What are these thingies on suspension bridge cables?

AI Thread Summary
The discussion centers around the identification and purpose of devices clamped to bridge cables, specifically Stockbridge dampers. These dampers, a type of tuned mass damper, are designed to suppress vibrations in cables, preventing structural damage and fatigue. They are also applicable to power lines and other cable-based structures. The conversation touches on the history of Stockbridge dampers, invented in the 1920s by George H. Stockbridge, who patented various methods for damping vibrations. Participants express appreciation for the photo shared and engage in light-hearted banter about the topic, while also speculating on other elements in the image, such as a red shadow, which is identified as a truck. Overall, the thread combines technical insights with casual conversation, highlighting the aesthetic and engineering marvel of bridges.
matthyaouw
Gold Member
Messages
1,125
Reaction score
5
Since I know there are a lot of engineer-types in these parts, maybe someone knows what these things are.

bridgee.jpg


Ther's a thing clamped high up on to the cable on the right, and every other cable on the bridge but I can't for the life of me work out what they are there for. any insight?
 
Physics news on Phys.org
I haven't taken any engineering courses in my studies yet, but my guess is some sort of balance or stabilization mechanism? I'd imagine the cables could get pretty shifty in heavy winds, waves, etc. I'd guess that those "things" can be adjusted to take the wobble out of the cables?

Again, I'm no engineer; just throwin' it out there.
 
Those are Stockbridge dampers, a type of tuned mass damper. They're used to suppress vibrations in the cable and thus prevent structural damage and fatigue in the bridge. They're also used on some power lines and other cable-based structures.
 
What's that red shadow for? A truck? Anyways, cool pic!

Oh for that thingy, I don't know but my guess would be to absorb vibrations caused by Earthquakes, if any by contacting those cables to a free ended solid material!


P.S. you beat me Vasara, damn it! I'm slow
 
Vasara said:
Those are Stockbridge dampers, a type of tuned mass damper. They're used to suppress vibrations in the cable and thus prevent structural damage and fatigue in the bridge. They're also used on some power lines and other cable-based structures.

Wonderful, thanks!
:smile:
 
Another great picture matthyaouw!
 
Those are nice marbles, we put on bridges to make them look neat :-p
 
Love the photo, and I got to learn something new. Now how can I work "Stockbridge dampers" into a conversation?
 
hypatia said:
Love the photo, and I got to learn something new. Now how can I work "Stockbridge dampers" into a conversation?

Agreed :biggrin:, I wouldn't bring them up in conversation though, it won't resonate well.
 
  • #10
Cyrus said:
Agreed :biggrin:, I wouldn't bring them up in conversation though, it won't resonate well.

bahaha, that made me giggle. :smile:
 
  • #11
Very interesting:

The Stockbridge damper was invented in the 1920s by George H. Stockbridge, who was at the time working as an engineer for Southern California Edison. Stockbridge obtained US patent 1675391 on 3 July 1928 for a "vibration damper".[6] His patent described three means of damping vibrations on lines: a sack of metal punchings tied to the line; a short length of cable clamped parallel to the main cable; and a short (30 in, 75 cm) cable with a concrete mass fixed at each end.[6] It would be this last device that developed into the widely used Stockbridge damper.

http://en.wikipedia.org/wiki/Stockbridge_damper
 
  • #12
Cyrus said:
Agreed :biggrin:, I wouldn't bring them up in conversation though, it won't resonate well.

:smile: GROAN! (I've never been able to resist laughing at groaners. ...and since I've seen Danger back around...not THAT kind of groaner. )
 
  • #13
Sorry, I didn't mean to string you all along.
 
  • #14
drizzle said:
What's that red shadow for?

Looks like matthyaouw is going to keep us in suspense.
 
  • #15
Moonbear said:
...and since I've seen Danger back around...

Did I hear my name taken in vain?

Cyrus said:
it won't resonate well.
That was horribly good. It will echo in my mind for years...
 
  • #16
lisab said:
Looks like matthyaouw is going to keep us in suspense.

HIyoooooooooo!
 
  • #17
Wow, I learn something new every day(no surprise)
 
  • #18
Yeah Drizzle, it's a truck. Sorry to keep you hanging around!
I feel bad that's the best I could come up with...

Glad people like the photo :smile:
 
  • #19
Humber?

Last time I went, I walked the length of it. It was a windy day and you could see the expansion joints taking out a couple of inches every few seconds.

It's been my profile picture for ages!
 
  • #20
brewnog said:
Humber?

Last time I went, I walked the length of it. It was a windy day and you could see the expansion joints taking out a couple of inches every few seconds.

It's been my profile picture for ages!

I love standing with one foot either side of the joint. It's a really unusual feeling :biggrin:
Magnificent piece of construction it is. Seeing it so often there's times I hardly notice it but every now and then I just think 'holy crap, that's amazing'
 
Back
Top