A power line heads underground

[Doug Kerr]

This was just a grab shot I took while walking back to my car from a shoot yesterday morning.

Douglas A. Kerr: Distribution primary heads underground​

This is ex camera except for downsizing for display and a little attendant sharpening.

No, I do not yet understand all the details we see in the shot!

Best regards,

Doug

 

[Asher Kelman]

This was just a grab shot I took while walking back to my car from a shoot yesterday morning.

Douglas A. Kerr: Distribution secondary heads underground​

This is ex camera except for downsizing for display and a little attendant sharpening.

No, I do not yet understand all the details we see in the shot!

Doug,

Taken at face value, this seems like a metaphorical comment on out life tied to wires and cables. A post modern industrial Roman punishment.

Asher

 

[Doug Kerr]

Hi, Asher,

Taken at face value, this seems like a metaphorical comment on out life tied to wires and cables. A post modern industrial Roman punishment.

Well said!

Best regards,

Doug

 

[Doug Kerr]

I will comment on one thing we see here that is common in pole line construction, the loop nuts (sometimes, loopnuts) seen (3 of them) on the near face of the crossarm.

These are sometimes called eye nuts (or eyenuts), but that term is more properly reserved for a similar fitting with a more-nearly round "eye".​

Often these are used to attach a fitting on one side of a pole or crossarm such that a small guy wire or such can be connected to the far side, but we don't see them here in that role.

Here, they are just nuts, but can be tightened with a rod (in a pinch, a large screwdriver), easier to do (especially when one is aloft in a bucket) than using any kind of actual wrench.

The elongated loop prevents the rod from getting pinched in the eye as its angle might be changed while tightening.

The item goes way back, and has well served for many years.

Best regards,

Doug

 

[Tom Robbins]

Isn't it amazing how such fine detail can be hidden in plain sight?

Thanks for pointing out the loop nuts, Doug. I imagine every component of this assembly has an interesting history of development and a long list of people associated with each.

Do you know what is often wrapped around individual power conductors in a loose spiral? From the ground they look a bit like snakes looped around the line. I've always figured that they serve to dampen any resonance the conductor might have to passing wind, but this is just guess. They appear to be made of some sort of heavy resin, usually grey in color and close to an inch thick.

 

[Doug Kerr]

Hi, Tom,

Isn't it amazing how such fine detail can be hidden in plain sight?

Indeed.

Thanks for pointing out the loop nuts, Doug. I imagine every component of this assembly has an interesting history of development and a long list of people associated with each.

There must be a million great stories. And of course that is really not my field, so I don't know a lot of them!

Do you know what is often wrapped around individual power conductors in a loose spiral? From the ground they look a bit like snakes looped around the line. I've always figured that they serve to dampen any resonance the conductor might have to passing wind, but this is just guess..[/QUOTE]

Yes, you are quite right. There are many different approaches to that problem, of which you mention one.

In other cases, small discrete units are attached to the conductor periodically. They have a piston in a chamber filled with oil (a "dashpot") which dissipates a little energy on each cycle of movement of the conductor. (We need not dissipate a lot of energy on each cycle - the objective is just that the total amount if energy not build steadily, by virtue of the resonance of the conductor, until the amplitude of vibration of the conductor becomes undesirably great.)

There is also a system (mostly used on telephone and video cables) comprising aluminum "wings" (they look like the wings of origami cranes). I don't even know the theory of their operation - perhaps they are just dampers with air as their "working fluid".

Best regards,

Doug

 

[Tom Robbins]

Thanks for the explanation, Doug. I've seen those little origami cranes (good description) from time to time.

 

[Doug Kerr]

Hi, Tom,

Thanks for the explanation, Doug. I've seen those little origami cranes (good description) from time to time.

Here is a feeble poop sheet for one of them:

http://www.google.com/url?sa=t&rct=...3v56pSuCiIfiR0sy__X9UNw&bvm=bv.70138588,d.aWw

I'm not sure yet of the principle - probably just as they move up and down in the air there is resistance, which absorbs some of the energy.

Best regards,

Doug

 

[Doug Kerr]

Hi, Tom,

This may be the type of damper you mentioned (perhaps a different manifestation for telecom cables):

http://www.google.com/url?sa=t&rct=...dr3po6698eTJCFgwFkTZtmA&bvm=bv.70138588,d.aWw

This company (Preformed Line Products) is also the original manufacturer of the spiral grip termination for guy wires and other cables such as we see in my picture on the guy wire that comes down from just below the crossarm.

A couple of my college chums knew the family that founded that company (the Petersons).

Best regards,

Doug

 

[Tom Robbins]

Hi Doug,

Bingo on both counts! Thanks for the scoop, as usual. I've got book cases scattered around the house that contain—besides boring old books—some curious rocks, old railroad spikes, glass ceramic and rubber insulators, and bits of broken PVC spiral vibration damper. I'll no longer be shrugging my shoulders when asked about those bits of curly snake.