The BS/Telecommunications Department is planning a project to install new telephone cable between a manhole near the CDF Assembly Hall and Lab C, following a route along Road D and Eola Road. The cable will be buried in a trench along most of the path. This Design Note describes the CD/Distributed Computing Department’s desire to include a segment of tube cable in the trench between Manhole C6 and a handhole at the Eola/Batavia Road intersection.

The purpose of laying tube cable along this path is to extend our data communications point of presence to a strategic location capable of servicing several on-site locations, some of which are not easily reachable from current data communications establishments. From the Road D/Batavia Road handhole for example, we will be able to install fiber optic cable to Site 52 at lower cost (and less danger to existing power and gas lines) than from PS6. This handhole will also provide a point of presence for alternate cable routes to the Village, C0, D0, and the Lab A-D/New Muon areas.

The most expensive and ecologically disruptive part of installing buried cable is the trenching work. Laying in a data communications cable along with the originally planned telephone cable during the same trenching operation is cost-efficient.

Tube cable is a multi-cell conduit for air-blown fiber optic bundles. When a bundle of fiber optic strands is required between two locations already connected by tube cable, it is blown in quickly and economically using compressed gas. If more fiber strands are needed later, they can be added through another cell, or the original bundle can be pulled out (and spooled for future use) and replaced with the new bundle. Air-blown fiber is currently available in 2-, 6-, and 18-strand bundles of multimode or singlemode strands.

A 7-cell laminated aluminum polyethylene tube cable (Sumitomo FutureFlexÔ TC07TLW) would be laid along with telephone cable in a 36"-48" deep trench from a handhole next to Manhole C6 to a handhole near the "cut-through" intersection of Road D and Batavia Road. The cables will be laid separately in the trench, with sand fill below, between and above them.

It would be desirable to pull a 7-cell water-blocking tube cable (FutureFlex TC07TOX) from the C6 handhole to the existing tube distribution unit (TDU) in the CDF Assembly Hall (west wall) via Manhole C23.

This tube cable is obtainable in 1500-foot spools from stock, or can be special ordered in longer lengths but the lead time would then be 8-10 weeks. Since the estimated linear distance from C6 to the Road D/Batavia Road handhole is 4200 feet, two additional intermediate handholes would be required along the path to join multiple segments of tube cable. One of these handholes may be co-located with a planned telephone cable splice point.

Each handhole will be a fiberglass 36"Lx24"Wx36"D in-ground vault with a surface-level cover and gravel floor. The handhole will be positioned next to, but not over, the trench line. A 12"x12"x6" water-resistant (NEMA 3R) fiberglass enclosure (e.g., Cantex 5133713) will be mounted to one wall of the vault. Both tube cable segments from the trench will enter the NEMA box from opposite sides through water-proof fittings, and their individual tubes will be joined with FutureFlex DE06MC tube couplers. A 4" conduit will connect the C6 handhole with Manhole C6, and will employ a bend radius of no less than 24".

It will be desirable to pull another segment of 7-cell tube cable (TC07TOX) from the C6 handhole to the existing TDU in the northwest corner of CDF. This contiguous tube cable would follow conduits from the C6 handhole to C6, C6 to C23, and C23 into the building, a distance of approximately 180 feet. A recent Ameritech survey revealed there is conduit space available in and out of C23. This tube cable would be coupled to the C6-Batavia Road run. Note: cable to the Industrial Center Building was also considered, but ICB is reachable from C23, not C6.

All seven cells will be "BB-tested" (a BB shot will be blown the entire distance to verify an uninterupted path), then pressurized and capped at both ends. If the run is not completed between C6 and the CDF TDU, this operation will be conducted between C6 and Batavia Road.