The continuing rapid increase in bandwidth demand has created an urgent need for data centers to increase the capacity of optical fiber networks. Within and between existing data center buildings, it has become necessary to maximize the fiber count in existing conduit to avoid the expensive and time-consuming creation of new installations.
An experiment conducted at the Mie, Japan, facility of Furukawa Electric Co. (FEC) demonstrated the installation of a 6912-fiber optic cable with an outer diameter of 1.14 in in a 696 ft long conduit with three 90° Source: Furukawa Electric Co. Source: Furukawa Electric Co. curves and an inner diameter of 1.25 in. The conduit used was a standard product installed in conventional data center campuses. Engineers confirmed a maximum pulling tension of 84 lb, well below the maximum pulling tension of 600 lb specified for the cable.

The cable was also installed in a 1.25 in conduit with a maximum length of 1,411 ft in a North American data center campus in 2020 to support live traffic. The high fill ratio in this application is not typically recommended for outside plant cable installation. However, in this application, the end-user was willing to accept the installation risk in return for maximum fiber density. The installation demonstrated that FEC’s 6912 fiber optic cable can be successfully installed into 1.25 in conduit using appropriate tools, work procedures and optimum installation conditions.

According to the company, the fiber optic cable at least doubled the fiber count possible in a conduit of this dimension compared to competing available designs. FEC will continue to provide and improve its ultra-high fiber count cabling, featuring small diameter and high density, along with the tools and training necessary to successfully build high capacity networks.

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