Advanced Cable Design: Sterlite

N O V E M B E R 2 0 2 5 | W W W. W I R E N E T. O R G

WIRE & CABLE

Advanced Design

WRAPUPS + wire Kraków + wire Southeast Asia

BONUS FEATURE:

AI & R&D ... has its time come?

O F F I C I A L P U B L I C AT I O N O F T H E W I R E A S S O C I AT I O N I N T E R N AT I O N A L

F E AT U R E 6 O F 6

STL’s R&D unlocked record high-fiber density in new IBR cable On Sept. 4, India’s Sterlite Technologies Ltd. (STL) introduced its 864F Intermittent Bonded Ribbon (IBR) cable. The company—which also has a 168,000-sq-ft operation in Lugoff, South Carolina—describes it as the world’s slimmest such product. Below, Badri Gomatam, chief technology officer, shared with WJI how STL is able to pack a record 864 fibers into a cable diameter of just 11.7 mm.

WJI: When did the idea for this cable design first surface, and what sparked it?

Gomatam: This was a customer requirement to make the most of the duct space available for their network. This requirement pushed our R&D team to go beyond conventional cable designs and explore new pathways for achieving maximum fiber density in minimal space. It wasn’t just a response to a customer request. This was an opportunity for us to redefine the limits of compact cable engineering.

WJI: Did you start with an existing cable design that was “tweaked”?

WJI: What were the most difficult technical elements you faced and how did you overcome them?

Gomatam: There were two very demanding technical challenges.

The first was the requirement to make a cable with a diameter less than 12 mm that could fit 864 Gomatam fibers. This required precise optimization through numerous DoEs involving fiber selection, core design and compound rheology. The second was to meet the minimum blow distance of 2,700 feet in a stringent blow track with multiple bends.

These achievements reflect the depth of STL’s R&D expertise and its ability to translate complex engineering challenges into reliable, scalable solutions.

Gomatam: No, this was a ground-up innovation. STL did not previously have an 864F IBR cable using 200 μm fiber in its portfolio. To achieve such high density within a sub-12 mm diameter, we had to explore new fiber geometries and optimize material performance. While we had earlier developed an 864F WJI: How many staff people IBR cable using 250 μm fiber, were involved in this? which served as a useful referGomatam: We had a team ence, this new design demanded of about 10 expert staffan entirely different level of ers from areas that include precision. Our engineers applied new product development, learnings from past developments application engineering, QA, but ultimately engineered a new design framework that combined A group photo of staffers who power STL’s research work. program management, material science, and manufacadvanced fiber technology, microturing and supply (excluding structure optimization and matesales and regional AE’s). This project was a collaborarial science innovation. tive success. Insights from sales and regional teams into customer requirements guided the early design frameWJI: If you started at Point A and your goal was Point B, work. This integrated team structure exemplifies STL’s was the design path from A to B a straight line, or were culture of collaborative innovation and multi-discithere some/considerable zigs and zags along the way? plinary problem-solving.

Gomatam: The journey from concept to completion was far from linear. Multiple Design of Experiments WJI: Is AI part of your R&D toolbox? Can it be more than (DoEs) were run to meet the customer’s requirements. that, especially in the years to come?

This involved multiple design iterations and several DoEs Gomatam: We extensively leverage advanced modelto fine-tune every variable, from fiber packing to sheath ling and simulation tools to predict real-world cable material composition. Each phase presented unique chalperformance, especially in critical areas like STL’s R&D lenges, from maintaining mechanical robustness to ensurunlocked record high-fiber density in new IBR cable ing smooth air-blowing performance at high fiber densities. air-blowing efficiency, mechanical integrity and environThe process truly tested our R&D agility and our ability mental resilience. As our innovation roadmap evolves, we to balance mechanical strength, performance reliability foresee AI playing a much bigger role in predictive design and installation efficiency. The results prove it as the cable optimization, digital twin simulations and accelerated meets ICEA S-122-744 standards, is GR-20 compliant and can be installed in a 14/18 mm micro subduct.

(Feature continued, see p. 54)

5 2 W I R E J O U R N A L I N T E R N AT I O N A L N O V E M B E R 2 0 2 5

W W W. W I R E N E T. O R G

F E AT U R E 6 O F 6

material discovery, making the cable development process faster, smarter and even more precise.

bilities and our people. It took close coordination between material scientists, design engineers, and application specialists to get it right. Behind every milestone like WJI: What does this this sits a larger purpose: building accomplishment mean smarter, faster and more sustainto your company? able networks. Our R&D teams STL’s 864F Intermittent Bonded Ribbon (IBR) cable.

Gomatam: I am proud to note that operate out of world-class facilities our IBR cable portfolio now spans that allow us to model, simulate, from 12 fibers to an industry-leading and test every parameter before 6,912 fibers, with the company having produced and delivreal-world deployment. That gives us the confidence to ered multi-million fiber-km to customers across Europe innovate boldly while ensuring our customers get reliable, and the U.S. over the past five years. With 10 manufaclong-lasting performance. Another noteworthy point is turing facilities strategically located in North America, how we approach sustainability in cable design.

Europe and Asia, STL is well-positioned to meet diverse Whether it’s optimizing materials, reducing waste, or global connectivity needs swiftly and at scale. improving energy efficiency in manufacturing, we want every new design to contribute toward STL’s net-zero WJI: Any other points to share? goals. The 864F IBR project exemplifies how innovation and sustainability can coexist — delivering superior Gomatam: I want to stress the depth of research, experiperformance while minimizing environmental impact. mentation and teamwork that goes into creating a product This project brought together a passionate, cross-funclike the 864F IBR. Developing this wasn’t just a prodtional team that truly thrives on solving complex chaluct milestone, it was about pushing the limits of what’s lenges. We worked closely with our customers, listened to possible in high-density cable design. It represented the their evolving needs and co-created something that sets a culmination of years of investment in material science, new benchmark for optical cable design. advanced fiber technology, and precision extrusion capa-

W W W. W I R E N E T. O R G

N O V E M B E R 2 0 2 5 W I R E J O U R N A L I N T E R N AT I O N A L

53