Multiple shielding layers and reinforced cores block interference and withstand external pressure. Can harsh environment cables be used underground? Yes, their sealed construction resists water, dust, and chemical intrusion for underground and submersion use. While the glass fibers inside are fragile, modern fiber cables are engineered to withstand crushing forces, extreme temperatures, and even rodent attacks—making them vital for. Our harsh environment fiber optic cables are purpose-built to meet the real-world demands of industries where failure isn't an option. But what exactly helps these cables deliver flawless operation under the most unforgiving conditions? Built to Withstand More Than Just the Elements Standard cables. Isolation, mechanics, and lightning protection are all necessary. During. SEDI-ATI Fibres Optiques, thanks to its know-how and expertise in complex and extremes environments, can offer you solutions based on optical fibers that are resistant to very high pressures, up to 5 000 bars.