Cable Laying Process in Vertical Shaft Cable Trays

Cables in vertical shafts are typically installed using a combination of steel wire ropes, lifting devices, and cleats, with careful attention to weight balancing, cable fixation, and safety measures.

Key Steps in Vertical Shaft Cable Installation

1. Preparation and Planning Before installation, plan the cable route, determine the shaft configuration (rigid or flexible/snaked), and select appropriate cable trays or ladder systems. Ensure all personnel are trained and aware of the hazards associated with vertical installations, as these are high-risk operations . 2. Cable Lowering and Weight Management Cables are often temporarily bound to a steel wire rope and lowered using a steady car or lifting device. For heavy or long cables, the weight can cause twisting or winding between the cable and wire rope. To prevent this, the cable weight is balanced using multiple lifting devices, and the steel wire rope is detached before final fixation . 3. Fixation and Cleating Once the cable reaches the desired position, it is fixed to the shaft wall using cleats, clamps, or brackets. Spring-loaded cleats are recommended to maintain constant lateral clamping force and accommodate thermal expansion or contraction. Proper snaking of the cable may be used to reduce mechanical stress and allow for thermal movement . 4. Safety Measures

• Use fail-safe mechanisms to prevent cable free-fall in case of wire rope failure.
• Avoid closed loops of ferromagnetic steel when using metal structures to prevent magnetic interference.
• Ensure high tensile strength of cables, possibly with steel wire armor or integrated pulling members . 5. Post-Installation Checks After fixation, verify that the cable is free from slippage, twisting, or mechanical deformation. Check that thermal cycling will not cause conductor elongation or insulation cracking. Ensure all cleats and brackets maintain consistent clamping force .

Additional Considerations

• Rigid vs Flexible Installation: Rigid vertical installations are simpler and preferred for smaller conductor sections, while flexible/snaked configurations can reduce stress in larger or high-capacity cables .
• Cable Tray Standards: Use cable trays and ladder systems compliant with BS EN 61537 or equivalent standards, ensuring proper support and spacing .
• Professional Handling: Vertical shaft cable installation should be performed by experienced personnel due to the high risk of accidents and cable damage . By following these steps, vertical shaft cable installations can be performed efficiently, safely, and with minimal risk of cable damage or personnel injury.