A Whitall Tatum/Armstrong 51-2U in dark root beer amber in use on an open wire fire alarm line in Colonia, NJ. This is the only intact, functioning municipal open wire fire alarm circuit in central NJ of which the author is aware. This circuit has an interesting mélange of both glass and porcelain insulators, new and old. Many of the insulators are of types which would not ordinarily have been intended for fire alarm use, being intended either for primary service (as shown here) or for secondaries, or telegraph and telephone use, etc. Essentially this demonstrates that in this class of service just about anything is acceptable, as long as it insulates! The line has pintype/crossarm as well as some rack-and-spool construction at dead ends.