Ports, shipyards and offshore projects lift steel sections, marine engines, ship components and large modules in rain, humidity and salt-laden air. Vessel motion and restricted deck space add risk. Chain slings must be selected as part of an engineered system, not by diameter alone.
Ship block assembly
Port equipment maintenance
Marine engine installation
Offshore module transportation
Ship component positioning
Cargo terminal operations
Selection begins with verified mass, centre of gravity, certified lifting points, crane-hook dimensions, headroom, hitch, leg angle and environment. Offshore or vessel-to-vessel lifts may require project-specific dynamic factors and motion limits; no universal factor should be assumed.
Single-leg slings suit one designed point. Two-leg slings serve machinery or frames with two rated points. Three- and four-leg assemblies serve modules and ship sections with multiple padeyes.
Multi-leg use does not guarantee equal sharing. Unequal padeye heights, structural stiffness or an offset centre of gravity can concentrate force in fewer legs. Asymmetric lifts require engineered assessment.
TOPONE G80 adjustable chain slings allow each reach to be set before loading, helping place the crane hook over the verified centre of gravity. Use only designated shortening components; never twist, knot or bolt-shorten chain.
Large ship sections and offshore modules may require an engineered lifting frame or beam with compatible shackles and certified padeyes. Include beam mass, connection clearances and headroom in the lift plan.
Hooks must carry load in the hook bowl without tip, side or latch loading. Shackles must be correctly oriented.
ISO freight containers should use an approved spreader and corner-casting system; direct chain-hook attachment requires a specifically engineered and certified arrangement.
WLL applies to the complete sling and is limited by its lowest-rated component. Leg tension rises as chain moves farther from vertical. Use the WLL for the exact configuration and angle.
Verified TOPONE catalog example for 26 mm G80 adjustable assemblies:
Single leg: 21.20 t
Two legs, up to 45° from vertical: 29.60 t
Two legs, over 45° and up to 60°: 21.20 t
Three or four legs, up to 45°: 44.50 t
Three or four legs, over 45° and up to 60°: 31.80 t
These values apply only to the stated TOPONE assemblies and cannot be transferred to another hitch, component combination or offshore dynamic case. Do not estimate capacity above 60°. The catalogued safety factor is 4:1, but WLL remains the maximum working load.
TOPONE G80 assemblies are catalogued to EN 818-4. They use Grade 8 short-link alloy-steel chain with compatible master links, connectors, shortening components and hooks.
The catalog describes components as forged from special quenched-and-tempered alloy steel and marked with specification, grade and traceability code.
Surface options include polishing, black oxide, plastic coating, galvanizing and painting. Select the finish for actual exposure. No finish makes the sling immune to seawater corrosion or increases WLL. Remove salt contamination before inspection and limit moisture exposure during storage.
For applicable shipboard lifting appliances, SOLAS Regulation II-1/3-13 has applied since 1 January 2026 and includes associated loose gear. Applicable rules may require documented SWL, load testing, thorough examination, inspection and maintenance.
EN 818-4 designation alone does not establish marine class approval. If class certification, witnessed testing or project documents are required, agree the scope before manufacture with the responsible authority.
Before use, a competent person should inspect identification, links, welds, master links, connectors, shortening devices and hooks.
Corrosion, pitting, wear, cracks, gouges, stretch, bending, heat damage, damaged latches or enlarged hook openings require removal from service. Avoid shock loading, dragging and unapproved repair.
TOPONE can configure G80 single-, two-, three- and four-leg chain slings, including adjustable versions, around load geometry, reach and angle. Final selection must follow the assembly WLL, approved lift plan and applicable port, flag-state, offshore and class requirements.
