Drilling holes next to the vertical shaft cable tray

When drilling holes near a vertical shaft cable tray, ensure proper alignment, hole sizing, and secure support installation to maintain structural integrity and safe cable routing.

Hole Sizing and Placement

When installing vertical cable trays, holes in cross members or support structures should be slightly larger than the diameter of the threaded rods or fasteners to allow for easy adjustment and prevent thread damage. Typically, holes are 1/16" to 1/8" larger than the rod diameter to accommodate minor alignment adjustments during installation (Unitray Installation Guide) . Ensure that the holes do not compromise the structural strength of the tray or the supporting wall.

Support and Alignment

Vertical cable trays require secure and properly spaced supports to prevent sagging or misalignment. Threaded rods or hangers should be installed through the drilled holes, with cross members leveled and secured using nuts and washers. The distance between supports is generally maintained at a maximum of 1.2 meters to avoid tray sagging, and additional supports should be provided at bends, branches, or offsets (Method Statement for Cable Trays and Ladders) .

Safety Considerations

Drilling near vertical shafts can be hazardous. Ensure that the area is clear of personnel and that the tray is properly supported before drilling. Avoid using the tray itself as a lifting or attachment point for heavy equipment, as this can damage the tray or compromise safety (Unitray Installation Guide) . Always follow approved shop drawings and maintain adequate clearance for cable pulling and future maintenance.

Best Practices

• Use mushroom head screws or appropriate fasteners to prevent cable insulation damage during installation (Method Statement) .
• Verify that all materials and fasteners are as per approved specifications before drilling.
• Ensure horizontal and vertical alignment of the tray sections before final tightening of nuts and bolts.
• For vertical shafts, consider the weight of the cables and use fail-safe mechanisms if pulling heavy cables to prevent accidents (Cableizer Blog) . By following these guidelines, drilling and installing supports next to a vertical shaft cable tray can be performed safely, maintaining both structural integrity and compliance with electrical installation standards.