How to install cable trays on board

Installing cable trays onboard requires careful planning, proper tray selection, secure mounting, and adherence to safety and electrical standards to ensure reliable and safe cable management.

Planning and Preparation

Before starting, review the ship's electrical layout and approved shop drawings to determine the cable tray routes from switchboards and panels to their destinations . Ensure the work area is safe, materials are approved, and coordination with other services is completed to avoid conflicts . Mark the tray paths clearly using a laser level or chalk line to maintain straight and level runs .

Selecting the Right Cable Tray

Choose the appropriate tray type based on cable type, load, and environment:

• Ladder trays: Allow airflow and easy cable entry, ideal for heavy or high-voltage cables .
• Perforated trays: Suitable for lighter loads and good ventilation .
• Solid-bottom trays: Protect cables from dust, water, or mechanical damage .
• Wire mesh trays: Flexible routing and lightweight applications . Calculate tray width and depth according to the number and type of cables to prevent overcrowding and overheating .

Mounting and Support

• Use GI threaded rods (10mm for trays below 300mm, 12mm for above 300mm) to suspend trays from ceilings or bulkheads .
• Install slotted GI channels (41 x 41 x 2 mm) on the rods using nuts and washers, then mount the trays on these channels .
• Maintain support spacing typically between 1.5 to 3 meters depending on tray type and load to prevent sagging .
• For wall-mounted trays, use cantilever arms; for ceiling-mounted trays, use trapeze hangers .
• Ensure all trays are aligned, level, and securely fastened before installing cables .

Installation of Accessories

• Complete each tray run with bends, tees, and fittings before laying cables .
• Use splice plates to connect tray sections and maintain straight alignment .
• Provide adequate spacing around trays for cable installation and maintenance .
• Install earth link straps between tray sections to ensure electrical continuity .
• Apply fire stopping when trays pass through fire-rated bulkheads or partitions .

Cable Laying and Maintenance

• Only install cables after the tray system is fully mounted .
• Separate power and communication cables to reduce interference .
• Regularly inspect trays for sagging, corrosion, or loose fasteners and maintain according to manufacturer guidelines . By following these steps, cable trays onboard can be installed safely, efficiently, and in compliance with marine electrical standards, ensuring long-term reliability and ease of maintenance.