The Westinghouse OV-12 was the earliest small-sized luminaire in the Silverliner family. It was introduced around 1960, and was one of the strangest cobraheads ever made. On the surface, it might look like a regular cobrahead, but the types of access are very strange. The refractor is held by a hinged ring for access to the lamp and optical assembly. To access the ballast, capactior, slipfitter, and wiring, you will have to unscrew the three screws on the head, and take the upper half of the luminaire off and look in from above! No wonder the OV-12 was hard to find in many areas, although they were popular in the Bay Area along with the silver M-250 back in the mercury vapor days. The OV-12 was superseded in 1965 by the much more common OV-15, which is much more conventional and has a typical, full door for access to lamp and inside of luminaire from the bottom, like its bigger brother the OV-25 and most cobraheads.
This particular OV-12 is a 250 watt mercury vapor, and mounted on the California style S-shaped upsweep mastarm.
