TBD

A phase is a single direction of traffic that cannot be services with other phases in the same ring.

Any signal, or correctly a signal cluster, in which the various faces can be set at differing angles from one another. Compare with nonadjustable.

The number of aspects a signal has is basically saying how many indications it has. A single aspect beacon has one indication, for example.

The part of a signal that holds the lens and visor. It's typically used to access the inside of the signal to change the bulb or LED module in the signal.

The face of the signal is the side seen most often, featuring the indications and visors. While single-face signals have the housing on the other sides of the body, 4-way signals have 4 faces.

General descriptive term referring to several early styles of signals. These signals did not have a conventional rectangular/square door that opened to allow bulb and interior access; instead, the door was a minimial ring containing the lens and visor resembling the porthole window style on ships. In the case of Tokheim, Harrington-Seaberg, Autoflo [..]

Loosely termed as a way to describe a signal in which the various lense sections (IE Red, Yellow, Green) are physically seperate and not cast as a solid piece of metal. Both modern signals and the rodded style signals fall under this definition.

The hood, flange, or shield that is used to provide a tunnel effect around a lens. Common styles are the western Full Circle, exactly as its name suggests; the Tunnel (or Combination), a circle with no bottom, and the Cutaway or Cap, which is a tunnel with the sides also removed. These are typically from 7-10" long with various downward angles [..]