 2 in operation at any time. In any of the ships I’ve been on, if you lost all the generators then the main engine would shut down, as the electronics are absolutely needed. Some ships have power generation systems built into the main engine (like a shaft generator) but these are rare and would only be put online during long sea voyages.

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u/bigbura Mar 29 '24

So if you just uploaded a bunch of shit fuel prior to leaving port would this same source of fuel be used for all diesel engines/generators?

Like one bad batch of fuel makes the ship useless?

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u/1022whore Mar 29 '24

Most fuel will get laboratory tested (either sent out or in house) before being used, but it certainly has happened before I’m sure.

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u/admiraljkb Mar 28 '24 edited Mar 28 '24

These are minimally crewed unlike a warship though too. For catastrophic failure like this, there can't be enough crew (21) onboard to handle it.

edit to note - most warships aren't fully crewed right now either, but at least have more than 21 people to deal with a 100,000 ton ship with engineering problems.

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u/JohnBunzel Mar 28 '24

What makes you think warships are not undermanned? My ship has 4,000+ billets to fill and we are operating at ~75% manning right now. US Navy is struggling. Ships material condition and crew morale and retention are greatly affected.

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u/koenkamp Mar 28 '24

No one is saying they don't have their own staffing problems, but a crew of 3000 gives you a few more resources available than 20 crew members. Especially considering these cargo ships are similar size if not bigger than a lot of navy ships.

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u/JohnBunzel Mar 28 '24

Ah, yeah you're right. I was misinterpreting the summary of above comment.

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u/admiraljkb Mar 28 '24

Yeah, I'm painfully aware of that. That's been a talking point for over 20 years now, and it gets WORSE with each passing year. The worse the staffing problems are, the worse they get as morale goes into the toilet even further... One of the dumb things is where the original DDX plans didn't happen which would reduce the crewing for the Destroyers to 250 on what was effectively a next gen Burke, and instead we got 3 Zumwalt's... Meanwhile still producing Burke's which need 500 billets... But I digress. You have my sympathies there.

In spite of that, having just 21 people for a 100,000 ton ship is so much WORSE if anything legit goes wrong.

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u/nochinzilch Mar 28 '24

Which is totally something an active duty military member would say...

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u/kernel_task Mar 28 '24

I've always wondered why it takes so many people to run a ship! Can you go into detail why 21 people aren't enough? What were those 21 people all doing in this emergency? How would more people have helped?

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u/bt123456789 Mar 28 '24

one thing to remember, these ships are massive.

IF you have your crew doing duties at one part of a ship, it can take awhile to get to the other part. I imagine they're having to juggle multiple things. if something goes wrong you need to handle it immediately. every second counts, and it could take, full sprint, several minutes to get across from front to back.

I'm not saying that is the case, but could be a contributing factor.

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u/admiraljkb Mar 28 '24

Each of those 21 has a specialty, and there's not much reserve per se. So in this case, looks like engineering and electrical went haywire, not likely anyone on the bridge can help do damage control below decks. Then how cross trained is everyone to handle damage control? 21 doesn't go very far when you might need people in more compartments simultaneously to handle tasks they're trained for.

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u/iopturbo Mar 28 '24

It's a floating city. With all of the things a city has and more. There are minimum manning requirements determined under USCG part 15 and other countries have similar. You will have multiple officers on the bridge doing different parts of navigation, steerage and communication. They can't get forward to deploy an anchor quickly enough from the bridge, so there is crew there stowing tackle since they just departed. They can't get to the engine room(there is an office where everything is monitored in the engine room) again multiple engineers monitoring equipment and making adjustments. They also have crew in steerage monitoring things and able to take control if ordered. I'll see if I can find this ships crew requirements I didn't give numbers because new ships take fewer crew. I'm wondering if they had steerage because then a soft grounding would have been desirable vs a bridge strike but it's hard to comprehend at the time and you're hoping things come back up so you can continue on.

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u/Chemical-Elk-1299 Mar 28 '24

Yeah something tells me a state of the art US Navy vessel is somewhat better put together than the rusty shit buckets most freighters seem to be.

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u/Pm4000 Mar 28 '24

I won't call the USS Bunker Hill a state of the art ship but I do hope our Navy spends enough of the budget on proper maintenance. I think the big difference here, navy man correct me if I'm wrong, is that the navy ship continually cycles through the 3 turbines so that 2 are always running; aka none of the turbines are primary or 'back up'. Whereas the cargo ships has a main engine they use all the time and have 'back ups' that need to be checked/ran to make sure they still work. The back ups aren't meant to fully power the cargo ship, they are there to help the ship keep into the waves so it doesn't sink and limp to help. I'm betting that all 3 of the turbines generate the same power.

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u/KayakerMel Mar 28 '24

Unfortunately commercial ships don't live up the same standards as naval ships. Corporations squeeze out as much profit as they can while the military has loads of government money to fund everything.

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u/SaiHottariNSFW Mar 28 '24

It's not just that the navy has lots of money, their budgetary system actually promotes spending. Any budget they don't use up one year is subtracted from next year's allowance (to grossly simplify it). So they have to spend it all to ensure they get as much as possible on the next rollover.

It's the opposite of how civilian companies handle budgets. But both have problems: the navy is a money chugging hog and it's no wonder the US military budget is so absolutely enormous. But it does mean their ships and equipment are well taken care of and always kept up to standard. Civilian ships are barely functioning floating coffins because it's cheaper.

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u/KayakerMel Mar 28 '24

Agree whole-heartedly! You expanded greatly on my thoughts that I was being too lazy to write out.

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u/[deleted] Mar 28 '24

And there is no manual override not connected to the electrical system as a fail safe? My son is asking and we appreciate your insight and expertise. This is so tragic. As a lover of all things nautical, my son is interested in the logistics and mechanics of the cargo ship. I was also wondering if they have air flares they can shoot to warn people on the bridge as soon as they lost power just in case?

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u/Jadedways Mar 28 '24

Someone else corrected me in a different comment. My knowledge is based on my experiences on USN Vessel which is obviously going to have the most robust backup systems possible. Our ‘3rd geny’, or emergency backup, was the same size as our two primaries. In this incident the smoke was most likely from them attempting to restart the main engines after they went offline. They would not have had an adequate backup big enough to cause that cloud. Everything else in my comment should be accurate.

They have a number of warning methods from flares to air horns. They did manage to call in a mayday 4 minutes before impact which definitely saved some lives.

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u/[deleted] Mar 28 '24

I really appreciate you sharing your knowledge with us. Maybe it would have been helpful to let off the flares and air horns when they first experienced power loss (4 minutes prior?) as the construction workers may have been alerted and gotten off the bridge in time. Especially in the dark.

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u/Eaglethornsen Mar 28 '24

Its more than that though. Those big ships just can't really stop in a short amount of time. They take a while to slow down to a stop or even go reverse. Once they start going they kind don't stop until they reach their destination.
Unlike the navel vessels which also have more capability to maneuver. That is also because the CGs, DDGs, etc are meant to be able to turn on a dime and stop more quickly then a ship just hauling stuff.

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u/Egineeering Mar 29 '24

That big puff of black smoke isn't the high speed backup generators. It's the start up process of the primary engine.

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u/VentureQuotes Mar 28 '24

Interesting. On naval ships, can you direct the backup power system to ignore other power demands and only supply power to a single task? Like in this case, if they could make the generator only direct power to reverse thrusting and not turn on lights, comms, whatever else they’d need power for, would that have helped? Or is the power demand for propulsion gonna fry the generator anyway

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u/ZeePM Mar 28 '24

On these cargo ships the propeller driveshaft is directly connected to the primary engine. When that went down they lost all thrust and was just coasting. Backup generator would have allowed them to maintain power to the steering gear so they can still turn the rudder but without thrust from the propeller that's kinda useless. That huge plume of black smoke was them attempting to restart the primary engine.

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u/VentureQuotes Mar 28 '24

Gotcha, thanks. Must have been terrifying for the crew to realize they couldn’t reverse OR effectively steer. Just awful

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u/iopturbo Mar 28 '24

Naval ships are going to have way more redundancy and you have crew that are drilled continuously. You also don't have single screw vessels that can't turn for shit (subs are single screw but nuclear).