Baltimore Bridge

[Terminal_Boy]

Aight who's going to name a bridge that's been engineered to withstand a 200,000 ton cargo ship strike on a support.

Call the new bridge Chuck Norris and nothing will dare hit it again.

 

[Demon]

These ships are not "piloted" they are largely autonomous, the course is plotted and the ship navigates on its own, very little manual navigation is done, even less so on vessels this large.

If the ship lost power multiple times, navigation would have failed or the ability for the ship to correct its course would be why it hit the bridge.

Look at how large its turning circle is to leave the port, your talking almost a kilometre to just turn. So just a few seconds of navigation failure would have been enough considering its heading, speed and the sheer mass of the vessel.

Bow/Stern thrusters are standard these days, and allow much better manoeuvring in port/slow speed.. they can spin on the spot if needed. I don't know in an emergency if they employ rudder/thrusters how quickly they can turn but I would imagine it's a lot better than most people think..

And in terms of control, during pilotage (which this ship was), there is a pilot who overseeing everything.. and using autosteer as an assist is normal, but it's still done under a pilots 'control'.. they have 'manual' control (well it's all control by wire).. so temporary power outages could have had the bow/stern thrusters move that boat sideways fairly quickly, however, from the brief video and my armchair its impossible to say.. hell, the last second power outage might have been them suddenly firing up all (electrically powered) thrusters on full power and overloaded everything..
Even with MASS (Maritime Autonomous Surface Ship) which I worked on proposals 10 years ago (hydraulic thrusters), pilotage is done with a remote 'pilot' who would have to assume control when necessary.

I could hazard a situation to fit the video.. stuck rudder, only realised quite late, then put all thrusters on max to counteract the rudder, it initially arrests rotation, but causes electrical overload, everything goes down and the ship is now in a straight line heading for the bridge support.. i.e. the crew did everything they could, but sadly it all culminated in the wrong outcome.. Or it might have been sheer human incompetence.. most issues tend to be!

 

[Mason-]

Well the bridge stopped it?

So surely something else could stop it sooner.

Guys we've solved it. Just build two other dummy bridges either side of the real bridge.

 

[StriderX]

Guys we've solved it. Just build two other dummy bridges either side of the real bridge.

Well it doesn't matter now does it?

The new bridge will be designed with absorption/deflection in mind.

 

[Mason-]

Well it doesn't matter now does it?

The new bridge will be designed with absorption/deflection in mind.

Was just having a bit of fun

 

[dowie]

You need to know the direction of travel because with that you can calculate the angle of impact.

To deflect an object you must stop its velocity it one direction and then accelerate it in another direction.

We're talking about a barrier, it doesn't actively react or move based on the angle of approaching ships.

You know roughly which way most ships are going to approach in either direction if that's what you're referring to but you don't know it exactly for any given ship nor do you need to, these things already exist and have been built.

 

[Grim5]

According to MAGA voters, if America didn't send old weapons to Ukraine then this Singaporean ship would not have lost power and gone straight into a bridge support

 

[Freakbro]

According to MAGA voters, if America didn't send old weapons to Ukraine then this Singaporean ship would not have lost power and gone straight into a bridge support

Yep, makes sense....

 

[Grim5]

Seen this on the news this morning, crazy how fast that came down. Was speaking with a colleague who is In the region, used a lot for shipping and ports around there

I wouldn't want to be driving over that when it hit

Happens elsewhere too, this bridge one month ago in China suffered a similar fate

 

[Chuk_Chuk]

We're talking about a barrier, it doesn't actively react or move based on the angle of approaching ships.

You know roughly which way most ships are going to approach in either direction if that's what you're referring to but you don't know it exactly for any given ship nor do you need to, these things already exist and have been built.

What are you arguing exactly? Are you downplaying the importance of the impact angle in crash barrier design?

Just want confirm that is what you are saying before I write out a wall of text on why impact angles is a necessary quantity when designing barriers.

 

[dowie]

What are you arguing exactly? Are you downplaying the importance of the impact angle in crash barrier design?

Nope, like I said you already know that roughly and barriers already exist so what exactly is your objection?

For example, you're aware that motorway barriers exist and function well right? You don't need to know the exact angle of approach for every single car that crashes into them in order for that to be true, they're entirely stationary and reactive.

Re: my initial post:

You don't need to stop it you just need to deflect it, various bridges do actually have this sort of protection and in the case of the Baltimore bridge there appear to be some other poles in the water in front of the bridge that are protected, sadly the bridge itself isn't.

Here is a photo:

Those are barriers to protect the poles.

Here is another bridge built to replace a previous one that collapsed after a ship hit it, when it was rebuilt they constructed it to include barriers/circular blocks to deflect ships that might otherwise run into it:

I'm pretty sure I will be able to come back to this thread, once a new bridge has been built in Baltimore, and also show a photo drawing attention to some barriers/blocks added as additional safety features.

edit2 see this CNN article for example:

https://edition.cnn.com/2024/03/27/world/bridge-accident-dangers-baltimore-collapse-intl-hnk

When vessels do strike bridge piers, it can be “catastrophic,” because that’s the weakest point of the bridge, he said.

He pointed to the 1980 collapse of the Sunshine Skyway Bridge in Florida after being hit by a freighter, killing 35 people.

That incident prompted the engineering and transportation community to “really look at how to design piers that can withstand that,” he said.

There are ways to prevent these kinds of disasters – or at least to minimize the damage.

Additional structures like bumpers can be added to bridges, under the water and out of sight, deflecting ships that veer too close, Andrawes said.

They're not 100% guaranteed but the point is it's not some impossible task and solutions do exist and deflecting a ship (ergo slowing it down and changing it's course) is generally going to require less force than trying to bring one to an immediate halt.

 

[Deleted User 234324]

You can be sure that any bridge in the US that has an active shipping lane will also be making sure bridges have the sufficient protection to prevent this sort of thing happening in the future.

 

[Hagar]

You can be sure that any bridge in the US that has an active shipping lane will also be making sure bridges have the sufficient protection to prevent this sort of thing happening in the future.

Not knowing the geology but looking at the importance of this port to the US economy and future development an undersea tunnel either bored or cast sections in a dredged trench would be a good option to consider.

 

[Chuk_Chuk]

Nope, like I said you already know that roughly and barriers already exist so what exactly is your objection?

For example, you're aware that motorway barriers exist and function well right? You don't need to know the exact angle of approach for every single car that crashes into them in order for that to be true, they're entirely stationary and reactive.

Re: my initial post:


Here is a photo:

Those are barriers to protect the poles.

Here is another bridge that collapsed after a ship hit it, when it was rebuilt they constructed it to include barriers/circular blocks to deflect ships that might otherwise run into it:

Motorway barriers are designed with a max impact angle of 20 degrees (some may be more). EN1317-2 is the international standard for certifying crash barriers in the EU. And it has a table of impact angles that you must test at. So Yes impact angle matters in crash barrier design hence it is brought up in certification requirements. No idea where you got the reactive idea from or why you keep bringing it up.

Table from EN1317



The images of the barriers is irrelevant to what I actually said.

But good to know what I said was along the right lines

I think they only thing that could protect the bridge legs is a concrete island surrounding it.

They're not 100% guaranteed but the point is it's not some impossible task and solutions do exist and deflecting a ship (ergo slowing it down and changing it's course) is generally going to require less force than trying to bring one to an immediate halt.

The bolded section is what I originally spoke about. Though the wording has changed. You cannot make this claim without knowing the impact angle. Judging by the fact that when you responded to post #158 You snipped out the bit where I loosely discussed the angle of impact at the effect on the energy required I can only conclude it is because you just don’t understand it. That’s fine nothing wrong with that.

 

[dowie]

The bolded section is what I originally spoke about. Though the wording has changed. You cannot make this claim without knowing the impact angle. Judging by the fact that when you responded to post #158 You snipped out the bit where I loosely discussed the angle of impact at the effect on the energy required I can only conclude it is because you just don’t understand it. That’s fine nothing wrong with that.

This is what you claimed:

I think deflecting would be just as hard if not harder, since you don’t know the direction of travel.

I'd suggest you don't seem to understand if you think that bringing a ship to a halt is going to be harder than deflecting it - that's basic physics, it will require more force to bring to a halt, you know the rough direction of travel too. I don't need to know if it's 5 degrees to 10 degrees or 15 degrees to point out that deflecting it via a side-on impact is going to require less force than say colliding head-on into an object that isn't designed to deflect the ship and trying to bring it fully to a halt.

I've provided examples because this stuff exists, there are barriers built specifically to deflect ships.

Think about what you're saying re: motorway barriers "Motorway barriers are designed with a max impact angle of 20 degrees " - what happens if you crash perpendicular to one (i.e. it's not going to deflect the vehicle rather it's either going to stop it or the vehicle will fly over or pass through... that's going to require a lot more force! Reduce the angle so you're closer to perpendicular to it and there is much less force to absorb and the vehicle is deflated.

In the case of these barriers look at the design of them, they have pointed ends facing up and down the channel ships use or are circular, they want ships to deflect off them, they're not aiming to absorb all the force required to halt a ship, the idea that deflecting a ship would be "just as hard if not harder" than bringing one to a complete halt is false.

 

[Hagar]

It is quite feasible to design dolphin structures that will mitigate to a large extent the 1000tf of impact that vessels of this size will impose at normal expected velocities (not the total weight of the vessel) and significantly slow them down.

 

[Chuk_Chuk]

This is what you claimed:



I'd suggest you don't seem to understand if you think that bringing a ship to a halt is going to be harder than deflecting it - that's basic physics, it will require more force to bring to a halt, you know the rough direction of travel too. I don't need to know if it's 5 degrees to 10 degrees or 15 degrees to point out that deflecting it via a side-on impact is going to require less force than say colliding head-on into an object that isn't designed to deflect the ship and trying to bring it fully to a halt.

I've provided examples because this stuff exists, there are barriers built specifically to deflect ships.

Think about what you're saying re: motorway barriers "Motorway barriers are designed with a max impact angle of 20 degrees " - what happens if you crash perpendicular to one (i.e. it's not going to deflect the vehicle rather it's either going to stop it or the vehicle will fly over or pass through... that's going to require a lot more force! Reduce the angle so you're closer to perpendicular to it and there is much less force to absorb and the vehicle is deflated.

In the case of these barriers look at the design of them, they have pointed ends facing up and down the channel ships use or are circular, they want ships to deflect off them, they're not aiming to absorb all the force required to halt a ship, the idea that deflecting a ship would be "just as hard if not harder" than bringing one to a complete halt is false.

So we’ve gone from impact angle and direction of travel doesn’t matter to it does matter as long as it is a shallow angle. So we’ve made progress. You did actually understand my point. That’s good.

You’ve also repeated what I wrote in post 158. So I’m glad that you were paying attention.

 

[dowie]

So we’ve gone from impact angle and direction of travel doesn’t matter to it does matter as long as it is a shallow angle. So we’ve made progress. You did actually understand my point. That’s good.

No, I think you weren't paying attention in the first place, again we're talking about ships approaching a bridge and the point being that you can deflect them rather stop them!

You don't need to know the direction of travel (though you'd have a reasonable idea from both directions) it's still easier (requires less force) than stopping it.

Why do you think the barriers take the shape they do?

This is false:

I think deflecting would be just as hard if not harder, since you don’t know the direction of travel.

On the left hand side you need to handle much more force to bring the ship or boat to a complete halt, on the right-hand side the ship still maintains some momentum and is deflected, that inherently requires less force.

 

[GGizmo]

I'm surprised the entire bridge collapsed. I thought it would have stopped at the other supports.

Also was there any cushions at the bridge foundations against accidental ship crashes?

 

[cu3ed]

Isn't the fact the multi-storey high overhang to the front the problem?..Seems the bow is fine its the mammoth front holding containers is what misses pretty much any "barrier" that would hit first.