WT4 Millimeter Waveguide System: Route Engineering and Sheath Installation

The goal of route engineering for any transmission system is to select the route layout which minimizes the total installed cost of the system while meeting other physical and legal constraints. Specific goals of route engineering for a WT4 waveguide system are the siting of repeater buildings on suitable property and the design and staking out of a trench centerline along a right of way for which easements can be obtained. The trench design must meet the conditions that it has a shape satisfactory for emplacement of a waveguide sheath and that it can be excavated economically by conventional trenching machinery. The transmission medium for a waveguide system differs from that for a cable system in two respects which strongly influence route engineering. First, the loss depends on the number, extent, and severity of route bends as well as the length of the route and, second, the mechanical (beamlike) properties of the waveguide and its sheath restrict the class of feasible route shapes. The siting of repeater stations for waveguide systems exerts somewhat less constraint on route selection than does 1953