The Universe of Discourse

Sat, 14 Apr 2018

Colored blobs on electric wires

The high-voltage power lines run along the New Jersey Turnpike for a long way, and there is this one short stretch of road where the wires have red, white, and yellow blobs on them. Google's Street View shot shows them quite clearly.

A thousand feet or so farther down the road, no more blobs.

I did Internet searches to find out what the blobs were about, and everyone seemed to agree that they were to make the wires more visible to low-flying aircraft. Which seemed reasonable, but puzzling, because as far as I knew there was no airport in the vicinity. And anyway, why blobs only on that one short stretch of wire?

Last week I drove Katara up to New York and when I saw the blobs coming I asked her to photograph them and email me the pictures. She did, and as I hoped, there in the EXIF data in the images was the exact location at which the pictures had been taken: !!(40.2106, -74.57726675)!!. I handed the coordinates to Google and it gave me the answer to my question:

Screengrab of a Google map showing
the section of the Turnpike under discussion.  The turnpike runs from
southwest to northeast.  A red 'location' marker shows the point at
which the photograph was taken.  About half a mile east of the marker,
with its main runway pointing almost directly at the marker, is an
area labeled 'Trenton Robbinsville Airport'

The wires with blobs are exactly in line with the runway of nearby Trenton-Robbinsville Airport. Mystery solved!

(It is not surprising that I didn't guess this. I had no idea there was a nearby airport. Trenton itself is about ten miles west of there, and its main airport, Trenton-Mercer Airport, is another five miles beyond that.)

I have been wondering for years why those blobs were in that exact place, and I am really glad to have it cleared up. Thank you, Google!

Dear vision-impaired readers: I wanted to add a description of the view in the iframed Google Street View picture above. Iframes do not support an alt attribute, and MDN says that longdesc is “not helpful for non-visual browsers”. I was not sure what to do.

(The image is a wide-angle shot of a view of the right-hand shoulder of a highway. There is a low chain-link fence in the foreground, and an autumnal landscape behind. The sky is blue but partly obscured by clouds. A high-voltage power pylon is visible at far left and several sets of wires go from it rightward across the whole top of the picture, reaching the top right-hand corner. On the upper sets of wires are evenly-spaced colored balls in orange-red, yellow, and white. Rotating the street view reveals more colored balls, stretching into the distance, but only to the north. To the south there is an overpass, and beyond the overpass the wires continue with no balls.)

In the future, is there a better place to put a description of an iframed image? Thanks.

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