Installing Cable Racks. Before cables are pulled into ducts, provision for supporting the cable ends on racks in the manholes is made. Allowing the cable ends to lie on the manhole floor enables them to be stepped on or damaged by falling objects. The rack support channel is fastened to the manhole wall with expansion bolts. Holes for the expansion bolts are drilled 3 in. deep. Safety goggles are worn when concrete or brick is being drilled.

The spacing between racks adjacent to the proposed cable splice is usually 3 ft. In general, a cable should be supported at points 6 in. from each end of the splice. Additional racks are spaced about 3 to 41/2 ft apart depending on the nature of the cable bends.

Selecting the duct. Before the start of cable installation, the duct to be occupied should be selected throughout the entire length of the conduit run. As far as possible, the same relative position in the duct bank should be maintained. In general, the longer cables should be installed in lower ducts and the shorter cables in upper ducts. In this way the vacant spaces will be left in the upper ducts, where they can be utilized later on without disturbing the cables already installed.

Automated Cable-Pulling Equipment. Portable cable-pulling equipment or its accessories and a winch truck can be used to clean a duct and pull the steel cable contained on the cable puller equipment or the winch line on a...