Ask Woody
Reprinted from "Crown Jewels of the Wire", June 1987, page 20
I am most grateful to Mr. N.R. Woodward, Houston, Texas for his willingness
to answer readers' questions. Mr. Woodward is the author of The Glass Insulator
in America and developed the Consolidated Design Numbers identification system
for glass insulators.
I am enclosing a picture of an insulator that I recently purchased. Notice
the extra wide saddle groove in the middle insulator. Both the Hemingray and the
other Columbias have a 1-1/2" saddle groove. The middle Columbia has a 2-3/8" groove and, like the CD 263 beside it, has threads that extend clear
to the bottom of the skirt. Is this a different CD or a variation of CD 263? The
green color of the glass looks like a Brookfield color to me. Are there many
around like this one? (Bob Harding, Pickering, Ohio)
The two Columbia insulators which you have are both listed as CD 263. On
saddle groove insulators, we have not usually attempted to assign different CD
numbers on the basis of width of saddle as long as the rest of the body of the
insulator has identical dimensions.
These two insulators are Brookfield products. The one with the saddle to
accommodate a one-inch diameter cable is listed as their No. 8, and one with the
wide saddle is listed as No. 7. The No. 8 is far more common, the size cables
they carried were quite standard for street railway applications, the primary
locations for the Columbias. Much heavier cables were used with elevated
railways and subways in the larger cities; thus, the demand for insulators with
a very wide saddle.
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