NEXUS · Engineering

Design and certification

Every NEXUS sling starts as a drawing of the lift it will make — the hook, the trunnion, the hitch, the length that has to come out right on the day. The rating, the test and the paperwork follow from that drawing.

Drawing of two round slings in basket hitch over a trunnion, eyes on twin hooks, with protection sleeves at each bearing point
Two 78 m NXRS 2870 slings in basket over a 914 mm trunnion, eyes on twin hooks. Yellow: bearing-point protection at each contact.

Design

Drawn around the lift

A sling rated in a table assumes a straight pull on a generous pin. Offshore it rarely gets either. We start from the rigging and size the sling to it.

  • Bend and hitch. Guidance on hitches, bearing points and protection, so the rated capacity is the capacity you get.
  • Basket skew included. In basket, the rating allows for a 45–55% split between legs rather than assuming a perfect share.
  • Protection where it bears. Reinforced HMPE/PA sleeves over each bearing zone, sized to the contact, not cut to a standard length.
  • Eyes made for the hook. Eye width and height are set to the hook throat and bow they will sit in.

Matched pairs

Matched where it matters

When two slings share a load, the shorter one takes more of it. In a parallel-laid HMPE core the stretch is small, so a few centimetres of difference decides the split. We match sets to the tolerance the job calls for, and we prove it under load rather than on a tape.

Length is measured on the test pins at 3% MBL, then recalculated for the hook and trunnion the slings will actually sit on. The pair is matched on your rigging, not on ours.

25 mm
Length difference over 39 m, basket pair
1,820
Metric tons proof load, the pair stretching together all the way up
0.06%
Measured pair offset at first reading
0 50 100 150 200 250 Extension from first reading [mm] 0 250 500 750 1,000 1,250 1,500 1,750 2,000 Load [metric tons] WLL 1,400 metric tons (basket) Proof 1,820 metric tons Sling A +230 mm Sling B +231 mm Length at first reading (3% MBL): A 38,984 mm · B 38,959 mm · Δ 25 mm (0.06%) NXRS 2870 matched pair (78 m), basket over 450/460 mm pins, proof loaded to 1,820 metric tons
Load against extension for both slings of a 78 m basket pair, recorded during proof load. Extension is measured from the first reading at 3% MBL. Two curves on top of each other mean two slings of the same stiffness, so the load split is set by the 25 mm length offset alone.

Certification

Certified, and documented

Certified to the standard the project calls for, with reference to BS EN 1492-2, ASME B30.9, AS 4497 and DNV requirements, or to the client's own procedure where one is specified. Every sling ships with the record to back it.

How we test →

Send us the lift

Weight, rigging, hook and trunnion sizes. We'll come back with a sling drawn to it.

Contact engineering