Bridge drawings as security sensitive information?

[HgTX]

Has anyone run into having your bridge plans and shop drawings declared to be SSI?

Considering that it doesn't take a whole lot of mechanical aptitude to eyeball a bridge, no plans in hand whatsoever, and determine what areas one would need to take out to bring down the structure, this notion is pretty ludicrous.

But that's not a decision most of us here get to make.

So...have you run into this? How does control of SSI work in a fabrication environment with dozens of workers, multiple customers, etc.? Or even an erection environment where it is just the one project but still dozens of workers and probably several different business and government entities?

Hg

Eng-Tips policies: faq731-376

 

[MiketheEngineer]

Doing some work for an addition to a major metro airport. VERY tight control on drawings....Not even supposed to mention the name of the airport. Had to sign all kinds of agreements. What amazes me is that the plans are on the Net and not too hard to get to?? Go figure....

If you have a thousand pounds of TNT - you could probably take out any bridge... BUT if you know how it was put together - maybe a pound or two would be enough.

During WWII - a British or US army unit lost much of their TNT. They were trying to hold off the Japs by blowing their bridges. Some ingenious guy kind of invented the "shaped" charge on the spot and they were able to do the work with about 10% of the TNT thought to be required.

Get used to it - it is a coming thing...

 

[bridgebuster]

A few years back I had a cut & cover tunnel project, which had to be bomb proof. The project was eventually cancelled but when it was active, everyone had to sign confidentiality agreements; drawings couldn't be released without the owner's approval; design criteria could not be discussed in public; the ususal.


When I was in college in the 70's my structursl snslysis professor gave a lecture on the World Trade Center design. He said all the strength is in the perimeter. In 1993 after the first WTC attack I thought to myself, those guys weren't paying attention in class that day becase they put the truck bomb in the middle of the footprint. Sadly, the next group of terrorists were paying attention in class that day.

 

[Bobber1]

When my wife and I lived in New York City, we used to love walking the bridges. Our favorite was the George Washington Bridge in upper Manhatten. On the west side of the bridge, there was a small concrete building on each side of the outer bridge deck. Being curious, we tried the door and it was unlocked! Of course we went in and found a staircase that went down to sort of a gallery. And we discovered that this is where the suspension cables splayed out and entered their individual anchorages to the rock at the abutment. A couple of thermite grenades could have brought the entire bridge down.

I suppose they lock the doors now.

 

[MiketheEngineer]

Most of our society is pretty open and I hope we can keep it that way. Example - just how hard is it to scale a 10 or 12 foot chain link fence or go under it or even through it. Yet many of our supposedly "guarded" facilities employ just that!! You may play hell getting through the front door - but just go around the corner and it is a piece of cake!! Been there - done that.

 

[csd72]

I would think this would be reasonable for highly strategic and iconic bridges such as the golden gate e.tc. but definately over the top for 99% of bridges.

 

[yakpol]

Back in the USSR we would provide a special pocket for TNT in the most volnurable location of a bridge. During WWII Soviet troups failed to destroy bridges over major rivers during initial retreat...

 

[CONEJO]

Here in Minnnesota, you can access almost all bridge plans online, since they "belong to tha people". Almost, all except for the big bridges crossing the Mississippi River. But y'all are correct: if you are a structural, you can figure out right away the best place to destroy a bridge. If you are not, you get a structural to tell you that.

 

[Duwe6]

HgTX, you handle the drawings like the Air Force does. The design criteria is very tightly controlled, and you are expected to lock the dwgs & spec's up when you leave the room. This especially includes the major drawings.

Then, using the tightly controlled drawings, you have the bridge "detailed".

The Detail drawings are broken down to "piece" drawings, and those are issued - openly - to the various fabricators. Without a Design, or Erection, drawing the individual "piece" drawings are meaningless. And to be even more devious, add in a few 'dummy' pieces to really mix up anyone trying to establish what the final design will look like.

 

[dik]

Not a really great idea...

Most engineers can look at a structure and know where the 'weak link' is or where damage would be greatest with a minimal charge.

By vetting contractors and restricting the documents, you are restricting youself to 10% of the construction firms with a huge increase in cost.

Dik