Aluminum Head Radial Wave Incandescents
The "radial wave" style was a common rural and side street streetlight style in the 1940's on into the 1960's. This was simply a disk of metal serving as a reflector and also as a rain shield for the lamp. The ripples around the edge made the reflector more resistant to warping or bending. When the reflectors developed rust after many years of service, the center was affected most, likely due to water tending to remain there for long periods of time. Once rust holes developed, which this writer has seen specimens with, the reflector had to be replaced as water dripping through then hit the hot lamp and cracked it.
The reflector was finished in porcelain enamel to retard corrosion. The Philadelphia Electrical Manufacturing Co. (Pemco) used a green enamel on top (left photograph). The Wheeler Reflector Co. used a gray enamel on top (right photograph). These reflectors are approximately 20 inches across. While the white underside softened the glare of the light compared with a mirror finished reflector, the filament of the lamp was not subdued.
Left: Pemco luminaire Right: Wheeler luminaire
The thin stripe in each picture indicates approximately one foot for size comparisons.
We are experimenting with solid color vignetting on the pictures since busy or mottled backgrounds cause the pictures to unnecessarily consume more of the limited web site space allotment and take longer to display.
The reflectors of our specimens have male threaded collars that screw either directly into the head, or into an intermediate ring that in turn is bolted or latched to the head. The heads are of the respective manufacturers. The Pemco head (left) is part no. 1804A and has external wiring and photocontrol socket. The Wheeler head (right) was not labeled with a part no.
The lower picture shows an anti-vandalism shield used with radial wave fixtures. This reduced lamp breakage from thrown rocks but also reduced light output. It did not protect from BB gun attack. One streetlight collector this writer has met confesses to breaking lamps in open fixtures "just to watch as the repair crew came out". Very shameful, especially for someone in our hobby.
Lamps with clear bulbs were preferred because the more distinct shadows cast by the light improved traffic safety. The lamp filament must be several inches below the reflector to minimize light going up into the head and being wasted. For example, if the filament were even with the reflector, fully half of the light would be so wasted.
A radial wave luminaire with a porcelain head is described on another page on this site (click here).
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