Soldato
Absolutely, it'll be a $1 billion+ and by the time it's done it'll have doubled or tripled in cost.
Baltimore Bridge
- Thread starter imtoooldforthis
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Absolutely, it'll be a $1 billion+ and by the time it's done it'll have doubled or tripled in cost.
Soldato
So many expert structural engineers on this thread.....
oh and the MV Dali was fully loaded with over 9000 containers (over 100,000 tons) and was leaving the Port to head to Sri Lanka; energy of the impact is a straightforward mass x velocity
oh and the MV Dali was fully loaded with over 9000 containers (over 100,000 tons) and was leaving the Port to head to Sri Lanka; energy of the impact is a straightforward mass x velocity
Associate
How do you get that like? Its capacity is over 9000 TEU’s. Most of them would have been forty foot containers so that’s not 9000 containers. The DWT figure is what it can carry and it is highly unlikely to be carrying its maximum tonnage.
Soldato
Call the new bridge Chuck Norris and nothing will dare hit it again.
Soldato
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!
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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.
Was just having a bit of fun
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.
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Yep, makes sense....
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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.
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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 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:
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edition.cnn.com
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.
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Soldato
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.
Soldato
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.
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.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:
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
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'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.
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Soldato
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.