Workmanship in aerial cable networks can affect the performance and reliability of the network, of course, but it can also make or break the aesthetics of the visible aerial cable plant.

Aerial cables should be installed “in a neat and workmanlike manner,” which can be interpreted as “what is correctly done also looks good.” Discussions with the Fiber Optic Association’s (FOA) worldwide network of technical advisers has helped create some guidelines for aerial installations.

The logical way to illustrate proper installation is to show an example. The cable shown in the photo above, right is around the corner from my office, and I have watched many crews working on this section of cable. The large bundle has about 10 cables overlashed on the same messenger. You can see the service loops are carefully lashed to the bundle with snowshoe fittings, and splice closures are tightly lashed to the bundle also. Look closely and you will even see a CATV amplifier.

The section of cables shown above was not always so neat, as you can see in the photo below it, which was taken earlier. 

Obviously, some fiber techs were as disturbed about the poor workmanship as I was and decided to clean it up.

Here are some guidelines for aerial installations. These guidelines refer primarily to “strand and lash” installations, cables lashed to a wire messenger. Some exceptions exist for all-dielectric self-supporting (ADSS) cables, which may be installed in the power or telecom space.

Installation guidelines

• Installers must follow local ordinances and customer requirements for the aerial cable plant.
• Cables on poles sharing electrical and telecom/CATV cables must be installed in the telecom space with proper clearance from both electrical cables and other low-voltage cables. This includes separation midspan where electrical cables and messenger/fiber cables both sag from their weight. The exception is ADSS cables, which are approved for installation in the power space by qualified personnel.
• All aerial cables should be installed clear of any obstructions, including buildings, trees and other cables. Weather conditions at the location, e.g., storms, icing or potential wildfires, may justify greater separation from trees.
• The span must be analyzed for the size of messenger, the tension required for the span length and cable weight to meet sag requirements. Sag is generally limited to less than 2% of span length and maximum tension of less than 30% of cable minimum breaking strength. I recommended referring to ANSI/ICEA P-79-561-2020, Guide for Selecting Aerial Cable Messengers and Lashing Wires.
• The steel messenger wire and lashing wire are electrical conductors and should be properly grounded.
• Cables must be sufficiently high above the ground to clear all obstacles, including traffic that may pass underneath them.
• All cables must be securely lashed to the messenger and/or cable(s) with no loose hanging cables anywhere along the span. Messenger wire must be neatly terminated at the ends.
• Splice closures should be attached to poles with necessary service loops using appropriate hardware. Closures attached to the messenger and their cable(s) must be attached and service loops secured along current cables with showshoe turnarounds or a cable loop that respect the cable’s minimum bend diameter.
• No service loops or cables awaiting further installation may be left hanging from the span. All cable loops must be secured to a pole at the end of the span. Excess cable awaiting installation may be secured at poles for short periods of time only.
• Overlashing must consider the current cable loading, the weight of the cable intended to be added and the effects on span tension and sag.
• Any damage done to current cables during one touch make ready or overlashing must be reported to the permitting authority and the owners of the other cables on the span.

At FOA, we created these guidelines to help describe what installation in a “neat and workmanlike manner” means. Feel free to use them.

Jim Hayes