Minimum clearances for conventional line construction, such as using a vertical suspension string, require an allowance for displacement of the string due to transverse winds and line angles (as in Fig 1). Replacing the vertical string with a horizontal line post type insulator (Fig. 2) fixes the conductor attachment point and allows for both reduced right-of-way widths and lower support structures. The challenge, however, has been that line post insulators typically have lower load carrying capacity than suspension insulators. In some cases this limits span lengths and conductor size.
An improvement in load carrying capacity can be achieved by adding a brace attached to the line end of the post and attached to the support structure at an appropriate angle (as in Fig. 3). Many of the advantages of the single-post insulator are retained with this type of insulator assembly, while increasing load carrying capacity.
