Hybrid flat elevator cables reach new heights

Fiber on the rise

This new hybrid flat elevator cable comprises copper control wires, copper telecom wires and optical fibers. Although all-copper elevator cables have long existed, this is the first cable to incorporate optical fibers, vastly expanding data capacity (for equipment and TV) without adding weight for long suspensions.

The ups and downs

These cables are used on London Tower 42, and hang freely in a U-form from 165 meters, which means that it is actually 330 meters long. At these heights, the cable not only assures multiple functions simultaneously, it must also constantly endure traction and bending along its length up to 60,000 times.

Meeting complex specifications

The elevator OEM had several basic criteria: assure control functions like buttons, position sensors, and security; provide high-speed data for passengers (audio, video, Internet access); and guarantee system reliability in terms of acceleration, bending, traction, and deceleration. The real challenge was assuring fiber performance under traction and stress. Our solution was a traditional flat construction in which traction is stabilized by steel cords. The cable contains a dozen elements, and the jacket is halogen-free for fire safety.

High Hopes

This accomplishment shows how know-how acquired in separate areas – like copper, mechanical resistance, hybridization, optical fiber – can be combined in one product. This was a collaborative effort between our Breitenbach and Cortaillod (Switz.) A similar project was undertaken several years ago with Nexans Cabling Solutions (NCS) for the Ostankino TV tower in Moscow, the tallest freestanding structure in Europe (540 meters). The cable’s operational stability at great heights has proven the validity of our new design.