Streetlights
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Streetlights are elevated lights, usually outside, intended to illuminate a road or a walkway. According to one treatise, “[t]he primary purpose of street lighting is to so illuminate the surface of roadway and sidewalk and the objects for 5 or 6 ft. above it that pedestrians and drivers of vehicles can travel safely.” Amory Prescott Folwell, Municipal Engineering Practice 261 (1917).
Generally, streetlights can be classified using the following characteristics:
(1) Arm
(2) Light inset
(3) Lamp
(4) Fixture
(5) Pole
Strung together, they can exhaustively describe a wide variety of streetlights using the following syntax:
[arm-type] [light inset type] [lamp-type] [fixture type] on a [pole-type]
Of course, not all descriptors are necessary at all time — usually just the arm and lamp-type will do. One may be able to adequately describe a streetlight by the use of just one characteristic. Similarly, use of make and model number can be extremely helpful and may suffice in itself as an adequate description.
Here is a compilation of lamp and arm advertisements from Street and Highway Lighting taken from 1957-1963.
Arms
—-Davit (light is suspended from above)
—–Compare and contrast with NYC Donald Deskey model.
—-Tapered Elliptical (light is suspended on an elliptical pole which tapers toward the light end)
—-Truss-Arm (arm is supported by structural component from below)
—-Single or Double-Guy (arm is supported by structural component from above)
—-Upsweep Arm
Fixtures
Cobrahead fixtures:
The OVL (up to 1000W) is a common streetlighting fixture. Its original design is traced back to the Westinghouse OV50, which was introduced in 1963. Cooper Lighting bought Westinghouse’s lighting unit in 1982 and the OV50 was reintroduced as the OVL. The outer housing was changed from a silver color to a light gray color. The older luminaires are known as “Silverliners” and the newer gray models are known as “Grayliners.” At 39″ end-to-end, it is considered a large fixture.
The OVD (150-400W), introduced 1998, traces its lineage through a long line of important streetlight designs, such as the Crouse-Hinds OVM (1985-1997) and Crouse-Hinds L250 (1983-1984), as well as the Westinghouse OV25. Cooper Lighting appears to have bought out the Westinghouse line in 1982 and acquired Crouse-Hinds in 1980. At 30″ end-to-end, the OVD qualifies as a medium-sized streetlight.
The OVG (50-250W) is slightly smaller than the OVD (just over 27″) and features a cutoff light. The OVY (50-250W) appears basically the same as the OVG, but slightly larger (30″).
Older Westinghouse models
The Westinghouse models (along with models by GE, described in greater detail below), were among the first “cobrahead” luminaires. Westinghouse produced the OV25 models in at least two phases: the first in 1957 featured streamlined and severe lines, the second in 1965 featured softer lines. See Forgotten NY’s excellent description for more information.
—Lamp
—-Mercury Vapor
—-Low-pressure sodium
—-LEDs
—Light inset
—-Non-cutoff, semi-cut-off, cut-off and full-cut-off
— Vintage
–Current Research / HOUSEstep(TM)/Controversies
—Spacing
—Height