I found this specimen at the Victor factory in 2008, This odd little glazeweld cable is only known to have been used on one line in the area of Scranton, Pa. The U-939c is a very odd little insulator. They have both an applied crown and are a two part glaze-weld so they likely required quite allot of effort to produce. Normally a small insulator of this type would be made as a single piece unit with a green trimmed conductor groove as indeed most later Fred Locke insulators of this size were . applying two separate marking stamps precisely on opposite sides of the piece also took a little extra time. all of the known specimens and shards of this insulator were made in late November and December of 1900. There is one whole white glazed unit and less then 10 whole or damaged tan glazed units. I believe only one or two whole ones were found on the Scranton interurban line. All the other examples came from the Victor dump. This exact shape was not specifically cataloged by Locke.

This short lived design was probably scrapped because it took to much labor to produce and it was soon found that a similar insulator could be made much more cheaply as a single piece green trimmed unit