Flyover Disaster

[JimB]

I had repaired a temperature controller for a furnace, what the furnace was used for I cannot remember, but it was not all that big about 1.5 metres on all dimensions from 40 years memory.

Anyway this furnace was needed ASAP so I took the controller along to where the furnace was located.
Now, demarcation and unions being what they were, I could not install this controller onto the furnace, an electrician had to do that because it was "an electricians job".
So I hung around for a few minutes until he arrived.
The guy only had one arm, he was a mono-dexter!
So for two minutes I became the shipyard electricians mate, holding up this controller, while he quite deftly with his one hand inserted the wires (all five or six of them) into the terminal block and tightened them up with his screwdriver.
Not one of my finest moments.

JimB

 

[bountyhunter]

Every government contract typically goes to the lowest bidder. Remember, the space program vehicles was low bidders as well.



In their report to the FWA adminstrator, in March of 1941, the Board of Engineers first conclusion was...



Of course, that could be a CYA move on their part.

There were Engineers involved with the project from all the entities associated with the funding of the project. There was silence from alot of engineers, probably due to the reputation of the design engineers.

Also in the report, I saw this tidbit ....



Does the name of the Engineer sound familiar?

There were more engineers involved with this project then you can shake a stick at ... and yet, it failed.

If you want to assign culpability, the list is large.

Actually, the list of responsibility is very small. The people at the top in charge of building the bridge are responsible. If they want the authority they also take the responsibility. You know, I would be more sympathetic if the failure mode had been unforseen like a sudden fracture of a truss or some kind of catstrophic break.... but this was so stupid they could have put it on Seinfeld:

The original designer says we need 25 foot long piers for stability.... the next guy says: :
"I'll save you money. Lets make them eight feet long." Of course the decision makers go with whatevers cheap.

And all the time the bridge is being built, THE BRIDGE SWAYS SO MUCH THAT THE PEOPLE BUILDING IT CALL IT GALLOPING GERTIE.

This is a comedy of idiocy and it underscores how nobody will step up and say: "Hey guys.... we got a problem"

As for what you quoted:

"The Tacoma Narrows Bridge was well designed and built to resist safely all static forces , including wind, usually considered in the design of similar structures. Its failure resulted from excessive oscillations caused by wind action."

I appreciate it because it was hilarious. The conclusions are that it was well designed (even though it fell down almost immediately) it was built to resist all static forces including wind, but fell down as a result of wind.

Somebody wrote that with a straight face?

Funny thing is, the 30 years I worked as an engineer, I was held responsible for my work. I wonder why it is people who (mis)manage projects, don't use sound judgement and take risks to cut costs always get to spread the blame like s 50 pound bag of fertilizer.

This whole thing is analogous to if Boeing had developed the new 777 Dreamliner and on its test flight the wings flapped like a seagull and somebody said:

"Don't worry. It's well designed and it can withstand the effects of that."

Really? A bridge with a deck that flaps like a belly dancer doesn't ring the alarm bell for anybody? Idiots.

 

[JimB]

if Boeing had developed the new 777 Dreamliner

Sorry for being picky but the "Dreamliner" is actually numbered as the Boeing 787.

JimB

 

[JoeJester]

Somebody wrote that with a straight face?

They sure did. Three engineers wrote that report.

The report to the FWA administrator lists all the engineers involved. Are you saying that all were incompetent, even the one who did the original design? What I am getting from that report that the State's Engineer, supervising the work, (the original designer whose design lost), was either too political or didn't have the nads to stop the work when they first noticed the galloping. I've assumed you perused that 1941 report to the administrator, if only for your amusement.

I wouldn't praise any of those engineers who were either the design team, the state engineer supervising the work, or the college professor who did the scaled simulations, after all, the college professor was right there up to the end, as one of the last people on the bridge.

Like all government projects, this one had "on site" changes to the contracted plan. There were three noted in the report. Eldridge is listed as the Tacoma Narrows Bridge Engineer, who the other articles I've read called the State's Engineer. I wonder who ordered the "changes" to the contracted plan? One of the notable changes was:

The floor system of the bridge was redesigned with a saving in both structural and reinforcing steel.

It's tough to argue about a design without noting the on site changes to the contracted design.

I'm sure one could argue the merits of the whole story, once the whole story is available. I don't know if there is an earlier report than the report to the FWA administrator which was dated March 28, 1941. Hopefully subsequent reports covered all aspects of the design, including the changes made during construction.

Each failure of a suspension bridge brought new knowledge. Why should this one be different?

As far as engineer's being held accountable and responsible, I agree. Were they in this case? No.

If someone veered from your design during the construction phase, you would be shouting loud and long that those changes could have been the mitigating factors in the failure of your design. This case would have been no different.

 

[KeepItSimpleStupid]

You know how they pour isolated concrete pads where I am? they poor the entire pad; break up the isolated area and pour it.

The one that bothers me to no end is I was aware of the plans for our building being modified to make a spacial lab where the doors had to open out, but not in the path of those in the hallways. I noticed that they were building it wrong and told my "boss", the micromanager. He asked me what I was doing in there? it's like WTF, I just saved you lots of time and money and I don't even get a thank you?

It did raise the idea of doing an inspection and we found a few things. The most unique was a handle for a duct valve was plastered into the wall so it was not movable.

Then later in the project I had found out while talking to the manufacturer that the gas detector we were re-installing with upgrades would be obsolete in less than 6 months. I got an earful for that "Warning". Somehow, "the micromanager" thought that I was insisting that they replace it now, which wasn't my intention.

In another case, same project, they just told "the electrician" to move "this stuff" "over there". It was the gas alarm stuff. The new location had to support 4 extra alarm channels and a number of strobes and two extra safety stops. The number one issue was the 3A power supply and the fact that the circuits needed to be class II.

It worked out OK, but the only real issue was I had to build on the fly and thus there was no documentation except scribbles before I left. The electrician was super and did what i asked. I wanted the cables to be individually strain relieved rather than bundled and filled with firestop. I got that. I also got a separate conduit for the Hydrogen sensors and another for the alarm signals.

I made a requirement that any communication from panels in other rooms must be with contact closures only. I would not allow a lamp to be powered from a panel 60 feet away.
there's no way I want to troubleshoot a short that's 60 foot away. That's why. The second reason is that the stuff I had to stay away from was easily demarked and if I cut power to replace a light bulb on the panel, I didn't have to know that I really had to turn off the panel 60 feet away. I did learn something, basically from the phone company that it makes a lot of sense to have an input/output block and then cross connect.

24 VDC might have been better than 24 VAC and maybe I should have designed in "monitored contacts" back in 1980 for the other part of the system. The new stuff was 24 VDC because it had to be.

Bottom line. I got screwed in the end for speaking up.

 

[JoeJester]

KISS,

We all raised alarms only to be ignored by superiors in the food chain. This is nothing new. What I am against is placing blame on one person when there were many who "could have" or "should have" spoken kept silent or were ignored, yet received accolades when they were involved in the whole disastrous event.

I've had superiors state that we didn't follow the NFPA codes because we were the military when I mentioned that in a class I was teaching. His mistake was telling someone with a big mouth and who didn't give a rats ass on what was on his collar, so I embarrassed him in the class by telling him to read the references cited in the manual.

All I am saying if you want to assign culpability in the discussed incident, the list of engineers is a long one. Don't hail the designer who lost the bid and was the on site engineer for the state while castrating the original designer who may or not have been consulted on the changes. Then consider three respected engineers as a joke for their statements in their report to the government. I'm sure the original designer had a harder time obtaining work after that incident.

There is more to the story than the written report, the subsequent articles, and all the studies done. Not everything was revealed. All the construction workers are dead by now and their personal recollections died with them.

Today's knowledge was built on yesteryear's knowledge, like it has been since mankind learned to communicate and invent.