Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Pittsburgh bridge collapse

Pittsburgh bridge collapse

RE: Pittsburgh bridge collapse

Too much reliance on weathering steel, too little attention to maintenance.

RE: Pittsburgh bridge collapse

That's a bit unfair, even from the news clip.

More like No one looked at or did anything about the recommendations from the inspection reports for 10 years....

So presumably this weathering steel doesn't like being submerged in water / kept constantly damp or with quite anaerobic conditions?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

RE: Pittsburgh bridge collapse

How is it unfair? I didn't fault the inspection, but rather the maintenance... which follows inspection. You are correct about weathering steel. And a big part of the lack of maintenance, also probably the design, was failure to ensure adequate drainage.

RE: Pittsburgh bridge collapse

Yup, Corten needs wet/dry cycles to prevent ongoing corrosion. It is the same reason why Corten is not a good choice in high chloride environments. The salt keeps the surface continuously damp and corrosion keeps getting deeper.

RE: Pittsburgh bridge collapse

I meant a bit unfair to ascribe to the NTSB a simplistic comment like that.

Heres the main NTSB page with downloads


Attached is the summary report issued 3rd May this year.

This bridge started seriously rusting from when it was built 17 years ago....

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

RE: Pittsburgh bridge collapse


Quote (Littleinch)

I meant a bit unfair to ascribe to the NTSB a simplistic comment like that.

Sorry, I paraphrased.

Here is the non-simplistic full quote.

Quote (NTSB Report)

However, as with any other steel, failure to properly maintain uncoated weathering steel can lead to corrosion damage,deterioration, and section loss in critical components, thus reducing the safety and service life of the bridge.

RE: Pittsburgh bridge collapse

Quote (LittleInch)

I meant a bit unfair to ascribe to the NTSB a simplistic comment like that.

I took it more as a jab at the owners/maintainers of these bridges. The fact that the NTSB would feel the need to make such a comment should be insulting to those that should know better.

RE: Pittsburgh bridge collapse

The comment was harsh... but, maybe in order. There may be 'hundreds' of bridges in the same condition that need immediate remedy. The full context of the quote was not available. This is a problem with many newscasters... they often don't ask the right questions and often 'get handed scripts'.

About a decade back, I repaired the hydraulic ram guiderails for a local floodway. The S24 beams were badly corroded. The problem was that they were Corten, in a wet environment. It was made worse because the wet environment was 'flowing' with particulate. It was a bad choice of material, but had been used because it was a relatively new product (at the time of construction) and seemed like an excellent material (I suspect, I didn't look into why it was selected.)... like a poor man's stainless.

So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates


RE: Pittsburgh bridge collapse

Here's an obvious solution:


Somebody should review the inspection reports, what a novel idea!!!!

We try to teach our technical staff that what they put in their field reports really matters. Maybe it doesn't, because nobody is reading them????

RE: Pittsburgh bridge collapse

"NTSB investigators found other Pennsylvania bridges with similar issues. The agency asked the Federal Highway Administration to develop a process for bridge owners to perform follow-up actions on bridges with uncoated weathering steel components."


Bridge owners, or their representatives, shall read and act on bridge inspection reports.

Anyone know where I can send a bill for the creation of this extensive directive? I'd surely like a few million dollars in my account.


RE: Pittsburgh bridge collapse

Quote (Proposed directive (spsalso))

Bridge owners, or their representatives, shall read and act on bridge inspection reports.

Quote (https://www.fhwa.dot.gov/bridge/nbis.cfm)

The National Bridge Inspection Standards (NBIS) are the standards established over the safety inspections of highway bridges on public roads throughout the United States. The U.S. Congress originally required the Secretary of Transportation to establish these standards in 1968. The original NBIS was published in 1971, creating our Nation's first nationally coordinated bridge inspection program.

Currently the requirement to act on inspection findings seems a bit weak. There could be implementing regulations that are more forceful.

Reference https://www.congress.gov/112/plaws/publ141/PLAW-11...

RE: Pittsburgh bridge collapse

Blaming weathering steel is a bit silly. This was a steel K-frame bridge and the web of some of the legs was so rusted out there were holes in it. That kind of damage doesn't happen overnight and was noted on the inspection reports. What kind of owner turns a blind eye to that?

RE: Pittsburgh bridge collapse

I don't think the blame is on the weathering steel, rather on the lack of knowledge of same. It goes to show you can't pick and choose your infrastructure or those you leave in charge on simplistic stereotypes of convenience. Ignorance bites.

RE: Pittsburgh bridge collapse


You forgot one part of your solution. They must also understand what they are reading.

I'll settle for 10% of your billing for creation of the directive, as a review fee.

RE: Pittsburgh bridge collapse

Does anyone see humor in the hand holding explanation of how the legs rotted out from under the structure? ... and it was documented over a span of a dozen years?

RE: Pittsburgh bridge collapse

The city of Pittsburgh was owner of the failed bridge.

The city of Pittsburgh was aware, or should have been aware, of the condition of the bridge, and that it needed repair.

The city of Pittsburgh took no action to do those needed repairs.

As a result, the bridge failed and people were hurt.

There is a new bridge. The city of Pittsburgh did not pay for the replacement. We did.

A person could wonder why we should pay for Pittsburgh's negligence.

If I own a structure that I know needs repair, and it fails, will the Federal government replace MY structure?

Can't see why not.

I also wonder about criminal charges. "Theft of services" comes to mind, since Pittsburgh had employees who were charged with maintenance, but did not do it.


Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login


Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close