Frequently Asked Questions

1. What is the difference between a bend stiffener and a bend restrictor?

1. While both protect cables from over-bending, they are used in different environments: While both components are engineered to protect subsea cables from over-bending, they serve distinct operational roles based on the environment. A bend stiffener is a conical-shaped polyurethane component specifically designed for dynamic applications where it provides a gradual increase in stiffness to smooth out transitions and prevent fatigue at connection points. Conversely, a bend restrictor consists of interlocking mechanical "half-shells" that act as a physical stop to prevent a cable from exceeding its Minimum Bend Radius (MBR). This makes the bend restrictor the preferred choice for static or quasi-static environments, such as protecting cables near subsea wellheads or where they cross over other infrastructure.

2. How are submarine cables protected from damage?

Protecting subsea infrastructure from environmental and man-made damage requires a robust, multi-layered strategy. The most effective primary defense is cable burial, where specialized jet trenchers or plows submerge the cable one to three meters beneath the seabed to avoid anchor snags and fishing gear. In areas where the seabed is too rocky for burial, engineers deploy physical barriers such as concrete mattresses or articulated cast-iron pipes to shield the line. These external protections are supported by internal steel wire armoring within the cable itself and real-time AIS monitoring to warn nearby vessels of the cable's location.

3. What is a Cable Hang-off and why is it necessary?

A cable hang-off is a heavy-duty mechanical assembly that is essential for the structural integrity of offshore wind turbines and oil platforms. Its primary necessity lies in load transfer, as it supports the massive weight of a suspended subsea cable and shifts that tension directly onto the platform's structure. Without a hang-off system, the electrical terminations would be forced to bear the weight of the cable, leading to imminent failure. Additionally, these systems provide a critical environmental seal at the cable entry point, protecting the interior of the tower or platform from corrosive seawater and salt spray.

4.Is a higher or lower bend radius better for cables?

In subsea and industrial cable management, a higher bend radius is always superior to a lower one because it indicates a gentler, wider curve. The bend radius is the measurement of the circle formed by the cable when it is bent; therefore, a higher radius minimizes the mechanical stress applied to internal copper cores and optical fibers. If the radius becomes too low—meaning the bend is too sharp—the cable may suffer from insulation cracking or signal loss. For maximum durability, operators must ensure the actual operating radius always remains above the manufacturer's specified Minimum Bend Radius (MBR).