Bridge Collapse

Ironman

The Francis Scott Key bridge, which carries I 695 around Baltimore, was struck by a foreign freighter and collapsed early this morning.

https://www.npr.org/live-updates/baltimore-bridge-collapse

Jamie Hall

oops... saw that. Rather spectacular.

Steamhead

At the moment they're still doing search and rescue. This will be a big mess for at least five years. If you're driving up and down the East Coast, don't come to Baltimore.

KC_Jones

Steamhead said:

At the moment they're still doing search and rescue. This will be a big mess for at least five years. If you're driving up and down the East Coast, don't come to Baltimore.

I think you are being optimistic. The original bridge took 5 years to build. In this case there will be cleanup, analysis of existing design for improvements, which most likely will involve adding barriers in front of any main span supports. After all that, then construction can begin, which will probably take at least 5 years like the original, I speculate longer.

NTSB probably won't allow anything beside cleanup to move forward until their investigation is complete, which could take a year or more. It's a mess.

Sylvain

I hope next bridge design would not transmit the failure all along the bridge in case of a single pier damage.

I read in the link:
"The crew of the Dali container ship alerted authorities that it was losing power"
"The Dali, which was traveling from Baltimore to Sri Lanka, had issued a "mayday" warning before the collision, which helped authorities reduce traffic on the bridge."

Couldn't they have dropped the anchors to try to stop her? Although keeping an already still ship in place against current and wind is not the same as stopping such a mass.

EBEBRATT-Ed

The ship was moving. They said it would take a mile to slow it down

Steamhead

If anyone reading this is planning to come down I-95 past Baltimore, you're better off taking US 13 south through Delaware and picking up US 301 just south of the C&D Canal. From there, you can cross the Bay Bridge and follow US 50 to DC, or stay on 301 which will take you to Richmond.

Sylvain

In addition to losing propulsion, she might also have had a rudder problem or her speed was already below steerage way?

EBEBRATT-Ed said:

The ship was moving. They said it would take a mile to slow it down

A nautical mile (1852 m) I guess ;-)

MaxMercy

Steamhead said:

If anyone reading this is planning to come down I-95 past Baltimore, you're better off taking US 13 south through Delaware and picking up US 301 just south of the C&D Canal. From there, you can cross the Bay Bridge and follow US 50 to DC, or stay on 301 which will take you to Richmond.

I imagine the traffic is going to be astounding.

Steamhead

MaxMercy said:

I imagine the traffic is going to be astounding.

Worse. The bridge was one of four main routes through or around Baltimore. The others are two tunnels- I-95 and I-895- and the northern part of the Beltway, I-695. That part of the Beltway has several active construction zones going, which are going to really get choked up with all the truck traffic that can't use the tunnels because of various restrictions.

Jamie Hall

Steamhead said:

If anyone reading this is planning to come down I-95 past Baltimore, you're better off taking US 13 south through Delaware and picking up US 301 just south of the C&D Canal. From there, you can cross the Bay Bridge and follow US 50 to DC, or stay on 301 which will take you to Richmond.

I second that. That's how we get to Richmond on the rare occasion that we need to. A very pleasant route (well, relatively speaking anyway...).

What no one has mentioned above -- the Port of Baltimore was a rather important port for shipping. What's left of the bridge has effectively close the harbour until it can be removed...

On the anchors... um, no. You could drop the anchors -- if there were crew up these all ready to go -- but to stop a ship of that size at that speed (say 4 knots or so -- perhaps more) you might just as well hang your foot over the side.

On single pier damage. I simply can't think of a bridge design of any sort which won't collapse if you take out one of the piers, which it looks as though is what happened here. In some designs you will only lose the spans directly supported by the pier. As it happens, in this design you lost the entire through truss structure-- which isn't too surprising, since it was intended to act in one piece, as it were -- which was, in effect, a single span, albeit a long one.

JUGHNE

Something wrong here.....you are headed halfway around the world and can't get out of the harbor?

There must be some checklist for propulsion before even starting.

KC_Jones

@Jamie Hall Ship was traveling at 8.5-8.7 knots on the approach to the bridge. This isn't uncommon as ships tend to not steer very well at low speeds.

I grew up boating on the Chesapeake bay and still do now, I can tell you those ships aren't letting any grass grow when traveling up and down the bay.

EBEBRATT-Ed

Probably the ship was run by microprocessor controls that failed

50 years ago it wouldn't have happened.

ChrisJ

EBEBRATT-Ed said:

Probably the ship was run by microprocessor controls that failed

50 years ago it wouldn't have happened.

Yeah,
EJ Smith never ran any ship into something and killed 1500+

SlamDunk

This will be an interesting investigation. Is the ship sail by wire? No back up gens? Multiple hydraulic systems with at least one system on gens? Why no pylons protecting bridge supports? What kind of power distribution does a ship like this have? Why such a total collapse? Will this come down to insufficient design because of the flag it flies under doesnt require robust designs? A lot to be learned with this one.

I drove US 13 a couple times. It is a longer drive. I think I'll get over my repulsion to flying.

DanHolohan

The ship did drop anchor. It made no difference. That ship is massive. Opening the harbor is the biggest challenge now. 

hot_rod

“Flags of Connivence” an international loop hole on the high seas. A recent DOT study indicated no U.S. flagged carriers were listed among the top 20 global carriers. It’s about 3 times more expensive to flag a ship in the U.S.

The International Maritime Organization, a branch of the UN sets the rules, for international waters, the country of registration dictates the legal and tax related criteria. Crimes committed more than 12 nautical miles from any counties shoreline default to the jurisdiction of the flag.

80% of all the goods we use and consume arrive by ship.

In 1826, 92% of the international trade fleet was flying the American flag.

Steamhead

For those interested, dispatch audio of the first 90 minutes of this event is here:

https://www.youtube.com/watch?v=g3lz-oBnmYE

The call originally came in as a "vehicle in the water" rescue- later they realized the magnitude of the situation.

Jamie Hall

SlamDunk said:

This will be an interesting investigation. Is the ship sail by wire? No back up gens? Multiple hydraulic systems with at least one system on gens? Why no pylons protecting bridge supports? What kind of power distribution does a ship like this have? Why such a total collapse? Will this come down to insufficient design because of the flag it flies under doesnt require robust designs? A lot to be learned with this one.

I drove US 13 a couple times. It is a longer drive. I think I'll get over my repulsion to flying.

I don't know that specific ship, @SlamDunk -- but a few very common arrangements. First of all, the there is only one main engine, and almost always direct reversing (that is, you have to stop the engine and start it running in the other direction to reverse). Second, it is common, but not universal, to have the main electric power from a shaft generator on the main engine. Some ships have separate main generators. Either way, an electrical fault will stop the main engine (a number of pumps are involved). It looked to me from the videos as though she may have managed to get the emergency generator started -- the 30 second or so initial blackout looks about right for that). That generator probably would have given them rudder control, but without the main engine running at that speed (i now understand around 8 knots -- minimum steerage) the rudder would have had little effect.

These ships are pretty much sail by wire -- that is, both the steering and engine controls are done normally from the bridge. That said, the engine can also be controlled from the engine room control booth -- but even if they got power back almost instantly the main engine takes several minutes to start *(I wonder if the smoke just before she hit was an attempt to start the main engine in emergency override?). The rudder normally does not have manual backup, but normally does have dual redundant hydraulics which can be controlled locally -- but only if there is electric power for the pumps.

Now the really big question is why there wasn't adequate fendering for the bridge -- particularly after the Sunshine Skyway bridge strike and collapse. So far as I can make out from the aerial photos of the bridge from before this event, there wasn't any -- the piers were protected from small boat impacts, but a close look at the videos shows that the overhang of the ship's bows extended well past the pier protection, and hit -- and broke -- one of the four support columns on that pier about half way up. Which, of course, was the end of the line.

So... yes, the ship had a problem. Stuff happens. But, in my humble opinion, if the highway folks responsible for that bridge had learned from the Sunshine Skyway failure and installed proper fendering, it would have been a nuisance and nothing more. Somebody dropped the ball.

EBEBRATT-Ed

I just saw a Captain interviewed on TV. Not "the " captain just a guy that knows ships he said when you lose power as they did and the back up gen comes on you only can control the rudder the engines will not run on back up. The rudder does 10% of the steering without the engines being on. he said you basically have no control.

Steamhead

SlamDunk said:

..... I drove US 13 a couple times. It is a longer drive. I think I'll get over my repulsion to flying.

It should actually take less time now that traffic is messed up in Baltimore.

hot_rod

The I 35 bridge  in Minnesota was replaced in 15 months, typically. 3 year project 

Larry (from OSHA)

The morning after the 35W bridge fell, we were all instructed to be in the office early for a meeting. It had been decided by the Governor that OSHA would NOT be doing any enforcement of that work zone. Only the Consultation Division would be involved but most of us in enforcement ended up doing shifts as safety consultants anyway. There was a 24/7 presence to try to keep everyone safe and the project moving. It was definitely a crazy time. I think it was a major engineering achievement that the new bridge could be designed and put into service in the short amount of time that it took. There were a lot of discussions about using the "design/build" approach since it was not something that was often done. I pass by and travel on that bridge frequently, and as far as bridges go, I think it's a plenty nice one. I also had the opportunity to see some of the construction process of the St. Croix River bridge where concrete sections were created several miles downstream on an island and floated to the worksite. That was also very impressive. It is more than unfortunate that often times a tragedy results in the most amazing and creative engineering and building skills that exist today. My sympathies to all who have been impacted by this event.

WMno57

Shipping industry impacts.
https://www.newsnationnow.com/us-news/northeast/shipping-industry-baltimore-bridge/

SlamDunk

@Jamie Hall  seems to me there is no redundancy on the ship.   I mean during the critical phase of leaving a harbor, back up gens should have been running, synched up to engine gen, and connected to the main buss to keep hydraulics and other critical systems running.    10% steering would have been better than nothing.   I checked the tidal charts.   At 1:30am, tide was at lowest point so they werent fight currents at that moment.   

The lack of fendering ( I called them pylons) is another issue for a busy harbor with  heavy ships.  

ChrisJ

SlamDunk said:

@Jamie Hall  seems to me there is no redundancy on the ship.   I mean during the critical phase of leaving a harbor, back up gens should have been running, synched up to engine gen, and connected to the main buss to keep hydraulics and other critical systems running.    10% steering would have been better than nothing.   I checked the tidal charts.   At 1:30am, tide was at lowest point so they werent fight currents at that moment.   

The lack of fendering ( I called them pylons) is another issue for a busy harbor with  heavy ships.  

Is that what I've heard others refer to as buffers?

Jamie Hall

Oh I rather agree. Redundancy is good. And, in fact, most ships do have pretty good redundancy -- provided there is time. Evenalmost all the accessory equipment for the main engine is duplicated. There is, however, only one main engine. Very few cargo ships have more than one main engine. Many cruise liners have two or more main generators, which in turn power electric motors which move the ship and provide other power on board, although even there certain electrical faults can black out the ship (there was a big ferry a few years back in British Columbia to which that happened).

It will be interesting to see how much control they got back over their rudder. A look at the track chart suggests that they may have gotten some back -- but I assure you, having done it, that on any reasonably large single screw ship or boat at minimum steerage way, if you don't have the prop wash over your rudder you are pretty much a passenger for any significant and quick course change.

They simply didn't have time. I'll grant that the engine shouldn't have quit. But... engines do.

I will maintain that the lack of fendering on those piers, particularly with the example of the Sunshine Skyway, set them up in the accident waiting to happen class of emergency preparedness...

Intplm.

When I see relatively lighter in weight cruise ships being escorted by tug boats but not a massive cargo carrier something is not right. Something is surely a-miss. It brings this to mind.
Why not extend the tug boats escort time along with the harbor pilots length of time on the bridge?

Sylvain

search for:
wiki dolphin structure

Jamie Hall

A couple of notes here... first is again, looking at the track charts and video... had she hit that bridge on a course about 30 meters north, nothing serious to the bridge might have happened. I think they tried...

Cruise liners, @Intplm. , are a nightmare. They have a huge sail area and very light draught (area below the water) and are seriously underpowered. They handle like a drunk late on Saturday night, and in anything more than a light breeze are completely helpless in tight quarters. And for all that they aren't all that light -- a number of the larger ones are over 100,000 dead weight tons -- but with the power plant of a World War I 1,000 ton destroyer.

They are seaworthy, within the meaning of the act -- but only just barely. They have to flee to shelter in any kind of filthy weather.

It's no wonder they are surrounded by tugs (big cargo ships are, too, dooring mooring and unmooring). There is no way I'd ever set sail on one of those things, never mind try to skipper one.

ChrisJ

@Jamie Hall You think they tried to what?

Intplm.

Jamie Hall said:

A couple of notes here... first is again, looking at the track charts and video... had she hit that bridge on a course about 30 meters north, nothing serious to the bridge might have happened. I think they tried...

Cruise liners, @Intplm. , are a nightmare. They have a huge sail area and very light draught (area below the water) and are seriously underpowered. They handle like a drunk late on Saturday night, and in anything more than a light breeze are completely helpless in tight quarters. And for all that they aren't all that light -- a number of the larger ones are over 100,000 dead weight tons -- but with the power plant of a World War I 1,000 ton destroyer.

They are seaworthy, within the meaning of the act -- but only just barely. They have to flee to shelter in any kind of filthy weather.

It's no wonder they are surrounded by tugs (big cargo ships are, too, dooring mooring and unmooring). There is no way I'd ever set sail on one of those things, never mind try to skipper one.

I certainly do agree. I have been on quite a few ships including cruise ships. They are sea worthy and to this discussion that's about all they are.
Some are being built with azipods to help with maneuvering.
But to reiterate my point. A longer requirement for the the harbor pilot and a longer escort with tug boats.
Maybe the NTSB and the USCG will put this into place in the future.

SlamDunk

ChrisJ said:

@Jamie Hall You think they tried to what?

steer 30m to the North.  

Jamie Hall

The harbour pilot was still on board and in command -- and I feel very sorry for the poor guy or gal, as they will get thrown under the bus by the media, if not the lawyers...

There's a problem with tugs. At low speed ;-- mooring or unmooring, or turning in place they are fine. Their ability to really affect things drops off fairly quickly as speed increases. (never mind the risks of handling them close to a large ship at anything more than three or four knots). It's a balancing act...

And yes, azipods do wonders for maneouvering, as do full powered bow and stern thrusters (although thrusters lose capability over about three knots). Azipods, however, are not much help if the main engines (generators) aren't running... but some of the newest full powered liners (as distinguished from cruise boats) do use them quite effectively.

KC_Jones

Based on what I see in the video suggests an aggressive throttle move, and a reversing event. With single screw ships such as that, and actually single screw inboard boats (what I learned on), Jamie is quite right about the steering, but there is another phenomena exclusive to these set ups, prop walk. When reversing the rudder, at almost any thrust amount is essentially useless because the thrust is away from the rudder. What does happen is prop walk. There are a lot of factors that cause it, but the effect is moving the stern of the vessel sideway, with a right handed rotation (for forward) and left handed rotation for reverse, in reverse would tend to move the stern of the vessel to the port (left), which is exactly what is shown in the video. Basic seamanship would also suggest that in an emergency, anything that can be done to stop the vessel would be utilized, reverse to slow the forward motion would be one method and doing that the moment power is restored would make sense, in the moment.

A ship that big and heavy does not alter course randomly, something has to happen to cause that. I know those waters, I've been on them many times. There are tides, there are currents, but in fairly normal conditions those currents aren't close to enough to alter the course of a large ship like that, at the rapid rate it did. And, the tide was effectively slack at 1:30 AM. Aggressive maneuvering reacting to an emergency event can cause some crazy things to happen.

I am very curious what the NTSB finds with this, based solely on limited information and a single video, prop walk causing the ship to veer off it's completely straight track makes the most sense to me.

KC_Jones

Jamie Hall said:

The harbour pilot was still on board and in command-- and I feel very sorry for the poor guy or gal, as they will get thrown under the bus by the media, if not the lawyers...

That is not true. Pilots are never in command of the vessel, they are essentially advisors. The captain is always in command no matter what. It has to be that way. The pilot can not possibly be able to know the intricate details of every ship on the planet, so the captain, familiar with the vessel is always in command, the Pilot simply advises him on local conditions and where to go.

SlamDunk

So, it looks like this falls under the category of Stuff Happens and shame on whoever is responsible for not protecting the bridge against stuff. 

TonKa

The chances of fendering surviving a head-on collision at its most vulnerable point with a ship of that size is next to zero. 

Fenders or not, it wouldn't have made a difference, IMO. That ship chewed through the underwater dolphins like they weren't there. Maybe an artificial island would have survived. Still, engineers would have to have in mind a ship twice the size and 3x the displacement of anything your harbor has seen before your original build or later upgrades to be sure.

SlamDunk

I’ll bet there will be fenders on the new bridge.   They may get destroyed like our cars’ crumple zones but Ill bet the ship would have been slowed down enough to save the bridge.   

Intplm.

@Steamhead

Just listened to the recording of EMS that you posted.

As a former EMS responder, I can't help but notice the level of professionalism offered in this mass casualty
event.
Mutual aid. The coordination of all agencies, and from all departments responding is second to none.
Thanks for posting. They are terrific, on the worst days.