The key to keeping binders together is to be sure to bundle them permanently THE MINUTE that the sheath is removed. There are special color-coded cable ties made for this, or often people just use scraps of wire of the appropriate color to secure the binders. In large counts like this, they used 300 pair super groups in order to maintain the finite number of colors available in the telecom color code. Each of these binders contains twelve regular 25-pair binders within an overall binder to keep them together. Generally, any cable over 2,700 pairs is only used in duct runs between the CO via manholes. You won't see cables this large in an aerial environment since they are nearly 4" in diameter. They usually originate in the CO's cable vault and only travel a short distance, tapering down to multiple smaller cables at each manhole splice. Their gauge (AWG) is also much smaller than traditional 24-26 gauge ones because they have to be under 3.75" in diameter to fit within standard 4" ducts. Believe it or not, these can be as small as 30AWG, which requires very careful splicing practices. Today's installations are usually heavier in fiber deployment to remote terminals that branch out into large copper distribution cables further out from the CO, which dramatically reduces congestion in cable ducts and vaults close to the CO. Although I've seen splices of 4,200 pair cable before, I've never worked with it. It's certainly not as easy as a 600 pair one would be.


Ed Vaughn, MBSWWYPBX