Container Ship hits Key Bridge in Baltimore Harbor

[lrrifleman]

I have my take on this situation, but I don't want this thread shut down.

Apparently the victims that are the focus of the search and rescue are members of the work detail. I haven't seen an estimate of how many vehicles plunged into the river. Sadly, I fear that the casualty estimates will skyrocket.

 

[LVSteve]

A ship without propulsion just becomes a floating brick going wherever the water sends it. The lights flickering in the videos suggest a major electrical failure/attempt to get the power back on.

As for the strength of the bridge, what was the collision spec 46 years ago? Did it account for the size of the ships we have today? A ballistic calculator would come up with some interesting energy numbers for a 95,000 ton object moving at 5-10 knots. I'd guess that's a lot of side load for any bridge, given that bridges are built to resist vertical stresses.

 

[oldbrownhat]

As for the strength of the bridge, what was the collision spec 46 years ago? Did it account for the size of the ships we have today? A ballistic calculator would come up with some interesting energy numbers for a 95,000 ton object moving at 5-10 knots. I'd guess that's a lot of side load for any bridge, given that bridges are built to resist vertical stresses.

This is what the British bridge designer was saying in the excerpt from the WaPo I posted in #26 above. Scary.

 

[taz666]

chief38 ... looking at the video it seemed to me that the bridge pylon took a lateral hit. That basically pulled the bridge apart at each section.

 

[ladder13]

Check for open containers.

 

[LVSteve]

From one of the WaPo articles:

...[British bridge designer] Firth noted that the bridge, which was built in 1977, was erected at a time when ships were not as big as they are now and the flow of traffic was not as busy. These days, structures are designed with better protective measures in place, he said, though he noted that even a brand new bridge would have "come down in the same way" if it were hit by such a large vessel traveling at speed.

...He said the large container ship would NOT have had to be traveling "very fast" to have had such an impact, one that the bridge was simply not engineered to withstand...​

Your original quote of the article was missing a "not" for some reason.

 

[Rustyt1953]

 

[oldbrownhat]

Your original quote of the article was missing a "not" for some reason.

Weird! But you are correct. The original DID say "not". I'll correct it now.

 

[LVSteve]

Weird! But you are correct. The original DID say "not". I'll correct it now.

I suspect it wasn't there when you did your cut and paste, removed by a sub-editor at WaPo who thought the "not" was wrong. It was put back later when it was pointed out that he/she has no clue about physics.

 

[Fishinfool]

When you start figuring mass & speed, there is a lot of energy there. The news was reporting "power failures", and that the crew had time to send an SOS, alerting authorities with enough time to close the entrances to the bridge to further traffic.

Once up to speed, large, heavy ships like that take miles to come to a stop. Even longer when there is no reverse thrust available.

I remember years ago watching a video of a large ship coming up to a heavy commercial ships dock at about 5 mph, on course for the end of the dock (Calif. ?). There were maybe a dozen people standing there, watching. When the ship hit the dock face on, it just rolled it up like an accordian. It looked like it was moving in slow motion, as the people ran in front of the bow as the dock disintegrated behind them. A great example of momentum.

Larry

 

[MTC(SS)Ret]

I am certainly no bridge engineer, but to this guy's eyes it seems to me that the bridge was inadequately engineered and built. For a bridge to be built so shoddy in a major trafficked passage, it was way to flimsy in my eyes. Lots of bridges on major passages are reinforced with thick concrete. For a bridge to totally collapse in less than 10 seconds it tells me someone approved an ill designed structure. Obviously I am just a non expert observer, but 10 seconds????? Really? Remember.... accidents do and will happen!

I'm no bridge engineer either but I doubt such bridge structures are designed to be able to withstand being struck by a 100,000 ton vessel traveling at 8 knots (according to news reports)

 

[Exaviator]

The design of that style of bridge whilst relatively easy to construct has one basic flaw, each span is relying on the integrity of the adjacent span. If one span fails, the additional load placed on the adjacent span causes it to fail in turn. If you watch the video footage you can track the structural failure as the loads are transferred.


When the ship lost power, and all control was lost, the prompt "Mayday Call" sent out by the crew and the resultant swift closing of the bridge to traffic, saved what could have been a catastrophic lost of life.

 

[Greyman50]

Key bridge was finished in 1977, Been over it many many times going I-95 N. Remember being at APG in 71 Before it was there and having to go all the way around Baltimore. Easier to just go down Eastern Shore and cross bridge/ tunnel to Southside of Va.
The boat that knocked bridge down has a history of maintenance problems. Looks like there needs to be some review and inspections of boats coming and going from out harbors. Norfolk Va is going to be overloaded now.

 

[glowe]

The bridge is 46 years old and that means
untold stresses have been endured as traffic,
including trucks, has pounded it all those years.

At this time I doubt anyone knows how much
force the ship delivered when it hit a support
structure . . .

Actually, it is a simple equation and we have all the information we need. The ship weighed 100,000 tons and was traveling at 10 mph. The force is therefore 100,000 x 10 = 1,000,000 tons of force hitting the bridge. That is an unbelievable force, one which no bridge pier anywhere could survive without extremely large bumpers that could withstand such forces.

 

[steelslaver]

Actually, it is a simple equation and we have all the information we need. The ship weighed 100,000 tons and was traveling at 10 mph. The force is therefore 100,000 x 10 = 1,000,000 tons of force hitting the bridge. That is an unbelievable force, one which no bridge pier anywhere could survive without extremely large bumpers that could withstand such forces.

actually to get ton miles of kinetic energy you would need to square the 10mph for 100

Or you could need to convert 10 mph into ft per second, before multiplying by itself then by the weight in grains then divide by 450,437 to get ft lb of energy then divide that by an addition 2000 to get ft tons of energy

10mph = 52,800f per hour/3600 seconds per hour or 14.66 fps call it 15fps, 100,000 tonsx2000=200,000,000x7000=1,400,000,000,000gr 15x15=225x14=315,000,000,000,000/450,437=6,993,000,000,000ftlb or

about 3,500,000,000 ft tons of energy

In any event this kind of force is more commonly refereed to as an MEGA THUD

The vibration that went up the pier and along the spans must have been tremendous. Think about hitting something solid with good blow with a 16# sledge hammer and then multiply it by 2 billion times because 1,000,000 tons by 2,000# per ton give you 2 billion and that makes one big hammer

 

[DWalt]

The actual impact force (not impact energy) would be in the neighborhood of at least 10 Million pounds (5000 tons) depending on some necessary but reasonable assumptions. The kinetic energy would be around 200-250 Million foot-pounds.

 

[BLACKHAWKNJ]

One line of investigation is that contaminated fuel is the cause of the ship losing power. Reminds me of Chapter One of the 1943 serial "The Masked Marvel" where the hero engages in an epic battle to keep traitors from sabotaging aviation fuel.
I wonder if there were any shortcuts, perhaps a little cheating in building that bridge. The recently demolished Tappan Zee Bridge was supposed to have a 50 year-actually 56 years-life, during its construction in the 1950s
a lot of critical materials were in short supply due to the Korean War, some of the steel used was all that was available, not what was desireable, hence it was planned to build a replacement.

 

[oldbrownhat]

...The boat that knocked bridge down has a history of maintenance problems...

If bad maintenance can be shown to have been a factor in the disaster, I would hope that the owners can be put on the hook for the massive repair costs. If so, they'll likely be bankrupted. The authorities have the ship's black boxes and should be able to get full maintenance records.

The lawyers will make out like bandits, no matter what happens


Addendum: From an AP report-

The cargo ship that lost power and crashed into a bridge in Baltimore underwent "routine engine maintenance" in port beforehand, the U.S. Coast Guard said Wednesday...

U.S. Coast Guard Rear Admiral Shannon Gilreath said at a news conference that authorities had been informed that the ship was going to undergo the maintenance.

"As far as the engine goes, we were not informed of any problems with the vessel," he said. "We were informed that they were going to conduct routine engine maintenance on it while it was in port. And that's the only thing we were informed about the vessel in that regard."

...The agency [NTSB] also is reviewing the voyage data recorder recovered by the U.S. Coast Guard and building a timeline of what led to the crash, which federal and state officials have said appeared to be an accident.​

This is a wake-up call for all major ports, including Vancouver, BC, a major player on the West Coast, and they have already implemented some safeguards:

...In 2017, the port authority changed the navigation channel under the Lions Gate bridge from a two-way to a one-way channel to allow ships to stay in the centre of the channel, he said.

In addition, tugboat support is required, with every foreign ship over 350 gross registered tons is required to use a local marine pilot when they enter B.C. waters...​

 

[CH4]

Check for open containers.

Haha
Good one

 

[Imissedagain]

Always advised yacht owners/Captains, to keep an aft hook ready to go, when traveling along the Intracoastal or anywhere.
On two occasions it prevented hitting a bridge before it was raised.
Transmission and broken shifter cable problems when headed out for seatrials.

Wonder if a giant aft Hook could have stopped that cargo ship?
Probably would have collapsed even at 3 knots.
Stopping a little 150' M/Y quickly, takes lotsa power in reverse.

 

[oldbrownhat]

...Wonder if a giant aft Hook could have stopped that cargo ship? ...

Not a chance! Apparently they did try dropping an anchor, but but it was (far) too little, too late.

 

[Beemerguy53]

It's somehow reassuring to see that Facebook isn't the only place where graduates of the Wikipedia School of Bridge Design and the Google Maritime Academy figured everything out before the NTSB even arrived on the scene...

Sorry for the sarcasm (not), but everybody in this area is just overwhelmed by this right now. That bridge is down in the main shipping channel of the Baltimore Harbor; nothing can get in or out of the port until the channel is cleared, and that is likely to take weeks. Baltimore Harbor has about 40 miles of shoreline, with businesses ranging from Domino Sugar to chemical companies to the busiest vehicle import/export terminal in the country...and all of them are out of business until the bridge debris is removed and the channel is cleared.

Six workers were on the bridge doing road maintenance when it collapsed. Two of them were found by divers today, in a pickup truck at a depth of 25 feet. Because of the extreme danger to divers, the USCG announced tonight that recovery of the remaining victims' bodies will happen during salvage operations, when that process begins.

To get north or south of Baltimore, vehicles can go through the city; or through one of two tunnels; or around the western side of the city on I-695 (the Baltimore Beltway); or around the east side on I-695, of which the Key Bridge is part. Hazardous Materials are prohibited from using either tunnel, so with the bridge out, those trucks, and many of the other 30,000 vehicles that use the Key Bridge daily, will detour around the city to the west...which will make a bad daily traffic situation even worse. My own forty-minute commute has been an hour each way since the collapse.

According to people with expertise in this sort of thing, getting this bridge rebuilt is going to take at least several years, and possibly as long as a decade. And there will be arguments and fights over everything from hiring the "right" contractors to changing the name.

There were bright spots in this tragedy. The Maryland Transportation Authority Police officers who closed the approaches to the bridge as soon as they learned a ship was headed toward it undoubtedly saved many lives. And my brothers from the Baltimore City Fire Department performed brilliantly as they arrived on the scene, sized up a truly hellish sight, and gathered the necessary resources to start to mitigate it. In the hours since the collapse, other local, state, and federal government agencies have proven to be invaluable in coordinating the response to this incident.

I've gifted the latest Post article on this situation to this page, so you can read it.

https://wapo.st/3TElD9M

https://wapo.st/3TElD9M

 

[Brian Parrish]

It's somehow reassuring to see that Facebook isn't the only place where graduates of the Wikipedia School of Bridge Design and the Google Maritime Academy figured everything out before the NTSB even arrived on the scene...
...

Thank you!
Just a thought about internet comments. The best way to learn is to declare something and allow for subsequent contradiction or. In class you do that, and the professor corrects you not thinking anything disparaging about you since you have a relationship, and your body language will convey teachableness.
I have developed the habit of adding the words, "Please correct me." to such forum declarations. It seems to help.
Please everyone who is able, you should contribute to rather than complain about Wiki entries. Fix them!

Kind regards and again thanks!
BrianD

 

[steelslaver]

Major wreck and it is amazing that more people didn't die

Lots of variables on how well and how fast an anchor will hook up and stop you The composition of the bottom, how much slope it has and how your anchor will drag on it. How much scope you have when it does hook up.

While they do work for an emergency brake, most anchor gear isn't set up to take the kind of forces that occur when dropped and any speed.

The same forces that struck that bridge would have ended up on that anchor gear if it had hooked up solid. I wouldn't have wanted to be anywhere near any of it. Because unless the hook drug long enough to slow you way down before it came taunt something was gonna give in a dramatic fashion. I saw an anchor winch get its shaft busted because the deck hand didn't use the brake instead of the drive and that happened just idling back to set the hook. The bang was Impressive. It was a major pain to recover the anchor gear.

In 2013 a bridge on I5 where I used to live north of Seattle had a support struck by a over height semi and it collapsed into a fair sized river. Luckily it was not rush hour. That one only took a hit from a semi truck to bring down.

 

[LVSteve]

The design of that style of bridge whilst relatively easy to construct has one basic flaw, each span is relying on the integrity of the adjacent span. If one span fails, the additional load placed on the adjacent span causes it to fail in turn. If you watch the video footage you can track the structural failure as the loads are transferred.

The design of river bridges is a balance between purpose, cost, aesthetics, and what the local conditions allow. There are many bridges built like this one where the failure of one span will likely result in a total collapse. It's easy in hindsight to say "they needed a more solid bridge", but in a tidal river I suspect the "ground" conditions under the river bed would preclude such construction. You can't build huge, weighty bridge supports if there is insufficient support underneath.

 

[ladder13]

Like everything else, some only think their sources are real. The facts will come out eventually. Maybe.

 

[taz666]

The design of river bridges is a balance between purpose, cost, aesthetics, and what the local conditions allow. There are many bridges built like this one where the failure of one span will likely result in a total collapse. It's easy in hindsight to say "they needed a more solid bridge", but in a tidal river I suspect the "ground" conditions under the river bed would preclude such construction. You can't build huge, weighty bridge supports if there is insufficient support underneath.

There is also expansion and contraction that has to be factored in. Each failure was most likely at these points along the span.

 

[Rustyt1953]

The Dali was carrying 4700 containers. At 8-10 knots that's a lot of energy transfer.

 

[CAJUNLAWYER]

From what I have read, the ship allegedly lost propulsion. Is that common? I also read that the 2 pilots were from India, I always thought that the idea of putting a pilot on a vessel was to put a local (familiar with the waters) on ships entering and exiting inlandwaterways!

Rather coincidental that the collision and collapse occurred on the 47th anniversary of the bridge's opening!

There was NO COLLISION. This was an Allision-big difference as I found out years ago when fighting insurance coverage or more importantly lack thereof. A maritime policy covering collision ain't gonna cover allision.

 

[CAJUNLAWYER]

actually to get ton miles of kinetic energy you would need to square the 10mph for 100

Or you could need to convert 10 mph into ft per second, before multiplying by itself then by the weight in grains then divide by 450,437 to get ft lb of energy then divide that by an addition 2000 to get ft tons of energy

10mph = 52,800f per hour/3600 seconds per hour or 14.66 fps call it 15fps, 100,000 tonsx2000=200,000,000x7000=1,400,000,000,000gr 15x15=225x14=315,000,000,000,000/450,437=6,993,000,000,000ftlb or

about 3,500,000,000 ft tons of energy

In any event this kind of force is more commonly refereed to as an MEGA THUD

The vibration that went up the pier and along the spans must have been tremendous. Think about hitting something solid with good blow with a 16# sledge hammer and then multiply it by 2 billion times because 1,000,000 tons by 2,000# per ton give you 2 billion and that makes one big hammer

What is that in Joules???