Why use lubricant for fiber optic cable pulling?
During fiber optic cable pulling, the outer jacket comes into contact with the duct walls. This contact creates friction, and as the length of the run or the number of bends increases, the tension required to move the cable can also increase.
A lubricant formulated for telecommunications cables helps reduce this resistance. This can facilitate cable advancement, reduce the effort of the installation team, and lower the risk of applying excessive tension.
Lubrication is especially important in underground runs, long conduits, routes with bends, and projects where the cable manufacturer's allowed tension margin is limited. Installation guides recommend pre-planning the route, checking bend radii, and considering both final tension and lateral force generated at bends.
The real problem isn't just “pulling harder.”
When a cable stops advancing, increasing the pulling force is not always the best solution. Excessive tension can compromise the jacket or exceed the cable's established limits.
The goal should be to control friction from the start. To achieve this, you need to:
- Inspect and clean the duct.
- Check the condition of manholes and bends.
- Confirm the available inner diameter.
- Respect the minimum bend radius.
- Select a lubricant compatible with the cable and the duct.
- Apply an adequate amount throughout the operation.
Can any slippery substance be used?
It is not advisable.
A product may feel slippery and still not be appropriate for a telecommunications installation. Its compatibility with materials such as polyethylene, high-density polyethylene, low-smoke jackets, and other compounds used in cables and ducts must be evaluated.
It is also convenient to consider its application method, ability to adhere to the jacket, performance during long installations, and behavior after drying.
A solution for long-distance underground installations.
Polywater F is an example of a lubricant developed for pulling communication cables, including underground fiber optics. Its consistency allows it to be poured into inner ducts or feeder tubes and distributed over the cable jacket during long runs. The manufacturer states that it is compatible with different jackets, including polyethylene, and that it leaves a lubricating film after its water-based carrier evaporates.
This does not mean that there is a universal lubricant for all works. The choice should be made according to:
- Cable type
- Jacket material
- Duct material and diameter
- Run length
- Number and geometry of bends
- Environmental temperature
- Available application method
Conclusion
Pulling lubricant helps control one of the most important variables of the installation: friction. Choosing it correctly can contribute to a cleaner, more predictable, and safer procedure for the cable.
Before starting, consult the cable manufacturer's specifications, calculate the expected tension, and verify that the lubricant is compatible with the materials present in the installation.
Are you planning a fiber optic pull?
Send us the details of your run, duct, and cable. We can help you identify the most suitable type of lubricant and presentation for your project.
