Context-Sensitive Design Concepts for Streetcar Electrification

As the interest in establishing new streetcar systems in various cities throughout the United States continues, concerns over the possible visual impact of the overhead wiring are sometimes expressed. These concerns are not without basis. In some cases the genesis of such concern is the trend to use catenary rather than traditional trolley wire on light rail transit lines. Catenary is unavoidably conspicuous. In addition to the contact wire, catenary comprises a thick messenger cable with multiple vertical hangers to support the contact wire and other appurtenances, all out over the middle of the street. The use of catenary in a street setting is a departure from traditional streetcar track electrification, which generally has only a single wire over the track. These concerns about the visual impact can be particularly acute at specific locations, such as where a line segment is bordered by a grand or historic edifice or is in a park setting. This is the case at particular locations in Washington, D.C., and San Diego, California, where the desire is to avoid even unobtrusive wiring. The time is propitious for a revisitation of overhead wire design concepts as an element in addressing visual impact concerns. This paper discusses the engineering designs that are available to satisfy these two needs, which are (a) electrification of the primary trackage of a network with minimal visual impact and (b) feasible onboard power storage to allow operation on nonelectrified track segments in zones where a total absence of overhead wire is considered essential.