Abstract: Disclosed is a kit of curvilinear duct components and a method of utilizing the same to provide an improved mode of simultaneously installing and protecting multiple electrical cables in underground duct installations. The components include tubular elbow members, a major portion of at least some of which are of D-shape in cross section and having a major internal width at least as great as the combined diameters of multiple cables to safeguard against cable jamming during installation and which portion converges at one end to a circular shape matable with adjacent linear ducting. The curvilinear components are formed of impervious, electrically nonconductive, abrasion resistant material, such as polymer, concrete or glass filled thermosetting plastic.