Background & Problem Statement

HFCL Limited is renowned for the quality and timely supply of OFC cables to its customers, which makes it a preferred supplier for many customers. While HFCL’s manufacturing facilities, processes and people are world-class, an integral reason for being a preferred OFC supplier is also its strong focus on customer engagement and remarkable post-sales service. HFCL has often gone beyond its scope of supply to understand and mitigate challenges faced by customers during the installation and deployment of OFC cables, thus ensuring complete customer satisfaction. HFCL treats customer’s problems as its own problems and takes ownership & pride in resolving them.
In 2018, a well-known telecom company in Saudi Arabia gave an order to HFCL to supply 2,400 kilometers of unitube micro cables that would provide last mile connectivity to premises of the end customers. Given its huge requirements, the company had also engaged other OFC suppliers for the same. While there was no problem in the manufacturing and supply of the cables, the company ran into a peculiar problem during the installation and commissioning of the cables. The problem was of fibers and jelly oozing out of the cables in joint closures and distribution boxes post-installation. During HFCL team’s communication with the company, they came to know about this issue and decided to take ownership & look into the problem closely to identify the root cause of this problem.

HFCL Takes Up the Challenge

HFCL went about identifying the problem in a structured, step-by-step manner

  • During the process of analysis, photographs and feedbacks received from different sites revealed that the issue is related to shrinkage of the sheath, which resulted in the exposure of Kevlar® Reinforced Plastic (KRP) and fibers in the closure tray.
  • Given the climate of Saudi Arabia, the shrinkage could not have happened after the cable came to its rest state post blowing. This led the team to ascertain that the shrinkage of sheath could be due to elongation caused because of tension induced during blowing or being mishandled like pulling etc.
  • On investigating the blowing process further, it was noticed that the outflow air temperature of the compressor was around 90-95 degree Celsius while the recommended installation temperature range for the cables was -10 to 40 degree Celsius (max. 60 degree Celsius).
  • Blowing at such high temperatures resulted in softening of outer sheath, which in turn caused longitudinal expansion of the cable under blowing tension. After the blowing process was complete, the cables gradually returned back to rest state and in the process, caused contraction of the outer sheath thus exposing the jelly, KRP and fibers.
  • Supply of OFC and its accessories with implementation of underground & aerial OFC network
  • As the fibers are arranged in a sinusoidal manner along the center of the tube, there is a higher slack in unitube cables due to higher window space compared to multitube cables, resulting in the shrinkage problem being more prominent in unitube cables.
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Resolution & Action Plan

Having understood the issue, the HFCL team prepared and implemented a step-wise remedial action plan that involved the following steps:

  • Step 1: Air coolers were placed along with compressor during blowing to contain blowing temperatures, which brought blowing temperature to 55-60 degree Celsius.
  • Step 2: Fibers were terminated in joint closures and Optical Distribution Boxes (ODBs) 48-72 hours after blowing to allow for a cooling period.
  • Step 3: While terminating fiber in closures and ODBs, a loop was made before fixing the cable on cable mounts to prevent sheath shrinkages.
  • Step 4: The cable construction was revisited with a recommendation of embedding strength members in sheaths. Doing so increases resistance to elongation or shrinkages of sheath.

Successful Result

With the implementation of the remedial action plan, it was found that there was a reduction in installation issues by 95%!
Thus, the simple act of going beyond our scope to understand our customer’s challenges and taking on the mantel to address them led to yet another satisfied customer.