Can optical cables be squeezed

Optical cables cannot be physically compressed without risking damage, but they can be efficiently installed using compressed air to reduce friction and facilitate movement through ducts.

Physical Compression of Optical Cables

Optical fibers are delicate and designed to maintain precise alignment of the glass cores that transmit light. Applying physical compression to the cable can cause microbending, macrobending, or breakage, which severely degrades signal quality or renders the cable unusable. Therefore, optical cables should never be compressed in the traditional sense of squeezing or reducing their diameter.

Air-Assisted Installation Techniques

Instead of physical compression, air-assisted methods such as cable blowing or jetting are used to move optical cables through ducts safely:

• Cable Blowing: A high-speed airflow is injected into a duct, creating a "floating" effect that reduces friction between the cable and the duct walls. The cable is pushed or guided mechanically while the air carries it along the duct, allowing long distances to be covered with minimal mechanical stress .
• Jetting: Similar to blowing, but uses a reaction head or parachute attached to the cable. The differential air pressure across the head generates a pulling force distributed along the cable length, further reducing sidewall pressure and friction . These methods allow longer cable runs, faster installation, and reduced risk of damage compared to traditional pulling techniques .

Role of Compressed Air

The compressed air used in these techniques is critical:

• It must be high-pressure and stable, typically in the range of 10–15 bar, to maintain the cable floating inside the duct .
• The air reduces friction, allowing the cable to move through bends and long distances without buckling or excessive tension .
• Proper selection of the air compressor is essential to match the duct size, cable type, and installation distance .

Key Takeaways

• Do not physically compress optical cables; this can damage the fibers.
• Use air-assisted techniques like blowing or jetting to move cables efficiently through ducts.
• Select the right compressor to ensure sufficient air pressure and flow for safe installation.
• These methods are widely used in modern fiber optic deployments, including FTTH and data center cabling, to reduce labor, material costs, and installation time .