Single Layer FIMT​

Single Layer Steel Tube Reinforcement

We design and manufacture Single Layer FIMT (Fiber in Metal Tube) to protect the integrated optical fibers from external influences such as mechanical stress, hydrogen, and various environmental effects. Producing quality products drives our research and development. Through innovation in R&D, we have built a metal-encased customizable solution for the most demanding environments.

We can now offer custom single-layer fiber optic cables that extend to 50 km. Every component of the solution will be customized to best match your challenge, from the optical fiber, the fiber count, the materials, design, dimensions, measurements, and the various protective techniques we apply to ensure the FIMT thrives in the unique conditions of the application.

The customizable 50 km single layer steel tube is an achievement in production that directly benefits you. It reduces connection on long-haul installations, especially in challenging environments, such as subsea and direct-buried installations. Therefore, the Single Layer FIMT is an ideal submarine offshore cable for the Marine Industry and a component for umbilical cable solutions in the Oil & Gas Industry; it’s also excellent within Optical Ground Wire (OPGW).

The metal-encased solution offers Distributed Temperature Sensing (DTS) and Distributed Acoustic Sensing (DAS). 192 fibers fit in a single layer steel tube if they have an OD of 200µm and 144 fibers if they have an OD of 250µm. Get in touch and speak to one of our experts today to see if our customizable Single Layer FIMT suits your project.


Product abbreviationSST
Cable usageData Transm. & Sensing
Outer diameter1.1 mm up to 7.0 mm
Wall thickness0.125 mm up to 0.300 mm
Approx. Cable weight3.5 kg up to 65 kg per km
Max. excess fiber lengthup to 1 % (highest accuracy)
Operational temperature range-40°C up to +85°C
Maximum fiber count144 (250µm), 192 (200µm)
Maximum continuous lengthUp to 50 km
Filling compoundH2 absorbing optionally
Steel materialsWide range possible

All values, product specifications and other given data are subject to change without notice to improve reliability, function, design or otherwise. Information contained in this data sheet are up-to-date as at the date of issue. As NBG cannot control or anticipate the conditions under which this product may be used, each user should review the information in specific context of the planned use. To the maximum extent permitted by law, NBG will not be responsible for damages of any nature resulting from the use or reliance upon the information contained in this data sheet.

Product overview created by Patrick Weissinger – 21.03.2019

Optical fibers

Metal tube


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