OPGW cables are primarily categorized into two main structural types:

1. Central Tube Type: In this design, a single central tube, often made of seamless aluminum or stainless steel, contains all the optical fibers. This structure is known for its compact design and is suitable for lower fiber counts.

2. Stranded or Multiple Tube Type: This design is used for higher fiber counts. It features multiple smaller tubes or fiber units that are helically stranded around a central strength member along with the metallic wires. This allows for increased fiber capacity and greater flexibility in design to meet specific electrical and mechanical requirements.