Baltimore's Francis Scott Key Bridge Collapses after Ship Strike

[ChemAir]

What would you bet that those guys work for many different customers, consulting and such. I bet their favorite hard hat is in their back of their truck and doesn't have a NTSB sticker on it. I don't imagine that would go over well with developers on normal job sites.

Call me cynical, but I doubt these folks have any hard hats, work boots, or gloves, of their own. They are probably the PR crew. Available for pictures, but not much else.

I'd rather see cranes/jack-up rigs moving to pick up this mess. And, its a big one (mess, that is).

 

[gmax137]

Call me cynical, but I doubt these folks have any hard hats, work boots, or gloves, of their own. They are probably the PR crew. Available for pictures, but not much else.

I'd rather see cranes/jack-up rigs moving to pick up this mess. And, its a big one (mess, that is).

Yeah, I wasn't too impressed by their actions on the video. Mostly wandering around snapping seemingly random photos with their cell phones. That's not forensic investigation, IMO.

 

[Vanadium 50]

As Eisenhower once said "There are armies for marching and armies for fighting". There are NTSB crews for photo-ops and NTSB crews for investigation.

 

[berkeman]

Sorry if this info is in the videos that I haven't watched, but the cause of the accident was loss of main engine power, right? And has there been any indication what could have caused that? Is it an unusual failure? (I would guess so, but I don't know). Thanks.

 

[Bystander]

Sorry if this info is in the videos that I haven't watched, but the cause of the accident was loss of main engine power, right? And has there been any indication what could have caused that? Is it an unusual failure? (I would guess so, but I don't know). Thanks.

Crickets, "aka.. 'the usual suspects,'" conspiracy theories...yada-yada-yada....

 

[Baluncore]

Sorry if this info is in the videos that I haven't watched, but the cause of the accident was loss of main engine power, right?

The fundamental cause has not been revealed. Which safety systems failed to operate has not been revealed.

My guess of a scenario at the moment, is a "jammed" rudder for some reason, followed by an attempt to reverse the engine to stop the turning ship.

 

[russ_watters]

Sorry if this info is in the videos that I haven't watched, but the cause of the accident was loss of main engine power, right? And has there been any indication what could have caused that? Is it an unusual failure? (I would guess so, but I don't know). Thanks.

Has main engine failure been positively identified? What I've seen for sure is power failure, which isn't necessarily the same thing (the main engine isn't necessarily driving a generator in addition to the screw). But either one is a no; no they are not terribly uncommon. Power failures in particular; can you imagine a worse environment in which to run a generator reliably?

 

[russ_watters]

Gotta be honest. New hard hats don't give me the confidence level that well used hard hats would.

et al; I don't understand the anti-NTSB flak/jokes here. The NTSB is maybe the best forensic engineering organization in the world. There's nobody else you would want to be investigating this, at least in terms of the crash itself (I think the 9/11 structural sims were done by NIST).

Do you think the people available for easily accessible media photos are the most critical? How many seats for the media are there on the helicopter? The RHIB? Other side of the coin: if your department has a bunch of newbies, and you have a major project, do you make them stay in the office or have them shadow you in the field?

BTW, COVID was a black hole and my company re-branded twice in the past 6 years, so I have two gleaming-white hard hats in addition to a beat-up one that I don't wear anymore unless both of the others migrate to my garage.

 

[Baluncore]

Has main engine failure been identified? What I've seen for sure is power failure, which isn't necessarily the same thing.

Main engine failure has not been identified.

As far as I can tell, the main engine is a two-stroke diesel engine, 9-cylinder, 41.5 MW, 82.5 rpm. It is directly coupled, without clutch or gears, to a fixed-pitch propeller. To go astern, the engine is first stopped, the valve gear is changed over, then it may be started again backwards.

The main engine powers two 3.8 MW electricity generators, one hot, one spare. There are also two auxiliary 4.4 MW diesel generators, for use in port or emergency, again one hot and one spare.

I hypothesise loss of rudder control, jammed on the starboard curved course. Unable to control the ship in the channel, the main engine was stopped, and the port anchor dropped to partly counter the turn. Stopping the engine would cut main electrical power, until an auxiliary diesel generator started, if it did. The main engine was then started in reverse, producing the black smoke, but too late to stop the ship in time.

There are many reasons why rudder control might be lost. Mechanical, electrical or hydraulic failure of the rudder drive machinery. Loss of a main generator, switchboard, or the main engine, without an auto-start of the hot auxiliary generator.

It would have been hectic in the engine room for those 5 minutes, not sure of what was happening or why.

There is a ships engineer, oral exam question. What would you do if, while the ship was turning into a narrow channel, your mate fell across the 4 kV main generator bus? The correct answer is to start an auxiliary generator immediately, the ship and the channel are more important than body recovery. It is unlikely the mate could survive the accident. The wrong answer is to isolate the generator and remove your mate.

 

[Rive]

et al; I don't understand the anti-NTSB flak/jokes here.

Right. That visit on the video is apparently not about work to be done but about the 'work' already done. The wear missing on the hats only means they are new, and nothing more.
Watch for the pictures about the people with the cutting torches... Those hats will got the wear soon enough.

 

[sophiecentaur]

Somewhere I read that there is only 12 to 18 inches of clearance for large ships.

The space between water and the highest point on a vessel is called 'air draught' A nice term which should tell you your headroom. According to Google, the tidal range in Baltimore harbour is less than 2 feet which is small compared with many places (many metres). Hitting overhead structures is not altogether rare; that's something that a Pilot should know all about.

 

[Vanadium 50]

Power failures in particular; can you imagine a worse environment in which to run a generator reliably?

Submarines.

 

[berkeman]

I've seen in a couple places that the Vessel Data Recorder (VDR) seemed to shut down during each of the power loss windows. That seems really strange to me that the VDR and all sensors are not battery backed up to enable recording during a ship power outage. Does anybody have any knowledge about VDR systems on ships?

1:24 a.m. -- The livestream camera shows the cargo ship's lights suddenly going off and then coming back on.

1:24:59 a.m. -- Numerous audible alarms go off on the bridge of the container ship. The VDR temporarily goes off.

https://abcnews.go.com/US/timeline-...llapse-shows-moments-cargo/story?id=108540377

 

[Vanadium 50]

Submarines.

I'm not being completely facetious. An engineering casualty at sea is bad. You can't run to the hardware store to grab a replacement part, and you can't run away if things go even more pear-shaped. All of those problems are worse on submarines.

Your options are to be very, very careful, or to litter the bottom of the ocean with sunken hulls. There are examples of both options.

8 knots is 13.5 feet per second. That means that in the time it takes to start the auxiliary diesels (too small to drive the ship), the ship will traverse the distance of two football fields. The kinetic energy is equivalent to 500-1000 pounds of high explosive. You really, really do not want to lose control of the vessel.

 

[gmax137]

There are also two auxiliary 4.4 MW diesel generators

8 knots is 13.5 feet per second. That means that in the time it takes to start the auxiliary diesels (too small to drive the ship), the ship will traverse the distance of two football fields.

So the aux diesel start time is ~45 seconds? Did you see this stated somewhere? I have been wondering about this.

The emergency diesels in the nuclear plants are smaller (typically 1.5 or 2 MW). In emergency conditions, they start and begin loading in 10 seconds, but this is very harsh service and the machines require a lot of maintenance. 45 seconds would be a little easier on the hardware but it's still pretty severe.

 

[Vanadium 50]

and the port anchor dropped

Do we know when this happened?

At 8 knots, an anchor will not stop the ship. It might - slightly - help turn it. But this is a "Hail Mary", as it were. At this point, the bridge knew they were in deep trouble.

 

[berkeman]

Do we know when this happened?

According to the ABCNews link in my post #103:

1:27:04 a.m. -- The pilot aboard the Dali orders the vessel's port anchor be dropped, according to the VDR.

 

[ChemAir]

et al; I don't understand the anti-NTSB flak/jokes here. The NTSB is maybe the best forensic engineering organization in the world. There's nobody else you would want to be investigating this, at least in terms of the crash itself (I think the 9/11 structural sims were done by NIST).

Do you think the people available for easily accessible media photos are the most critical? How many seats for the media are there on the helicopter? The RHIB? Other side of the coin: if your department has a bunch of newbies, and you have a major project, do you make them stay in the office or have them shadow you in the field?

BTW, COVID was a black hole and my company re-branded twice in the past 6 years, so I have two gleaming-white hard hats in addition to a beat-up one that I don't wear anymore unless both of the others migrate to my garage.

No shade thrown.

I have a clean hard hat for pictures, and a real one for work (fits better, tighter to head, and is less likely to fall off). My past life involved a great deal of these folks that would show up for pictures, and then left when the real work showed, usually after a fire, train derailment, or other issue (some dealing with pyrophoric materials or materials that would ignite with minor friction/impacts, contact toxins, and at least one chemical weapon precursor). Most of these incidents were unpleasant and we had to report to the "face people", even when they couldn't understand the work being done, why it was being done that way and what we had to do to mitigate issues. Very, very few had any kind of STEM/engineering/chemistry training.

I obviously don't know this bunch's job requirements or exactly what they do (and this isn't really a chemical incident). My comments were probably unhelpful and unwarranted.

I agree that there will be a great deal of work to do and they may be the best to do so, and report as accurately as we can expect.

 

[Vanadium 50]

So, if I read the timeline right, there was 5 minutes between the order to lower the anchor and the collision. That is not a lot of time. A US Navy vessel would have someone assigned at the anchor ready to go, but cargo ships have much smaller crews. They may have had to stop what they were doing to go there.

In 5 minutes the Dali would have traveled about a kilometer.

 

[Gheed]

I've seen in a couple places that the Vessel Data Recorder (VDR) seemed to shut down during each of the power loss windows. That seems really strange to me that the VDR and all sensors are not battery backed up to enable recording during a ship power outage. Does anybody have any knowledge about VDR systems on ships?

Not exactly an expert on VDR systems but decent with internet.
The VDR is a JCY-1900 module (seen in this NTSB video at 7:07 )
Quote from manufacturer's brochure:

There is also an internal UPS included as standard, which is able
to power the VDR for 2 hours in case of power failure. During
blackout only bridge audio is recorded and will automatically return
to normal condition after power is restored.

The systems diagram from the manufacturer's brochure is attached to see what could have been connected to the device. Sounds like a nice job to dissect the data, if it wasn't for everyone breathing down your neck...

Anyways all that is definitely captured in case of an outage is this microphone data. Maybe this will change in the future with different legislation, but who knows...

 

[Frabjous]

Apparently one of the cranes being used in the clean up helped build the Glomar Explorer (under a different name of course)
https://www.thebaltimorebanner.com/...e-chesapeake-1000-ZOKJTTQLGFGFFHRFVK7LQOV4XM/

 

[sophiecentaur]

et al; I don't understand the anti-NTSB flak/jokes here.

Investigators and inspectors all aways fair game. I don't think there's any doubt how useful these guys are. Of course, the 'Brass Hats' always turn up for major events so the clean hats may demonstrate that in this case.

 

[Frabjous]

Corps of Engineers says Port of Baltimore should reopen with limited access by end of April and be completely reopened by end of May.
https://www.baltimoresun.com/2024/04/04/goal-restore-access-port-baltimore-end-of-may/

 

[Borg]

U.S. Army Corps of Engineers develops tentative timeline to reopen Fort McHenry Channel following Key Bridge collapse​

 

[gleem]

Sorry if this info is in the videos that I haven't watched, but the cause of the accident was loss of main engine power, right? And has there been any indication what could have caused that? Is it an unusual failure? (I would guess so, but I don't know). Thanks

There was a post on the internet shortly after the accident by a former containership captain who said that he always had a drill for loss of engine or electrical power when leaving port. Such occurrences IIRC are not rare. He also said the first thing he does on loss of engine power is drop anchor. The captain of the DALI did not immediately drop anchor but instead called for tug support first which might have taken as much as a half hour to get to them. The call to drop the port anchor was about two minutes after the problems started. DALI has a bow thruster ( as seen by the decal on the bow) but it probably is run by an electric motor but was probably not available.

One other thing, the ship was traveling down the channel(rudder amidship) when the power was lost so I do not think the ship should have turned too much based on that. Dropping the port anchor should not have caused it to veer toward the support. However, the ship makes a relatively sharp turn toward the bridge support prior to inpact.

 

[Vanadium 50]

Bow thruster?

Skipper might as well have gotten the crew on deck and told them to blow real hard.

 

[Bystander]

Bow thruster?

Skipper might as well have gotten the crew on deck and told them to blow real hard.

Shades of Bridges at Toko-Ri.

 

[nsaspook]

Apparently one of the cranes being used in the clean up helped build the Glomar Explorer (under a different name of course)
https://www.thebaltimorebanner.com/...e-chesapeake-1000-ZOKJTTQLGFGFFHRFVK7LQOV4XM/

Let's hope it works to get the channel back open ASAP.

 

[Astronuc]

One other thing, the ship was traveling down the channel(rudder amidship) when the power was lost so I do not think the ship should have turned too much based on that. Dropping the port anchor should not have caused it to veer toward the support. However, the ship makes a relatively sharp turn toward the bridge support prior to inpact.

I heard on one video that the black smoke, ostensibly from the main engine restart was blowing/flowing laterally indicating a breeze from the port side, which would have pushed the DALI to starboard. I heard a conflicting comment that there was no breeze that evening.

In another video, someone mentioned a channel to the starboard side of the DALI, from which a current may have pushed the stern to port reorienting the ship toward starboard. The Curtis Bay Channel comes from the west to join the Fort McHenry Channel, which goes from NW to SE and is centered on the main span of the Francis Scott Key Bridge. Ostensibly, a current flow east in the Curtis Bay Channel may push the stern of the ship and be enough to turn the ship if it has no rudder control (rudder is stuck amidship).

https://fishing-app.gpsnauticalchar...ORE+HARBOR+boating+app#14.23/39.2192/-76.5270

I also heard some discussion with engineers that the bridge had less protection than others. So, the lesson here is that the bridge piers needed much better protection.

https://www.reuters.com/world/us/ba...need-protect-critical-foundations-2024-03-28/

As for the ship, the lesson learned here is that such ships need to have independent systems to ensure navigation/steering/rudder control in the event that the main power plant (or whatever systems provides power to the navigation/steering system) shuts down.

 

[gleem]

I heard on one video that the black smoke, ostensibly from the main engine restart was blowing/flowing laterally indicating a breeze from the port side, which would have pushed the DALI to starboard. I heard a conflicting comment that there was no breeze that evening.

There is a lot of ship underwater to resist such a motion and it would take a substantial wind to move the ship a significant amount in 4 min. Also typically a night the wind is usually light, especially in a harbor.

About current I doubt there is a significant cross-current in the channel since in a narrow harbor the tides would be basically flowing out of the harbor. The current in the channel would be lower than that near shore due to depth. The video I saw showed the ship distinctly turning not drifting toward the bridge. I don't think a difference in the speed of the current would significantly change in the length of the ship unless it was a huge CW vortex near the bridge but such a vortex would have moved the bow to port first before causing it to turn to starboard.

If the black smoke was of the engine going in full astern then that would have caused the ship to turn to starboard toward the bridge support. If the ship had it GPS nav equipment running we have a record of the track of the vessel. We'll eventually find out.

Another question I have is do they have a battery backup for certain equipment like nav or deck lights that you don't want to go out.