When is the intermediate pull technique necessary for installing fiber-optic cable in conduit?

The intermediate pull technique is essential when the route has multiple 90° bends in order to minimize the risk of damaging the fiber-optic cable and to ensure a smoother installation process. Bends in the conduit can create significant friction, making it challenging to pull the cable through. The intermediate pull involves stopping at certain points in the installation process to allow for additional pulling strength and management of the cable's tension. This technique helps alleviate the stress on the cable, ensuring it does not get kinked or stretched improperly as it navigates through the bends.

In contrast, when the cable is short, the need for such a technique is less critical, as shorter lengths are generally easier to pull through conduits with bends. Similarly, conventional pulling methods can suffice in simpler configurations without multiple sharp angles. As for underground installations, while they may present unique challenges, the necessity for the intermediate pull technique specifically arises from the nature of the bends rather than the environment. Thus, when multiple 90° bends are present, the intermediate pull technique becomes vital for a successful and safe installation.