In the 1950s, the company made the remote-ballasted OV10, OV20 and OV35. They were the answer to GE's Form series fixtures, and had a distinctive look of their own. Westinghouse's remote-ballasted fixtures have a flat refractor that gives them more of a resemblance to a peanut. The OV10 carried wattages of up to 250 watts, the OV20 up to 400 watts and the OV35 up to 1000 watts.
In 1957, Westinghouse introduced the first cobrahead luminaire, the OV25 Silverliner. For the next quarter-century, the OV25 would become the biggest threat to GE's M400.
In 1960, the Silverliner name would be applied to other fixtures. The OV12 Silverliner was the replacement for the OV10, and it would be followed by the OV15 in 1965. The OV12's profile resembles a shrunken-down OV50, and its refractor had previously appeared on the OV10.
In 1964, the OV25 underwent a minor facelift and it now had a more-rounded look. A remote-ballasted version of the OV25 was also available.
The OV50 was the largest member of the Silverliner family. Like GE's M1000, older versions had fins on top of them, but in later years, the OV50 would lose its fin.
In 1969, following the big-city riots, Westinghouse began experimenting with high-pressure sodium lighting. Washington, DC was one of the first cities to put up the HPS-lit OV25s. Soon, GE would also jump on the HPS bandwagon, and its M400A and M250R have become the dominant luminaires for these lights.
In the mid-1970s, both the OV15 and OV25 underwent a redesign that gave the luminaires a flat bottom. They were not nearly as popular as their predecessors, though.
In 1982, the Silverliners were discontinued, and Crouse-Hinds (later a division of Cooper) bought out Westinghouse's streetlighting division. But the Silverliners are alive and well in Canada, as the OV15, OV25 and OV50 are still available for sale. The OV50 is still available in the USA, and it's produced here under the OVL name (more in the Cooper/Crouse-Hinds section).