Especially in colder climates, where worst-case scenarios involving water are most likely to occur, protective measures are key. Blocking technologies Let s look first at the cables themselves and the water blocking technology that is built into them. Most of the fiber-optic cable currently in use thousands upon thousands of miles of it uses a traditional water blocking technology. Whether the cable contains 12 fibers, or whether it contains 288, water first is met by a flooding compound, a greasy interstitial filling, in which the buffer tubes containing the fibers swim. The buffer tubes themselves are filled, offering further protection from water in the unlikely event that the buffer tubes are breached.
Dry water blocking technology employs superabsorbent polymers.
These swellable, water-activated materials are impregnated on tapes and yarns inside the cable. While both water blocking techniques are very effective, for the person performing a cable splice or termination, the dry technology means less mess. You get it all over your hands, all over your clothes and all over your tools. Jerry Burrow, president of Fiber Optic Specialties Inc., in Merrillville, Ind., especially likes the user-friendly qualities and shorter prep time of the dry blocking. But, as with many new technologies, some view the dry fiber with caution.