To prevent fatigue damage to the steel wire rope of marine explosion-proof electric hoists, the following aspects should be considered and addressed comprehensively:

1. Proper Selection and Installation

Material and Construction:

Choose high-strength, corrosion-resistant wire ropes suitable for marine environments (e.g., galvanized or stainless steel).

Ensure the rope construction (e.g., 6x19, 6x37) matches the hoist's load requirements and flexibility needs.

Correct Installation:

Avoid sharp bends or kinks during installation. Use sheaves and drums with adequate diameters (typically ≥18x the rope diameter).

Ensure proper alignment to prevent side loading, which accelerates wear.

2. Regular Inspection and Monitoring

Visual Checks:

Inspect daily for broken wires, corrosion, fraying, or localized wear.

Look for signs of "birdcaging" (strand separation) or distortion.

Non-Destructive Testing (NDT):

Use magnetic particle inspection or ultrasonic testing periodically to detect internal damage.

Load Monitoring:

Install load cells or limit switches to prevent overloading, which is a primary cause of fatigue.

3. Maintenance and Lubrication

Lubrication:

Apply marine-grade lubricants regularly to reduce friction and corrosion. Lubricate the core and strands thoroughly.

Cleaning:

Remove salt, debris, and contaminants that can cause corrosion and abrasion.

Tension Adjustment:

Maintain proper tension to avoid excessive sag or stress. Adjust as needed based on load and environmental conditions.

4. Operational Controls

Avoid Sudden Load Changes:

Prevent jerky movements or shock loading, which can cause micro-cracks in the wires.

Limit Bending Cycles:

Minimize the number of times the rope is bent over sheaves or drums. Use larger sheaves if possible.

Prevent Twisting:

Ensure the rope does not twist during operation. Use swivels or anti-twist devices if necessary.

5. Environmental Protection

Corrosion Prevention:

Apply protective coatings or use sacrificial anodes if the hoist is exposed to saltwater.

Store the hoist in a dry environment when not in use.

Temperature Management:

Avoid operating the hoist in extreme temperatures that can degrade the rope's properties.

6. Replacement Criteria

Discard Based on Wear:

Replace the rope if 7 broken wires are found in one lay length or 3 broken wires in one strand in one lay length.

Discard if the rope diameter is reduced by >7% due to wear.

Age-Based Replacement:

Consider replacing the rope after a certain service life (e.g., 5 years in harsh marine environments), even if no visible damage is present.

7. Training and Documentation

Operator Training:

Train operators to recognize signs of fatigue damage and avoid practices that accelerate wear.

Maintenance Logs:

Document all inspections, lubrications, and replacements to track the rope's condition over time.

The main equipment produced by Hebei Makita: stage electric hoist, electric chian hoist, wire rope electric hoist，Hand chain hoist, lever hoist, pneumatic hoist and other lifting equipment