Fiber Optic Network Cable Pulling

Fibre optic cable can be damaged if pulled improperly. Broken or cracked fibre, for example, can result from pulling on the fibre core or jacket instead of the strength member. And too much tension or stress on the jacket, as well as too tight of a bend radius, can damage the fibre core. If this core of the cable is harmed, the damage can be difficult to detect.

A damaged Fibre Optic Cable during Termination

Once the cable is pulled successfully, damage can still occur during the termination phase. Field termination can be difficult and is often done incorrectly, resulting in poor transmission. One way to eliminate field termination is to pull preterminated cable. But this can damage the cable as well because the connectors can be knocked off during the pulling process. The terminated cable may also be too bulky to fit through ducts easily. To help solve all these problems, use preterminated fibre optic cable with a pulling eye. This works best for runs up to 2000 feet (609.6 m).

Setup for pulling

The first step is to mount the capstan to the 27/16-inch drive shaft. Because the combined weight of the drive section and the capstan drum assembled is approximately 80 to 100 pounds, manufacturers recommend that two people mount the assembled unit.

To mount the capstan, push the drive spindle onto the drive shaft and rotate it counterclockwise one-quarter turn until the bayonet pin locks. Then pull the unit toward you, away from the drive shaft, to lock the bayonet pin into place.

The next step is to wrap the pulling rope or tape around the capstan's working surface at least four turns in an overwind direction, which dissipates the tension of the pulling line across the capstan's surface area. When everyone is ready to begin the pull, slowly start the driving shaft, rotating the capstan clockwise and gradually increasing the shaft's speed as desired.

It is important to pay attention to the lay of the pulling line on the capstan surface, because binding may occur as the tape or rope enters and leaves the capstan. If binding occurs, you must peel off the line exiting the capstan. You can minimize binding by changing the pulling line's angle of approach.

In most cases, it is ideal for the pulling line to approach the capstan close to the inboard flange. As the capstan rotates, the tape will run outward along the working surface and exit the capstan. If the pulling line slips on the capstan surface due to excessive lubrication, make additional wraps until slippage stops.