Lift sling rigging company manufacture WLL 700T Polyester Round Slings,700000kg Heavy Duty Round Lifting Sling,700 Tonne Endless Round Sling,700Ton UHMWPE Round Sling.

WLL 700T Polyester Round Slings

A WLL 700T polyester round sling is rated 700,000 kg on a single vertical leg — a continuous loop of high-tenacity polyester yarn inside a heavy duty woven sleeve, with a minimum breaking load of 4,900,000 kg at 7:1 and a 1,400,000 kg proof load applied to every body before it is marked.

Four of them do not lift 2,800 tonnes.

That figure is the sum of four labels. It assumes legs that are vertical, four legs that share the load perfectly, and a master link rated to match — and a real lift meets none of those conditions. The distance between 2,800,000 kg and what a set actually carries is the whole of this page: the two deductions every set pays, the one worked example that decides the size, and the numbers a 700 t body leaves you with.

Four Slings, Four Labels, One Rating

A four-leg set is not four slings added up; it is an assembly with one rating. Two deductions come off the sum before the set has a figure at all, and a third item — the one above the slings — can cap it again. They happen in this order.

Where the Tonnes Go

The angle takes its share first

A leg rated 700,000 kg vertical is rated that in tension along its own axis. Tilt it 45° from vertical and only 0.707 of that tension lifts the load; at 60°, half. So four legs at 45° hold 1,980,000 kg before anything else is considered — a third of the arithmetic gone, purely to geometry.

Three legs carry, not four

A four-leg set is rated as three legs sharing the load, because a soft sling on a rigid load never shares equally: the shortest leg, the stiffest leg or the one tightened first takes more than its quarter, and the load shifts as the slings extend. That is why the factor for four legs is 2.1 and not 2.83 — 2.1 is three legs at 0.707, rounded — and why three-leg and four-leg sets carry the same rating.

The item above the slings caps the set

1,470,000 kg is the set rating only if the master link, the top shackle and the hook are rated for it. Put these slings under a 1,000 t hook and you have a 1,000 t set with an expensive margin in the slings. On a 700 t job the top item is the first thing to check, not the last.

A Worked Example: 1,400 Tonnes on Four Legs

Divide 1,400,000 kg by 2.1 and each leg is asked for 667,000 kg — 95% of a 700 t sling. That narrow band, roughly 1,300 to 1,470 tonnes on four legs at 45°, is what this size is built for. The same set at 60° is rated 1,050,000 kg, so the lift is out of scope: close the angle, or change the arrangement.

Anything over 100% means the lift sits outside the set’s rating at that angle — the slings are not overloaded as individual items, the assembly is. In practice the fix is a tighter angle, a spreader beam that holds the legs vertical, or a different body.

The Sling on Its Own

What 700 Tonnes Asks of the Site

• The coil is the handling unit. A 700 t body travels coiled, is landed by crane or forklift and stored flat on a pallet — that is a crane booking at each end, not a rigging detail.
• Stretch belongs in the headroom. Around 2–3% at working load: 400–600 mm on the 20 m body shown above, more on a longer one, and the leg angle opens as it happens.
• There is no colour to read. Above the colour-coded sizes, the sewn label and its set number are the only identification — a faded label retires the sling.

Technical Specifications

Marking, Proof and Set Records

Every body is proof loaded to 1,400,000 kg and the figure is written against its serial number before the label goes on. Slings sold as a set carry a set number on each label, so the four are proof loaded, inspected and retired together — and so a replacement for one leg of a set is made to the same length convention as the other three.

In Service

• Read the whole loop. The core is hidden inside the sleeve; cuts, glazing, hardening or core show-through anywhere on the loop take it out of service.
• Dress it, do not drag it. Position the body by hand or with a bar, never by dragging the load through the sleeve.
• Wear pads at the choke. The sleeve is the wear layer, and at this size the choke point is where it goes first.
• Keep the record with the coil. Drawing, proof record and lift plan travel with the sling; without them a 700 t body is an expensive unknown.

Applications

• Modules and skids too large to split, lifted on four legs from a single hook
• Pressure vessel sections and reactor shells where the load cannot be re-rigged mid-lift
• Steel plate and coil packs where a soft bearing is required and chain is not acceptable
• Long fabrications picked from a beam that holds the legs vertical
• Basket lifts under large rolls and machined bodies where the loop wraps the curve
• Port, shipyard and heavy fabrication work where water and grit rule out a fibre that rots

Related Products

• All round slings — the full range, from 1 t upwards
• 600 tonne polyester round slings — the size below, on the same build
• 500 tonne polyester round slings — the common top-end four-leg size
• 400 tonne heavy duty round sling — where the rigging concept is decided
• Endless round sling — the construction, without the tonnage
• Endless wire rope grommet — the steel equivalent for heat and sharp edges