Fiber optic cables can be crushed due to mechanical pressure, heavy equipment, environmental stress, or animal interference, all of which can severely disrupt data transmission.

Mechanical Pressure and Human Activity

Fiber optic cables are fragile, with cores thinner than a human hair, making them highly sensitive to physical stress. Direct crushing or pressure can occur when heavy equipment, such as construction vehicles, servers, or office chairs, rolls over floor-mounted or buried cables, compressing the core and causing signal loss or complete failure . Even light pressure, like 100N over 10 cm, can deform the fiber and reduce transmission efficiency . Improper installation, such as tight ties or over-stretching during pulling, can also crush the cable internally .

Environmental Factors

Natural events can contribute to crushing or deformation. Falling tree branches, ice accumulation on aerial cables, or ground shifts from earthquakes can physically compress or break the fiber . Temperature extremes and thermal cycling may cause expansion and contraction of cable materials, adding stress that can lead to crushing over time .

Animal Interference

Rodents and insects often chew through cable jackets and insulation, sometimes crushing the underlying fiber in the process. This is common in underground or rooftop installations where cables are exposed .

Construction and Excavation

Accidental damage during trenching, digging, or roadwork is a frequent cause of crushed fiber cables. Heavy machinery can inadvertently crush buried cables if their locations are not properly marked, leading to service outages .

Preventive Measures

To reduce the risk of crushing, fiber optic cables should be armored or encased in protective conduits, buried at appropriate depths, and routed away from high-traffic areas. Proper slack, bend-radius adherence, and cable management hardware can prevent mechanical stress. Regular inspections and maintenance, including monitoring for rodent activity, are also essential . In summary, fiber optic cables are vulnerable to crushing from mechanical, environmental, and biological factors, and careful installation, protection, and monitoring are critical to maintaining reliable communication networks.