Two late 1960s OV-25s, both 400 watt mercury vapor, the right one is a dayburner of course.
Westinghouse, like GE, was a big player in the roadway lighting market. In 1957 they introduced the orginial Silverliner luminaire (photo below) that was designed to have an intergral ballast and was designed for 400 watt mercury vapor lamps (although 250 watt versions also exist). There have been some talk that this may possibly be the very first true cobrahead luminaire put on the market, but it is still not completely known. However, the Silverliner was an extremely successful luminaire, probably second in popularity to the GE M-400. The orginial OV-25, which actually had two doors (but not a power door luminaire), was made from 1957 until around 1963 or 1964, when the updated, more rounded OV-25 (photo above) was introduced and had a single, full door. The second generation remained largely unchanged until the entire Silverliner line was discontinued sometime in the early 1980s. Some of the later ones were even factory fitted to use high pressure sodium lamps (photo coming later).
The real old orginial OV-25 with flater door (it's actually two doors!) than the second generation OV-25. Also note the unique ornate S arm, this is fairly common in Northern and Central California. Sweet luminaire isn't it?
