The overall diameter of a 288-core optical cable typically ranges from approximately 18 mm to 22 mm, depending on construction and armor type.

Cable Construction

A 288-core optical cable usually consists of 12 loose tubes, each containing 24 fibers, arranged around a central strength member. For example, the Belden GCCF288 cable uses 12 tubes of 2.5 mm diameter each, with glass yarns for strength and a corrugated steel tape (CST) armor for rodent protection, all enclosed in a low smoke zero halogen (LSZH) jacket . Other designs, such as Corning SST-UltraRibbon or CommScope TeraSPEED cables, may use single or multiple buffer tubes with ribbonized fibers, gel-free or water-blocking tapes, and additional strength members, which slightly affect the overall diameter .

Approximate Diameter Calculation

• Tube diameter: 2.5 mm
• Number of tubes: 12
• Arrangement: Tubes are typically helically stranded around a central member
• Armor and jacket thickness: Adds 2–4 mm depending on material (CST, PE, LSZH) Using these parameters, the overall cable diameter is generally in the range of 18–22 mm for armored 288-core cables, while non-armored indoor cables may be slightly smaller, around 16–18 mm .

Practical Considerations

• Installation: Ensure ducts or trays can accommodate the cable diameter plus bending radius.
• Weight and flexibility: Armored cables are heavier and less flexible than non-armored designs.
• Environmental factors: Outdoor cables may include water-blocking tapes or gel-free designs, slightly increasing diameter. In summary, while the exact diameter depends on the manufacturer and cable type, a 288-core optical cable with 12 tubes of 24 fibers each typically measures around 18–22 mm in diameter for armored designs and slightly less for indoor, non-armored versions .