Shipyard gantry crane capacity for heavy lifting

I. Scientific Calculation: What is Your True Requirement?

• WblockWblock​ (Max Block Net Weight): Recommend inflating mainstream large-vessel data by 20% as redundancy.
• WspreaderWspreader​ (Spreader Weight): Heavy-duty hydraulic spreaders typically account for 5%–15% of block weight; this cannot be ignored.
• KsafetyKsafety​ (Dynamic Load Factor): Based on ISO/FEM standards, accounting for impact and inertia, typically 1.1–1.25.

Case Study: If the block weighs 600 tons, the spreader 80 tons, and the factor is 1.15 $\to$ An 800-ton class (or higher) gantry crane is required.

II. Four Key Technical Deciders

1. Duty Class: Shipyard environments are harsh. Cranes must reach A6–A8 (Heavy to Very Heavy) duty classes to ensure fatigue strength of the steel structure under long-term heavy loads, preventing deformation and cracking.
2. Rated Load Across Full Span: Reject limitations to “specific radii.” Regardless of whether the span exceeds 40 meters, the rated capacity must be achievable across the entire span.
3. Dual-Hook Synchronization & Micro-Speed: Heavy-duty turning operations require main/auxiliary hook synchronization errors <5mm and ultra-low micro-speed capabilities <0.5m/min to ensure millimeter-level precision during docking.
4. Ultimate Wind Stability: For outdoor operations, automatic rail clamps, anchoring devices, and wind shoes are essential. The design survival wind speed must withstand Force 12+ typhoons.

III. Our Solution