Issue link: https://www.e-digitaleditions.com/i/1347119
42 I ICT TODAY FIGURE 11: The air-jetting equipment set-up. FIGURE 12: Fusion splice trucks. FIGURE 10: Shown are several thousand feet of micro cable ready to be air-jetted through the 7-way duct. The duct was placed between 32-inch round under- ground concrete pull boxes (PBs) spaced at a maximum of 1,500 feet (457 m) in rural areas and 750 feet (229 m) in urban areas. Also, 48-inch round pull boxes were used for micro cable splicing locations during construction and placed in strategic locations for future connectivity to the singlemode 432-fiber strand OSP non-armored micro cable. The duct was delivered on 1600-2000-foot reels to match the spacing between the PBs on the project. The micro cable was placed in preparation for air-jetting, which is the manufacturer's term for its blowing installation method (Figure 10). Once the blown cable duct or micro duct fiber pathway is completed, then the benefits of a blown cabling system begin. At the sending end, compressed air was injected into a sealed micro duct through which the micro cable would be air jetted (Figure 11). The micro cable was pushed into the sealed micro duct by the air-jet equipment's spinning drive wheels that were controlled and monitored for pressure and traction. The compressed air carried the micro cable through the micro duct minimizing friction to extremely low levels that allowed the micro cable to be air-jetted several thousand feet at a time. The micro ducts had initially been designed and manufactured with a ribbed interior wall to reduce friction by limiting contact with the 7-way duct jacket, allowing the micro cable to be carried at high speeds by compressed air. Specialized jetting lubricants were also used to reduce the drag and friction even more. The 432-strand micro cable was shipped on 20,000-foot (6096 m) reels. Phase 1's fiber run was approximately 200,000 feet (60,960 m) and, therefore, used 10 reels of micro cable. Phase 2 required approx- imately 235,000 feet (71,628 m) and used 12 reels of cable. In total, 10,368 fusion splices were required to connect all 22 reels of micro cable together with fusion spliced factory-terminated 12-fiber MPO con- nectors on to the ends of both cables at the TRC's telecom building and the MDC's MDF room. For this installation, only one of the seven micro ducts was used, leaving six empty micro duct fiber pathways for future expansion. Once a micro duct is cabled, there is no need to ever re-enter the duct, since any MACs, rerouting, and trouble shooting can be done at the TRC and MDC.