Baltimore Bridge collapse

[unclebilly]

Originally Posted by flatbutt

what is that?

Hella big pothole?

[TimT]

That pic is looking down on one of the destroyed piers

Imagine looking at this pier from above...

[masraum]

Originally Posted by TimT

No way is something like that going to happen here...

Depending on the design of the replacement...i.e. steel truss, precast concrete, cable stayed, simply procuring and fabricating the the various elements takes time.. Evn though this project will definately be "accelerated"

Steel mills don't have stock of millions of pounds of various shapes "in-stock", with a project like this pressure will be put on the mills to "cut the line" and roll the required shapes for this bridge ahead of current orders..

Ordering bulk steels shapes usually takes months.. and certain shapes are not even rolled in the States..

Many of the jobs I've worked on have a Buy American Clause in the specs.. One job in particular the contactors detailer specified a shape that was not rolled in the States... an exception was made because of time constraints and redesign costs.. The shapes were sourced from a mill in Germany

Just some pics from the Manual of Steel Construction.. I have the Silver more recent addition somewhere..

The designer has to strike a balance of the lightest member, the most economical construction method, availability, domesticity.

Mill don't have stock of all the various weights of shapes.. Contractor need to order the shapes, then wait in line for the mills to produce the members required.. The the raw product is shipped to a fabricator to cut and drill the pieces.. mills sometimes only cut certain lengths.. So if you need a 46' member, and the mill only supplies 50 footers... you get 4' of waste on every piece...

What goes on behind the scenes to build infrastructure is really remarkable...

Originally Posted by unclebilly

Don't be so sure... I've been the professional engineer that did the failure analysis on fractured and blown high pressure lines (rated to 15,000 psi) several times. And I've written peer reviewed SPE papers on the matter, one made the JPT.

We also deal with sour gas pipelines here - not something you have much of in the US. When H2S leaks, people die. Failures involving H2S usually involve HIC but thats a different story.

Thanks for posting folks. It's great to have knowledgeable information sources available!

[pmax]

Originally Posted by flatbutt

what is that?

Originally Posted by unclebilly

Hella big pothole?

[unclebilly]

Originally Posted by masraum

Thanks for posting folks. It's great to have knowledgeable information sources available!

This is Tim’s wheelhouse. It’s awesome having his expertise chime in on this bridge disaster.

[HobieMarty]

https://youtu.be/rWQ-PQddGS4?si=37s2KiKdvLZs4xFj

Sent from my SM-S916U using Tapatalk

[HobieMarty]

https://youtu.be/jxeKXjDVqMA?si=FgEMlRpaLcCUycvz

Sent from my SM-S916U using Tapatalk

[HobieMarty]

https://youtu.be/JElUSyNIJGo?si=JZqzC30j_WIgCKqE

Sent from my SM-S916U using Tapatalk

[TimT]

I wonder how frequently these ships experience loss of power/steerage..

This ship had three tugs assisting it, but required three more tugs to bring it under control


https://nypost.com/2024/04/07/us-news/massive-container-ship-loses-power-near-nycs-verrazzano-bridge-days-after-baltimore-key-bridge-disaster/

[A930Rocket]

Good question on loss of propulsion frequency. What would’ve happened if there was not an extra three tugs or the three tugs did not make it in time?

I see the ship left for Charleston SC after repairs. Note to self, stay off bridges for the next few days!

[unclebilly]

Originally Posted by A930Rocket

Good question on loss of propulsion frequency. What would’ve happened if there was not an extra three tugs or the three tugs did not make it in time?

I see the ship left for Charleston SC after repairs. Note to self, stay off bridges for the next few days!

Craig’s post above is thought provoking…

Seems like a tremendous way to destroy infrastructure is to disable the control of a large ship just before it passes under a bridge.

[TimT]

I forgot to mention, the Verrazzano has a robust protection system around the towers.. basically tons of riprap around the tower base/pier caps..

Though I wonder if even that is enough...The impact energy of a 100,000 ton ship going 8 knots hitting an object at 90 deg is like a really big hard to comprehend number

[TimT]

Expanding on why this will not be an easy fix...

A few other structures were mentioned that were put back in service "ahead of time"

LA, Philly, and Atlanta? were mentioned.. those are all small simple span bridges..

Access is easy, you can drive right up with 10 wheelers and loaders and start removal of the rubble... Its easy to erect new steel, easy to support the structure while it being built..

This is cribbing and a jacking frame being built so this structure (and approach ramp to the GW bridge) Highbridge in the background.. can be jacked up and the old rocker bearings removed, and new MR bearings installed..



And simply scale.. The span of they Key bridge is, just guessing 3, 500 foot spans to be replaced, and a portion of one of the approaches that was also damaged..

I would imagine they are going to use the remaining approaches to build from..

In these pics are deck panels for the 59th St bridge.. a few months production





Con't

[TimT]

A lot goes on behind the curtain.. that guy is mag particle testing welds on a section cut from a sacrificial deck panel.. And if you think that beam looks curved, it is...the beams are rolled and camber is put into the beam/panel.. so when it is in place its flat with no preload...




We all love tools... bad ass table saw



This is a pic from one of the first jobs where I was a chief.. superstructure steel..

Willy B .. replacement of outer roadway floor beams and deck, demolition and replacement of existing approaches.. and a full repaint..




We had 6 Manitowoc crawlers, that big barge mounted crane... a gantry to deliver the panels.. The pic is crappy on the main span much of the outer roadway is already removed... on the nearest span you see... lead remediation is taking place prior to demo.. and the near tower is surrounded by a scaffold system.. waiting for the negative pressure containment system.. All while maintaining pedestrian, train, auto and ship traffic..

[A930Rocket]

Originally Posted by TimT

I forgot to mention, the Verrazzano has a robust protection system around the towers.. basically tons of riprap around the tower base/pier caps..

Though I wonder if even that is enough...The impact energy of a 100,000 ton ship going 8 knots hitting an object at 90 deg is like a really big hard to comprehend number

When they built the Ravanel bridge in Charleston, they have big islands around each tower base. But as you mentioned, is that enough?

[A930Rocket]

Thank you for the pictures and information, Tim. Keep it coming!

[Alan A]

Originally Posted by TimT

And if you think that beam looks curved, it is...the beams are rolled and camber is put into the beam/panel.. so when it is in place its flat

I’m calling BS. We all know the bridges are like that because the tire manufacturers kick back 25% of the replacement costs from every blowout in NYC…

[Sooner or later]

Great info, Tim. Thanks!

[pmax]

[unclebilly]

so... nearly a month later.

https://www.cbsnews.com/baltimore/news/salvage-recovery-key-bridge-collapse-baltimore-one-month/

I wonder what design work is underway to replace the bridge and what that timeline could look like. I get that they are still cleaning up but I dont understand why design and procurement couldn't be a parallel path to cleanup (hopefully they are).

There are 3 temporary channels open now and it sounds like the latest one may be able to support some cargo ship traffic. Is this big enough? I have no idea.

The new temporary path, with a controlling depth of 20 feet (6.1 meters), a horizontal clearance of 300 feet (91.4 meters) and a vertical clearance of 135 feet (41.2 meters), allows a greater variety of vessels to access the port while crews work to reopen the main channel, Coast Guard and port Capt. David O’Connell said in a news release.

https://toronto.citynews.ca/2024/04/20/third-temporary-channel-opens-for-vessels-to-baltimore-port-after-bridge-collapse/