[OffRoadFun]

For those wondering if this is because of outdated bridge design, NYtimes ran a story about how much force (momentum) the ship carried at 7.8knots speed.

It was more than 150 tons of TNT equivalent energy. I doubt any bridge is designed to take that kind of impact even today. It was equivalent to a rocket launch in terms of energy.

In couple of seconds, the ship slowed from 5.6knots to 0 and had a weight of 100k tons.

[Thad E Ginathom]

Originally Posted by arnieshwartz

This article

I should like to read that, but I can't reach the page or the site

[arnieshwartz]

Originally Posted by Thad E Ginathom

I should like to read that, but I can't reach the page or the site

My apologies, no idea what happened to the direct link to that page but the Google AMP one is still loading for me. Please check it out here.

[sagarpadaki]

Originally Posted by Mystic

There are 2 parties to this tragedy. One is the ship itself and a lot of experts have already talked about it. The other party is the bridge which is my interest as a person who has done research in civil engineering. I think we need to learn something from this incident in general across the world.

I do not think any continuous truss bridge can take the huge spike in lateral loading caused by an object weighing thousands of tons with huge momentum hitting it.

From what basic knowledge I have about bridges, they can tolerate lot of vertical loading and are designed with additional factors of safety on the vertical loading front. Remember the Golden Gate bridge sagging when 3 lakh people occupied it. It sagged but it did not buckle under the load!

https://www.sfgate.com/local-donotus...r-13896571.php

[Mystic]

Pls check the animation below. The first point of contact of ship is the concrete pillar. Concrete is good in compression but weak in tensile strength and hence we put steel inside. To make it handle even extreme impacts and natural earthquakes etc , piers are sometimes constructed with prestressed concrete ( Pre-stressed concrete is a form of concrete where initial compression is given in the concrete before applying the external load so that stress from external loads is counteracted in the desired way during the service period. This initial compression is introduced by high-strength steel wire or alloys (called ‘tendons’) located in the concrete section.

I am impressed that the direct hit on the concrete pier without any fenders etc is able to STOP the ship from going any further. My take on this is below:

1. In 1977, the technology for the concrete used in pier construction may not be good enough to resist direct impacts of modern ships. It might have taken an impact of the ships of those days.

2. Even if the bridge is rebuilt today with the same code as in 1977, it might have taken the impact as the concrete is still strong and not deteriorated in corrosive marine environment for 5 decades.

3. Tomorrow, a new bridge would be constructed with 2024 code and what is the guarantee that another ship will not have a direct impact in another 50 years from now with double the size of the biggest container ships of 2024. The bridge MUST take the impact and any reasoning saying that it is the rarest of the rare event is totally unacceptable.

4. Don’t build a bridge again and build an underwater tunnel if we donot have the technology for a direct impact.

5. Just imagine the design of a nuclear reactor dome in which we design prestressed concrete to be of such high strength as lead equivalent concrete that a direct hit by an aeroplane will not have any issues. Now a days we have super sized aircraft’s like A380 and jumbo jets. The nuclear reactor in no circumstances can be compromised for safety even in the scenario of the rarest of the rare situations of aeroplane impact. We all know what happens to a nuclear reactor and the surrounding 100 miles after collapse of the concrete dome.

https://youtu.be/rqqrPPYRg0U?feature=shared

[Thad E Ginathom]

Originally Posted by arnieshwartz

Please check it out here.

Cheers! Although not much there that is not already covered by experience of contributors here and discussed.

[NomadSK]

Few sonar images from the US Navy are out, looks like ship has bottomed out also while hitting the pylon.

This imagery, supplied by the U.S. Navy’s Naval Sea System Command (NAVSEA) Supervisor of Salvage and Diving (SUPSALV), shows the wreckage resting at the bottom of the river where the Francis Scott Key Bridge once stood. These 3D images show the sheer magnitude of the very difficult and challenging salvage operation ahead.

[Ruzinvincible]

Originally Posted by Mystic

I am impressed that the direct hit on the concrete pier without any fenders etc is able to STOP the ship from going any further. My take on this is below:

There are 2 tunnels which cross the bay, no hazmats are allowed to be transported through the tunnels.

The bridge will be replaced by another bridge as it is the only means of transportation of hazmats across the bay.

[Moto_MP]

The video tries to give some insights of possible reasons of power loss which led to collision with the Bridge and ultimate collapse of the Key Bridge in Baltimore, these scenarios are usually always practiced by navigators & engineers in simulators but again what happened in real world will only be clear after the full investigation is out.

https://www.youtube.com/watch?v=jxeKXjDVqMA&t=0s

[Thad E Ginathom]

Originally Posted by Moto_MP

The video tries to give some insights of possible reasons of power loss which led to collision with the Bridge

Thank you! I'll watch that one tomorrow. I just watched this one...

EDIT: ha ha it's the same video!

Yes, very interesting and well presented by a Chief Engineer with a big youtube sideline. I watched a few of his some time ago. Very useful for both the wannabe or armchair sailor

[SR-71]

Close on heels of the Baltimore Key Bridge disaster, another huge cargo ship loses propulsion near New York's Verrazzano bridge. Looks like the tugboats guiding the ship were able to steer it safely without causing any incident until the ship regained propulsion!

[Old_Salt]

This doesn’t look good. Usually during investigations, people speak, unknowingly, of some past instances which may/may not be related to the present incident , but can have serious consequences on the whole case as investigators start connecting dots/theories.


https://amp.theguardian.com/us-news/...-investigation

[BlackBeard]

Originally Posted by Thad E Ginathom

Yes, very interesting and well presented by a Chief Engineer with a big Youtube sideline. I watched a few of his some time ago. Very useful for both the wannabe or armchair sailor

The technical aspects have been explained well.

Originally Posted by Old_Salt

This doesn’t look good. Usually during investigations, people speak, unknowingly, of some past instances which may/may not be related to the present incident , but can have serious consequences on the whole case as investigators start connecting dots/theories.

True that, most landlubbers do not know how a ship is operated (technical, crewing, commercial...etc) hence these off the cuff remarks!

Apparently the FBI has started investigations of criminal negligence i.e if any crew member knew of technical defects beforehand resulting in the accident, so the crew onboard and ships management company are in for thorough scrutiny!

[Old_Salt]

It has been ascertained that there was a power issue(possibly black out) on the ship, before she sailed out.
This is bad news both for owners and crew and if it is proved that the ship was “unseaworthy”, the owners will not be able to limit liability.

https://www.usatoday.com/story/news/...e/73426706007/

[kosjam]

Originally Posted by Old_Salt

It has been ascertained that there was a power issue(possibly black out) on the ship, before she sailed out.
This is bad news both for owners and crew and if it is proved that the ship was “unseaworthy”, the owners will not be able to limit liability.

https://www.usatoday.com/story/news/...e/73426706007/

I don't think it can be called "ascertained", more like it is assumed, basis the above mentioned article. Just because alarms were blaring on some refrigerated containers, doesn't automatically point out to power issues.
There are a myriad of issues that could cause such problems, such as a local breaker tripping, switching off power to some containers to allow for loading/unloading and in general there could be a dozen other reasons for alarms to be blaring.

Now that the immediacy of the accident is gone, everybody is starting the blame game, and unfortunately, the blame will ultimately be passed onto the ship's crew, as it is generally the lowest factor in such cases, and the easiest to make a scapegoat out of.

Lets see what happens in this matter.