Cargo Crane

Common issues

• Hydraulic cylinder seals leak over time, especially on the luffing cylinder under sustained load
• Wire ropes on the hoist and luffing systems show wear, corrosion or broken wires, often first noticed at the sheaves
• Slew bearing develops wear or backlash, felt as play when slewing under load
• Load moment indicator calibration drifts, giving an inaccurate safe working load display
• Hydraulic hoses deteriorate from weather exposure, especially at flex points
• Boom/jib structure and pivot pins corrode, particularly at welds and pin bushings exposed to seawater
• Limit switches for overload or over-hoist fail or drift out of adjustment

Inspection checklist

• Visually inspect the boom, jib and structure for cracks, deformation or corrosion
• Inspect wire ropes along their full length for broken wires, corrosion, wear and lubrication condition per the applicable wire rope standard
• Check the hydraulic system for leaks and verify oil condition
• Function-test all safety devices - overload cutout, limit switches and anti-two-block if fitted
• Check slew bearing mounting bolts for tightness and check for backlash
• Verify brake holding capacity on hoist and slew motors
• Check load moment indicator calibration against a known test load
• Inspect pins and bushings at boom/jib pivot points for wear
• Confirm current annual thorough examination and load test certificates are on board and the load chart is displayed in the operating position

Service intervals

Typical intervals for this design class, not the manufacturer’s figures for your model. The manufacturer’s manual is binding.

Typical wear limits

Ranges are typical for this design class. Always confirm against the manufacturer documentation for your serial number.

Critical spares

• Wire rope of the correct type, diameter and construction for this crane, per the approval
• Hydraulic cylinder seal kits
• Hydraulic hoses
• Brake linings
• Limit switch assemblies

Safety

• Never work or stand under a suspended load
• Hydraulic system holds stored pressure - relieve before opening any line or component
• Wire rope failure risk increases sharply if inspection or discard criteria are not followed - do not defer a flagged rope
• Crush and entanglement hazard at the slew ring and boom/jib pivot pins
• Overload risk if the load moment indicator is not correctly calibrated - do not rely on it without a current calibration check

Class survey

Cargo cranes as lifting appliances are subject to statutory/class annual thorough examination and periodic dynamic load testing, commonly every 4 or 5 years per flag state; class checks maintenance records, wire rope inspection records, load moment indicator calibration certificate and confirms the safe working load marking and load chart are available in the operating position.